Erythrocytosis after renal transplantation: review of 101 cases.

Posttransplant erythrocytosis is increasingly recognized as a complication of kidney transplantation. In a retrospective analysis of 500 recipients, we observed 101 patients (20.2%) with persistent elevation of hematocrit value. It was more frequent in men (82.2%) than women (17.8%). It occurred 2 to 50 months after engraftment (mean value was 11.2 +/- 8.9 months), but most often developed in the first 24 months (86%). Spontaneous remission of established erythrocytosis was observed in all cases within 3 to 93 months. It frequently occurred in patients with a well-functioning renal graft; in 82.2% of cases the serum creatinine concentration was less than 1.5 mg/dL. It was 1.5 to 2 mg/dL in 15.8% of patients. There was no correlation between diabetes mellitus and erythrocytosis, compared with a control group. It was more common in patients who received cyclosporine compared to those who were not on cyclosporine. Predisposing factors included male gender, retention of native kidneys, cyclosporine use, and a rejection-free course with a well-functioning renal graft. In conclusion, posttransplantation erythrocytosis, a frequent problem in renal transplant patients, is a self-limited complication that can result in thromboembolic disease.