Transforming growth factor beta-1 influence on fetal allografts during pregnancy

An understanding of how the fetus escapes the maternal immune system may be relevant for the prevention of transplant rejection. There is evidence that the same immunosuppressive cytokines contribute to a successful pregnancy and transplant success. Transforming growth factor beta (TGF-beta) is a multifunctional cytokine that exhibits potent immunoregulatory and anti-inflammatory properties and may prolong graft survival. Recent reports suggest a role for TGF-beta in the generation of T-regulatory lymphocytes. Also, the role of TGF-beta in trophoblast differentiation and hypertension prompted us to evaluate maternal serum TGF-beta1 levels in normal allopregnant women and in pregnancies complicated by preeclampsia (PE), a disorder characterized by increased blood pressure, proteinuria, and end organ damage. Sixty-one pregnant preeclamptic women (32 cases with severe and 29 with mild PE), 22 normotensive healthy pregnant, and 20 nonpregnant controls formed the study groups. The active form of serum TGF-beta1 was investigated by an indirect ELISA technique. The results showed that TGF-beta1 was highly expressed in all three pregnant groups compared with the nonpregnant controls. No changes in TGF-beta1 serum levels was found in PE compared with a normal pregnancy. The results suggest that: (1) TGF-beta1 may function as a regulatory factor in fetal allograft survival during pregnancy and (2) TGF-beta1 does not have a pathophysiological role in PE.