Walter P R, Garin Y, Blot P
Am J Pathol. 1982 Dec;109(3):330-42.
Placenta malarial changes (PMCs) related to maternal plasmodium infection were present in 33% (247 cases) of a series of 741 placentas collected from an unselected population living in an area of high malarial endemicity (Haut-Ogooué, Gabon, Africa). Plasmodia were found on material thick blood films taken at the time of delivery in 42% of the women with and 24% of women without associated PMCs. Plasmodium falciparum was the most frequent infecting organism. PMCs were more frequent and, in general, more marked in primiparas. The primiparas were significantly (P less than 0.001) more numerous in the group with PMCs than in the control group without such changes. The mean weight of term placentas with malarial changes was significantly (46 g; P less than 0.001) less than that of placentas without such changes. The morphologic changes were a combination of the following features: 1) presence of parasites in the intervillous spaces; 2) macrophage concentration in the intervillous spaces; 3) malarial pigment deposits; 4) excess of perivillous fibrinoid deposits; 5) syncytiotrophoblastic damage; and 6) trophoblastic basal lamina thickening. Plasmodia were found in placental intervillous spaces in 42% (105/247). Local parasitemia varied in magnitude; in a few cases, 30% or more of the maternal erythrocytes were infected. Macrophage concentration in the intervillous spaces was present in 29% (72/247) and was always associated with local parasitemia. Macrophages phagocytized red blood cells and malarial pigment, and their number varied inversely with that of the local parasites. It seems, therefore, that macrophages play an important role in local parasite clearance. Malarial brown pigment was observed in all cases from the series. It had characteristic ultrastructural features and occurred in perivillous deposits of fibrinoid, in macrophages, or free in intervillous spaces. Excessive perivillous fibrinoid deposits were a constant histologic finding and were usually associated with syncytiotrophoblastic necrosis or ultrastructural damage such as partial microvilli loss, filamentous material accumulation in intracytoplasmic vacuoles, and "podocytelike" cytoplasmic projections on the basal surface. At these sites the trophoblastic basal lamina was usually thickened. Previously reported morphologic data and our own findings suggest that the peculiar placental changes in malaria, restricted to intervillous spaces and to villous surfaces, may be related to an immunopathologic process.
在从非洲加蓬上奥果韦一个疟疾高度流行地区的未经过挑选的人群中收集的741份胎盘样本中，33%（247例）存在与母体疟原虫感染相关的胎盘疟疾改变（PMC）。在分娩时采集的血涂片上，42%伴有PMC的女性和24%不伴有PMC的女性检测到疟原虫。恶性疟原虫是最常见的感染病原体。PMC在初产妇中更常见，且通常更明显。有PMC的组中初产妇的数量显著多于（P<0.001）无此类改变的对照组。有疟疾改变的足月胎盘平均重量显著低于（46g；P<0.001）无此类改变的胎盘。形态学改变包括以下特征的组合：1）绒毛间隙存在寄生虫；2）绒毛间隙巨噬细胞聚集；3）疟色素沉积；4）绒毛周围纤维蛋白样物质沉积过多；5）合体滋养层损伤；6）滋养层基膜增厚。42%（105/247）的胎盘绒毛间隙发现疟原虫。局部寄生虫血症程度各异；少数情况下，30%或更多的母体红细胞被感染。29%（72/247）的胎盘绒毛间隙存在巨噬细胞聚集，且总是与局部寄生虫血症相关。巨噬细胞吞噬红细胞和疟色素，其数量与局部寄生虫数量呈反比。因此，巨噬细胞似乎在局部寄生虫清除中起重要作用。该系列所有病例均观察到疟褐色素。它具有特征性超微结构特征，见于绒毛周围纤维蛋白样物质沉积、巨噬细胞或游离于绒毛间隙。绒毛周围纤维蛋白样物质沉积过多是恒定的组织学表现，通常与合体滋养层坏死或超微结构损伤相关，如部分微绒毛丢失、胞质空泡内丝状物质积聚以及基底面“足细胞样”胞质突起。在这些部位，滋养层基膜通常增厚。先前报道的形态学数据和我们自己的发现表明，疟疾时胎盘的特殊改变局限于绒毛间隙和绒毛表面，可能与免疫病理过程有关。
