Cyclosporin A treatment for Diamond-Blackfan anemia.

Diamond-Blackfan anemia (DBA) is characterized by a variable response to corticosteroid therapy. Patients poorly responsive to acceptable doses of steroid treatment require long-term transfusion therapy. We have treated three patients with DBA with the immunosuppressive agent cyclosporin A with limited success. Patients 1 (DS) and 2 (LS), half-siblings, were 13 and 9 years old, respectively, and remained transfusion independent for many years on steroid therapy. Both patients manifest steroid-associated growth failure and osteopenia, with resultant orthopedic complications. Oral cyclosporin therapy sufficient to achieve trough serum levels of 100-200 ng/ml was associated with a brisk 50-100% increase in hematocrit within 1 month of initiation of treatment and allowed for a gradual tapering of prednisone dose to approximately 20% of prior established maintenance dose. After 7-8 months, both patients developed progressive decline in hematocrit level requiring increased prednisone dose and, ultimately, transfusion support. Patient 3 (RD), a 5-year-old child with steroid refractory, transfusion-dependent DBA, was entirely unresponsive to cyclosporin therapy. No cyclosporin-associated toxicity occurred. Our observations indicated that cyclosporin A can transiently ameliorate the hematologic course of some patients with DBA. Further studies are in order to determine its mechanism of action and potential clinical utility in patients unresponsive to acceptable doses of steroid.