Outcome of pregnancy in women with recurrent spontaneous abortion following immunotherapy with allogeneic lymphocytes.

The efficacy of immunotherapy in the prevention of habitual abortion remains controversial. It has been suggested that the benefits are predominantly due to psychological factors. We have evaluated the success of pregnancy outcome following immunotherapy with allogeneic lymphocytes, in relation to the subsequent development of anti-paternal cytotoxic antibodies (APCA). It was observed that in women who developed an APCA titre of > or = 1:16, live births occurred in 16 out of 21 cases (76%), while only two out of seven (28%) women who failed to achieve an APCA titre of > or = 1:16 had successful pregnancies (P < 0.05). In eight women who had an APCA titre of 1:16 on initial screening, and were, therefore, excluded from the trial, successful pregnancy outcome was noted in 62.5% of cases. Although these results are based on a small sample and on an open, non-randomized trial, they show that the efficacy of immunotherapy is related to immune response to allogeneic lymphocytes, and is not simply a placebo effect. Measurement of APCA titre could serve as a marker for immunopotentiation.