[Genesis and importance so-called inflammatory infiltration of the placenta. II. Immunohistochemical findings]

We investigated the morphologically distinct forms of inflammatory infiltration of the placenta both histologically and immunohistologically (n = 24). Our material included cases of membraneous inflammation (chorioamnionitis), inflammatory infiltration of arteries in the chorionic membrane, basal and intervillous placentitis. NACE staining was used to detect myeloid cells and monoclonal antibodies (LCA, CD3, CD8, CD20, CD68). To detect lymphoid and macrophageal cells we also measured the proliferation activity with MiB 1. In cases of chorioamnionitis and subchorial demarcation and in the arteries of the chorionic membranes the main inflammatory cell is the myeloid cell (most often the mature neutrophil granulocyte). T-lymphocytes were only occasionally found. In cases of intervillous placentitis, on the other hand, lymphocytic infiltration predominates, consisting of T-lymphocytes which are mostly CD8 negative, and some monocytes and macrophages. Basal inflammation in the demarcation zone was characterized by T-lymphocytes. We interpret this as indicating basal demarcation. According to our histological and immunohistological observations, "asphyxial infiltrates" are abortive forms of a placental (bacteriological) inflammation, possibly infective in origin. We do not consider asphyxial infiltration to be a separate entity with its own causal pathogenesis.