Antibody-mediated pure red cell aplasia in a dialysis patient receiving darbepoetin alfa as the sole erythropoietic agent.

The introduction of recombinant human erythropoietin (epoetin) transformed the management of anaemia for the vast majority of dialysis patients. The immediate benefit of transfusion-independence was a lower risk of contracting blood-borne infections and iron overload. The raised haematocrit led to improvements in quality of life, which in turn has been associated with improved long term survival [1,2]. For the first decade or so, various brands or formulations of epoetin were available, including epoetin alfa (Epogen, Procrit in the US; Eprex, Erypro in Europe). A second-generation erythropoietic agent (darbepoetin alfa) was developed by incorporating an additional two glycosylation chains to the erythropoietin molecule, resulting in a product with a longer half-life and a consequent reduced dosing frequency [3]. Since 1998, there has been a rapid increase in the incidence of epoetin therapy-associated pure red cell aplasia (PRCA), largely associated with the Eprex brand of epoetin, but described with the Epogen and NeoRecormon brands of epoetin. In 2002, Casadevall et al. [4] described a new complication of epoetin therapy, that of PRCA associated with antierythropoietin antibodies. To date, however, no cases of anti-erythropoietin mediated PRCA has been described with darbepoetin alfa, and indeed it has been suggested that the additional glycosylation may cause this molecule to be more resistant to antibody generation than epoetin. We describe what we believe to be the first case of antibody-mediated PRCA associated with the administration of darbepoetin alfa alone.