Reduced risk for placental malaria in iron deficient women

Abstract

BackgroundNutritional iron deficiency may limit iron availability to the malaria parasite reducing infection risk, and/or impair host immunity thereby increasing this risk. In pregnant women, there is evidence of an adverse effect with iron supplementation, but the few reported studies are strongly confounded.MethodsA case control study in pregnant Malawian women was undertaken in Chikhwawa southern Malawi in order to describe iron status in relation to placental malaria controlling for several confounding factors. Pregnancy characteristics were obtained and a blood sample at delivery. A full blood count was performed and serum ferritin and transferrin receptor quantified by enzyme-linked immunoassay. DNA analysis was used to identify genetic polymorphisms for ABO phenotype, hemoglobin HbS, and glucose -6 phosphate dehydrogenase deficiency. Placental tissue was obtained and malaria histology classified as active, past or no malaria infection.Results112 cases with placental malaria were identified and 110 women with no evidence of placental infection. Iron deficiency was less frequent in women with placental Plasmodium falciparum infection. In those with acute, chronic or past placental infections the odds ratio for iron deficiency was 0.4, 95% CI 0.2-0.8, p = 0.01; for acute and chronic infections 0.4, 0.2-0.8, p = 0.006; for acute infection 0.3, 0.1-0.7, p = 0.001. The association was greater in multigravidae.ConclusionWomen with either acute, or acute and chronic placental malaria were less likely to have iron deficiency than women without placental malaria infection There is a priority to establish if reversing iron deficiency through iron supplementation programs either prior to or during pregnancy enhances malaria risk.

Cord Blood Hepcidin: Cross-Sectional Correlates and Associations with Anemia, Malaria, and Mortality in a Tanzanian Birth Cohort Study

“…12 In addition, recent experiments have also found that hepcidin-induced iron redistribution away from hepatocytes arrests the growth of intrahepatocytic parasites and thereby prevents the occurrence of malaria superinfections. 13 Epidemiological studies lend support to these findings: pregnant women and children who are iron deficient are observed to have lower risks of malarial disease, [14][15][16][17][18] and pediatric iron supplementation has been shown to heighten the risk of both clinical and severe malaria. 19,20 In addition to malaria, elevated iron has been associated with poor prognoses in cases of bacterial and viral infections 21 and may be associated with child mortality in communities with high burdens of communicable disease.…”

Host iron status and iron supplementation mediate susceptibility to erythrocytic stage Plasmodium falciparum

“…Similarly, in Tanzanian children, baseline iron deficiency significantly decreased the odds of subsequent parasitemia (23%) and severe malaria (38%) 6 . In addition, in two studies of pregnant women, iron deficiency was associated with a decreased prevalence of placental malaria, a major cause of neonatal and maternal morbidity 3,4 . Our results—that iron-deficient RBCs impair parasite propagation in vitro (Fig.…”

How I treat anemia in pregnancy: iron, cobalamin, and folate

“…103 In a case control study in Malawi, iron deficiency was less frequent in 112 women with placental malaria than in 110 women without. 104 In a 2016 Cochrane systematic review of 35 randomized controlled trials assessing iron supplementation in children living in areas with hyperendemic or holoendemic malaria transmission, iron did not cause an excess of clinical malaria. 105 This review did not include pregnant women.…”