Serum levels of heat shock protein 70, a biomarker of cellular stress, are elevated in patients with systemic sclerosis: association with fibrosis and vascular damage

摘要

OBJECTIVES:To determine the clinical significance of heat shock protein (Hsp) 70, a sensitive biomarker for monitoring cellular stress, in systemic sclerosis (SSc), we investigated the prevalence and clinical correlation of serum Hsp70 levels in SSc patients. METHODS:Serum Hsp70 levels were examined in 48 patients with SSc by enzyme-linked immunosorbent assay. RESULTS:Serum Hsp70 levels were significantly elevated in SSc patients compared to normal controls (n=30), and were similar between patients with diffuse cutaneous SSc (n=26) and those with limited cutaneous SSc (n=22). Serum Hsp70 levels were elevated in 27% of total SSc patients with 30% of diffuse cutaneous SSc patients and 23% of limited cutaneous SSc patients. Hsp70 levels were significantly increased in SSc patients with pulmonary fibrosis or contracture of phalanges compared with those without pulmonary fibrosis or contracture of phalanges. Serum Hsp70 levels correlated positively with modified Rodnan total skin thickness score, renal vascular resistance, serum levels of monocyte chemotactic protein-1, C-reacting protein, and serum levels of 8-isoprostane. CONCLUSIONS:Serum Hsp70 levels were increased in SSc patients and were associated with pulmonary fibrosis, skin sclerosis, renal vascular damage, oxidative stress, and inflammation. These results suggest that Hsp70 is a useful serological marker for evaluating cellular stresses and the disease severity in SSc.