Assessment of blocking activity in patients with at least two consecutive spontaneous abortions.

The activity of the blocking factor (BF) was studied in 88 patients affected by recurrent abortion syndrome (RAS) by means of the determination of lymphocyte proliferation rate (LPR) in one-way mixed maternal-paternal lymphocyte cultures (MLC). Forty patients (45.5%) showed inadequate blocking activity (LPR greater than 80%). Pearson's correlation did not reveal any link between patient age and LPR (m2 = 0.031), or between LPR and number of aborted pregnancy (m20.058). Fifteen of the 88 patients had had only two consecutive abortions, but Pearson's correlation did not result in any particular differences in the link between LPR and number of abortions in this group; we therefore felt perfectly justified in extending the study to these subjects.