Risk factors of erythrocytosis post renal transplantation.

Post-transplant erythrocytosis (PTE) is characterized by persistently elevated hematocrit level >or= 51%. This complication is reported to develop in 10-20% of renal allografts recipients, mostly 2 years after kidney transplantation. PTE is self-limited in 25% of the patients; however it may persist in patients with an increased susceptibility for thrombosis and potential fatal outcome. To evaluate the prevalence and risk factors of PTE in our center, we reviewed the records of 235 patients who received renal allografts from 1999 to 2004. Polycythemia was found in 45 (19%) patients. There was no significant correlation of polycythemia and age, history of hypertension, diabetes, pre-transplant hematocrit level, pre-transplant history of transfusion, graft's function, and source of kidney. A significantly higher proportion of PTE patients were males, patients with history of polycystic kidney disease, and patients with glomerulonephritis. We conclude that PTE is an important complication of kidney transplantation. There are several risk factors that should be addressed to prevent this complication.