ABSTRACT
Objective:Establish the decision threshold value of mean fluorescence intensity of anti-human leukocyte antigen(HLA)antibody through statistical analyzing the results of international proficiency testing(PT)organized by American Society for Histocompatibility and Immunogenetics(ASHI).Methods:Single antigen reagent and liquid chip(Luminex)technique were used to detect anti-HLA antibody. A retrospective analysis of the HLA antibody PT results of 55 quality control samples from 11 times organized by ASHI from 2012 to 2019 was reviewed.Results:Among 79 kinds of HLA-I antibodies, 21, 43 and 15 types of HLA-A, B and Cw antibodies were detected respectively, while among 44 kinds of HLA-Ⅱ antibodies, 18, 7 and 19 types of HLA-DRB1, DQB1 and DPB1 antibodies were detected respectively. After analyzing the MFI detection value of different specific antibodies in each PT samples at our laboratory and the coincidence rate of the negative / positive results judged by ASHI through summarizing the results of multicenter participating in the same period, MFI values of HLA antibody were arranged from high to low into the intervals of possible saturation value, positive decision value, positive judgment threshold value, suspicious positive reference value and suspicious negative reference value , according to the coincidence rate of 95%, 90%, 80%, 79%~50% and <50%.Thus, the decision limit value table of HLA specific antibody at our laboratory was established. And 42 kinds of HLA antibody types were detected with complete data.When the MFI values of various HLA-I or HLA-Ⅱ antibodies are found to be 80% or more in the table, it can be used to judge the detection of HLA antibodies. When HLA antibody MFI value reaches the positive decision value, it may have a certain guiding significance for clinical diagnosis and treatment. And when antibody MFI value reaches the saturation value and lies in the suspicious positive or suspicious negative reference threshold, it just suggests that the clinical need for dynamic follow-up of anti-HLA antibody detection.Conclusions:The decision limit value of MFI of laboratory HLA antibody is established based on the international PT experimental results, which is of reference value for the interpretation of experimental results and clinical diagnosis and treatment. A transplant ation center should pay attention to the quality control of comparison test between laboratories in the detection of HLA antibodies.
ABSTRACT
Objective@#To analyze family-based haplotype frequencies of HLA-A, -B, -C, -DRB1 and -DQB1 genes and their clinical significance.@*Methods@#The data of HLA genotyping in 3568 families undergoing related haploidentical transplantation between 2012 and 2017 at the First Affiliated Hospital of Soochow University were retrospectively evaluated. The HLA genotyping was performed by PCR amplification with sequence-based typing (PCR-SBT) and sequence-specific oligonucleotide probe (PCR-SSOP) methods. The family genetic analysis and haplotype frequencies were also investigated.@*Results@#All the families were divided into 3 groups, including group1 of 1 422 entire families; group2 of 1 310 patients and either of their parents or one of their children; group3 of 836 patients and their HLA≥5/10 matched sibling donors. In the haplotypes with frequencies greater than 0.1% in group1+ group2, the frequency of A*11∶01-B*40∶01-C*03∶04-DRB1*11∶01-DQB1*03∶01, A*02∶07-B*51∶01-C*14∶02-DRB1*09:01-DQB1*03∶03 were significantly different between group1 and group2 (P=0.029, 0.033) . The frequency of A*11∶01-B*46∶01-C*01∶02∶01G-DRB1*09∶01-DQB1*03∶03 was significantly different between group1 and group3 (P=0.035) . The frequency of A*02∶01-B*40∶01-C*07∶02-DRB1*09∶01-DQB1*03∶03 was significantly different between group1 and group2 (P=0.034) , or group1 and group3 (P=0.034) . The frequency of A*24∶02-B*13∶01-C*03∶04-DRB1*12∶02-DQB1*03:01 was significantly different between group2 and group3 (P=0.046) .@*Conclusion@#In this study, we summarize the prevalence of haplotype frequencies in terms of HLA-A, -B, -C, -DRB1 and-DQB1. Based on the database of family haplotype analysis, patients and donor candidates are sorted with matched HLA genotype while unmatched HLA haplotype. Even in patients without entire family information, HLA haplotype analysis assists in choosing the optimal related or unrelated donors.