Erythrocythemia following renal transplantation: influence of diuretic therapy.

Post-transplant erythrocythemia (PTE) is a common finding in renal allograft recipients, although the etiology of this disorder has not been clearly established. We identified 22 patients (9.8%) with PTE from among 225 renal transplant recipients followed for an average of 5.5 years. To characterize possible predisposing factors and to study the clinical significance of PTE, these patients were compared with a control group matched for age, race, sex and etiology of renal failure. Plasma volume (PV) and red blood cell mass (RBCM) were measured in the majority of patients with PTE. Peripheral serum erythropoietin (Ep) levels were determined in the majority of patients in the control and PTE groups. PTE occurred an average of 11.4 months after transplantation. Risk factors for the development of PTE were pretransplant hypertension, retention of native kidneys, higher pretransplant hematocrit, and diuretic use for treatment of post transplant hypertension. Ep levels in the PTE and control groups were not significantly different. Twenty of the 22 patients with PTE were receiving concurrent diuretic therapy, and hematocrits fell to normal levels in all of these patients following cessation or dose reduction of diuretic. No other treatment of PTE was utilized, excluding the phlebotomy of a single unit of blood from one patient. No thromboembolic complications were noted during the follow-up period. We conclude that PTE is frequently induced by overzealous diuretic therapy for treatment of post-transplant hypertension. Discontinuation or reduction of diuretic therapy results in resolution of PTE in nearly all patients. From this experience we have developed an algorithm for the investigation and management of PTE.