Impact of homocysteinemia on long-term renal transplant survival

Aim. We prospectively followed a cohort of 202 renal transplant recipients for 5 years to examine the impact of fasting homocysteinemia on long-term patient and renal allograft survival. Methods. Cox proportional hazards regression analysis was used to identify independent predictors of all-cause mortality and graft loss. Results. Hyperhomocysteinemia (tHcy > 15 mu mol/L) was present in 48.7% of the 202 patients, predominantly among men (55.8%) as opposed to women (37.1%). At the end of the follow-up period, 13 (6.4%) patients had died including 10 from cardiovascular disease, and 23 had (11.4%) had lost their grafts. Patient death with a functioning allograft was the most prevalent cause of graft loss (13 recipients). Levels of tHcy were higher among patients who died than among survivors (median 23.9 vs 14.3 mu mol/L; P =.005). Median tHcy concentration was also higher among the patients who had lost their allografts than those who did not (median 19.0 vs 14.1 mu mol/L; P =.001). In a Cox regression model including gender, serum creatinine concentration, transplant duration, traditional cardiovascular risk factors, and associated conditions, such as past cardiovascular disease, only tHcy concentration (In) (FIR = 5.50; 95% CI, 1.56 to 19.36; P =.008) and age at transplantation (HR = 1.07; 95% CI, 1.02 to 1.13; P =.01) were independent predictors of patient survival. After censoring data for patient death, tHcy concentration was not a risk factor for graft loss. Conclusions. This prospective study shows that tHcy concentration is a significant predictor of mortality, but not of graft loss, after censoring data for patient death.