Chronic Lymphocytic Leukemia and Autoimmune Cytopenias: Pathogenesis, Diagnosis and Treatment

Abstract

Chronic Lymphocytic Leukemia (CLL) is a clonal proliferation of B cells in bone marrow, lymph nodes, peripheral blood, spleen and other lymphoid tissues. CLL is mostly associated with dysregulated immune system. Intrinsic immune dysfunction results in increased frequency of autoimmune disorders and susceptibility to infections at the time of diagnosis or during course of the disease. Autoimmune cytopenias especially Autoimmune Hemolytic Anemia (AIHA) is observed frequently. AIHA is the most common immune cytopenia ranging between 5-10 % and it is followed by less frequent Immune Thrombocytopenia (IT) (1-5%). Autoimmune Neutropenia (AIN) and Pure Red Cell Aplasia (PRCA) are rare entities (<1%). In CLL patients, the differential diagnosis of autoimmune cytopenias is important since there are many confounding factors which may cause cytopenia in CLL patients such as infiltration of bone marrow by malignant cells, chemotherapy and infections. A careful diagnostic workup should be performed including history taking, physical examination, laboratory tests and bone marrow aspiration and biopsy. The treatment of AIHA and IT is similar to their counter parts primary AIHA and IT where the steroids are the treatment of choice. In PRCA, steroids are mostly ineffective and immunosuppressive agents should be tried. AIN is a very rare entity in CLL patients. Granulocyte stimulating factors, immunosuppressive therapies may be options in symptomatic patients.