In situ identification of lymphoreticular cells in benign and malignant infiltrates by membrane receptor sites.

Immunologic membrane markers have been utilized for the in situ identification of lymphoreticular cells within lymphoreticular tissues and in inflammatory and neoplastic lymphoreticular infiltrates of the skin. Frozen sections were layered with untreated sheep red blood cells (SRBC) for the detection of the E receptor on T cells, SRBC coated with 7S antibody for the detection of the Fc receptor (IgGEA) and SRBC coated with 19S antibody and complement (IgMEAC) for the detection of the C3 receptor. In normal lymphoreticular tissue, IgGEA selectively bound to areas colonized by macrophages, IgMEAC to B-dependent areas, whereas E showed no adherence. In chronic lymphatic leukemia, a predominant and selective adherence of IgMEAC was found in lymphoreticular organs which supports the B-cell nature of the neoplastic cells; in leukemic reticuloendotheliosis a selective IgMEAC adherence was observed and this favors a monocytoid origin of the hairy cells. Adherence of any indicator cell was practically absent from skin infiltrates of mycosis fungoides, which represents an additional piece of evidence for the T-cell nature of this disease process. In psoriasis, a considerable binding of IgGEA was observed, whereas IgMEAC did not adhere at all. This result indicates that the lymphocytic part of the infiltrate in this disease consists mainly of T cells.