[Analysis of HLA antigens and immunotherapy for infertile couples who failed to conceive after in vitro fertilization-embryo tubal replacement (IVF-ETR)].

: The results of IVF-ETR strongly suggest the existence of implantation failure of unknown etiology. A selected group of 41 couples with long-standing infertility who had one or more failed IVF-ETR cycles were analysed for HLA antigen sharing, and 19 wives were immunized with their husband's purified lymphocytes just before the subsequent trial. Both the number and frequency of shared HLA antigens in these patients were significantly increased, compared with control couples of normal fertility (p < 0.05). After immunization, 7 patients (36.8%) conceived by IVF-ETR, and 5 (71.4%) delivered a healthy baby at term. The pregnant couples shared significantly fewer HLA antigens compared with those who failed to conserve (p < 0.05). Interestingly, the MLR blocking effect was enhanced in the pregnant group after immunization, suggesting the induction of blocking antibodies which are believed essential for the survival of the developing fetus. In contrast, the blocking effect was rather decreased in the nonpregnant group. These results implicate that HLA sharing and inadequate maternal anti-paternal immunity may be related to implantation failure, and immunotherapy can be used to potentiate the maternal immune response, leading to successful implantation in selected patients.