CHITOTRIOSIDASE AS A NON-LIPID MARKER OF ATEROSCLEROSIS AND PROGNOSTIC FACTOR IN CARDIOVASCULAR EVENTS



Tatiana A. Korolenko, Ph.D., Institute of Physiology and Basic Medicine, Novosibirsk, Russia

Objectives. The search of new serum non-lipid markers of atherosclerosis and predictors of cardiovascular events is important in contemporary society. The aim: to evaluate the activity of serum chitotriosidase (CHIT1) and compare it with inflammatory (hs-CRP) and common lipid markers in patients with atherosclerosis.

Background. Chitinases are enzymes – effectors in both innate and acquired immunity. Recently enhanced expression and activity of CHIT1 in humans was suggested as a possible marker of atherosclerosis. In clinical proteomics, CHIT1 was included in the list of 177 biomarkers associated with the development of CVD.

Methods. 107 persons, male were enrolled: 1) group of low ischemic heart disease (IHD) risk, 25 donors (aged 31.4±6.5); 2) high IHD risk, 50 patients with hypertension, aged 56.8±2.9; 3) 32 patients with IHD (56.5±6,9) undergoing coronary bypass surgery (1 month, 1, 2 and 3 years after surgery, treated or non-treated by simvastatin, 20-40 mg/kg), Novosibirsk Regional Cardiovascular Unit. Patients with diabetes mellitus, kidney insufficiency were excluded from this study. Serum chitotriosidase activity was determined by fluorescent method against 4-methylumbelliferyl-beta-D-N-N’-N’’-triacetylchitotrioside as a substrate (Guo et al., 1995).

Results. Serum CHIT1 activity (an enzyme released from the activated macrophages) was significantly increased in aged persons (p<0.01) as well as hs-CRP concentration (correlated with serum cholesterol and triglyceride levels). Baseline level of CHIT1 increased in patients of high risk of IHD (before operation, p<0.01 and 3-8 hrs after cardiosurgury, p<0.001). Simvastatin treatment (I month, 1, 2 and 3 years after cardiosurgery) significantly decreased serum CRP-hs, total cholesterol and non-HDL-cholesterol. However, simvastatin treatment of these patients had no effect on CHIT1 activity steady significantly increased at all periods studied (1, 2 and 3 years after surgery).

Conclusion. CHIT1 has been suggested to represent a new, independent non-lipid biomarker for the development of atherosclerosis.