Association between plasma thiols and immune activation marker neopterin in stable coronary heart disease.
BACKGROUND
Studies have associated elevated plasma levels of the thiols homocysteine and cysteine with an increased risk of atherosclerosis. Their relationship with systemic inflammatory parameters and sclerosis scores was investigated in this study.


METHODS
Total homocysteine, total cysteine, neopterin and C-reactive protein (CRP) concentrations were measured in blood samples of 242 patients undergoing elective coronary angiography. A total of 181 patients had coronary artery disease (CAD), as defined by occlusion of > 75% of at least one of the three main coronary arteries, and 61 subjects did not have relevant coronary stenoses.


RESULTS
Total cysteine concentrations were higher in patients suffering from coronary artery sclerosis with stepwise increases relative to the extent of coronary artery sclerosis (p < 0.001). In contrast, neither total homocysteine nor the inflammatory markers, CRP and neopterin, differed between patients and controls. However, total homocysteine concentrations correlated with total cysteine (r = 0.468) and neopterin concentrations (r = 0.290), as well as serum creatinine (r = 0.226; all p < 0.001), the latter indicating a dependence of total homocysteine concentrations on kidney function. Total cysteine concentrations were associated with increased neopterin levels (r = 0.231, p < 0.001).


CONCLUSIONS
Total cysteine concentrations were well suited to estimate the extent of coronary artery sclerosis, while in our study of stable CAD patients total homocysteine was not increased compared to controls. The association between homocysteine, cysteine and parameters of immune activation and inflammation in our study suggests that these markers of CAD may be interdependent.
Department of General Internal Medicine, Innsbruck Medical University, Innsbruck, Austria.
Katharina
K
Schroecksnadel
Roland B
RB
Walter
Guenter
G
Weiss
Michael
M
Mark
Walter H
WH
Reinhart
Dietmar
D
Fuchs
D000368:Aged; D015415:Biomarkers / Q000097:blood*; D017023:Coronary Angiography; D003327:Coronary Disease / Q000097:blood* / Q000175:diagnosis*; D003545:Cysteine / Q000097:blood; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D019798:Neopterin / Q000097:blood*; D011237:Predictive Value of Tests; D013438:Sulfhydryl Compounds / Q000097:blood*
D015415:Biomarkers; D013438:Sulfhydryl Compounds; D006710:Homocysteine; D019798:Neopterin; D003545:Cysteine