Pathology of Placental Malaria in Areas of Different Endemicity: A Histologic Grading Scheme
A Muehlenbachs, M Fried, R McGready, TK Mutabingwa, CL Fligner, F Nosten, PE Duffy. University of Washington, Seattle, WA; Seattle Biomedical Research Institute, Seattle; Shoklo Malaria Research Unit, Mae Sot, Thailand; National Institute of Medical Research, Dar Es Salaam, Tanzania, United Republic of
Background: During placental malaria (PM), Plasmodium falciparum infected erythrocytes sequester in the placenta and cause an inflammatory response that is harmful to the fetus and the mother. The clinical and epidemiologic features of PM differ by transmission intensity. Placental malaria episodes have been histologically classified as acute or chronic. However chronic placental malaria is a broad category that encompasses several distinct features of infection, specifically placental inflammation and malarial pigment deposition.
Design: Using frozen section histology from placentas from Tanzania, we describe a pathologic grading and staging scheme to evaluate inflammation and pigment deposition during placental malaria at delivery (n=91). For comparison, samples from placentas from Karen women on the Thai-Burma border were selected from the small fraction of women known to have had P. falciparum at least 10 days prior to delivery (n=19).
Results: In the Tanzanian cohort, the placental inflammation grade was associated with levels of inflammatory markers at delivery, and the pigment deposition stage was independently associated with birth weight. In the cohort from Thailand, inflammation and pigment deposition were associated with birth weight, and pigment deposition had an inverse trend with the number of antenatal clinic visits. The samples from Thailand had decreased pigment deposition, but similar inflammation scores when compared to samples from Tanzanian first time mothers.
Conclusions: The proposed pathological grading system is simple yet captures increased complexity of PM episodes, suggesting that combining these two measures can improve immunocorrelation for clinical trials across areas of differing endemicity.
Monday, March 22, 2010 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 204, Monday Morning