High anti-paternal cytotoxic T-lymphocyte precursor frequencies in women with unexplained recurrent spontaneous abortions

A number of cases of unexplained (idiopathic) recurrent spontaneous abortio ns may be attributable to immunological mechanisms. Several lines of eviden ce indicate that some immunocompetent effector cell populations play an imp ortant role in the pathogenesis of unexplained miscarriages. However a suit able method is lacking for defining an existing immunological background of recurrent spontaneous abortions. We tried to find a useful cellular immuno logical method, that is suitable for predicting the eventual immunological cause in the case of unexplained recurrent spontaneous abortions. We have e xamined the anti-paternal cytotoxic T-lymphocyte precursor frequencies by c ell-mediated lympholysis and limiting dilution analysis in the peripheral b lood of women with recurrent spontaneous abortions in order to reveal the f unctional role of this cell population in spontaneous abortions. An extreme ly high partner allo-antigen-specific cytotoxic T-lymphocyte precursor freq uency was determined in the case of all those habitual aborters, where no o ther than an immunological cause could be responsible for the abortions. Th is phenomenon supports the important role of the T-lymphocytes in this diso rder. We suggest that the immunological background of recurrent spontaneous miscarriages might be determined on the basis of a very high cytotoxic T-l ymphocyte precursor frequency. This diagnostic test might be useful in sele cting patients for immunotherapy.