Long‐term outcome of patients with acquired chronic pure red cell aplasia (<scp>PRCA</scp>) following immunosuppressive therapy: a final report of the nationwide cohort study in 2004/2006 by the Japan <scp>PRCA</scp> collaborative study group

<jats:title>Summary</jats:title><jats:p>Immunosuppressive therapy has been employed as the initial treatment for acquired chronic pure red cell aplasia (<jats:styled-content style="fixed-case">PRCA</jats:styled-content>), such as idiopathic, thymoma‐associated, or large granular lymphocyte (<jats:styled-content style="fixed-case">LGL</jats:styled-content>) leukaemia‐associated <jats:styled-content style="fixed-case">PRCA</jats:styled-content>, which is thought to be immune‐mediated. To explore the overall long‐term outcome following immunosuppression and to identify the risk factors for death in these disorders, we conducted nationwide surveys in Japan 2004 and 2006, and identified a total of 185 patients with acquired chronic <jats:styled-content style="fixed-case">PRCA</jats:styled-content>, including 72 idiopathic, 41 thymoma‐associated and 14 <jats:styled-content style="fixed-case">LGL</jats:styled-content> leukaemia‐associated cases of <jats:styled-content style="fixed-case">PRCA</jats:styled-content> for whom data was available. The present study evaluated 127 patients with these three subsets of <jats:styled-content style="fixed-case">PRCA</jats:styled-content>. The median overall survival has not yet been reached in idiopathic <jats:styled-content style="fixed-case">PRCA</jats:styled-content>. The estimated median overall survival times in patients with thymoma‐associated and <jats:styled-content style="fixed-case">LGL</jats:styled-content> leukaemia‐associated <jats:styled-content style="fixed-case">PRCA</jats:styled-content> were 142·1 and 147·8 months, respectively. Twenty‐two deaths were reported, and the response to induction therapy and relapse of anaemia were found to be associated with death. The major causes of death were infection in seven patients and organ failure in another seven patients. The results suggest that maintenance therapy and the management of infectious complications are crucial for improving the prognosis of chronic <jats:styled-content style="fixed-case">PRCA</jats:styled-content>.</jats:p>