Erythrocytosis after renal transplantation. A prospective analysis

A prospective analysis of all cyclosporine treated renal transplants performed between 1987 and 1990 was performed to determine the incidence and etiologic factors of post transplant erythrocytosis (PTE) and its effect on short-term outcome. PTE developed in 25 (8.1%) recipients (mean age, 41 +/- 10 years). PTE occurred more frequently in men (12.8%) than women (1.6%) (p < 0.001), diabetic patients (22.9%) than nondiabetic patients (6.2%) (p < 0.001), and rejection-free recipients (11%) compared with those with early rejection (4%) (p < 0.05) but was independent of recipient race and donor source. Sixteen patients in whom PTE subsequently developed had pretransplant hematocrits above 30%. PTE occurred most frequently in the first year posttransplant (range, 2-29 months). Serum erythropoietin levels were inappropriately elevated in all patients (mean, 24 +/- 2.2 mU/ml), but serum iron, folate, and B12 levels were all normal. Mean serum creatinine and creatinine clearance were 1.7 +/- 0.5 mg/dl and 58 +/- 20 ml/min, respectively. Twenty-three patients underwent phlebotomy (mean, 3.5 +/- 0.5 units) and six had PTE-related complications. In 14 patients, PTE persisted with hematocrit of 53 +/- 1.5% (range, 51-56) compared with 57 +/- 2.6% (range, 54-64) at the time of PTE onset. In conclusion, PTE occurs primarily in the first year posttransplant and is characterized by inappropriate elevation of erythropoietin. Predictors for PTE include male gender, diabetes mellitus, pretransplant hematocrit above 30%, absence of rejection, and excellent renal allograft function.