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

The introduction of recombinant human erythro-poietin (epoetin) transformed the management ofanaemia for the vast majority of dialysis patients.The immediate benefit of transfusion-independencewas a lower risk of contracting blood-borne infectionsand iron overload. The raised haematocrit ledto improvements in quality of life, which in turn hasbeen associated with improved long term survival [1,2].For the first decade or so, various brands orformulations of epoetin were available, includingepoetin alfa (Epogen, Procrit in the US; Eprex,Erypro in Europe). A second-generation erythropoieticagent (darbepoetin alfa) was developed by incorporat-ing an additional two glycosylation chains to theerythropoietin molecule, resulting in a product with alonger half-life and a consequent reduced dosingfrequency [3].Since 1998, there has been a rapid increase in theincidence of epoetin therapy-associated pure red cellaplasia (PRCA), largely associated with the Eprexbrand of epoetin, but described with the Epogen andNeoRecormon brands of epoetin. In 2002, Casadevallet al. [4] described a new complication of epoetintherapy, that of PRCA associated with anti-erythropoietin antibodies.To date, however, no cases of anti-erythropoietinmediated PRCA has been described with darbepoetinalfa, and indeed it has been suggested that theadditional glycosylation may cause this molecule tobe more resistant to antibody generation than epoetin.We describe what we believe to be the first case ofantibody-mediated PRCA associated with the admin-istration of darbepoetin alfa alone.