Hyperhomocysteinemia in pediatric and young adult renal transplant recipients

Abstract

Hyperhomocysteinemia (HHcy) has been recently identified as an important and reversible cardiovascular risk factor in adult and pediatric renal transplant recipients. A retrospective cross-sectional analysis of 70 pediatric and young adult renal transplant recipients was performed to determine the prevalence, and important clinical and laboratory correlates of HHcy. Total homocysteine concentration, free and protein bound, was determined by fluorescence polarization immunoassay using an IMX analyzer. Hyperhomocysteinemia was defined as a serum homocysteine (Hcy) level above the 95th percentile for age. Fifty-four of 70 patients (77%) had HHcy. Comparison of patients with HHcy with patients without HHcy demonstrated no statistical difference in age (p = 0.35), gender (p = 0.76) or donor type (p = 0.20). Patients with HHcy had significantly lower calculated creatinine clearance values (Ccr) (p = 0.02), 67.3 ± 21.2 mL/min/1.73 m2 vs. 90.7 ± 32.3 mL/min/1.73 m2 for patients without HHcy. Immunosuppression did not correlate with the diagnosis of HHcy. Stepwise logistic regression identified patient age (0.18, p = 0.013) and Ccr (-0.04, p = 0.011) as significant variables. In conclusion, HHcy is more common than expected in pediatric renal transplant recipients. Patients with Ccr < 80 mL/min/1.73 m2 were statistically more likely to have a diagnosis of HHcy. We recommend that Hcy levels should be evaluated in this high risk population.