Home About us Contact
|
Home About us Contact | ||
|
|
||
Positive Sera (positive + sera)
Selected AbstractsPrevalence of immunoglobulin E for fungi in atopic childrenCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2001G. Nolles Background The prevalence of sensitization to fungi in young atopic patients in relation to age and clinical importance is largely unknown. Objective The aim of this study was to investigate the prevalence of sensitization to different fungi in atopic children in relation to age and other aeroallergens. Methods A total of 137 atopic children (male 62%, female 38%; mean age 5 years and 9 months, range 5 months,14 years) were studied. Sera of all patients were routinely tested for total IgE and specific IgE against aeroallergens and milk. Positive sera were also tested for IgE against Alternaria alternata, Aspergillus fumigatus, Cladosporium herbarum and Penicillium chrysogenum, using the Pharmacia Enzyme CAP procedure. Results In this study in atopic children total IgE showed a significant linear relation with age, whereas specific IgE against outdoor fungi, indoor fungi and house dust mite showed significant non-linearity with age. Prevalence of specific IgE for Cladosporium ranked first, followed closely by Aspergillus and Alternaria. Calculation of the sensitization of indoor and outdoor fungi showed maximum prevalence at 7.8 years, followed by lower values at higher ages. A similar significant relation was also found for Alternaria, while this relation was not significant for the other individual fungi. Specific IgE for indoor and outdoor fungi was associated with the presence of specific IgE for aeroallergen and milk. We found that all children aged 4 years and older showed IgE for house dust mite that did not decline with increasing age. Conclusions Sensitization to fungi is prevalent in childhood, with an age-dependent distribution reaching maximum values at 7.7,7.8 years, followed by a decline for all fungal sensitization with increasing age. The importance and relative contribution of fungal sensitization to airway disease, compared with the other allergens, remains to be established. [source] Genetic characterization of hepatitis C virus strains in Estonia: Fluctuations in the predominating subtype with timeJOURNAL OF MEDICAL VIROLOGY, Issue 4 2007Tatjana Tallo Abstract During the last decade, there has been a dramatic increase in intravenous drug use in young adults in Estonia with an increased incidence of both hepatitis B and C as a consequence. Since genetic data are limited regarding hepatitis C virus (HCV) strains in Estonia, the aim of the study was to characterize HCV strains in different risk groups to determine their relatedness to strains from other geographical regions. Three hundred fifty-three anti-HCV positive sera collected during 1994,2004 from hospitalized patients, blood donors and health care workers were used as source of HCV RNA. Two hundred nine (59%) of the sera were positive for HCV RNA by PCR directed to the 5,-UTR region. For 174 strains the HCV subtype was determined by analyses of the NS5B and/or the 5,UTR-core regions. 1b (71%) was the most common subtype followed by 3a (24%), 2c (2%), 1a (1%), and 2a (1%). The 1b and 3a strains were similar to strains from other regions of the former USSR. Within genotype 1b there were several HCV lineages. However, for 3a there seemed to be two separate introductions into Estonia. There was a relative shift from subtype 1b to 3a in 1999,2000 with a further replacement of 3a with 1b in intravenous drug users in 2001 and onwards (P,<,0.05). However, both subtypes were found to co-circulate in the community independent of risk factors. One patient was infected with the 2k/1b recombinant presumed to originate from St. Petersburg being the first isolate of this recombinant recovered outside Russia. J. Med. Virol. 79:374,382, 2007. © 2007 Wiley-Liss, Inc. [source] Dichotomy in cross-clade reactivity and neutralization by HIV-1 sera: Implications for active and passive immunotherapy,JOURNAL OF MEDICAL VIROLOGY, Issue 2 2005Lisa A. Cavacini Abstract The identification of broadly reactive and cross-clade neutralizing antibodies will facilitate the development of a more universally effective vaccine for human immunodeficiency virus (HIV). Antibodies in sera from individuals infected with Clade B HIV bind native primary viral isolates, and virus binding correlates with neutralization and stable clinical disease. In this study, we quantified cross-clade antibody reactivity and neutralization by Clades B and C sera. Primary viral isolates were captured by serum IgG bound to anti-human IgG and quantitated as p24 released by lysis of captured virus. Neutralization was determined using PHA-stimulated PBMC. Clade B antibodies reacted more frequently with Clade B R5 virus, but positive sera captured quantitatively more X4 virus than R5 and R5X4 virus. Clade B sera reacted less frequently and captured less Clade C virus than Clade B virus. Antibodies in Clade C sera captured Clades B and C isolates with equal frequency and quantity. There was no difference in neutralization of Clade B virus by either group of sera; however, Clade C sera neutralized Clade C virus, whereas Clade B sera were ineffective against Clade C virus. Thus, there are distinct differences in cross-clade reactivity of and neutralization by antibodies induced in response to Clade C infection compared to Clade B infection. Understanding antibody responses to native virions after Clade C infection and cross clade antibody behavior has implications for understanding pathogenesis and vaccine development. J. Med. Virol. 