Increased plasma homocysteine in liver cirrhosis

Background: Homocysteine (Hcy), is an atherogenic and thrombogenic risk fac tor which has also been proposed to be involved in hepatic fibrinogenesis. Hey metabolism depends on the cofactors folate, vit. B12, and the vit. B6 v itamer pyridoxalphosphate (PLP). Metabolism of these vitamins is frequently disturbed in cirrhotics, but little is known about plasma Hey levels in th ese patients. Methods: Plasma le levels of Hcy, methionine, serine, cystein e, PLP, vit. B12 and folate, and standard clinical/biochemical parameters o f liver disease were measured in 43 postabsorptive patients with biopsy pro ven cirrhosis of different origin. Results: 74% of the patients had elevate d plasma Hey levels defined as > 13.4 mu mol/l (mean + 2SD of healthy age m atched controls). Increased plasma Hcy concentrations were seen in alcoholi c as well as in non-alcoholic cirrhosis. Excluding patients with impaired r enal function (n = 7), Hey concentrations remained elevated in 69% of the p atients. We found a high prevalence of pathological plasma vitamin concentr ations of 33% for increased vit. B12 levels and 5% and 80% for decreased fo late and vit. B6 levels, respectively. Mean plasma vitamin B12 concentratio ns increased, folate remained unchanged and PLP concentrations decreased wi th deteriorating liver function. Hey concentrations were correlated with le vels of creatinine (r = 0.44, P < 0.01), serine (r = -0.46, P < 0.01), and cysteine (r = 0.38, P < 0.05), but showed no association with parameters of liver function and with plasma levels of folate, vit, B12 und vit. B6. Thi s was contrary to data obtained in healthy individuals. In a stepwise multi ple regression serine and cysteine best explained the variance in Hey level s. Conclusions: Elevated basal Hey-plasma levels are frequently seen cirrho tic patients. Variations of Hey concentration in liver cirrhosis are not ex plained by plasma levels of cofactors of Hey metabolism. <(c)> 2001 Elsevie r Science Ireland Ltd. All rights reserved.