Anti-paternal antibodies by flow cytometry in the management of alloimmunization on recurrent miscarriages

Problem: There is no reliable laboratory test available to diagnose immunologically mediated miscarriages. We investigated the clinical significance of maternal anti-paternal leukocyte antibodies by flow cytometry after alloimmunization. Method of study: The flow cytometry crossmatch (FCXM) was performed in 158 patients with a history of three or more unexplained first-trimester miscarriages without live birth. After negative FCXM patients were immunized, subsequent pregnancy outcomes and FCXM results were followed. Results: Of 112 subsequent pregnancies, 83 of 100 (83.0%) FCXM-positive patien ts after immunotherapy had successful pregnancy outcomes, whereas seven of 10 (70.0%) FCXM-negative patients had miscarriages (P = 0.0001). The percent live birth ratio was 2.77 (CI, 1.07-7.16; P = 0.0001) for FCXM-positive patients compared to FCXM-negative patients. The calculated predictive value showed that 75.6% of FCXM-negative patients would have subsequent miscarriages. Conclusions: Positive FCXM is closely associated with successful pregnancy outcome following immunotherapy. We propose that FCXM might be included in the routine laboratory tests for the management of recurrent miscarriages.