[Primary Waldenström's macroglobulinemia associated with pure red cell aplasia in which Ts/c lymphocytes inhibiting erythroid precursors were detected].

Waldenström's macroglobulinemia (WMG) is a malignancy of B lymphocytes manifesting heavy accumulation of monoclonal IgM in the plasma. In about 80% cases of WMG, Normocytic normochronic anemia (NNA) is complicated. A case of WMG complicated with pure red cell aplasia (PRCA) and the results of in vitro CFU-E colony assay of bone marrow mononuclear cells (BMMNC) cultured with the patient's serum and/or peripheral lymphocytes were described. A 59-year-old male was admitted with serum total protein Level of 9.7g/dl and 48.2% of gamma globulin. The diagnosis of WMG was made by monoclonal IgM in immunoelectrophoresis. Severe NNA was initially demonstrated on admission and gradually deteriorated further. Both reticulocytes in peripheral blood and erythroid precursors in bone marrow were markedly decreased. Erythropoietin showed high values in plasma. Complication by PRCA was considered to be present in vitro study of a CFU-E colony formation of BMMNC from a normal volunteer showed significant suppression on addition of the patient's peripheral lymphocytes and adverse enhancement by adding the patient's serum. This inhibition of CFU-E colony formation was most prominent by the addition of suppressor/cytotoxic T lymphocytes (Ts/c) and was dose dependent. This result showed the existence of inhibitory Ts/c against proliferation of allogeneic erythroid precursors.