Pure red cell aplasia responsive to interferon-α in a patient with hepatitis C virus infection

A 51-year-old man presented with severe anemia, mild splenomegaly and elevated serum aspartate aminotransferase and serum alanine aminotransferase levels. The bone marrow findings were consistent with pure red cell aplasia (PRCA) with a 'maturation arrest' at the level of pronormoblast. The patient has been transfusion-dependent for 8 months. Following diagnosis of chronic active hepatitis due to hepatitis C virus (HCV), therapy with interferon-a was initiated. Two weeks later, the hemoglobin level stabilized, and he has not required any transfusion ever since. In spite of ongoing HCV viremia, cessation of interferon therapy, and deterioration of the liver function tests, the patient, followed for 2 years, maintains a high-normal hemoglobin level. To the best of our knowledge, this is the first report of prolonged PRCA corrected by interferon-alpha therapy, with or without an ongoing HCV infection. We speculate that the 'maturation arrest' of the erythroid lineage seen in the bone marrow was the result of an immune mechanism, possibly induced by the HCV, and that the elimination of this mechanism, rather than the elimination of the HCV, provided the opportunity for regeneration of erythropoiesis.