Hyperhomocysteinaemia in chronic liver diseases: role of disease stage, vitamin status and methylenetetrahydrofolate reductase genetics

Background/Aims: The liver plays a key role in sulphur aminoacid metabolism hence, homocysteine metabolism may be impaired in chronic liver diseases. The aim of this study was to investigate, in patients affected by chronic liver diseases, (1) the prevalence of hyperhomocysteinaemia and (2) the role of its determinants such as the stage and the aetiology of disease, vitamin status, genetic documented alterations (methylenetetrahydrofolate reductase deficiency) and presence/absence of documented malignant evolution (hepatocellular carcinoma). Materials and methods: One hundred and thirty patients with chronic liver disease (34 with chronic active hepatitis, 12 with fatty liver and 88 with liver cirrhosis) and 50 healthy age-matched control subjects were included into the study. Results: Hyperhomocysteinaemia was defined as homocysteine plasma levels greater than 12.6 mumol/l. Hyperhomocysteinaemia prevalence in liver cirrhosis group was 40.9%, significantly higher (all P<0.01) with respect to controls (12%), chronic active hepatitis (14.7%) and fatty liver (25%) groups and increased with Child-Pugh stage [Child A: 22.2%, Child B (50%); Child C (58.3%)]. In chronic-active hepatitis and liver cirrhosis, the prevalence of subjects with methylenetetrahydrofolate reductase C677-->T mutation (both as CT and as TT) and hyperhomocysteinaemia results in significantly higher levels with respect to controls. Methylenetetrahydrofolate reductase C677-->T mutation and disease stage showed to be the most important predictive factors of hyperhomocysteinaemia in liver cirrhosis whereas the influence of homocysteine-related vitamin status seems to have a secondary role. Conclusions: In conclusion hyperhomocysteinaemia is highly prevalent in liver cirrhosis but not in other chronic liver diseases; it may contribute to fibrogenesis and vascular complication of liver cirrhosis.