Theophylline modulates erythrocytosis after renal transplantation.

Erythrocytosis occurs in 10-15% of renal transplant recipients and there is evidence that the production of erythropoietin is modulated by adenosine. We prospectively evaluated the effects of theophylline, a nonselective adenosine antagonist, in 8 patients with erythrocytosis after renal transplantation. All patients were given triple-drug immunosuppressive therapy with methylprednisolone (8 mg/daily), azathioprine (2 mg/kg b.w. daily) and cyclosporin A (4 mg/kg b.w. daily). After an 8-week course of theophylline treatment (Theodur 300 mg x 2 daily), the mean serum erythropoietin levels were significantly reduced (from 61 mIU/ml before to 16.5 mIU/ml after treatment, p < 0.05). Also the hematocrit was reduced from 0.58 before to 0.50 after treatment (p < 0.05). The previous requirement of monthly phlebotomy was eliminated in all transplant recipients. The above effects were reproducible when the patients were rechallenged with theophylline after a recovery period. It is suggested that theophylline modulates the production of erythropoietin as well as the hematocrit levels in patients with erythrocytosis after renal transplantation and may be useful in the treatment of this condition.