Mitogen-induced cytokine responses of maternal peripheral blood lymphocytes indicate a differential Th-type bias in normal pregnancy and pregnancy failure

PROBLEM: Profiles of Th1- and Th2-type cytokines were studied in women with a history of successful pregnancy and in women with a history of unexplain ed recurrent spontaneous abortions (RSA) with the objective of elucidating Th1- and Th2-type bias in normal pregnancy and pregnancy failure. METHOD OF STUDY: Peripheral blood mononuclear cells (PBMCs) from 54 women w ith a history of normal pregnancy and 23 women with a history of unexplaine d RSA, obtained at delivery or on the day of abortion, respectively, were s timulated with phytohemagglutinin (PHA), followed by the estimation of four Th2 cytokines and four Th1 cytokines. RESULTS: Significantly greater levels of Th2 cytokines were produced by the normal group than by the RSA group. On the other hand, significantly highe r levels of Th1 cytokines were produced by the RSA group than by the normal pregnancy group. CONCLUSIONS: These data support the concept that unexplained recurrent spon taneous abortion is associated with an increase in Th1-type reactivity, whi le Th2 dominance is a feature of successful pregnancy.