Immunohistochemical identification of leucocyte populations in normal tissue and inflamed synovium of the rabbit.

A panel of monoclonal antibodies which recognizes well-defined markers of rabbit leucocytes has been used in an immunohistochemical survey of normal rabbit spleen, thymus, and liver, and of inflamed synovial tissue. The results demonstrate that these antibodies are well suited for the identification of leucocytes in frozen sections of rabbit tissues and that T lymphocytes, macrophages, and neutrophils can be readily distinguished. Antibodies to CD44 differentiate between medullary and cortical thymocytes, with the cortical cells being almost entirely negative for this marker. Antibodies to RLA class II show that periportal lymphocytes in the liver express RLA-DR but not RLA-DQ. The type A cells of the synovial lining from inflamed joint tissue are stained by antibodies that recognize macrophages in a manner similar to that found in the human synovial lining.