Alloantibody responses to antigens recognized by rabbit antitrophoblast antisera in trophoblast and mononuclear cell (MNC) membranes by primary aborting women before and after paternal leukocyte immunization.

PROBLEM

Because shared allogeneic antigens are expressed on peripheral blood lymphocytes, as well as trophoblasts, it has been proposed that lymphocyte transfusions may appropriately sensitize recurrent spontaneous aborters (RSA) to trophoblast and lead to pregnancy conservation. The degree to which these responses are affected by this treatment, however, has not been defined.

METHOD

SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analyses were used to study the alloantibody responses in RSA patients both before and after immunization with paternal leukocytes (MNC) against membrane proteins isolated from peripheral blood mononuclear cells (MNC), first trimester and full term chorionic villi (CV).

RESULTS

A distinct set of antigens with apparent molecular weights of 32, 36, 41, 63, 65, and 85 kDa was identified in both MNC and trophoblast membranes by rabbit anti-trophoblast antisera. In addition, a 55 kDa protein was recognized by MNC membranes. Thirty-eight percent of primary RSA sera recognized this 55 kDa protein. After paternal MNC immunization, all primary RSA samples displayed increased reactivity or produced antibodies to this 55 kDa protein when compared with preimmunization sera. The protein was identified as MCP using a rabbit polyclonal anti-MCP antisera. In contrast, reactivity to the other antigens present in the membrane preparations decreased after paternal MNC immunization.

CONCLUSION

Changes in immune reactivity in RSA patients after paternal MNC immunization suggest that immunization alters serum immune reactivity to MNC and trophoblast shared antigens.