[Post-transplant erythrocytosis].

Post-transplant erythrocytosis is defined as an increase in hematocrit above 55%. It occurs in 10%-15% of renal transplant recipients, most commonly from 8 to 24 months after transplantation. Twenty-five percent of patients experience spontaneous remission within 2 years, while 75% develop symptoms and signs of hyperviscosity (headache, hypertension, plethora). The etiology is multifactorial and includes erythropoietin, renin-angiotensin system (RAS) and IGF-1 as the main factors. RAS inhibition with either ACE inhibitors or angiotensin receptor blockers is efficient therapy which decreases hematocrit in 90% of patients within 2 to 6 weeks, thus decreasing the incidence of fatal complications (like pulmonary embolism and stroke).