Possible susceptibility of the HLA-DPB1*0402 and HLA-DPB1*04 alleles to unexplained recurrent abortion: Analysis by means of polymerase chain reaction-restricted fragment length polymorphism method

PROBLEM: To clarify whether HLA-DP antigens are associated with patient pop ulation of unexplained recurrent abortion. METHOD OF STUDY: The frequency of HLA-DPB1 alleles in patients with unexpla ined recurrent abortion, and the compatibility of HLA-DPBI alleles between patient couples, were studied using a polymerase chain reaction (PCR)-restr icted fragment length polymorphism (RFLP) method. Thirty patients who had a history of unexplained primary recurrent abortion, and their husbands, wer e typed for HLA-DPB1 genotype. Two hundred and ninety-nine base pair fragme nts from the second exon of HLA-DPB1 genes were selectively amplified using the PCR-primers. After amplification, the DNAs were digested with restrict ion endonucleases, and subjected to electrophoresis in a 12% polyacrilamide gel to determine HLA-DPB1 genotype. RESULTS: The frequency of HLA-DPB1*0402 and DPB1*04 alleles in the patient group (n = 30) was significantly increased, as compared to that in the norm al fertile women (n = 30). The frequency of HLA-DPB1*04 allele in the patie nt group was significantly increased, as compared to that in the general po pulation (n = 112). No significant compatibility of HLA-DPB1 alleles could be observed between patient couples and normal fertile couples. CONCLUSION: These findings suggest a possible new class II association with patient population of unexplained recurrent abortion.