Establishment of an HLA-matched Platelet Donor Registry for the Management of Patients with Platelet Refractoriness

Park, Myoung Hee; Han, Tae Hee; Han, Kyou Sup; Ahn, Hyo Seop; Choi, Kyung Hwan

Abstract

BACKGROUND
Heavily transfused patients commonly become refractory to platelet transfusion. Patients with platelet refractoriness due to HLA alloimmunization need HLA-matched platelet transfusion. We have established an hospital-based donor registry of HLA-typed platelet donors for the first time in Korea and evaluated the possibility of HLA-matched platelet supplies.
METHODS
A total of 450 donors were registered and typed for HLA class I (A, B, C) antigens. A computer program was developed and used for the donor registry and HLA-matched donor search. A simulation study was performed on the availability of HLA-matched platelets for 100 patients from a pool of 450 donors. The availability of HLA-matched and cross reactive epitope group (CREG)-matched donors were analysed for HLA-A, B antigens. The CREGs defined by Fuller, Rodey, and UCLA criteria were used. RESLUTS: Among 100 patients, 63% had HLA-identical or HLA-matched (match grade: A, B1U, B2U) donors with only a low number of donors (mean 1.4) available per patient. Including CREG-matches (match grade: B1X, B2UX, B2X), majority (98%) of the patients had HLA- or CREG-matched (match grade: A~B2X) platelet donors with a higher number of donors (mean 26.6~40.5 by different CREG criteria) available per patient. Majority (86-98%) of the patients had 20 or more A~B4X matched donors, and about two thirds (61-74%) of the patients had 20 or more A~B2X matched donors. However, the number of ABO-identical matched donors was less than 30% of the total HLA- or CREG-matched donors.
CONCLUSION
We established an HLA-matched platelet donor registry and using a donor pool size of < 500 donors, attainable in an hospital-based donor registry, the possibility of HLA-matched platelet supplies was confirmed in this study. However, for more satisfactory and ABO-matched platelet supplies a larger pool size is needed.