A 50-years-old female was admitted because of the anemic symptoms lasting past two months On admission, the blood examination revealed severe anemia of hemoglobin 4, 6 g/dl, but the leukocyte count was within the normal range with normal differentiation. The bone marrow biopsy disclosed hyperplastic marrow with severely depressed erythropoiesis and normal granuloand megakaryo-poiesis with local diffuse invasion of small lymphoid cells. Analysis of phenotypes of these small lymphoid cells indicated the clonal proliferation of B cells. From the findings of the biopsied lymph node and bone marrow, she was diagnosed as having B cell malignant lymphoma, small lymphocytic. The peripheral blood mononuclear cells with 90.8% T cells and 10.8% B cells inhibited CFU-E derived colony formation of normal cells, but did not inhibited BEU-E and CFU-C derived colony growth. The lymph node cells also inhibited CFU-E derived colony formation.
These data suggest that inhibition of CFU-E derived colony growth by peripheral mononuclear cells may play a role in the development of PRCA in the malignant lymphoma in this patient.
