Paternal Leukocyte Immunization in Primary Recurrent Spontaneous Aborters

Abstract

This was a pilot study to investigate the possible roles of human lymphocyte antigen (HLA), antipaternal lymphocytotoxic antibodies, and maternal antipaternal mixed lymphocyte reaction (MLR) blocking antibodies in the maintenance of pregnancy following paternal leukocyte immunization for patients with recurrent abortions. A total of 36 patients with unexplained, first trimester, primary recurrent spontaneous abortions were investigated for the detection of these two antibodies. There was a 43.3% rate of discordance in the presence of the two antibodies (P <0.05). A total of 26 of these women who lacked either antibody were immunized with paternal leukocytes on two occasions and the assays were repeated postimmunization. The seroconversion rate was 50% for lymphocytotoxic antibodies and 61.5% for maternal serum (MLR) blocking antibodies. Twenty patients achieved pregnancies postimmunization, 11 completed their pregnancies successfully, and 9 re-aborted. A total of 83.3% of patients who developed MLR blocking antibodies post-immunization had successful pregnancies while those who failed to seroconvert aborted again. This difference is statistically significant (P <.05). A total of 50% of patients who developed lymphocytotoxic antibodies post-immunization had successful pregnancies while only 40% who failed to seroconvert reaborted. This difference, we felt, was not statistically significant. The development of MLR blocking antibodies post-immunization is a better indicator of subsequent successful pregnancies than lymphocytotoxic antibodies.AM Bahar, AG White, IH Al-Abdullah, Paternal Leukocyte Immunization in Primary Recurrent Spontaneous Aborters. 1993; 13(2): 130-135 Certain instances of unexplained spontaneous abortions may be due to the failure of immunological recognition and adaptation to the fetoplacental unit. The precise nature of this interaction is not completely understood; however, one feature may be the failure of the fetus to stimulate in the mother protective antibodies that alter antigen expression as well as promote growth of the trophoblast [1,2].Treatment by immunization with paternal or donor leukocytes to stimulate antibody production to leukocyte trophoblast crossreactive epitopes has been tried by different groups with encouraging results [3]. In these groups, the criteria for selection of patients for immunotherapy differ. One criterion is the sharing of HLA antigens [4]. There is evidence of increased antigen sharing between recurrently aborting women and their partners with sharing frequencies more than can be expected by chance alone [5][6][7]. Other criteria include the lack of paternal HLA lymphocytotoxic antibodies [8][9][10] or the lack of mixed lymphocytic reaction (MLR) blocking antibodies [11][12][13]. These antibodies are commonly present in the sera of normal multiparous women but found to be lacking in the sera of recurrently aborting women [14][15][16][17][18][19][20].The results of immunotherapy on successful pregnancy outcome using different criteria for selection are...