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Enzyme Immunoassay (enzyme + immunoassay)
Kinds of Enzyme Immunoassay Terms modified by Enzyme Immunoassay Selected AbstractsPrevalence of hepatitis B and C: A Jinnah Postgraduate Medical Centre experienceJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 3 2009Shehla Sami Abstract Aim:, To determine the prevalence of carriers of hepatitis B and C viruses among the obstetrical and gynecological population, the incidence of vertical transmission in obstetrical patients and to ascertain the risk factors associated with their transmission. Methods:, We conducted a prospective study over a 1-year period, from 1 January to 31 December 2005, comprising of an obstetrical population of 5902 deliveries and 548 major gynecology surgery patients. The study population was recruited by simple convenient sampling at Unit-I, Department of Obstetrics and Gynecology, Jinnah Postgraduate Medical Centre, Karachi, Pakistan. Booked obstetrical and major gynecological surgical patients were routinely screened by Enzyme Immunoassay for hepatitis B surface antigen (HbsAg) and anti-hepatitis C antibodies (anti-HCV) on venous blood samples. Liver function and carrier profile tests were performed on mothers who were positive for HBsAg. Babies of mothers with HbsAg were tested at birth for both HbsAg and HbeAg. Results:, Hepatitis B was detected in 275 pregnant women (4.6%) and in 70 (12%) gynecological patients. Hepatitis C was detected in 108 (1.8%) pregnant women and in 89 (16%) gynecological patients. Babies born to mothers with HBV or HCV infections tested negative. Four gynecological patients tested positive for both HBV and HCV infections. Unsafe surgery, injections and inadequately screened blood transfusions were the main underlying causes of infection. Conclusion:, Routine screening of the obstetrical population detected more cases of HBV infection than HCV, whereas HCV was more prevalent in the gynecological population, emphasizing the need for safe medical practices and patient education. [source] Donor Screening for Human T-cell Lymphotrophic Virus 1/2: Changing Paradigms for Changing Testing CapacityAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2010D. R. Kaul Organ Procurement and Transplant Network (OPTN) policy currently requires the testing of all potential organ donors for human T-cell lymphotrophic virus (HTLV)-1/2. Most Organ Procurement Organizations (OPO) use the Abbott HTLV-I/HTLV-II Enzyme Immunoassay (EIA). This assay will no longer be manufactured after December 31, 2009; the only commercially available FDA-licensed assay will be the Abbott PRISM HTLV-I/II assay which poses many challenges to OPO use for organ donor screening. As a result, screening donors for HTLV-1/2 in a timely manner pretransplant after December 31, 2009 will be challenging. The true incidence of HTLV-1 in United States (U.S.) organ donors is not well described but appears to be low (,0.03,0.5%). HTLV-1 is associated with malignancy and neurological disease; HTLV-2 has not been convincingly associated with disease in humans. Donors that are HTLV-1/2 seropositive are infrequently used despite most results being either false positive or resulting from HTLV-2 infection. There is urgent need to encourage the development of assays, instruments and platforms optimized for organ donors that can be used to screen for transmissible disease in donors; these must have appropriate sensitivity and specificity to identify all infections while minimizing organ loss through false positive testing. [source] Association between color doppler vascularity index, angiogenesis-related molecules, and clinical outcomes in gastric cancerJOURNAL OF SURGICAL ONCOLOGY, Issue 7 2009Chiung-Nien Chen MD Abstract Purpose This study was conducted to evaluate the correlation between color Doppler vascularity index (CDVI), clinical outcomes and five angiogenesis-related molecules including vascular endothelial growth factor (VEGF), placenta growth factor (PlGF), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), and calreticulin (CRT) in gastric cancer, and to develop an effective model selected from these five molecules to predict patient survival. Patients and Methods CDVI could be obtained preoperatively by transabdominal ultrasound from 30 patients. Enzyme immunoassay was adopted to determine protein level of VEGF and PlGF, and immunohistochemistry was used to detect COX-2, iNOS and CRT expression. Correlation between CDVI and five individual molecules was assessed. Multiple molecules model was developed using classification and regression tree (CART) analysis from five molecules, and was tested for patient survival in another 45 patients. Results CDVI was significantly correlated with patient survival (P,=,0.00907) and absolute number of metastatic lymph nodes (P,=,0.01). There was no significant association between CDVI and any individual molecule. The model, developed by CART consisting of VEGF and PlGF, could differentiate high and low CDVI and survival in testing group (P,=,0.00257). Conclusions CDVI was associated with lymph node metastasis, combined VEGF and PlGF expression status and patient survival in gastric cancer. J. Surg. Oncol. 2009;99:402,408. © 2009 Wiley-Liss, Inc. [source] Enzyme immunoassay for total immunoglobulin E in dried blood spotsAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2007Susan Tanner Elevated circulating levels of total immunoglobulin E (IgE) are associated with both allergic disease and repeated macro-parasitic infections. Population-based research on IgE has been limited by the logistical constraints associated with obtaining and processing venipuncture blood samples. In this short report, we present an enzyme immunoassay protocol for quantifying circulating total IgE levels in capillary whole blood, collected from a finger prick and dried on filter paper. The assay demonstrated acceptable levels of accuracy, precision, and reliability. IgE remained stable at room temperature for only 2,4 days and degraded rapidly at higher temperatures suggesting that samples should be refrigerated or frozen within 1,2 days of collection. It is hoped that the relative ease of blood spot collection will expand opportunities for population-based research on IgE.Am. J. Hum. Biol. 19:440,442, 2007. © 2007 Wiley-Liss, Inc. [source] Recent Advances in Electrochemical Enzyme ImmunoassaysELECTROANALYSIS, Issue 21 2005María Díaz-González Abstract Enzyme immunoassays (EIAs) are currently the predominant analytical technique for the quantitative determination of a broad variety of analytes in clinical, medical, biotechnological, and environmental significance. Although the most common detection methods for EIAs are based on spectroscopic measurements, electrochemical techniques, due to their high sensitivity, selectivity, simplicity