[Discrepancies between human leukocyte antigen registry typing and confirmatory typing results of unrelated hematopoietic stem cell donors].

Background: In unrelated hematopoietic stem cell transplantation, the accuracy of HLA registry typing (RT) of donors is important for timely search and coordination of HLA-matched donors. We analyzed discrepancies between HLA RT and confirmatory typing (CT) results of stem cell donors in Korean and foreign registries.

Methods: We analyzed the HLA typing results of 834 donors for whom CT was performed at Seoul National University Hospital between April 1997 and March 2010. For CT, DNA typing was used in majority of the cases and HLA-A and HLA-B serological typing was used in some early cases. The discrepancies between the typing results were analyzed at the serological/generic level.

Results: The overall discrepancy rate (RT error rate) was 3.2%, and the rate was similar in the Korean and foreign registries. The discrepancy rates in the Korean and foreign registries were more than 10% in the 1997-2001 searches, but decreased to less than 3% in the 2002-2010 searches. Analysis of 19 cases of RT errors in the Korean registry revealed 3 cases of sample switchover errors and 16 cases of typing errors in one of the HLA-A, HLA-B, or HLA-DR loci. The RT error rate in Japan Marrow Donor Program was lower than those in other foreign registries.

Conclusions: The error rate of HLA RT results of unrelated stem cell donors in the Korean registry was similar to those in the foreign registries, and has decreased in the recent searches following the change in the typing method from serological to DNA typing.