• Habitual abortion;
  • HLA-tissue typing;
  • blocking antibodies;
  • vaccination with husband's lymphocytes

ABSTRACT: To elucidate an immunological mechanism in terms of the effectiveness of vaccination of the unexplained habitual aborters with their husband's lymphocytes, 20 patients were selected as the experimental group, and 10 fertile couples were selected as the control group.

Subjects were studied by mixed lymphocyte reaction-blocking assay so as to determine whether they had blocking antibodies (BAbs) in their sera. In the experimental group, BAb levels were found to be significantly lower as compared to the ten control multiparous wives; 17 cases (85%) of them were proved not to have sufficient BAbs. Significant sharing of HLA-D/DR antigens was observed in experimental couples.

Then, 10 out of 17 patients with evidence of no produced BAbs were vaccinated with their husband's lymphocytes, and all of them were observed to produce BAbs within three vaccinations. After vaccination, seven out of ten patients have so far become pregnant, five of these pregnancies have been successful, with evidence of continuing production of BAbs.

In conclusion, vaccination of the patients with husband's lymphocytes was found to stimulate a production of BAbs, and it was thus strongly suggested that this may lead to their production in a subsequent pregnancy, which would allow its success.