Studies on pure red cell aplasia. Maintenance therapy with immunosuppressive drugs

Two patients with pure red cell aplasia, whose marrow cells were capable of increasing their rate of haem synthesis when incubated in vitro with erythropoietin concentrate, had a complete remission associated with the administration of cyclophosphamide and prednisone. Both patients relapsed when the drugs were withdrawn. The patients again went into remission when therapy was reinstituted. Maintenance of normal erythropoiesis was dependent on the continued administration of these drugs. This study provides additional evidence for a causal relationship between immunosuppressive therapy and the resumption of erythropoiesis in patients with this disease and demonstrates the value of this therapy for the maintenance of a remission.