Prevalence of Erythrocytosis and Associated Clinical Manifestations in Renal Transplant Recipients

Erythrocytosis, also known as polycythemia is commonly defined as increase in red blood cells (RBCs) or hemoglobin concentration in the body. Polycythemia can cause blood clots and increases the risk of life threatening thromboembolic complications such as, pulmonary embolism, stroke, deep vein thrombosis (DVT), and heart attack. PTE is frequently seen among renal transplant recipients with an incidence of 10-15%, however, higher prevalence has been recorded in other communities worldwide. Risk factors associated with PTE development include male gender, renal artery stenosis, retained native kidney, hypertension, hydronephrosis, and diabetes. Role of sex hormones, smoking, polycystic kidney disease, inhibition of renin -angiotensin aldosterone system, and excessive use of immunosuppressive medications, mainly containing mycophenolic acid derivate, have been well documented. Onset of erythrocytosis is usually seen by 8 to 24 months in well- functioning grafts. In some patients it resolves spontaneously, whereas in others, can persist for more than two years. Common clinical symptoms associated with PTE are headache, vision problem, lethargy, dizziness, plethora, and increased risk of thromboembolic phenomena, including deep venous thrombosis (DVT), stroke, myocardial infarction (MI), though some patients remained asymptomatic. To study this a retrospective single-center study was conducted at Pakistan Kidney and Liver Institute & Research Centre. Our study showed that out of a total population of 80 recipients, 31.2% of patients (n=25) developed PTE while 68.8% of patients (n=55) did not develop PTE. We also found that in 60% of the patients (n=15), polycythemia resolved within 6 months. It was also found that male gender was at increased risk of erythrocytosis, indicating strong association (p=0.02). Our study did not show any co-relationship between PTE and other predisposing factors as previously reported. A larger trial with prospective analysis is needed to find any significant association.