76:146,152, 2005. © 2005 Wiley-Liss, Inc. [source] Sequential changes in hepatitis A virus genotype distribution in Estonia during 1994 to 2001JOURNAL OF MEDICAL VIROLOGY, Issue 2 2003Tatjana Tallo Abstract Hepatitis A virus (HAV) isolates from a large outbreak and from non-outbreak cases in Estonia were characterized by sequencing the aminoterminal VP1 region. From January 1998 to December 1999, a total of 1,084 cases of hepatitis A were reported to the Harjumaa-Tallinn and Ida-Virumaa Health Protection Services in Estonia. The attack rate was highest among males aged 15,29. Initial cases were noted to be associated with injecting drug use. IgM anti-HAV positive sera were available from 107 hospitalized outbreak cases and from 68 patients sampled during 1994 to 2001. HAV RNA was detected in 42% of sera from 1994,1996 and in 88% of sera from 1998,2001. It was possible to obtain HAV sequences from 83 outbreak and 29 background cases. The outbreak strain was represented by five different sequences, all belonging to subtype IIIA. During the outbreak, this IIIA strain also spread into the general population. All available non-outbreak isolates from 1994 to 2001 but one belonged to genotype IA and formed distinct clusters as compared to isolates from other parts of the world. One subtype IIIA isolate from 1995 was unrelated to the outbreak strain. Subtype IA had been dominating in Estonia during 1994,2001, but the outbreak strain from 1998 to 1999 was IIIA. This subtype was encountered previously in addicts in Sweden during the 1980s and in Norway at the end of the 1990s. This study supports the use of limited sequencing within the aminoterminal VP1 region for studying the molecular epidemiology of hepatitis A. J. Med. Virol. 70: 187,193, 2003. © 2003 Wiley-Liss, Inc. [source] Identification of spore allergens from the indoor mould Aspergillus versicolorALLERGY, Issue 4 2008D. Benndorf Background:, Indoor mould growth and dampness are associated with respiratory health effects and allergies and several studies demonstrated that mainly Aspergillus versicolor and Penicillium expansum are responsible for indoor mould exposure. In contrast, commercialized test systems to diagnose allergic reactions to this mould species are not available. In this study, allergenic proteins from spores of the indoor relevant species A. versicolor and P. expansum should get detected and identified. Methods:, We used two-dimensional (2D)-gel electrophoresis of spore proteins and immunoblotting with sera from patients participating in an epidemiologic study about indoor exposure of moulds and their influence on the development of allergies (ESTERSPEGA). Sera were screened for IgE antibodies specific for proteins from A. versicolor, A. fumigatus and P. expansum in one-dimensional blots and in 2D immunoblots. From the 2D gels, the corresponding spots were picked and identified by mass spectrometry. Results:, More than 20 allergens from A. versicolor were identified; in particular, seven major allergens were selected, which were detected by more than 90% of the positive sera. The most abundant allergen was glyceraldehyde-3-phosphate dehydrogenase, followed by an unnamed protein, which displays a high homology to sobitol/xylose reductase. The other allergens were identified as catalase A, hypothetical protein AN6918.2, enolase, hypothetical protein AN0297.2 and a protein with homology to a fungal malate dehydrogenase. Conclusions:, The results indicate an important role of spore proteins from A. versicolor for sensitization against indoor moulds and identification of the major allergens might enable species-specific diagnosis of allergic reactions. [source] Rheumatoid arthritis,specific autoantibodies to peptidyl arginine deiminase type 4 inhibit citrullination of fibrinogenARTHRITIS & RHEUMATISM, Issue 1 2010Isabelle Auger Objective Autoantibodies to citrullinated proteins are specific for rheumatoid arthritis (RA) and recognize epitopes centered by citrulline, a posttranslationally modified form of arginine. Peptidyl arginine deiminase type 4 (PAD-4), the enzyme that converts arginine into citrulline, is in itself a target for RA-specific autoantibodies. This study was undertaken to assess whether anti,PAD-4 autoantibodies interfere with citrullination in vitro in patients with RA, and to identify peptide targets of anti,PAD-4 antibodies that can activate or