INFLUENCE OF METHILENETHETRAIDROFOLATE REDUCTASE POLYMORPHISM ON TOTAL HOMOCYSTEINE PLASMA LEVELS IN HEART TRANSPLANT RECIPIENTS

Background. Homocysteine metabolism is often impaired in heart transplant recipients. Moreover, increased total homocysteine plasma level (Thcy) may represent a risk factor for the development of heart allograft vascular disease. C6673 T mutation of 5-10 methilenethetraidrofolate reductase (MTHFR) is associated to high Thcy levels in the general population, however MTHFR polymorphism and its relationships with Thcy in heart transplant recipients remains unclear. Methods. Thcy, serum folate (SF), serum creatinine and MTHFR genotype were determined in 57 consecutive heart transplant recipients referred for routine follow-up (age 55611 yy, 23% female, 48642 months from transplant). None of the study patients was taking folate supplements. Results. Patients characteristics according to MTHFR genotype are noted in table 1. At multivariate analysis, MTHFR genotype and SF were the only independent predictors of Thcy (p50.005). Median SF was 6.5 ng/mL. In patients with SF , 6.5 ng/mL Thcy was 1665, 2066 and 34618 mmol/L in CC, CT, and TT genotypes, respectively (p50.048). Notably, no significant differences in Thcy according to genotypes were noted in patients with SF . 6.5 ng/mL (p50.342). Conclusions. This study demonstrates that 1) presence of C6673 T MTHFR mutation in heart transplant recipients is independently associated to high Thcy. Moreover 2) folate supplementation in patients with inadequate folate status may overcome genetic predisposition to hyperhomocysteinemia.