Remission of monoclonal chronic T-cell expansion associated with severe anemia

A 49-year-old male with an 8 year history of lowered Hb level, granulocytopenia and fatigue presented in 1986 with progressive fatigue, a dramatically reduced Hb level (45 g/l) and an increased lymphocyte count (6.6 x 10(9)/l). Clinical picture and laboratory studies led to the diagnosis of chronic T lymphocytosis with expansion of CD8+ T cells expressing CD16 IgG Fc receptors (Fc gamma RIII). DNA analyzed with T-cell receptor (TcR) gamma and beta probes revealed extra rearranged bands representing a clonal expansion of T lymphocytes. These T lymphocytes expressed T-cell receptor alpha beta as evaluated by staining with monoclonal antibodies. Because of the severe progressive anemia the patient was transfused with packed red cells. He was then treated with cyclophosphamide. After one month of treatment the transfusions could be discontinued and two months later cyclophosphamide treatment was stopped because of normalized Hb level and lymphocyte counts. The patient remained in a hematologically stable condition, though a minor T-cell population representing the clonal expansion, an inverted CD4/CD8 ratio and low immunoglobulin levels persisted. This is the first report of regression of proven monoclonal CD8+ T gamma-cell expansion and the associated anemia following cyclophosphamide therapy. These observations implicate the expanded monoclonal CD8+ lymphocytes in the pathogenesis of the anemia and granulocytopenia.