Two-Year Study on the HLA Typing Proficiency Survey in Korea, 1996-1998

Park, Myoung Hee; Whang, Dong Hee; Kim, Byoung Cheol

Abstract

BACKGROUND
To standardize the histocompatibility testing among different laboratories, we have developed and performed a proficiency survey (external quality control) program in HLA typing with participation of nationwide HLA laboratories in Korea.
METHODS
During a two-year period, four trials of proficiency survey were performed with 35-39 participating laboratories. Test number and items included in each survey were 3 HLA class Iantigen typings, 2 class II DNA typings, and 6 HLA crossmatch tests (3 cells x 2 sera).
RESULTS
HLA class I serological typing was performed on a total of 12 whole blood specimens representing 7 HLA-A and 17 HLA-B antigens. More than 90% of the laboratories correctly identified 7 HLA-A (A2, A3, A11, A24, A26, A30, A33) and 13 HLA-B antigens (B7, B8, B13, B14, B27, B35, B48, B51, B52, B54, B58, B60, B61). Lower consensus (<90%) was obtained for B62, B67, B75, and B15 (B*1511). Considerable difference in antigen detection rate was observed between different commercial trays used. HLA class II DNA typing was performed on a total of 8 DNA specimens representing 13 HLA-DRB1 and 11 DQB1 alleles. For HLA-DRB1 typing (16-26 laboratories), correct assignment rate was very high (98%) for generic level, but lower (80%) for allele level. For DQB1 typing (5-8 laboratories), 100% consensus was obtained for allelic level. With respect to HLA crossmatching, detection rate of incompatibility was very low in the 1st trial. HLA crossmatch workshop on the standardization of typing methods was performed after the 1st trial, and thereafter the number of laboratories using sensitive methods were increased and the detection rate of incompatible crossmatch was much improved (1st 29-46%, 2nd 78-97%).
CONCLUSIONS
Through these HLA typing proficiency surveys, standardization of test methods and improvement of typing results were obtained. A continuous survey program would play an important role for improving success rate of organ transplantations in Korea.