Induction of MLR-Bf and protection of fetal loss: a current double blind randomized trial of paternal lymphocyte immunization for women with recurrent spontaneous abortion

The present study was conducted to evaluate the efficacy of paternal lymphocyte (PL) immunotherapy and its relation with the development of mixed lymphocyte reaction blocking antibodies (MLR-Bf) and the success of pregnancy outcome in women with recurrent spontaneous abortion (RSA). A total of 124 women with unknown causes of abortions was registered for immunotherapy under double blind randomized trial by using the list of computer-generated numbers. Each 5×106 autologous lymphocyte (AL), third party lymphocyte (TPL) and PL was dissolved separately in 1 ml of sterile normal saline (NS). Each 1 ml of cell suspension and neat NS was injected in women with RSA through intramuscular (250 μl), intradermal (250 μl), subcutaneous (250 μl) and intravenous (250 μl) routes. All women participants with RSA received six identical immunizations at the regular interval of 4 weeks, and were then screened for the development of MLR-Bf after the completion of immunization course, and also at the first, second and third trimesters (12th, 24th and 36th weeks) of pregnancy. However, nonimmunized MLR-Bf positive women with RSA did not receive any kind of therapy (NT) and were used as one of the control group in the present study. We have observed that PL-immunized women with RSA showed a significantly increased level of MLR-Bf (>30) and pregnancy success (84%) as compared to those women with RSA who received either AL (33%), TPL (31%), NS (25%) or those who did not receive any kind of treatment (NT, 44%; P<0.001). Our results indicated the importance of immunotherapy with PL in women with RSA and also showed that MLR-Bf can be considered as one of the important factors for pregnancy improvement.