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 established human leukemic J6-1 cell line. To further understand its biological significance, we studied the expression of this membrane-associated growth factor in the lymph nodes of lymphoma patients and bone marrow smears from patients with hematologic diseases by immunohistochemical staining using anti-M-CSF MAb. We detected a high incidence of m-M-CSF expression in 75 % (9/12) of the lymph node sections from patients with Hodgkin's Disease (HD). The antigens were detected primarily in large clusters of mononuclear Hodgkin's cells and the extracellular matrix (EM) surrounding them. In one HD patient with abundant multi-nucleated Reed-Sternberg (R-S) cells, all of them were 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-hematologic malignancies and other diseases. A high response also was detected in bone marrow smears obtained from patients with hematologic malignancies, which include myeloid leukemias (32.5 %), lymphomas with bone marrow metastasis (50 %) and myelod ysplastic syndromes (MDS) (37.5 %). By comparison, only 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 some types of lymphomas, especially HD. and myeloid leukemias, and may play a role in the development of these hematologic malignancies.