Lack of an Association between Antibodies toPlasmodium falciparumGlycosylphosphatidylinositols and Malaria-Associated Placental Changes in Cameroonian Women with Preterm and Full-Term Deliveries

Abstract

Sequestration ofPlasmodium falciparumparasites within the placenta often leads to an accumulation of macrophages within the intervillous space and increased production of tumor necrosis factor alpha (TNF-α), a cytokine associated with placental pathology and poor pregnancy outcomes.P. falciparumglycosylphosphatidylinositol (GPI) anchors have been shown to be the major parasite component that induces TNF-α production by monocytes and macrophages. Antibodies againstP. falciparumGPI (anti-PfGPI), however, can inhibit the induction of TNF-α and inflammation. Thus, the study was undertaken to determine whether anti-PfGPI antibodies down-regulate inflammatory-type changes in the placentas of women with malaria. Anti-PfGPI immunoglobulin M (IgM) and IgG levels were measured in 380 pregnant women with or without placental malaria, including those who delivered prematurely and at term. Results showed that anti-PfGPI antibody levels increased with gravidity and age and that malaria infection boosted anti-PfGPI antibodies in pregnant women. However, no association was found between anti-PfGPI antibodies and placental TNF-α levels or the presence of acute or chronic placental malaria. Furthermore, anti-PfGPI antibody levels were similar in women with preterm and full-term deliveries and were not associated with an increase in infant birth weight. Thus, these results fail to support a strong role for anti-PfGPI antibodies in the prevention of chronic placental malaria infections and malaria-associated poor birth outcomes.