and low cost, have emerged as a very attractive alternative to carry out the detection step in this kind of assays. The intention of this review is to cover the progress and development in integrating electrochemical detection methods with EIAs, over the past five years. [source] Keloid-derived fibroblasts show increased secretion of factors involved in collagen turnover and depend on matrix metalloproteinase for migrationBRITISH JOURNAL OF DERMATOLOGY, Issue 2 2005M. Fujiwara Summary Background, ,A keloid is a specific skin lesion that expands beyond the boundaries of the original injury as it heals. Histologically, it is characterized by the excessive accumulation of collagen. However, the reasons for the expansion and the invasive nature of keloids remain unknown. Objectives, We evaluated collagen degradation and migration by cultured keloid fibroblasts based on the assumption that these variables were of functional relevance to the expanding and invasive nature of keloid lesions. Methods, Collagen production was investigated by the detection of type 1 collagen (procollagen type 1C peptide: P1P). Matrix metalloproteinase (MMP)-1 (interstitial collagenase) and MMP-2 (gelatinase-A), were investigated as elements of the collagen degradation system. Enzyme immunoassays were performed to measure the production of P1P, MMP-1, MMP-2, and tissue inhibitor of metalloproteinase (TIMP)-1. To assess the production of MMP-2 its gelatinolytic activity was measured by zymography using gelatin-containing gels. The participation of transforming growth factor-,1 (TGF-,1) in the production and degradation of collagen was also investigated. Finally, the migratory activity of keloid fibroblasts was evaluated using a colony dispersion assay. Results, The production of type 1 collagen, MMP-1, MMP-2, and TIMP-1 by keloid fibroblasts was 3-fold, 6-fold, 2·4-fold, and 2-fold greater than that of normal dermal fibroblasts, respectively. Production of P1P was increased when TGF-,1 was added to cultures of keloid fibroblasts, while it was decreased when anti-TGF-,1 antibody was added to the cultures. In contrast, the production of MMP-1 was decreased by the addition of TGF-,1 to cultured keloid fibroblasts, while it was increased when anti-TGF-,1 antibody was added to the cultures. The production of MMP-2 increased after treatment with TGF-,1, but did not change significantly when anti-TGF-,1 antibody was added to the cultures. Production of TIMP-1 did not change significantly when either TGF-,1 or anti-TGF-,1 antibody was added to the cultures. Keloid fibroblasts showed a 2·5-fold increase of migratory activity compared with normal dermal fibroblasts, while the migratory activity of these fibroblasts was reduced to the control level by treatment with a broad-spectrum MMP inhibitor (GM 6001). Conclusions, Cultured keloid fibroblasts showed increased production of collagen and MMPs, and TGF-,1 played a role in this regulation of production. In addition, increased production of MMPs had a role in the high migratory activity of cultured keloid fibroblasts. [source] Pigment-dispersing factor in the locust abdominal ganglia may have roles as circulating neurohormone and central neuromodulatorDEVELOPMENTAL NEUROBIOLOGY, Issue 1 2001Magnus G. S. Persson Abstract Pigment-dispersing factor (PDF) is a neuropeptide that has been indicated as a likely output signal from the circadian clock neurons in the brain of Drosophila. In addition to these brain neurons, there are PDF-immunoreactive (PDFI) neurons in the abdominal ganglia of Drosophila and other insects; the function of these neurons is not known. We have analyzed PDFI neurons in the abdominal ganglia of the locust Locusta migratoria. These PDFI neurons can first be detected at about 45% embryonic development and have an adult appearance at about 80%. In each of the abdominal ganglia (A3,A7) there is one pair of lateral PDFI neurons and in each of the A5,A7 ganglia there is additionally a pair of median neurons. The lateral neurons supply varicose branches to neurohemal areas of the lateral heart nerves and perisympathetic organs, whereas the median cells form processes in the terminal abdominal ganglion and supply terminals on the hindgut. Because PDF does not influence hindgut contractility, it is possible that also these median neurons release PDF into the circulation. Release from one or both the PDFI neuron types was confirmed by measurements of PDF-immunoreactivity in hemolymph by enzyme immunoassay. PDF applied to the terminal abdominal ganglion triggers firing of action potentials in motoneurons with axons in the genital nerves of males and the 8th ventral nerve of females. Because this action is blocked in calcium-free saline, it is likely that PDF acts via interneurons. Thus, PDF seems to have a modulatory role in central neuronal circuits of the terminal abdominal ganglion that control muscles of genital organs. © 2001 John Wiley & Sons, Inc. J Neurobiol 48: 19,41, 2001 [source] MCE enzyme immunoassay for carcinoembryonic antigen and alpha-fetoprotein using electrochemical detectionELECTROPHORESIS, Issue 19 2009Shusheng Zhang Abstract An MCE electrochemical enzyme immunoassay protocol for the determination of carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) was reported. Two antigens (Ag), CEA and AFP, were incubated simultaneously with an excess amount of horseradish peroxidase-labeled antibody (Ab*). The free Ab* and the Ab*,Ag complex produced in the solution were first separated through a postcolumn reaction and then traced by the enzyme substrate o -aminophenol. The 3-aminophenoxazine produced in enzyme reaction was detected with downstream amperometric detection. The separations were performed at a separation voltage of +1.4,kV and were completed in less than 60,s. The better analytical performance and distinct miniaturization/portability for MCE at less assay time and sample volume consumption was achieved. The detection limit of CEA and AFP was calculated to be 0.25 and 0.13,ng/mL, respectively. Therefore, MCE could be used as a sensitive and new tool in separation science and offered considerable promise in biological sample analysis or quick clinical diagnosis. [source] The effects of acetylsalicylic acid on proliferation, apoptosis, and invasion of cyclooxygenase-2 negative colon cancer cellsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2002H.