Immunohistochemical reactivity of anti-myeloid/stem celi work-shop monoclonal antibodies in thymus, lymph node, lung, liver and normal skin

Monoclonal antibodies (mAbs) against human monocytoid cells are “relatively specific” (1,3) and spurious cross-reactivity with other cell types can be detected “in vitro” in experimental models (3). Thus, instead of a single mAb it is customary to identify a specific cell type by the use of a panel of mAbs. Among the system of mononuclear phagocytes (MPS) (2,4), however, some cell types show characteristic histological distribution in the various organs and the specificity of a mAb for each single cell type is relatively simple to assess by immunohistochemical methods. In order to test the reactivity of the anti-myeloid stem cell mAbs of the Workshop, various tissues, including most of the cell types belonging in the mononuclear phagocytic system, were studied.* In addition GR positivity was easily detected in the tissues studied.