Treatment of refractory fludarabine induced autoimmune haemolytic with the anti-cd20 monoclonal antibody rituximab

Rituximab in chronic lymphocytic leukemia

Rituximab is a class I chimeric anti-CD20 antibody that has shown efficacy in chronic lymphocytic leukemia (CLL), both as a single agent and in combination with traditional chemotherapies. The modest activity demonstrated in early studies evaluating rituximab in relapsed CLL was improved with higher doses or more dose-intensive regimens that overcame the unfavorable pharmacokinetic features commonly found in CLL. These studies led to a variety of combination trials of rituximab with chemotherapy, where both phase II and later phase III studies have shown great promise for the advancement of CLL therapy. Despite the therapeutic success of rituximab in CLL, studies demonstrating the definitive relative mechanism of tumor clearance are still lacking and this requires further investigation. In addition to being used as a therapy for CLL, rituximab is an effective treatment for autoimmune CLL complications such as hemolytic anemia and immune thrombocytopenia (ITP). Patients with CLL may experience early infusion-related side effects that can be diminished with corticosteroid pretreatment and stepped-up dosing. Risk factors for infusion-related toxicity may relate to atypical CLL expressing bright CD20 antigen expression, although several different studies have not clearly implicated elevated white blood cell count as a risk factor. Other adverse events, including delayed cytopenias, reactivation of hepatitis B, and development of progressive multifocal leukoencephalopathy, are rare. Future efforts focusing on novel combination-based strategies will be required to fully appreciate the benefit of this therapy in CLL.

Chronic lymphocytic leukemia-associated autoimmune hemolytic anemia

The clinical course of patients with B-cell chronic lymphocytic leukemia (CLL) is often made complicated by autoimmune phenomena which mainly target the blood cells. Among them, the autoimmune hemolytic anemia (AIHA) is the most common form. On the other hand, it is believed that CLL is the most common of the known causes of AIHA. The source of any putative autoantibody (bystander nonmalignant cells or tumor cells) is not clear yet. Recently, it has been hypothesized that leukemic B-cells may also act as professional antigen presenting cells (APCs). With respect to the management of CLL-associated AIHA, steroids still represent the first-line treatment option. Intravenous immunoglobulin, immunosuppressive drugs, and splenectomy are also frequently used for steroid-refractory forms. Furthermore, although the case series is still too small, encouraging data is now supporting the use of monoclonal antibodies, in particular anti-CD20 rituximab, in managing this often life-threatening autoimmune complication of CLL.

Primary chronic cold agglutinin disease: an update on pathogenesis, clinical features and therapy

Chronic cold agglutinin disease (CAD) is a subgroup of autoimmune hemolytic anemia. Primary CAD has traditionally been defined by the absence of any underlying or associated disease. The results of therapy with corticosteroids, alkylating agents and interferon-a have been poor. Cold reactive immunoglobulins against erythrocyte surface antigens are essential to pathogenesis of CAD. These cold agglutinins are monoclonal, usually IgMκ auto antibodies with heavy chain variable regions encoded by the V_H4-34 gene segment. By flowcytometric and immunohistochemical assessments, a monoclonal CD20⁺κ⁺B-lymphocyte population has been demonstrated in the bone marrow of 90% of the patients, and lymphoplasmacytic lymphoma is a frequent finding. Novel attempts at treatment for primary CAD have mostly been directed against the clonal B-lymphocytes. Phase 2 studies have shown that therapy with the chimeric anti-CD20 antibody rituximab produced partial response rates of more than 50% and occasional complete responses. Median response duration, however, was only 11 months. In this review, we discuss the clinical and pathogenetic features of primary CAD, emphasizing the more recent data on its close association with clonal lymphoproliferative bone marrow disorders and implications for therapy. We also review the management and outline some perspectives on new therapy modalities.

Management of cold haemolytic syndrome

Most haemolytic disease is mediated by immunoglobulin G (IgG) antibodies and leads to red blood cell destruction outside of the circulatory system. However, rare syndromes, such as paroxysmal cold haemoglobinuria, show IgG antibodies causing intravascular destruction. Haemolysis may also occur because of immunoglobulin M antibodies. Historically, these antibodies have been termed 'cold agglutinins' because they cause agglutination of red blood cells at 3 degrees C. Cold agglutinin haemolytic anaemia has been associated with a number of autoimmune and lymphoproliferative disorders, and its management differs substantially from warm antibody-mediated haemolytic anaemia. This review of cold haemolytic syndromes describes new therapies and clinical strategies to determine a correct diagnosis.