-G. Yu Summary Background Acetylsalicylic acid (ASA, aspirin), the most common nonsteroidal anti-inflammatory drug (NSAID), has been shown to have a protective effect against the incidence and mortality of colorectal cancer. However, the mechanism of its anticancer function remains unclear. The aim of this study was to determine the effects of acetylsalicylic acid on proliferation, apoptosis, and invasion in human cyclooxygenase-2 (COX-2) negative colorectal cancer cell lines. Materials and Methods After treatment with various concentrations of ASA, cell proliferation was measured in the human colon cancer cell line SW480. Apoptotic cells were identified by transmission electron microscopy, acridine orange staining, and flow cytometry. The invasive potential of SW480 cells was detected using an in vitro invasion assay. The production of carcinoembryonic antigen was measured by microparticle enzyme immunoassay. Expression of Bcl2, Bax, CD44v6, and nm23 were evaluated by immunocytochemistry. Results ASA significantly inhibited the proliferation of SW480 cells and stimulated apoptosis. Production of carcinoembryonic antigen and the invasive potential of SW480 cells were also inhibited by ASA. After treatment with ASA, down-regulation of Bcl2 and CD44v6 expression and up-regulation of nm23 expression were observed in SW480 cells. No obvious effect of ASA was found on Bax expression. Conclusion Our findings reveal that ASA inhibits the proliferation and promotes apoptosis in the human colon cancer cell line SW480. Down-regulation of Bcl2 expression might represent a potential mechanism by which ASA induces apoptosis in this COX-2 negative colon cancer cell line. Our results also suggest that ASA decreases the invasive potential of these colon cancer cells. Decreased CEA content and CD44v6 expression and elevated nm23 expression may contribute to the effect of ASA on invasive potential of SW480 colon cancer cells. [source] Testosterone response to GnRH in a female songbird varies with stage of reproduction: implications for adult behaviour and maternal effectsFUNCTIONAL ECOLOGY, Issue 4 2007JODIE M. JAWOR Summary 1Despite considerable recent interest in plasma and yolk testosterone (T) in female birds, relatively little is known about environmental regulation of female T, individual variation in female T or the relationship between plasma and yolk T. 2In breeding females of a wild population of dark-eyed junco (Junco hyemalis), we assessed variation in the responsiveness of the hypothalamo-pituitary-gonadal (HPG) axis to a challenge with gonadotropin-releasing hormone (GnRH) by measuring circulating T before and 30 min after a standardized injection of GnRH. We asked whether response to challenge varied seasonally or with stage of reproduction and whether it was repeatable within individuals or related to T deposited in eggs. 3Initial and post-challenge levels of T were measured using enzyme immunoassay. In a subset of these females, luteinising hormone (LH) was measured using radioimmunoassay (RIA). In addition, eggs were collected from nests of 15 females that had received a GnRH challenge, and yolk T was measured using RIA. 4During most of the breeding season, plasma T did not increase in response to GnRH. GnRH consistently caused increases in plasma T only during the 7 days before oviposition, when females were rapidly depositing yolk in eggs but had not yet begun to lay them. Among a small subset of females we found a positive correlation between the magnitude of this increase in plasma T in response to GnRH during egg development and the amount of T deposited in the yolk of eggs collected at a later time. 5These results suggest that ovarian response to GnRH-induced increases in LH is greatest when females are actively depositing yolk into eggs. Factors that stimulate the release of GnRH during egg formation may result in higher levels of plasma T which could influence adult female behaviour. Further, because plasma T was correlated with later yolk T, factors that stimulate GnRH release may also lead to higher levels of yolk T potentially influencing offspring development or behaviour. [source] Comparison of a Stool Antigen Test and Serology for the Diagnosis of Helicobacter pylori Infection in Mass SurveyHELICOBACTER, Issue 2 2009Tadashi Shimoyama Abstract Background: Serum antibody to Helicobacter pylori is tested in mass screening for gastric cancer along with the level of serum pepsinogens (PG) I and II. Recently, stool antigen tests have been developed as a new non-invasive test. We examined H. pylori infection by both serology and stool antigen test in a mass survey and compared the results to estimate applicability of stool antigen test for mass survey. Methods: A total of 994 healthy adults who received mass survey in April 2005 were tested. There were 379 men and 615 women, and the mean age was 57.7 years old. Stool samples were used to measure a H. pylori- specific antigen by enzyme immunoassay. Serum samples were tested for the prevalence of IgG antibody to H. pylori, and the level of PGs I and II was also measured to determine the presence of atrophic gastritis. Results: Infection of H. pylori was defined as positive 61.4% and 56.4% by serology and stool antigen test, respectively. The concordance of both tests was not affected by gender and age of the subjects but difference was seen in subjects with atrophic gastritis. In particular, positivity of stool antigen test (81.8%) was significantly lower than that of serology (88.7%, p < .05) in 303 subjects with severe atrophic gastritis. Conclusions: Stool antigen test, which detects present but not previous infection of H. pylori, would be applicable to diagnose H. pylori infection in mass survey. Usefulness of stool antigen tests for the screening of gastric cancer should be examined. [source] Helicobacter pylori Infection is Associated with Reduced Circulating Ghrelin Levels Independent of Body Mass IndexHELICOBACTER, Issue 5 2005Akiko Shiotani ABSTRACT Background., Ghrelin stimulates growth hormone and has orexigenic and adipogenic effects. Plasma ghrelin levels are reduced in obesity and possibly in Helicobacter pylori infection. Aim., To investigate whether there was a relation between H. pylori infection, body mass index (BMI) and serum ghrelin or leptin levels. Methods., University students undergoing an annual health check-up were invited to participate. H. pylori status was based on the presence of specific IgG H. pylori antibodies in urine. Fasting serum ghrelin, leptin levels, and pepsinogen I and II levels were measured by enzyme immunoassay (EIA). Results., Eight hundred and one students volunteered. There was no significant difference in the height and BMI between those with and without H. pylori infection. The population of ghrelin study consisted of 132 (66 H. pylori -positive and 66 H. pylori -negative) students matched for age, sex, and BMI. The ghrelin level in the H. pylori -positive group was significantly lower (median 55 pmol/l) compared to the H. pylori- negative group (103 pmol/l) (p < .00001). Leptin, triglyceride, total cholesterol, and HDL-cholesterol were not different between the two groups, whereas LDL-cholesterol levels were significantly higher (106 versus 100 mg/dl) (p = .03) in the H. pylori -positive group. Leptin levels correlated with the BMI (r = 0.53) (p < .00001). Among H. pylori -positive subjects, ghrelin correlated only with pepsinogen I levels (r = 0.26, p = .04). Conclusions.,H. pylori infection was associated with a reduction in circulating ghrelin levels independent of sex and BMI. [source] Serum hepatitis B surface antigen and hepatitis B e antigen titers: Disease phase influences correlation with viral load and intrahepatic hepatitis B virus markers,,HEPATOLOGY, Issue 6 2010Alexander J.V. Thompson Although threshold levels for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) titers have recently been proposed to guide therapy for chronic hepatitis B (CHB), their relationship to circulating hepatitis B virus (HBV) DNA and intrahepatic HBV replicative intermediates, and the significance of emerging viral variants, remains unclear. We therefore tested the hypothesis that HBsAg and HBeAg titers may vary independently of viral replication in vivo. In all, 149 treatment-naïve CHB patients were recruited (HBeAg-positive, n = 71; HBeAg-negative, n = 78). Quantification of HBeAg and HBsAg was performed by enzyme immunoassay. Virological characterization included serum HBV DNA load, HBV genotype, basal core promoter (BCP)/precore (PC) sequence, and, in a subset (n = 44), measurement of intrahepatic covalently closed circular DNA (cccDNA) and total HBV DNA, as well as quantitative immunohistochemical (IHC) staining for HBsAg. In HBeAg-positive CHB, HBsAg was positively correlated with serum HBV DNA and intrahepatic cccDNA and total HBV DNA (r = 0.69, 0.71, 0.76, P < 0.01). HBeAg correlated with serum HBV DNA (r = 0.60, P < 0.0001), although emerging BCP/PC variants reduced HBeAg titer independent of viral replication. In HBeAg-negative CHB, HBsAg correlated poorly with serum HBV DNA (r = 0.28, P = 0.01) and did not correlate with intrahepatic cccDNA nor total HBV DNA. Quantitative IHC for hepatocyte HBsAg confirmed a relationship with viral replication only in HBeAg-positive patients. Conclusion: The correlation between quantitative HBsAg titer and serum and intrahepatic markers of HBV replication differs between patients with HBeAg-positive and HBeAg-negative CHB. HBeAg titers may fall independent of viral replication as HBeAg-defective variants emerge prior to HBeAg seroconversion. These findings provide new insights into viral pathogenesis and have practical implications for the use of quantitative serology as a clinical biomarker. (HEPATOLOGY 2010) [source] Intrafamilial transmission of hepatitis C in Egypt,HEPATOLOGY, Issue 3 2005Mostafa K. Mohamed The incidence of hepatitis C (HCV) infection and associated risk factors were prospectively assessed in a cohort of 6,734 Egyptians from 2 rural villages who were negative for antibodies to HCV (anti-HCV). Initial and follow-up sera were tested for anti-HCV by enzyme immunoassay (EIA), and possible incident cases were confirmed by using the microparticle enzyme immunoassay (MEIA) and tested for HCV RNA. All follow-up serum samples converting from negative to positive without detectable HCV-RNA were further tested by recombinant immunoblot assay. Over an average of 1.6 years, asymptomatic anti-HCV seroconversion occurred in 33 people (3.1/1,000 person-years [PY]), including 28 (6.8/1,000 PY) in the Nile Delta village (AES), where prevalence was 24% and 5 (0.8/1,000 PY) in the Upper Egypt village (baseline prevalence of 9%). The strongest predictor of incident HCV was having an anti-HCV,positive family member. Among those that did, incidence was 5.8/1,000 PY, compared (P < .001) with 1.0/1,000 PY; 27 of 33 incident cases had an anti-HCV,positive family member. Parenteral exposures increased the risk of HCV but were not statistically significant; 67% of seroconverters were younger than 20 years of age, and the highest incidence rate (14.1/1,000 PY) was in children younger than 10 who were living in AES households with an anti-HCV,positive parent. In conclusion, young children would especially benefit from measures reducing exposures or preventing infection with HCV. (HEPATOLOGY 2005.) [source] Zoonotic risk of hepatitis E virus (HEV): A study of HEV infection in animals and humans in suburbs of BeijingHEPATOLOGY RESEARCH, Issue 12 2009Yibin Chang Aim:, To investigate hepatitis E virus (HEV) infection among different animals and workers in pig farms and slaughterhouses, and analyze the genotype of HEV isolated in this study. Methods:, Serum samples were collected from adult swine, cows, sheep, younger swine (< 3 months), and workers in pig farms and slaughterhouses (professional group). Fecal samples were collected from younger swine in the south suburbs of Beijing. Anti-HEV antibody was evaluated by direct sandwich enzyme immunoassay. HEV RNA was extracted from fecal samples and amplified by nested reverse transcription polymerase chain reaction (RT-nPCR). The PCR products were sequenced, and the sequence homology and phylogenetics of the HEV strains isolated from swine were analyzed. Results:, The anti-HEV positivity rates in adult swine, cows, sheep, younger swine, professional group and general population were 98.23% (222/226), 29.35% (54/184), 9.80% (20/207), 60.73% (99/164), 42.51% (105/247) and 20.29% (522/2572), respectively. The HEV RNA positivity rate of fecal samples was 22.89% (19/83) and 16/19 samples were positive for HEV RNA amplified with both primers, HEV open reading frame (ORF)1 and HEV ORF2. Sequence analysis of these 16 samples showed that there were two groups, designated BJ-1 and BJ-2. The nucleotide homology of BJ-1 and BJ-2 was 99%. Phylogenetic analysis indicated that both of these groups belonged to genotype 4d. Conclusion:, Workers in pig farms and slaughterhouses were more likely to contract HEV infection than the general population because of close contact with swine with a high prevalence of anti-HEV. [source] IL-6 levels decrease with SSRI treatment in patients with major depressionHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 7 2005Ayse Devrim Basterzi Abstract Objective Some evidence indicates that an immune response with an increased production of proinflammatory cytokines often accompanies major depression. The objective of this study was to examine the serum levels of IL-6 in patients with major depression and the changes occurring in IL-6 levels during treatment with selective serotonin reuptake inhibitors (SSRI). Method Twenty-three patients with a DSM-IV diagnosis of major depressive disorder and 23 healthy matched controls were included in the study. The severity of depression was measured with the Hamilton rating scale for depression. Blood samples for IL-6 levels were obtained at baseline and at week 6 of treatment and IL-6 concentrations were evaluated using a solid phase sandwich enzyme immunoassay. All