Cystathionine-β-synthase (
CBS) deficiency is the main cause of
homocystinuria.
Homocysteine (Hcy),
methionine, and other metabolites of Hcy accumulate in the body of affected patients. Despite the fact that
thromboembolism represents the major cause of morbidity in CBS-deficient patients, the mechanisms of cardiovascular alterations found in
homocystinuria remain unclear. In this work, we evaluated the
lipid and inflammatory profile, oxidative
protein damage, and the activities of the
enzymes paraoxonase (PON1) and
butyrylcholinesterase (BuChE) in plasma of CBS-deficient patients at diagnosis and during the treatment (
protein-restricted diet supplemented with
pyridoxine,
folic acid,
betaine, and
vitamin B12). We also investigated the effect of
folic acid and
vitamin B12 on these parameters. We found a significant decrease in
HDL cholesterol and
apolipoprotein A1 (ApoA-1) levels, as well as in PON1 activity in both untreated and treated CBS-deficient patients when compared to controls. BuChE activity and
IL-6 levels were significantly increased in not treated patients. Furthermore, significant positive correlations between PON1 activity and sulphydryl groups and between
IL-6 levels and carbonyl content were verified. Moreover,
vitamin B12 was positively correlated with PON1 and
ApoA-1 levels, while
folic acid was inversely correlated with total Hcy concentration, demonstrating the importance of this treatment. Our results also demonstrated that CBS-deficient patients presented important alterations in biochemical parameters, possibly caused by the metabolites of Hcy, as well as by oxidative stress, and that the adequate adherence to the treatment is essential to revert or prevent these alterations.