PLASMA M-CSF AS AN INDICATOR OF RESPONSE TO CHEMOTHERAPY IN ADULT T-CELL LEUKEMIA PATIENTS

The plasma concentration of macrophage colony-stimulating factor (M-CS F) was measured in 10 patients with acute type adult T cell leukemia ( ATL) during the clinical course before and after chemotherapy. M-CSF c oncentration decreased significantly when the patients achieved comple te remission (CR) or partial remission (PR) (t-test: p = 0.0001). Five of the patients showed disease progression after several months of PR , and plasma M-CSF increased at that time (t-test: p = 0.0456). Thus, plasma M-CSF concentration appeared to accurately reflect the disease activity in ATL. In support of these results, all three ATL cell lines established from these patients secreted M-CSF in vitro after stimula tion with phorbol myristate acetate (PMA) or concanavalin A (Con A). P lasma M-CSF concentration, however, increased transiently when the pat ients were febrile (t-test: p = 0.0001), even though their ATL conditi on was unchanged. Taken together, these results indicate that there ar e two sources of increased plasma M-CSF concentration in ATL; ATL cell s themselves and normal parenchymal cells that cause this increase as the result of elevated body temperature due to inflammation.