Pure Red Cell Aplasia

Pure red cell aplasia is a rare complication of CLL, but can be a complication of fludarabine treatment. It can be caused by either T cells or antibody attacking the red cell precursors. A rare cause is the production of antibodies against erythropoietin in patients who have been treated by Epo. Occasionally it is cause by parvovrus B19 not being properly controlled because the patient is immunodeficient.

And yes it can recur.

It is diagnosed by a bone marrow, but the absence of reticulaocytes (young red cells that have blue granules in them under certain stains) in the blood is a good clue.