PREDICTION OF BONE-MARROW INVOLVEMENT IN PATIENTS WITH MALIGNANT-LYMPHOMA BY GM-CSF STIMULATION TEST

Recently, a stimulation test with colony stimulation factors was found useful to predict bone marrow cellularity. We examined the usefulness of this test to predict the bone marrow involvement in patients with malignant lymphoma. A single dose of GM-CSF (5 mu g/kg) was given subc utaneously to 12 patients with malignant lymphoma. Six patients had no rmocellular bone marrow. Five of these 6 patients showed an increase i n neutrophils of more than 5 x 10(9)/l after GM-CSF administration. Th e remaining 6 patients who had bone marrow lymphoma involvement had a neutrophil count of less than 5 x 10(9)/l. Therefore, the change in ne utrophil count with a cut-off value of 5 x 10(9)/l distinguished the m arrow lymphoma involvement with a sensitivity and specificity of 83% a nd 100%, respectively. The nadir neutrophil count was significantly hi gher in patients with normal marrow than in patients with marrow invol vement after chemotherapy (P < 0.02). In conclusion, the GM-CSF stimul ation test is useful to predict the marrow involvement in patients wit h malignant lymphoma.