Placental pathology in malaria: A histological, immunohistochemical, and quantitative study

doi:10.1016/S0046-8177(00)80203-8

Human Pathology

Volume 31, Issue 1, January 2000, Pages 85-93

https://doi.org/10.1016/S0046-8177(00)80203-8 Get rights and content

To characterize the histological changes in malarial placentas and their relationship with parity and maternal and cord parasitemias, we conducted a histological study on 1,179 placentas from Ifakara, Tanzania, an area with intense and perennial malaria transmission. Immunohistochemical and quantitative studies for CD45, fibrin, and villous area were performed in 60 cases. Four hundred fifteen placentas (35.2%) showed parasites (active infections); in 303 of them, parasites co-existed with pigment covered by fibrin (chronic infections), and in 112 only parasites were detected (acute infections). Four hundred seventy-five cases (40.3%) showed hemozoin deposition without parasites (past infections). Of women with parasitized placentas, 46.3% did not show parasites in the peripheral blood. Basal membrane thickening (P = .002), fibrinoid necrosis (P = .004), and prominence of syncytial knots (P = .031) were associated with active malarial infection. No quantitative differences for perivillous fibrin deposition or villous area were found. The most significant association with active malarial infection was intervillous infiltration by mononuclear inflammatory cells (P < .001). Chronic infections were associated with the most severe changes, particularly intervillous mononuclear inflammation (OR, 28.7; 95% CI = 16.0 to 51.5, P < .001). Past infections showed only minimal differences with noninfected placentas. Primiparas showed chronic infections more frequently than multiparas (52% v 15%, P < .001). They also showed significantly higher placental parasitemias and intervillous inflammatory infiltrate. In conclusion, placental histology is more sensitive than peripheral blood examination in detecting malarial infection during pregnancy. Most malarial infections recover during pregnancy, leaving few residual changes in the placenta. Intervillous inflammation is the most frequent finding associated with malaria and is especially severe in primiparas, suggesting that mechanisms other than immunosuppression are responsible for the high susceptibility in this group.

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Citation Excerpt :
The increment is due to migration and accumulation of host inflammatory cells at the site of infection for the clearance of parasite [41,47,72–75]. Apart from parasite clearance, these cells may also be responsible for impairment in materno-foetal exchange either by decreasing the maternal blood output or releasing cytokines [41,74]. This increase in inflammatory cells is reported to be associated with complications in pregnancy due to malaria, such as anaemia, intrauterine growth retardation and LBW [9,18,41,72,73].
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Pregnant women with peripheral parasitaemia for P. falciparum and P. vivax (20 each) were included in the present study, along with 15 age-matched uninfected healthy pregnant women. Placentae were analysed for the presence of local parasitaemia along with pathological lesions caused due to the parasite. Immunohistochemical staining for CD20, CD45 and CD68 cells was performed for examining the specific leucocytes in the intervillous space of the placenta.
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^*: The IHRDC and the SFDDH receive major core funding from the Swiss Agency for Development and Cooperation. The study has been supported through grants of the Spanish Agency for International Cooperation and Fondo de Investigaciones Sanitarias (number 95/863). This trial received financial support from the UNDP/World Bank/WHO Special Program for Research and Training in Tropical Diseases.

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Original ContributionPlacental pathology in malaria: A histological, immunohistochemical, and quantitative study*

Parasitol Today

Trans R Soc Trop Med Hyg

Pathol Res Pract

Lancet

Lancet

Am J Obstet Gynecol

Trans R Soc Trop Med Hyg

Trans R Soc Trop Med Hyg

Immunol Today

Malaria, anaemia and pregnancy

Ann Trop Med Parasitol

An analysis of malaria in pregnancy in Africa

Bull World Health Org

Malaria infection of the placenta in Gambia, West Africa: Its incidence and relationship to stillbirth, birthweight and placental weight

Trans R Soc Trop Med Hyg

Malaria parasites in the placental blood

Ann Trop Med Parasitol

Pregnancy-associated depression of cell-mediated immunity

Rev Infect Dis

Suppressed peripheral and placental blood lymphoproliferative responses in first pregnancies: Relevance to malaria

Am J Trop Med Hyg

Adherence of Plasmodium falciparum to chondroitin sulfate A in the human placenta

Science

Cytoadherence of Plasmodium falciparum to intercellular adhesion molecule 1 and chondroitin-4 sulfate expressed by the syncytiotrophoblast in the human placenta

Infect Immun

Original Contribution
Placental pathology in malaria: A histological, immunohistochemical, and quantitative study*