Expression of membrane-associated macrophage colony-stimulating factor (M-CSF) in Hodgkin's disease and other hematologic malignancies

We have identified a membrane-bound form of M-CSF (m-M-CSF) from an establi shed human leukemic J6-1 cell line. To further understand its biological si gnificance, we studied the expression of this membrane-associated growth fa ctor in the lymph nodes of lymphoma patients and bone marrow smears from pa tients with hematologic diseases by immunohistochemical staining using anti -M-CSF MAb. We detected a high incidence of m-M-CSF expression in 75 % (9/1 2) of the lymph node sections from patients with Hodgkin's Disease (HD). Th e antigens were detected primarily in large clusters of mononuclear Hodgkin 's cells and the extracellular matrix (EM) surrounding them. In one HD pati ent with abundant multi-nucleated Reed-Sternberg (R-S) cells, all of them w ere intensely stained with anti-M-CSF MAb. In non-Hodgkin's lymphomas (NHL) , the incidence (17.6 %) of m-M-CSF expression was lower (3/17). Yet, no m- M-CSF antigens were detected in the lymph nodes from six cases of non-hemat ologic malignancies and other diseases. A high response also was detected i n bone marrow smears obtained from patients with hematologic malignancies, which include myeloid leukemias (32.5 %), lymphomas with bone marrow metast asis (50 %) and myelod ysplastic syndromes (MDS) (37.5 %). By comparison, o nly 6.8 % of bone marrow smears from non-malignant hematologic diseases and 2.7 % of lymphoid leukemias showed positive staining with anti-M-CSF MAb. Our results showed that high expression of m-M-CSF antigens is linked to so me types of lymphomas, especially HD. and myeloid leukemias, and may play a role in the development of these hematologic malignancies.