Autoimmune cytopenia does not predict poor prognosis in chronic lymphocytic leukemia/small lymphocytic lymphoma

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is characterized by an acquired immune defect that can cause autoimmune complications, including anemia and thrombocytopenia. We conducted an observational study of the epidemiology, clinical presentation and significance of autoimmune complications of CLL/SLL in 132 patients from a large population (>45,000 veterans), in which at least 90% of patients with CLL/SLL have been previously identified. Over a period of 12.5 years, 12 patients (9.1%) had autoimmune complications; of these, 6 (4.5%) had autoimmune hemolytic anemia (AIHA), 5 (3.8%) had immune thrombocytopenia (ITP), and 1 (0.8%) had pure red blood cell aplasia (PRBA). All 6 cases of AIHA had a positive direct immunoglobulin test for IgG and C3d. In 6 patients, CLL/SLL was an incidental finding at the time of presentation with autoimmune cytopenia. Nine out of 10 patients responded to immunosuppressive therapy, which was complicated by serious infection in 7 cases, one of which was fatal. The major cause of mortality in patients with autoimmune complications of CLL/SLL was secondary malignancy. Survival of patients with immune cytopenia was not significantly different from CLL/SLL patients without immune cytopenia. Among patients with anemia or thrombocytopenia, mortality was significantly higher in those with bone marrow failure compared to an autoimmune etiology. We show that in a non-referred population with a high incidence of CLL/SLL, autoimmune cytopenia can occur early in the natural history of the disease. These data suggest that the Rai and Binet classifications for CLL need to be modified for patients with autoimmune cytopenia.