patients were treated with an SSRI. Results The IL-6 levels showed no statistically significant difference between the patients and the controls at baseline. However, IL-6 levels after treatment with SSRIs were significantly lower compared with the baseline IL-6 levels of both the patients and the controls. Conclusion The results of this study suggest that proinflammatory cytokines show some changes during the course of treatment of major depression. These findings might also be considered as supporting the hypothesis of a modulatory role of antidepressants on the immune system. Copyright © 2005 John Wiley & Sons, Ltd. [source] Predictors of Interleukin-6 Elevation in Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 9 2009Shuhan Zhu BS OBJECTIVES: To investigate the characteristics of older adults who develop high interleukin-6 (IL-6) levels at 3-year follow-up. DESIGN: Population-based study of adults living in Tuscany, Italy. SETTING: Community. PARTICIPANTS: Adults aged 65 and older and were selected for this study. Of 1,155 baseline participants aged 65 and older, 741 had IL-6 measurements at baseline and 3-year follow-up. MEASUREMENTS: The uppermost quartile of IL-6 was used as the threshold for defining high IL-6 (,4.18 pg/mL). Serum IL-6 levels were assessed using enzyme immunoassay. RESULTS: Of the 581 participants with IL-6 levels less than 4.18 pg/mL at baseline, 106 (18.2%) had developed high IL-6 at follow-up. Although women had lower IL-6 levels at baseline than men, the risk of developing high IL-6 did not differ according to sex. High adiposity, defined as a body mass index of 30.0 kg/m2 or higher (odds ratio (OR)=2.63, 95% confidence interval (CI)=1.40,4.96), and large waist circumference, defined as 102 cm or greater for men and 88 cm or greater for women (OR=2.05, 95% CI=1.24,3.40), were significant predictors of developing high IL-6 at follow-up. Other significant predictors were presence of three or more chronic diseases (OR=3.66, 95% CI=1.54,8.70), higher baseline IL-6 (OR=1.82, 95% CI=1.39,2.38) and higher white blood cell count (OR=1.24, 95% CI=1.06,1.45). Faster walking speed associated with decreased risk of progressing to elevated IL-6 (OR=0.83, 95% CI=0.74,0.92). CONCLUSION: Older age, greater adiposity, slower walking speed, higher disease burden, and higher white blood cell count were associated with greater risk of IL-6 elevation over a 3-year period. Future research should target older adults with these characteristics to prevent progression to a proinflammatory state. [source] The sensitive hare: sublethal effects of predator stress on reproduction in snowshoe haresJOURNAL OF ANIMAL ECOLOGY, Issue 6 2009Michael J. Sheriff Summary 1.,Prey responses to high predation risk can be morphological or behavioural and ultimately come at the cost of survival, growth, body condition, or reproduction. These sub-lethal predator effects have been shown to be mediated by physiological stress. We tested the hypothesis that elevated glucocorticoid concentrations directly cause a decline in reproduction in individual free-ranging female snowshoe hares, Lepus americanus. We measured the cortisol concentration from each dam (using a faecal analysis enzyme immunoassay) and her reproductive output (litter size, offspring birth mass, offspring right hind foot (RHF) length) 30 h after birth. 2.,In a natural monitoring study, we monitored hares during the first and second litter from the population peak (2006) to the second year of the decline (2008). We found that faecal cortisol metabolite (FCM) concentration in dams decreased 52% from the first to the second litter. From the first to the second litter, litter size increased 122%, offspring body mass increased 130%, and offspring RHF length increased 112%. Dam FCM concentrations were inversely related to litter size (r2 = 0·19), to offspring birth mass (r2 = 0·32), and to offspring RHF length (r2 = 0·64). 3.,In an experimental manipulation, we assigned wild-caught, pregnant hares to a control and a stressed group and held them in pens. Hares in the stressed group were exposed to a dog 1,2 min every other day before parturition to simulate high predation risk. At parturition, unsuccessful-stressed dams (those that failed to give birth to live young) and stressed dams had 837% and 214%, respectively, higher FCM concentrations than control dams. Of those females that gave birth, litter size was similar between control and stressed dams. However, offspring from stressed dams were 37% lighter and 16% smaller than offspring from control dams. Increasing FCM concentration in dams caused the decline of offspring body mass (r2 = 0·57) and RHF (r2 = 0·52). 4.,This is the first study in a free-ranging population of mammals to show that elevated, predator-induced, glucocorticoid concentrations in individual dams caused a decline in their reproductive output measured both by number and quality of offspring. Thus, we provide evidence that any stressor, not just predation, which increases glucocorticoid concentrations will result in a decrease in reproductive output. [source] Negative Regulation by p70 S6 Kinase of FGF-2,Stimulated VEGF Release Through Stress-Activated Protein Kinase/c- Jun N-Terminal Kinase in Osteoblasts,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 3 2007Shinji Takai Abstract To clarify the mechanism of VEGF release in osteoblasts, we studied whether p70 S6 kinase is involved in basic FGF-2,stimulated VEGF release in osteoblast-like MC3T3-E1 cells. In this study, we show that p70 S6 kinase activated by FGF-2 negatively regulates VEGF release through SAPK/JNK in osteoblasts. Introduction: Vascular endothelial growth factor (VEGF) plays an important role in bone metabolism. We have previously reported that fibroblast growth factor-2 (FGF-2) stimulates the release of VEGF through p44/p42 mitogen-activated protein (MAP) kinase and stress-activated protein kinase/c- Jun N-terminal kinase (SAPK/JNK) in osteoblast-like MC3T3-E1 cells and that FGF-2,activated p38 MAP kinase negatively regulates VEGF release. However, the mechanism behind VEGF release in osteoblasts is not precisely known. Materials and Methods: The levels of VEGF released from MC3T3-E1 cells were measured by enzyme immunoassay. The phosphorylation of each protein kinase was analyzed by Western blotting. To knock down p70 S6 kinase in MC3T3-E1 cells, the cells were transfected with siRNA to target p70 S6 kinase. Results: FGF-2 time-dependently induced the phosphorylation of p70 S6 kinase. Rapamycin significantly enhanced the FGF-2,stimulated VEGF release and VEGF mRNA expression. The FGF-2,induced phosphorylation of p70 S6 kinase was suppressed by rapamycin. Rapamycin markedly enhanced the FGF-2,induced phosphorylation of SAPK/JNK without affecting the phosphorylation of p44/p42 MAP kinase or p38 MAP