Cost effectiveness in screening of class I HLA antibodies in Thai pregnant women.

Fifty-seven sera obtained from pregnant women who attended antenatal clinic were screened for class I HLA antibodies by standard microlymphocytotoxicity test. The age ranged from 20 to 40 years (mean +/- SD = 30.4 +/- 5). The lymphocytes obtained from 98 HLA-typed persons were used as the panel which would include all common HLA-A and HLA-B antigens and as many rare antigens as possible. Eight out of 57 sera (14%) had HLA antibodies which reacted as follows: 3 sera had nonspecific antibodies, 3 sera had multispecific antibodies (B60 + B48 + B7, B60 + B61 + B13 and B51 + B35 + B53), one serum had a monospecific antibody (A2) and one serum was unidentified. The identified antibodies showed strong reactivity (r > 0.8). These sera will be used as HLA typing sera and exchanged with other HLA laboratories. The screening test for class I HLA antibodies in pregnant women attending the antenatal clinic is useful and practical. Several HLA antisera can be obtained at low cost. The cost of self-screening antisera was US$90/ml while the cost of commercial HLA typing sera is approximately US$250/ml, a factor to be considered by a new HLA laboratory with limited budget.