Positive Rate of HLA Class I Antibodies in Multiparous Korean Women / 대한임상병리학회지

BACKGROUND: Anti-HLA antibodies are most frequently induced by transfusion or pregnancy, and these anibodies can be used as antisera for HLA typing. However these antibodies may elicit adverse reactions such as transfusion reaction or rejection of transplanted organs. In this study, frequency and specificities of antibodies against HLA class I antigens were determined in multiparous Korean women. METHODS: Sera from 671 multiparous women were tested for anti-HLA antibody screening by standard microlymphocytotoxicity test using 49~50 lymphocyte panels. PRA(panel reactive antibody) values were calculated as percentage of postive panels among total lymphocyte panels tested. HLA antibody specificities and reaction strengths were determined by analysis of serologic reaction patterns. RESULTS: A total of 671 sera were tested and 124 sera(18.5%) were positive for HLA antibodies. Among HLA antibody-positive sera(n=124), 117(94.4%) showed PRA values of 50%. Specificities of HLA antibodies were identified in 51 sera(41.1%) and 18 sera(14.5%) contained reagent quality antibodies(r> or =0.8, SI> or =70%), corresponding to 2.7% of total multiparous women. Among these, 4 sera had monospecific HLA antibodies and 14 sera had HLA antibodies against two or more antigens: 4 sera containing HLA antibodies against 7 CREG(cross reactive group), 5 sera containing antibodies against 5 CREG. CONCLUSION: Through the analysis of frequency and specificity of HLA antibodies in 671 multiparous women, it is concluded that HLA antisera can be obtained from multiparous women as effectively as from pregnant women. The frequency of high level of sensitization(PRA>50%), which can elicit problems in relation to transfusion or organ transplantation, is very low(1.0%).

A Study the Procurement of HLA Class I Typing Trays Using Gushed Out Blood During Placental Delivery

BACKGROUND: Microlymphocytotoxicity test is most widely used for HLA Class l typing but almost all laboratories depend on imported HLA Class 1 typing trays. Matching criteria for the selection of HLA- matched platelets to treat platelet refractoriness is not as strict as for bone marrow transplantation. Therefore, with the acquisition of various antisera against high frequency HLA antigens, self-made HLA typing trays can be used for HLA typing of HLA-matched platelet donors. METHODS: 140 samples obtained during placental delivery were tested for the presence of HLA antibodies against a well-characterized panel of 90 cells. Specificity of HLA antisera were determined by evaluating the correlation coefficient r of the 2 x 2 table, x2 test. Antisera strength was evaluated by the strength index. RESULTS: HLA antibodies were detected in 25 samples by primary screening and 23 samples also showed a positive reaction in secondary screening(16%). Among 23 samples, 1 1 antisera were of reagent grade quality and 7 were monospecific antisera. DISCUSSION: Imported HLA typing trays can be replaced by harvesting HLA antisera against HLA antigens which are relatively common in Koreans through continuous HLA antibody screening using gushed out blood during placental delivery. (Korean J Blood Transfusion 10(1): 53-60, 1999)

Procurement of HLA Class I Antisera from Multiparous Blood Donors / 대한임상병리학회지

BACKGROUND: HLA antisera are procured mainly from placental blood or blood of multiparous women. The latter has a merit that a large volume of antisera could be obtained, once the antisera are found to be of good quality. METHODS: A total of 1,437 multiparous blood donors were screened for the presence of anti- HLA antibodies. After the first screening with 20 panel cells, initially reactive sera were re- screened with 30 panel cells. RESULTS: Of 1,437 sera, 50 sera (3.5%) were reactive to both the first and the second screening panel cells. Among 50 sera, 25 (50.0%) sera could be assigned for their antibody specificity with r value of 0.8 or more. Only 14 samples (1.0%) showed reactivity to two or more panels with same antigen specificity and strength index of 80% or more. Four donors repeatedly donated blood with specificities of A24, A26, B7, and B7+B40, respectively. CONCLUSIONS: Screening of HLA class I antibodies in multiparous blood donors showed that HLA antisera of good quality could be obtained in about 1% of the donors in Korea.