[Non-Hodgkin's T cell lymphoma associated with marked eosinophilia]

A case of non-Hodgkin's T cell lymphoma (diffuse lymphoma, large cell type) associated with marked eosinophilia and pleurisy in a 57-year-old male is reported. The leukocyte count was 12.5 x 10(3)/microliters and eosinophil count was 53% and the absolute count of 6.6 x 10(3)/microliters. The patient's serum and pleural effusion fluid, containing abundant lymphoma cells, showed eosinophil colony stimulating factor (Eo-CSF) activity. Conditioned medium (CM) prepared from patient's T cells (T-CM) produced Eo-CSF and this was enhanced by interleukin-2 (IL-2) stimulation. We demonstrated that the patient's serum contained a significant amount of interleukin-5 (IL-5) and the patient's T-CM, particularly after IL-2 stimulation contained a significant amount of granulocyte-macrophage colony-stimulating factor (GM-CSF). These findings suggest that Eo-CSF produced by neoplastic T cells or normal T cells activated by tumor antigen stimulated the production of eosinophils in this patient and that both IL-5 and GM-CSF might play a role in Eo-CSF activity.