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Complete Concordance (complete + concordance)
Selected AbstractsHLA-B27 typing: Evaluation of an allele-specific PCR melting assay and two flow cytometric antigen assaysCYTOMETRY, Issue 1 2005Michael T. Seipp Abstract Background Human leukocyte antigen B27 (HLA-B27) is a major histocompatibility complex class 1 molecule that is strongly associated with the disease ankylosing spondylitis. Testing for HLA-B27 is of diagnostic value because 90% of patients with ankylosing spondylitis have the B27 antigen. Two commonly used HLA-B27 flow cytometric assays are commercially available. Methods An allele-specific polymerase chain reaction (PCR) melting assay for HLA-B27 was compared with two available antigen assays on 371 clinical samples. The accuracy of the assays was measured by receiver operating characteristic analysis using the PCR method and sequencing as the reference standard. Results When PCR results were compared with those of the antigen assays, complete concordance was observed except for five discrepant results that were resolved by sequence analysis. Using DNA sequencing as the gold standard, the sensitivity and specificity of PCR were 99.6 and 100.0, those of the best single antigen assay were 98.2 and 97.6, and those of a reflex combination of both antigen assays were 98.8 and 97.6. Conclusions The allele-specific PCR melting assay for HLA-B27 genotyping is easy to perform and has better sensitivity and specificity than antigen assays. The performance of the two flow cytometric antigen assays depends on the antibody used and the positive cutoff values assigned. © 2004 Wiley-Liss, Inc. [source] Quantitative assessment of WT1 gene expression after allogeneic stem cell transplantation is a useful tool for monitoring minimal residual disease in acute myeloid leukemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2009Anna Candoni Abstract Introduction:,WT1 overexpression is described in several oncological diseases including acute myeloid leukemia (AML). Quantification of WT1 in bone marrow samples may be useful as a marker of minimal residual disease (MRD) and may predict the relapse of AML after allogeneic hematopoietic stem cell transplant (HSCT). Methods and results:, The quantitative expression of WT1 was measured in 38 AML patients (16 males and 22 females) at diagnosis, at the time of transplant and after the allogeneic HSCT (at precise time points). All cases showed high WT1 expression levels at diagnosis with a mean of 4189 (SD 3325) and a median of 3495 (range 454,13923) copies WT1/104Abl. At transplant, 25 patients (66%) were in complete cytologic remission (CcR) and 13 (34%) had refractory or relapsed AML. Bone marrow samples from patients transplanted in CcR showed significantly lower WT1 expression levels during HSCT compared with the samples from patients with a relapsed or refractory AML (P = 0.004). After HSCT, a rapid decline in WT1 expression levels was observed in all patients who attained or maintained a condition of CcR. Six of 38 patients (13%) relapsed after HSCT and all of them had an increase in WT1 expression at/or before relapse. Five of these six patients died of leukemia and one was successfully reinduced with donor lymphocyte infusion (DLI) + chemotherapy with a rapid reduction of WT1 levels. Besides, we found a complete concordance between WT1 expression levels and other disease markers (when available). Conclusions:, In our experience, there was a complete concordance between WT1 expression levels (measured by quantitative RT-PCR at precise time points) and status of AML before and after allogeneic HSCT. WT1 may be useful as a non-specific leukemia marker for monitoring MRD and as a predictor of AML clinical relapse. Based on these results, cases with increase of WT1 levels after HSCT and without graft vs. host disease may be candidate to discontinuation of immunosuppression and/or DLI therapy. [source] Evidence of intrafamilial transmission of rotavirus in a birth cohort in South IndiaJOURNAL OF MEDICAL VIROLOGY, Issue 10 2008Indrani Banerjee Abstract Transmission of rotavirus infection was studied in a birth cohort of children based in an urban slum in Vellore and their familial contacts. Contemporaneous samples from index patients and their familial contacts were collected for analysis in three different settings. Firstly, samples were collected from familial contacts during a period of rotavirus infection in children from the cohort. Secondly, on occasions when a family member had rotavirus diarrhea, samples from the cohort child were taken for analysis. Lastly, asymptomatic surveillance samples collected at predetermined time points from both the cohort child and familial contacts were analyzed. From 560 samples collected from family members during symptomatic and asymptomatic rotavirus infections in these children, three rotavirus transmissions were identified, accounting for a secondary attack rate of 0.54%. In four instances of rotavirus diarrhea in a family member, one infection was transmitted to the cohort child. Nucleotide sequence and phylogenetic analysis demonstrated a high degree of similarity in all these pairs ranging between 99% and 100% at both the nucleotide and the deduced amino acid levels, highly suggestive of person-to-person transmission of rotavirus infection. There was complete concordance of rotavirus genotyping between these pairs. No transmission events were noted from 14 asymptomatic rotavirus infections identified during routine surveillance of family members. This study is the first to use phylogenetic analysis to study the intrafamilial spread of rotavirus infection. J. Med. Virol. 80:1858,1863, 2008. © 2008 Wiley-Liss, Inc. [source] A sensitive model for prediction of relapse in adult acute myeloid leukaemia with t(8;21) using white blood cell count, CD56 and MDR1 gene expression at diagnosisBRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2004Markus Schaich Summary Acute myeloid leukaemia (AML) carrying t(8;21) has an overall favourable prognosis. However, relapse occurs and the impact of multidrug resistance gene (MDR1) expression on recurring disease in this group of patients is not known. We determined quantifiable MDR1 expression in the bone marrow of 28 AML patients with t(8;21) by a validated real-time polymerase chain reaction assay. Using MDR1 expression, white blood cell count and CD56 expression at diagnosis we observed complete concordance of predicted and observed relapses. A calculated logit out of these three variables was a strong independent prognostic factor for overall (P = 0·007) and disease-free survival (P = 0·002). [source] | |||||||||||||