Malaria and pregnancy: placental cytokine expression and its relationship to intrauterine growth retardation

Ann M. Moormann, University of Massachusetts Medical School
Amy D. Sullivan, University of Michigan
Rosemary A. Rochford, University of Michigan
Stephen W. Chensue, University of Michigan
Paul J. Bock, University of Michigan
Thomas Nyirenda, Malawi Ministry of Health
Steven R. Meshnick, University of Michigan

Abstract

Malaria infections during pregnancy can lead to the delivery of low-birth-weight infants. In this study, cytokine mRNA was measured in placentas from 23 malaria-infected and 21 uninfected primigravid women who had delivered in Mangochi, Malawi, a region with a high rate of transmission of falciparum malaria. Significantly increased expression of interleukin (IL)-1beta, IL-8, and tumor necrosis factor (TNF)-alpha and decreased expression of IL-6 and transforming growth factor-beta1 were found in malaria-infected compared with uninfected placentas. TNF-alpha and IL-8 were produced by maternally derived hemozoin-laden placental macrophages. Increased TNF-alpha expression was associated with increased placental hemozoin concentrations. Increased TNF-alpha or IL-8 expression in the placenta was associated with intrauterine growth retardation but not with preterm delivery. The results suggest that malaria infections induce a potentially harmful proinflammatory response in the placenta.