kinase. SP600125, a specific inhibitor of SAPK/JNK, suppressed the amplification by rapamycin of the FGF-2,stimulated VEGF release similar to the levels of FGF-2 with SP600125. Finally, downregulation of p70 S6 kinase by siRNA significantly enhanced the FGF-2,stimulated VEGF release and phosphorylation of SAPK/JNK. Conclusions: These results strongly suggest that p70 S6 kinase limits FGF-2,stimulated VEGF release through self-regulation of SAPK/JNK, composing a negative feedback loop, in osteoblasts. [source] Capsaicin-Sensitive Sensory Neurons Contribute to the Maintenance of Trabecular Bone Integrity,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2005Sarah C Offley Abstract This investigation used capsaicin to selectively lesion unmyelinated sensory neurons in rats. Neuronal lesioning induced a loss of trabecular integrity, reduced bone mass and strength, and depleted neuropeptides in nerve and bone. These data suggest that capsaicin-sensitive sensory nerves contribute to trabecular bone integrity. Introduction: Familial dysautomia is an autosomal recessive disease in which patients suffer from unmyelinated sensory neuron loss, reduced BMD, and frequent fractures. It has been proposed that the loss of neurotransmitters synthesized by unmyelinated neurons adversely affects bone integrity in this hereditary syndrome. The purpose of this study was to determine whether small sensory neurons are required for the maintenance of bone integrity in rats. Materials and Methods: Ten-month-old male Sprague-Dawley rats were treated with either capsaicin or vehicle. In vivo DXA scanning and ,CT scanning, and histomorphometry were used to evaluate BMD, structure, and cellular activity. Bone strength was measured in distal femoral sections. Body weight and gastrocnemius/soleus weights were measured and spontaneous locomotor activity was monitored. Peroneal nerve morphometry was evaluated using light and electron microscopy. Substance P and calcitonin gene-related peptide (CGRP) content in the sciatic nerve and proximal tibia were determined by enzyme immunoassay (EIA). Substance P signaling was measured using a sciatic nerve stimulation extravasation assay. Results: Four weeks after capsaicin treatment, there was a loss of BMD in the metaphyses of the tibia and femur. In the proximal tibia, the osteoclast number and surface increased, osteoblast activity and bone formation were impaired, and trabecular bone volume and connectivity were diminished. There was also a loss of bone strength in the distal femur. No changes occurred in body weight, 24-h grid-crossing activity, weight bearing, or muscle mass after capsaicin treatment, indicating that skeletal unloading did not contribute to the loss of bone integrity. Capsaicin treatment destroyed 57% of the unmyelinated sensory axons, reduced the substance P and CGRP content in the sciatic nerve and proximal tibia, and inhibited neurogenic extravasation. Conclusion: These results support the hypothesis that capsaicin-sensitive sensory neurons contribute to the maintenance of trabecular bone integrity. Capsaicin-sensitive neurons have efferent functions in the tissues they innervate, effects mediated by transmitters released from the peripheral nerve terminals. We postulate that the deleterious effects of capsaicin treatment on trabecular bone are mediated by reductions in local neurotransmitter content and release. [source] Switching from HPLC/UV to MEIA for whole blood sirolimus quantitation: comparison of methodsJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2006Luigi Alberto Pini Abstract Sirolimus is a immunosuppressive agent for renal transplant recipients. Monitoring of whole blood sirolimus concentration is necessary in order to improve clinical outcomes. An increasing number of clinical laboratories (4,14% during 2005) are using microparticle enzyme immunoassay (MEIA) for sirolimus quantitation but previous reports indicated a high variability, with a mean difference of 17% for MEIA method vs. high-performance liquid chromatography/ultraviolet (HPLC/UV). This study was aimed at comparing the reliability of MEIA with the HPLC/UV method. Blood samples from transplant patients were processed using both HPLC/UV and MEIA assays. Comparison and Bland-Altman plots, as well as regression analysis and paired t -test were used to compare results of the assays. Concentrations were stratified into three groups and used to investigate whether any observed difference between methods could be influenced by sirolimus concentration. Regression analysis yielded a coefficient of correlation R of 0.9756, the line of best fit being y=0.9832x+0.1976. The statistical analysis showed no difference between the two sets of experimental data. The average percentage difference between the two methods was found to be ,0.2±19.2%. On the basis of our present results, the tested MEIA assay is able to quantify sirolimus concentration with a clinically acceptable imprecision, similar to that of HPLC/UV method. J. Clin. Lab. Anal. 20:239,244, 2006. © 2006 Wiley-Liss, Inc. [source] Novel rapid immunochromatographic test based on an enzyme immunoassay for detecting nucleocapsid antigen in SARS-associated coronavirusJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2005Hiroyuki Kogaki Abstract A novel severe acute respiratory syndrome-associated coronavirus (SARS-CoV) has been discovered. The detection of both antigens and antibodies in SARS-CoV from human specimens with suspected SARS plays an important role in preventing infection. We developed a novel rapid immunochromatographic test (RICT) based on the sandwich format enzyme immunoassay (EIA) with an all-in-one device for detecting the native nucleocapsid antigen (N-Ag) of SARS-CoV using monoclonal antibodies (MoAbs), which we produced by immunizing recombinant N-Ag to mice. RICT is a qualitative assay for respiratory aspirates and serum specimens. With this assay, a positive result can be judged subjectively by the appearance of a blue line on the device 15 min after the sample is applied. RICT with several pairs of MoAbs showed a high sensitivity for the detection of recombinant N-Ag as well as viral N-Ag of SARS-CoV. rSN122 and rSN21-2 were the best MoAbs for immobilized antibody and enzyme labeling, respectively. With regard to analytical sensitivity, RICT detected N-Ag at 31 pg/mL for recombinant N-Ag, and at 1.99×102 TCID50/mL for SARS-CoV. The specificity of RICT was 100% when 150 human sera and 50 nasopharyngeal aspirates (NSPs) were used. RICT based on an EIA using the rSN122/rSN21-2 pair is a sensitive, specific, and reliable rapid assay for detecting N-Ag in SARS-CoV treated with either heat or Triton X-100. J. Clin. Lab. Anal. 19:150,159, 2005. © 2005 Wiley-Liss, Inc. [source] Relationship between levels of urinary type IV collagen and renal injuries in patients