Prevalence and clinical significance of cathepsin G antibodies in systemic sclerosis

Abstract

Objectives: To evaluate the prevalence and clinical significance of cathepsin G antibodies in patients affected with systemic sclerosis (SSc, scleroderma). Methods: 115 patients affected by SSc, 55 (47,8%) with diffuse scleroderma (dSSc) and 60 (52,2%) with limited scleroderma (lSSc), were tested for cathepsin G antibodies by ELISA method. Moreover these sera were evaluated by indirect immunofluorescence (IIF) on ethanol and formalin fixed human neutrophils. Results: By means of the ELISA method 16 (13,9%) patients were found to be sera positive for anti-cathepsin G, 2 (12.5%) of which showed a perinuclear fluorescence pattern (P-ANCA) and 4 (25%) an atypical ANCA staining, while 10 (62,5%) were negative on IIF. The IIF on scleroderma sera revealed 5 (4,3%) P-ANCA and 18 (15,7%) atypical ANCA patterns. The anti-cathepsin G antibodies significantly prevailed in scleroderma sera (p=0.02) when their frequency was compared with that of healthy controls; while they were not significantly associated to any clinical or serological features of SSc patients. Conclusions: The anti-cathepsin G antibodies were significantly frequent in scleroderma sera; however, no clinical correlations were found. Thus, the significance of their presence in SSc still needs to be clarified

Cathepsin G and Its Role in Inflammation and Autoimmune Diseases

“…However, the exact role in scleroderma needs to be clarified. 52,53 The mRNA levels of CTSG increase in peripheral blood mononuclear cells and muscles of dermatomyositis patients. The activity of serum CTSG also increase in dermatomyositis and correlate with creatine kinase and lactate dehydrogenase levels; moreover, patients with Jo-1 auto-antibody have higher activity of CTSG.…”