Autoimmune hemolytic anemia: causes and consequences.

INTRODUCTION: Autoimmune hemolytic anemia (AIHA) is classified according to the direct antiglobulin test (DAT) and thermal characteristics of the autoantibody into warm and cold forms, and in primary versus secondary depending on the presence of associated conditions. AREAS COVERED: AIHA displays a multifactorial pathogenesis, including genetic (association with congenital conditions and certain mutations), environmental (drugs, infections, including SARS-CoV-2, pollution, etc.), and miscellaneous factors (solid/hematologic neoplasms, systemic autoimmune diseases, etc.) contributing to tolerance breakdown. Several mechanisms, such as autoantibody production, complement activation, monocyte/macrophage phagocytosis, and bone marrow compensation are implicated in extra-/intravascular hemolysis. Treatment should be differentiated and sequenced according to AIHA type (i.e. steroids followed by rituximab for warm, rituximab alone or in association with bendamustine or fludarabine for cold forms). Several new drugs targeting B-cells/plasma cells, complement, and phagocytosis are in clinical trials. Finally, thrombosis and infections may complicate disease course burdening quality of life and increasing mortality. EXPERT OPINION: Beyond warm and cold AIHA, a gray-zone still exists including mixed and DAT negative forms representing an unmet need. AIHA management is rapidly changing through an increasing knowledge of the pathogenic mechanisms, the refinement of diagnostic tools, and the development of novel targeted and combination therapies.

Treating chronic lymphocytic leukemia with obinutuzumab: safety and efficacy considerations.

INTRODUCTION: Obinutuzumab is a novel glycoengineered type II anti-CD20 monoclonal antibody (MoAb) with a higher affinity for CD20 epitope. It was approved by the United States Food and Drug Administration (FDA) in November 2013 for use in combination with chlorambucil for previously untreated chronic lymphocytic leukemia (CLL). AREAS COVERED: This article evaluates the safety of obinutuzumab in CLL patients, also addressing pharmacokinetics/pharmacodynamics (PK/PD), clinical use and efficacy. Moreover, a comparison with other anti-CD20 MoAb is performed. The principal available studies on obinutuzumab are reviewed, focusing on CLL. A PubMed literature search (August 2002 to September 2015) was conducted using the terms obinutuzumab, GA101, anti-CD20 antibody, and CLL. EXPERT OPINION: Obinutuzumab, a third-generation anti-CD20 MoAb, is a safe and effective treatment for elderly patients who are un-fit for fludarabine-based regimen. Its use, proven in the CLL11 study and the results of many ongoing trials evaluating other obinutuzumab-based regimen can lead obinutuzumab to be a candidate to replace rituximab as the first-line treatment option.

Clinical Applications of Hemolytic Markers in the Differential Diagnosis and Management of Hemolytic Anemia.

Several hemolytic markers are available to guide the differential diagnosis and to monitor treatment of hemolytic conditions. They include increased reticulocytes, an indicator of marrow compensatory response, elevated lactate dehydrogenase, a marker of intravascular hemolysis, reduced haptoglobin, and unconjugated hyperbilirubinemia. The direct antiglobulin test is the cornerstone of autoimmune forms, and blood smear examination is fundamental in the diagnosis of congenital membrane defects and thrombotic microangiopathies. Marked increase of lactate dehydrogenase and hemosiderinuria are typical of intravascular hemolysis, as observed in paroxysmal nocturnal hemoglobinuria, and hyperferritinemia is associated with chronic hemolysis. Prosthetic valve replacement and stenting are also associated with intravascular and chronic hemolysis. Compensatory reticulocytosis may be inadequate/absent in case of marrow involvement, iron/vitamin deficiency, infections, or autoimmune reaction against bone marrow-precursors. Reticulocytopenia occurs in 20-40% of autoimmune hemolytic anemia cases and is a poor prognostic factor. Increased reticulocytes, lactate dehydrogenase, and bilirubin, as well as reduced haptoglobin, are observed in conditions other than hemolysis that may confound the clinical picture. Hemoglobin defines the clinical severity of hemolysis, and thrombocytopenia suggests a possible thrombotic microangiopathy or Evans' syndrome. A comprehensive clinical and laboratory evaluation is advisable for a correct diagnostic and therapeutic workup of the different hemolytic conditions.