Alterations in the immune system of children from mothers treated with immunosuppressive agents during pregnancy.

Many of the immunosuppressive drugs that are used during pregnancy can cross the placental barrier and enter the foetal circulation, with a possible impact on the foetal immune system. We have evaluated the immune function of children born from mothers treated with immunosuppressants for connective tissue diseases. A total of nine babies, whose six mothers had been taking cyclosporine A (two), azathioprine (one) and dexamethasone (three) during pregnancy, together with 14 babies from mothers with similar diseases but who had not been treated (controls) were investigated. Complete blood count, IgA, IgG, IgM, IgG subclasses, and lymphocyte subpopulations were determined in all cases. Moreover, serum levels of anti-HBsAg and presence of autoantibodies (ANA, ENA) were also evaluated. Patients were tested at a mean age of 11 months (range, 1-17). Only a minor proportion of our patients displayed low values for age (mainly, IgA and IgG2), but none of the parameters tested resulted significantly different in patients than in controls. All children responded satisfactorily to hepatitis B vaccination. Although our results are preliminary, we conclude that prenatal exposure to immunosuppressive drugs does not have a profound effect to the developing immune system. More data and a longer follow-up are needed to confirm these results.