Antimacrophage monoclonal antibody D11 in the diagnosis of tumors of histiocytic origin.

OBJECTIVE: To investigate the possible application of the human antimacrophagal antibody D11 (MAb D11) to the diagnosis of tumors of histiocytic origin. STUDY DESIGN: Biopsy and surgical materials from 181 patients with nonepithelial tumors and tumorlike lesions were used in the study. The reactivity of MAb D11 with tumor cells was assayed as the percentage of positively reacted cells in cryostat sections and on smears of tissues determined by the immunoperoxidase method. RESULTS: According to the reaction, all tumors could be divided into three groups: group 1, 39 cases, including all malignant fibrous histiocytomas (MFH) (24 cases); all tumors were D11 antigen positive; group 2, 130 cases, tumors with the same nosologic forms revealed positive, as well as negative, reactions with MAb D11; and group 3, 12 cases, all tumors exhibited a negative reaction with MAb D11. CONCLUSION: Although MAb D11 gave a positive reaction with all tumors in the histiocyte series, its reactivity with some tumors of other histogeneses limits the application of MAb D11 for differential diagnosis of MFH. Nevertheless, MAb D11 may be used for the exclusion of tumors from the MFH group in the case of a negative reaction. The results support the view that MFH is derived from cells of the mononuclear phagocyte system.

Reactivity of anti-macrophage monoclonal antibody D11 in human leukemia and malignant lymphoma.

We have studied the reactivity patterns of a previously described pan-macrophage monoclonal antibody (MAb) D11 in 324 cases of acute leukemia and malignant lymphoma (ML). Reaction of D11 in tissue sections was restricted to histiocytes and macrophages. In non-Hodgkin's ML, D11 helped to confirm or to establish the histiocytic nature in 8 of 96 cases, i.e., in 4 of 6 histiocytic MLs; 2 of 13 anaplastic large-cell lymphomas; 1 of 4 large-cell immunoblastic clear-cell MLs; and 1 of 2 histiocytosis X cases. Positive reaction of D11 in acute lymphoblastic leukaemia (ALL) was found in 9 of 86 cases (all belonging to early B-lineage leukemia), of which 4 were CD34-positive and 5 co-expressed 1 or more myeloid/monocytic antigens. MAb D11 did not react in 42 cases of acute-myeloblastic-leukemia (AML) FAB variants M0-M5, except 1 acute mixed-lineage leukemia M1/pre-pre-B. Comparative study of the MAb D11 and a standard CD68 MAb KP- 1 showed that the antigens belong to different epitopes of different molecules.

D11, a novel monoclonal antibody specific for human mature macrophages and peripheral blood monocytes.

A new monoclonal antibody designated Mab D11 is described, which shows a restricted reactivity to cells of the monocyte/macrophage system. When tested by light and electron microscopic immunoperoxidase methods, Mab D11 specifically reacts with blood monocytes and stains resident macrophages in a wide variety of human tissues; it does not mark the macrophages of other species, i.e., rat, swine and mouse. Antigen-presenting cells, e.g., Langerhans cells, are Mab D11 negative. Mab D11 reveals the antigen on cryostat and paraffin tissue sections. Ultrastructurally the antigen recognized by Mab D11 in all macrophage types studied is located on the plasma membrane and within cytoplasmic structures including lysosomes. On immunoblotting, Mab D11 detects the 125-kDa antigen in human liver and the 135-kDa protein in tumours of histiocytic origin. The similarity of Mab D11 to known "pan-macrophage" monoclonal antibodies is discussed.

The antigen of bile canaliculi of the mouse hepatocyte: identification and ultrastructural localization.

The AgB10 antigen of bile canaliculi of the mouse hepatocyte was identified using monoclonal antibodies. The Mr value of 116000 for AgB10 was measured by immunoblotting. The tissue localization of AgB10 was studied by light and electron microscopy using the immunoperoxidase technique. AgB10 was predominantly present on the microvillus membrane of bile canaliculi, the brush border of intestinal mucosa and apical surfaces of the epithelial cells in some other organs. A small amount of AgB10 was detected on the basolateral domain of the hepatocytes. AgB10 was specific for hepatocytes and was not found in the other cell types of the liver. In primary hepatocyte culture, AgB10 was localized on the surface of cells during the first 24 h, predominantly at the sites of cell-cell and cell-substratum contacts. After 48 h of culture AgB10 gradually disappeared from contacting cell surfaces and became concentrated only in the reconstituted bile canaliculi.