The elastin metabolism in systemic sclerosis (SSc) has been known to be abnormal. The authors investigated relationship between the clinical manifestations of systemic sclerosis (SSc) and serum levels of soluble elastin-derived peptide (S-EDP) and anti-elastin antibodies. Serum samples were obtained from 79 patients with SSc and 79 age- and sex-matched healthy controls. Concentrations of serum S-EDP and anti-elastin antibodies were measured by ELISA. The serum concentrations of S-EDP in SSc patients were significantly higher than in healthy controls (median, 144.44 ng/mL vs 79.59 ng/mL, P < 0.001). Serum EDP concentrations were found to be correlated with disease duration in SSc (P = 0.002) and particularly in diffuse cutaneous SSc (P = 0.005). Levels of anti-elastin antibodies were found to be more elevated in SSc patients than in healthy controls (median, 0.222 U vs 0.191 U, P = 0.049), more increased in diffuse cutaneous SSc than limited cutaneous SSc (median, 0.368 U vs 0.204 U, P = 0.031). In addition, levels of anti-elastin antibodies were also found to be negatively associated with presence of anti-centromere antibody (P = 0.023). The S-EDP levels were not found to be correlated with levels of anti-elastin antibodies. The increased S-EDP and anti-elastin antibody levels and association with clinical and laboratory characteristics may reflect the abnormal metabolism in SSc.
Adult ; Antibodies, Anti-Idiotypic/*blood/immunology ; Centromere/immunology ; Elastin/*blood/immunology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Middle Aged ; Peptides/*blood/immunology ; Scleroderma, Systemic/*metabolism/pathology

PURPOSE: Elastin is a major arterial structural protein, and elastin-derived peptides are related to arterial change. We previously reported on a novel assay developed using aortic elastin peptides; however, its clinical implications remain unclear. In this study, we assessed whether anti-elastin antibody titers reflect the risk of coronary artery disease (CAD) or its characteristics. MATERIALS AND METHODS: We included 174 CAD patients and 171 age- and sex-matched controls. Anti-elastin antibody titers were quantified by enzyme-linked immunosorbent assay. Parameters of arterial stiffness, including the augmentation index (AI) and heart-to-femoral pulse wave velocity (hfPWV), were measured non-invasively. The clinical and angiographic characteristics of CAD patients were also evaluated. Associations between anti-elastin levels and vascular characteristics were examined by linear regression analysis. RESULTS: The median blood level of anti-elastin was significantly lower in the CAD group than in the controls [197 arbitrary unit (a.u.) vs. 63 a.u., p<0.001]. Levels of anti-elastin were significantly lower in men and in subjects with hypertension, diabetes mellitus, hyperlipidemia, or high hfPWV. Nevertheless, anti-elastin levels were not dependent on atherothrombotic events or the angiographic severity of CAD. In a multivariate analysis, male sex (beta=-0.38, p<0.001), diabetes mellitus (beta=-0.62, p<0.001), hyperlipidemia (beta=-0.29, p<0.001), and AI (beta=-0.006, p=0.02) were ultimately identified as determinants of anti-elastin levels. CONCLUSION: Lower levels of anti-elastin are related to CAD. The association between antibody titers and CAD is linked to arterial stiffness rather than the advancement of atherosclerosis.
Aged ; Angiography ; Antibodies/*blood ; Atherosclerosis/*blood/immunology ; Coronary Artery Disease/blood/*immunology ; Elastin/*blood/immunology ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Hyperlipidemias ; Hypertension/complications ; Male ; Middle Aged ; Pulse Wave Analysis ; Vascular Stiffness/*immunology/physiology