Successful management of alloimmunized patients by transfusing HLA compatible and crossmatched platelets.

An average of three (range 0-22) perfect matches for 65 patients could be found in 1490 filed HLA-typed donors. It could increase to 8.7 (0-45) if strong cross-reactive antigens were added. Three methods of platelet crossmatching, i.e, lymphocytotoxicity test (LCT), platelet suspension immunofluorescence test (PSIFT) and solid phase red cell adherence test (SPRCA), were used to search for compatible donors. Forty episodes of apheresis platelet transfusion were evaluated in seven patients. Using one-hour posttransfusional corrected count of increment (CCI), greater than 7500 microliters as a guideline to assess the reliability of these three methods, we found that the efficiency of PSIFT, LCT and SPRCA were 67.5%, 97.5% and 97.5% respectively. Retrospectively, we did the HLA-A, B typing of those matched donors. There was no significant difference in CCI among different HLA match grades. The concordance of LCT and SPRCA was 100%, indicating that all the antibodies were of HLA specificity and there was no platelet specific antibody. We concluded that HLA donor-file and platelet crossmatching technique could be used together in selecting suitable donors for alloimmunized patients.

[Blood group phenotyping and their application in Taiwan].

During the 1950's and 60's as new blood group systems were identified, antigen distribution studies were performed in Europe and North America among Caucasians and American Blacks. However, to date only limited studies have been performed in Africa and Asia. Because of lack of knowledge of the antigen distribution of most other than ABO and Rho (D) blood group systems within these areas and among the people of non-Caucasian races, questions of testing needs and problems have occurred. In recent years, three big matters have been encountered off and on in blood banking in Taiwan. First, multiple-transfusion recipients develop so many alloantibodies that finding compatible donors becomes a difficult task. Second, since bone marrow transplantation technology is being instituted in many teaching hospitals, it is a task of blood banks to monitor the antigen changes of other blood group systems (including of Rh system other than D) before and after transplantation. Third, more than enough disputed paternity cases that can not be resolved by simple ABO testing. Therefore, blood banks should be staffed with suitable backgrounds to cope with the procedures needed for analysing all blood group antigens. In order to resolve all the problems effectively, we ran the tests for blood group antigens other than ABO and D in our blood bank from 1984 to 1986. A total of 31 sets of antisera were used to identify the specificity of 13 blood group system antigens of the Chinese population ranging from 99 to 2257. Based on the datum obtained, we found a significant difference between Chinese and Caucasians in the distribution of eight blood group systems (Rhesus, MNSs, Kell, Duffy, Kidd, P, Lutheran and Colton). The antigen frequency of Fya and s are 99.74, 99.91 respectively. The results are higher than those of the Caucasian population. On the other hand, Fyb and S are 9.22 and 6.56, much lower than those in Caucasians. We found no K, Lua and Cob antigens among the Chinese. We conclude that this study is a significant contribution to the knowledge of blood group antigen systems and antigen distribution, and also will benefit this population in many areas of medical care.

Blood group phenotypes in Taiwan.

This report describes a study of 31 red cell antigens in 13 blood group systems tested over a period of 3 years in the Chinese population of Taiwan. The study provides evidence that major differences exist between Taiwanese and whites or blacks in five blood group systems: Rh, MNSs, Duffy, P, and Xg.