Evidence based therapeutic apheresis in autoimmune and other hemolytic anemias.

PURPOSE OF REVIEW

This article reviews recent publications that bear on the evidential basis for therapeutic apheresis in diseases in which hemolytic anemia is a prominent feature.

RECENT FINDINGS

Therapeutic plasma exchange continues to be reported sporadically in severe autoimmune hemolytic anemia, with inconsistent results. Autoimmune deficiency of ADAMTS13 has provided a compelling rationale for therapeutic plasma exchange in some patients with thrombotic thrombocytopenic purpura; conversely such deficiency is consistently absent in certain clinically similar syndromes for which therapeutic plasma exchange is not or may not be beneficial. Refinements in assays for ADAMTS13 should further clarify its role in idiopathic thrombotic thrombocytopenic purpura. Oral iron chelators have shown promise in recent trials in chronically transfused patients with sickle cell disease and may provide an alternative to red cell exchange to prevent iron overload.

SUMMARY

The proper role of therapeutic plasma exchange in the treatment of autoimmune hemolytic anemia remains uncertain. Therapeutic plasma exchange continues to be indicated for idiopathic thrombotic thrombocytopenic purpura regardless of ADAMTS13 levels, but more accessible and physiological ADAMTS13 assays may raise questions about the rationale for and value of plasma exchange in ADAMTS13 nondeficient patients. Oral iron chelation may obviate the need for red cell exchange as a means to prevent iron overload in chronically transfused patients with sickle cell disease.