inhibit citrullination. Methods To test whether autoantibodies to PAD-4 influence citrullination, an in-house citrullination assay was developed using purified autoantibodies to PAD-4. To map B cell epitopes on PAD-4, 65 overlapping 20-mer peptides encompassing the entire PAD-4 were analyzed for their reactivity in RA sera. Results Autoantibodies to PAD-4 inhibited PAD-4,mediated citrullination. Three linear peptides on PAD-4 were recognized almost uniquely by PAD-4 autoantibodies in the sera of patients with RA. One peptide was located in the N-terminal, calcium-binding domain of PAD-4, while 2 other peptides were located in the C-terminal, substrate-binding domain of PAD-4. Conclusion Autoantibodies to PAD-4 inhibit in vitro citrullination of fibrinogen by PAD-4. Most anti,PAD-4,positive sera recognize peptides located both in the N-terminal domain (211,290) and the C-terminal domain (601,650) of PAD-4. [source] Patients with pulmonary tuberculosis are frequently positive for anti,cyclic citrullinated peptide antibodies, but their sera also react with unmodified arginine-containing peptideARTHRITIS & RHEUMATISM, Issue 6 2008Prasanthi Kakumanu Objective The anti,cyclic citrullinated peptide (anti-CCP) enzyme-linked immunosorbent assay (ELISA) has high sensitivity and specificity for rheumatoid arthritis (RA). However, detection of anti-CCP in patients with active pulmonary tuberculosis (TB) has recently been reported. To determine whether this activity was specific for the citrullinated residue, the specificity of anti-CCP,positive sera for CCP versus that for unmodified arginine-containing peptide (CAP) was examined in patients with TB and compared with that in patients with RA. Methods Anti-CCP and anti-CAP in sera from patients with pulmonary TB (n = 49), RA patients (n = 36), and controls (n = 18) were tested by ELISA. Sera were available at diagnosis from most TB patients. All TB patients were treated with a combination of 2,4 antibiotics for at least 6 months, and sera were collected over time. Results Anti-CCP was found in 37% of TB patients and in 43% of RA patients. CAP reactivity was more common in TB than in RA. High anti-CCP:anti-CAP ratios (>2.0) were seen far more commonly in anti-CCP,positive RA patients than in anti-CCP,positive TB patients (94% versus 22%). Anti-CCP was inhibited by CCP peptide in sera from RA patients, but not in sera from TB patients. A slight increase in anti-CCP was common after initiating treatment for TB, although the anti-CCP level decreased after 1,2 months. Conclusion Anti-CCP is frequently present in patients with active TB. However, many anti-CCP,positive TB sera also reacted with CAP, and anti-CCP:anti-CAP ratios in TB sera were low. Anti-CCP:anti-CAP ratios should be useful clinically for distinguishing CCP-specific reactivity seen in RA from reactivity with both CCP and CAP frequently seen in pulmonary TB. [source] Anti-La/SSB antibodies transported across the placenta bind apoptotic cells in fetal organs targeted in neonatal lupusARTHRITIS & RHEUMATISM, Issue 6 2002Hai B. Tran Objective To determine whether La and/or Ro epitopes on apoptotic cells in fetal organs that are targeted in neonatal lupus syndrome (NLS) are accessible for binding by autoantibodies in vivo, we traced the fate of transplacental autoantibodies in a murine passive transfer model. Methods Pregnant mice at day 15 of gestation (E15) were injected intraperitoneally with human anti-Ro/La,positive sera or control sera, and transplacental transfer of human autoantibodies was tested by enzyme-linked immunosorbent assay with recombinant antigens. Multiple cryostat sections at the level of the heart of E17 fetuses were visualized simultaneously for human IgG binding and apoptosis (TUNEL) under confocal microscopy. Serial paraffin sections of E17 and E19 fetuses were examined for histologic evidence of inflammation. Results Human IgG anti,52-kd Ro, anti,60-kd Ro, and anti-La autoantibodies were transported efficiently into the fetal circulation. Human IgG,apoptotic cell complexes were detected in the heart (atrial trabeculae and atrioventricular node), skin, liver, and newly forming bone of fetuses from mothers injected with anti-Ro/La sera but not control sera. The IgG binding was fetal-specific and organ-specific; transplacental autoantibodies did not bind to apoptotic cells in the fetal thymus, lung, brain, or gut. The complexes were not associated with an inflammatory reaction. Injection of mothers with affinity-purified anti-La autoantibodies (but not anti-Ro/La Ig depleted of anti-La) revealed an identical location of IgG binding to apoptotic cells in the fetuses. Conclusion This is the first study to demonstrate that transplacental anti-La autoantibodies bind specifically to apoptotic cells in selected fetal organs in vivo, similar to the organ involvement in NLS. We hypothesize that additional factors are required to promote proinflammatory clearance of IgG,apoptotic cell complexes and subsequent tissue damage. [source] | ||||||||||