The Role of Soluble Tumor Necrosis Factor Receptor Types I and II and Tumor Necrosis Factor–α in Malaria during Pregnancy

In a prospective study of rhesus monkeys inoculated with Plasmodium coatneyi or saline on an infection/ gestational timeline, we determined the serum levels of tumor necrosis factor–a (TNF-a), soluble tumor necrosis factor receptor type I (sTNFR-I), and soluble tumor necrosis factor receptor type II (sTNFR-II) in peripheral blood throughout primigravid pregnancy, malaria infection, and a combination of the two. Our goal was to determine the association between levels of TNF-a and of its 2 soluble receptors and the course of pregnancy and/or malaria and infant outcome. We found that any detectable level of TNF-a was always associated with fetal death and that the sTNFRs may be important for fetal protection, possibly through neutralizing the toxic effects of TNF-a. Our findings also showed that increased levels of sTNFR-II were associated specifically with malaria and not with normal pregnancy or even pregnancy with low birth weight due to other causes. In contrast, increases in sTNFR-I levels during the later half of normal pregnancies indicate that sTNFR-I may be important in regulating TNF-a levels in preparation for normal labor and delivery.