Plasma homocysteine levels in renal transplanted patients on cyclosporine or tacrolimus therapy: effect of treatment with folic acid

Hyperhomocysteinemia. an independent risk cardiovascular factor, has been r eported in renal transplanted patients (RTP). The aim of the present study was to evaluate homocysteine levels in RTP treated with cyclosporine or tac rolimus, and the changes observed in the two groups of patients after treat ment with folic acid. Forty-two RTP with stable function (21 treated with c yclosporine and 21 with tacrolimus, matched by gender and age) were studied , Forty healthy control subjects were matched by age and gender with the pa tients. In RTP, homocysteine was increased compared with the controls (16.4 +/- 5.2 vs 8.0 +/- 1.8 mu mol/L; p < 0.001), but there was no difference i n vitamin B12 and folic acid levels. Thirty-three patients and one control showed hyperhomocysteinemia (78.5 vs 2.5%; p < 0.001), Homocysteine correla ted negatively with creatinine clearance in the patients (p = 0.04). but no correlation was found with vitamin B12, folic acid and lipoproteins. By un ivariate analysis, patients treated with cyclosporine had higher homocystei ne than those treated with tacrolimus (p = 0.03), but multivariate analysis did not confirm these results. In 21 patients with hyperhomocysteinemia an d folate levels similar to those of the controls, folic acid (5 mg/d for 3 months) was administered, Homocysteine decreased significantly (19.1 +/- 4. 8 vs 13.2 +/- 3.4 mu mol/L; p < 0.001). with a median reduction of 31% and with no differences observed in patients treated with either cyclosporine o r tacrolimus. We concluded that hyperhomocysteinemia is very frequent in RT P, but homocysteine levels are not different in patients treated with cyclo sporine or tacrolimus. Folic acid therapy produces a significant decrease i n homocysteine concentrations. in the absence of clear folate deficiency, w ithout differences in relation to immunosuppressant therapy.