[Acquired pure red cell aplasia in a patient with B cell chronic lymphocytic leukemia after fludarabine therapy].

A 67-year-old woman was diagnosed with chronic lymphocytic leukemia (CLL) in October 2001. In August 2004, she received chemotherapy consisting of fludarabine and cyclophosphamide (FC therapy). After three cycles of FC therapy, the number of tumor cells was markedly decreased. However, anemia progressed. She was diagnosed with pure red cell aplasia (PRCA) by bone marrow examination and was successfully treated with cyclosporin A (CsA). In October 2008, anemia progressed with the exacerbation of CLL and she received three cycles of fludarabine therapy. Although the number of tumor cells diminished, the anemia did not improve. She was diagnosed with PRCA recurrence and was again successfully treated with CsA. PRCA is a rare complication in patients with CLL and has been attributed to T cell-mediated mechanisms. Six cases with PRCA that developed after fludarabine therapy for CLL have already been reported. Fludarabine therapy may be toxic to Treg, resulting in the loss of self-tolerance. It is important to consider the possibility of PRCA in patients with progressive anemia after fludarabine therapy for CLL.