with IgA nephropathyJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 1 2004Hiroaki Io Abstract Because type IV collagen is synthesized by podocytes and mesangial cells, we investigated the relationship between levels of urinary type IV collagen (uIV) and renal injuries in patients with IgA nephropathy. uIV was measured by a highly sensitive one-step sandwich enzyme immunoassay prior to renal biopsy. Patients with IgA nephropathy were classified into four grades (grade 1 = good prognosis, grade 2 = relatively good prognosis, grade 3 = relatively poor prognosis, and grade 4 = poor prognosis) by the prognostic criteria of the Ministry of Health, Labor, and Welfare of Japan. Levels of uIV in grade 4 were significantly higher than those in grades 1,3. These levels tended to increase gradually due to progression of renal injuries. The grades were further divided into two groups: group I (good or relatively good prognoses) and group II (relatively poor or poor prognoses). Patients with proteinuria of <1.0 g/day were defined as groups Ip and IIp. The levels of uIV in group II were significantly higher than those in group I, and those in group IIp were significantly higher than those in group Ip. It appears that the level of uIV can be a useful marker for detection of renal injuries in IgA nephropathy. J. Clin. Lab. Anal. 18:14,18, 2004. © 2004 Wiley-Liss, Inc. [source] Homogenous enzyme immunoassay for cyclosporine in whole blood using the EMIT®2000 cyclosporine specific assay with the COBAS MIRA-plus analyzerJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 6 2001Shigeki Kimura Abstract We describe the evaluation of the EMIT®2000 cyclosporine specific assay kit, an enzyme-multiplied immunoassay for cyclosporine in whole blood, with a COBAS MIRA-plus analyzer. The enzyme used for the assay was glucose-6-phosphate dehydrogenase (EC 1.1.1.49 G6PDH) from Leuconostoc mesenteroides; the monoclonal antibody is fairly specific for cyclosporine, and is not reactive with most metabolites. The assay principle is based on competitive immunoassay with G6PDH-labeled cyclosporine and cyclosporine in sample to the anticyclosporine mouse monoclonal antibody binding site. The within-assay coefficient of variation (CV) of this method was 2.7,4.2% (n = 10) at the levels of 56.2,339.7 ,g/L. Day-to-day CVs ranged from 4.2,8.1% at the levels of 47.2,350.2 ,g/L. The within-day CVs ranged from 2.0,6.4% at the levels of 43.3,330.5 ,g/L. The functional detection limit was 24.9 ,g/L. Samples treated with pretreatment reagent were stable at least 5 hr. Calibration was stable at least 10 days. The analytical recovery was 81,109%. The correlation between values obtained with the EMIT®2000 cyclosporine specific assay kit (y) and fluorescence polarization immunoassay (FPIA) (TDxFLx) (x) was: y = 0.880x , 13.053 ,g/L (r = 0.984, Sy/x = 15.968, n = 71) with a mean difference of 31.42 ± 19.89 ,g/L ((TDxFLx , EMIT®2000) ± SD); for the FPIA (AxSYM) (x): y = 0.989 , 4.144 ,g/L (r = 0.981, Sy/x = 17.478, n = 71) with a mean difference of 5.56 ± 17.38 ,g/L ((AxSYM , EMIT®2000) ± SD); and for the radioimmunoassay (RIA, CYCLO-Trac SP) (x): y = 0.893 , 6.764 ,g/L (r = 0.993, Sy/x = 10.582, n = 71) with a mean difference of 22.18 ± 14.98 ,g/L ((RIA , EMIT®2000) ± SD) using the Bland-Altman technique. J. Clin. Lab. Anal. 15:319,323, 2001. © 2001 Wiley-Liss, Inc. [source] Plasma cortisol and 11-ketotestosterone enzyme immunoassay (EIA) kit validation for three fish species: the orange clownfish Amphiprion percula, the orangefin anemonefish Amphiprion chrysopterus and the blacktip reef shark Carcharhinus melanopterusJOURNAL OF FISH BIOLOGY, Issue 3 2010S. C. Mills Commercially available enzyme immunoassay (EIA) kits were validated for measuring steroid hormone concentrations in blood plasma from three fish species: the orange clownfish Amphiprion percula, the orangefin anemonefish Amphiprion chrysopterus and the blacktip reef shark Carcharhinus melanopterus. A minimum of 5 µl plasma was required to estimate hormone concentrations with both kits. These EIA kits are a simple method requiring minimal equipment, for measuring hormone profiles under field conditions. [source] Cimetidine inhibits epidermal growth factor-induced cell signalingJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2007Tatsuya Fujikawa Abstract Background:, Cimetidine, a histamine-2 (H2) receptor antagonist, has been demonstrated to have anticancer effects on colorectal cancer, melanoma and renal cell carcinoma. In the current study, we clarified that cimetidine inhibits both epidermal growth factor (EGF)-induced cell proliferation and migration in hepatocellular carcinoma (HCC) cell lines. Method:, HCC cell lines (Hep3B, HLF, SK-Hep-1, JHH-2, PLC/PRF/5 and HLE) were used and cell proliferation was assessed by [3H]-thymidine incorporation assay. Cell migration was measured by in vitro cell migration assay. Biological effects of cimetidine were assessed with human EGF receptor (EGFR)-expressing mouse fibroblast cells (NR6-WT). The autophosphorylation of EGFR and the activation of other downstream effectors were analyzed by immunoprecipitation and immunoblotting. The concentration of intracellular cyclic AMP (cAMP) was measured by competitive enzyme immunoassay. Results:, Cimetidine inhibited both EGF-induced cell proliferation and migration in Hep3B, HLF, SK-Hep-1 and JHH-2, while cimetidine did not affect EGF-induced cell proliferation and migration in PLC/PRF/5 and HLE. Cimetidine was revealed to disrupt the EGF-induced autophosphorylation of EGFR and its downstream effectors, mitogen activated protein kinases and phospholipase C-,. To define the molecular basis of this negative regulation, we identified that cimetidine significantly decreased intracellular cAMP levels and that decrement of cAMP inhibited autophosphorylation of EGFR. The cell permeable cAMP analog, CPT-cAMPS reversed the cimetidine-induced inhibition of EGF-induced cell proliferation and cell migration by restoring autophosphorylation of EGFR. Conclusion:, Cimetidine inhibited EGF-induced cell proliferation and migration in HCC cell lines by decreasing the concentration of intracellular cAMP levels. Cimetidine may be a candidate chemopreventive agent for HCC. [source] Detection of Chlamydia pneumoniae by polymerase chain reaction,enzyme immunoassay in intestinal mucosal biopsies from patients with inflammatory bowel disease and controlsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2002Wangxue Chen Abstract Background and Aim : It has been suggested that Chlamydia is an organism that may have the potential to cause inflammatory bowel disease (IBD) in susceptible individuals. Chlamydia pneumoniae has emerged as an important human pathogen in the last decade. The objective of the present study was to investigate the frequency of the