EVALUATION OF AN APPROPRIATE SIZE OF UNRELATED DONOR POOL FOR HLA-MATCHED PLATELET TRANSFUSION AND BONE MARROW TRANSPLANTATION

• Published in: Journal of the Japan Society of Blood Transfusion Vol. 38; no. 3; pp. 475 - 481
• Main Authors: Akaza, T., Fujino, K., Juji, T., Endoh, N., Tsuchida, H., Takahashi, K., Umezawa, K., Kamata, H., Tokunaga, K., Uchikawa, C., Watanabe, I.
• Format: Journal Article
• Language: Japanese
• Published: The Japan Society of Transfusion Medicine and Cell Therapy 1992
• ISSN: 0546-1448; 1883-8383
• DOI: 10.3925/jjtc1958.38.475

In order to determine frequencies of HLA-A, -B haplotypes and HLA-A, -B, -DR haplotypes in Tohoku area of Japan, we collected blood samples from parents and their three children in each of 155 families and examined HLA types of these members. Then the frequencies of each possible HLA phenotype and of corresponding possible matched donors were calculated with computer from the table of frequencies of the informative haplotypes in this population. We could determine 613 haplotypes of the unrelated parents. HLA haplotypes in Tohoku area are rather homogeneous than those in other areas of Japan (obtained from the 300 families in the 8th Japan Workshop, 1981), and there are significant differences in distribution of several haplotypes between these two populations. Calculated from the 613 HLA-A, -B haplotypes data in Tohoku area, to enable more than 80 percent of patients to have at least 5 matched platelet donors, registry of just 2, 500 potential donors would be required in this population. This size was smaller than 5, 000, the size previously reported based on the 300 families data from the other parts of Japan. Calcualted from the 613 HLA-A, -B, -DR haplotypes data in Tohoku area, to enable more than 80 percent of patients to have at least one bone marrow identical donor, registry of just 25, 000 potential donors would be enough for this population. This size was smaller than 50, 000, the size previously reported based on the 300 families data from the other parts of Japan, which might reflect less polymorphic distribution in Tohoku area. Japanese National Marrow Donor Program (JNMDP) had better recruit unrelated BM donors not only from the several big cities but from any areas in Japan, because some unique HLA haplotypes might exist just in the very restricted districts.