Asymmetric antibodies and pregnancy

PROBLEM: Asymmetric IgG antibodies (AAb) possess a mannose-rich oligosaccha ride residue bound to one of the Fab regions, making them unable to activat e immunoeffector mechanisms. The proportion of asymmetric antibodies is inc reased after prolonged immunization with particulate antigens like cellular spleen cells. During pregnancy, AAb were found in serum and bound to place nta with specific activity to paternal antigens. No previous reports about the status of AAb in recurrent spontaneous abortion (RSA) patients have bee n published to date. Therefore, the aim of the present study was to analyze the percentage of asymmetric IgG molecules in serum samples of(a) healthy pregnant and non-pregnant women, (b) pregnant women with a history of RSA, and (c) non-pregnant RSA patients receiving paternal lymphocyte immunothera py (LIT) or intravenous gammaglobulin therapy (IVIgs). METHOD OF STUDY: A previously-described differential ELISA technique was us ed to determine the percentage of IgG that was of the asymmetric type. RESULTS: During normal pregnancy, there was an increase in the percentage o f high ConA affinity IgG serum molecules with a major increase at the secon d trimester. Pregnant RSA patients at the second trimester had lower values . When evaluating non-pregnant RSA patients who received LIT, it was observ ed that the immunized patients expressed a higher percentage of asymmetric IgG antibodies. The pregnant patients who received IVIgs had a percentage o f AAbs comparable to normal pregnant patients. Additionally, the presence o f IgG asymmetric molecules was confirmed in commercial gammaglobulin prepar ations. CONCLUSION: Results suggest a protective role of AAb during pregnancy.