presence of C. pneumoniae DNA in intestinal biopsies from patients with IBD and from non-IBD controls. Methods : The DNA was extracted from 222 colonoscopic biopsies, which were obtained from 11 patients with Crohn's disease (CD), 18 patients with ulcerative colitis (UC) and from 37 non-IBD control patients. The presence of the C. pneumoniae omp1 gene and C. trachomatis 16S rRNA gene was determined using a rapid and sensitive polymerase chain reaction-enzyme immunoassay (PCR-EIA). Results : The C. pneumoniae -specific DNA was detected in 32 (14.4%) of 222 endoscopic biopsies. Among them, C. pneumoniae DNA were found in nine of 42 (21.4%) biopsies from patients with CD, nine of 59 (15.3%) biopsies from patients with UC, and 14 out of 122 (11.4%) biopsies from non-IBD control patients, respectively. Moreover, the percentage of patients with at least one biopsy positive for C. pneumoniae was higher, although not statistically significant, in CD (36.4%) and UC patients (38.9%) compared to non-IBD controls (16.2%). In contrast, C. trachomatis DNA was detected in only two of 222 (0.9%) biopsy samples. Conclusion : The C. pneumoniae DNA was detected in the intestine of both patients with IBD and in non-IBD control patients, probably reflecting the high prevalence of this organism in the environment. The moderate yield of positive biopsies in our IBD patients and the fact that the detection rate of C. pneumoniae DNA was similar in endoscopic biopsies from IBD patients and non-IBD controls does not support a direct role for this organism in the pathogenesis of IBD. © 2002 Blackwell Publishing Asia Pty Ltd [source] Association between human papillomavirus infection and laryngeal squamous cell carcinomaJOURNAL OF MEDICAL VIROLOGY, Issue 6 2010Kamal Morshed Abstract The aim of this study was to compare the prevalence of human papillomavirus (HPV) infection in laryngeal squamous cell carcinoma using two methods: PCR-DNA enzyme immunoassay (PCR/DEIA) and immunohistochemistry (IHC) for detection of HPV in specimens of laryngeal squamous cell carcinoma and to correlate the presence of HPV with the epidemiological and clinicopathological features of recurrence and survival. HPV DNA was amplified from 93 paraffin-embedded laryngeal squamous cell carcinoma tissue specimens by the short PCR fragment (SPF 10) primer set using PCR/DNA method. HPV detection using monoclonal anti-human papilloma virus antibodies Clone K1H8 for IHC reaction was performed on 130 specimens. HPV was identified in 35.5% of patients with laryngeal squamous cell carcinoma using PCR/DEIA and 27.7% using IHC. There was no statistically significant association between the presence of HPV and the epidemiological and clinicopathological features and recurrence. There was no statistically significant association between the presence of HPV and overall survival nor disease specific survival. Statistically significant correlation between HPV detection using PCR/DEIA technique and IHC technique was found. The presence of HPV infection in 27.7% and 38.9% of the patients suggests a possible role in the etiology of laryngeal squamous cell carcinoma. The SPF10 PCR/DEIA technique is the most accurate method for detection of HPV in laryngeal squamous cell carcinoma. J. Med. Virol. 82:1017,1023, 2010. © 2010 Wiley-Liss, Inc. [source] Current HIV-2 diagnostic strategy overestimates HIV-2 prevalence in China,JOURNAL OF MEDICAL VIROLOGY, Issue 5 2009Maofeng Qiu Abstract A significant number of HIV-2 infections have been reported in China using Western blot as per current guidelines for HIV-2 diagnosis in China. However, most specimens were also positive on HIV-1 Western blot suggesting cross-reactivity and possible overestimation. We carried out the current study to evaluate a strategy to diagnose the HIV-2 infections in China. A total of 119 specimens received from 16 provinces were likely to be HIV-2 when tested according to current guidelines in China using the Genelabs Western blot (HIV Blot 2.2 WB). Further testing by HIV-2 WB (Bio-Rad New LAV Blot II or Genelabs HIV Blot 1.2 WB) scored 56 (47.1%) of 119 samples with banding pattern suggestive of HIV-2 infection, and 63 (52.9%) were HIV-2 indeterminate. A peptide-based HIV-1 and HIV-2 enzyme immunoassay for differential diagnosis of HIV-1 and HIV-2 infections was validated and used. This in-house EIA demonstrated that only 1 (0.8%) of 119 specimens had HIV-2 specific antibodies, while 2 (1.7%) were dually reactive. These results were highly concordant (>99%) with those by Inno-LIA HIV-I/II (Innogenetics, Belgium), which also use specific peptides for type-specific diagnosis. Our data demonstrates that HIV-2 infection is rare in China, and HIV-2 Western blot may overestimate the prevalence of HIV-2 in the population with HIV-1. The HIV-2 diagnostic strategy in China needs to be revised to include more specific peptide-based immunoassays. J. Med. Virol. 81:790,797, 2009. © 2009 Wiley-Liss, Inc. [source] HIV antigen,antibody combination enzyme immunoassay,the experience of a London Teaching HospitalJOURNAL OF MEDICAL VIROLOGY, Issue S1 2007Simon Goldenberg Abstract The introduction of the fourth generation HIV antigen,antibody combination enzyme immunoassay (HIV Ag,Ab EIA) has led to a reduction in the diagnostic "window period" when HIV antibody is negative during primary infection. This facilitates earlier laboratory diagnosis during sero-conversion. An HIV Ag,Ab EIA (AxSYM, Abbott Laboratories, Kent, UK) was introduced to a London Teaching Hospital since 2004 as the primary screening test. Confirmation was performed using another HIV Ag,Ab EIA (Vironostika, BioMérieux, Hampshire, UK) and an HIV Ab only assay (Bispot, Orgenics, Yavne, Israel). Retrospective analysis identified a total of 20 sero-converting patients who would have been missed if the standard antibody-only HIV tests had been used as the primary screening test. This accounted for approximately 3% of the new diagnoses made by the laboratory. The median time from onset of illness to sero-conversion was 18 days. Two patients had multiple samples analyzed between initial presentation and eventual sero-conversion. One had a prolonged sero-conversion illness lasting for over 137 days; the other sero-converted within 17 days. A plotting of the signal to cut-off ratio with time of the two HIV Ag,Ab EIAs showed a V-shaped curve and both tests were below cut-off at some time-points during sero-conversion. These two cases highlighted the difficulties in diagnosing HIV infection during sero-conversion. On the basis of these results, it is recommended that a fourth generation HIV Ag,Ab EIA could be considered for use as the standard of care, particularly in any population with a high rate of HIV infection. J. Med. Virol. 79:S23,S26, 2007. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||||||||||||||