Results of immunotherapy for patients with unexplained secondary recurrent abortions.

Twenty-six unexplained secondary recurrent aborters underwent vaccinations by using their husband's mononuclear leukocytes according to the protocol adopted for primary recurrent aborters (group I). No mixed lymphocyte culture reaction-blocking antibodies (MLR-BAbs) detected by one-way MLR between spouses were observed in these patients prior to vaccination. In all 26 patients, MLR-BAbs appeared in their sera after vaccination with the husband's mononuclear leukocytes. Of 22 newly pregnant patients after vaccinations, pregnancy successfully continued in 20; thus, the success rate of the therapy was 90.9%. Pregnancy outcome was also analyzed in unexplained secondary recurrent aborters who revealed positive MLR-BAbs without immunotherapy (group II). In this group, in 9 of 12 patients (75.0%), the pregnancy continued successfully. The rate of continuation of pregnancy was not significantly different between groups I and II. Furthermore, the outcome of 11 pregnancies in 9 unexplained secondary recurrent aborters was analyzed in those who were negative for MLR-BAbs and had become pregnant without immunotherapy (group III). Pregnancy was successfully continued in only 2 cases (18.2%) in this group. The rate of successful pregnancy in experimental groups I and II was significantly higher compared with that in group III (P < 0.0005 and P < 0.01, respectively). Thus, immunotherapy using the husband's mononuclear leukocytes on unexplained secondary recurrent aborters with negative MLR-BAbs appears to be effective.