Background Clinical manifestations of systemic vasculitis may be postulated as a consequence of the immune response abnormalities in the course of connective tissue diseases (CTD).
Objectives The aim of this study was to elucidate the significance of different antibodies and proinflammatory cytokines in the diagnosis of vasculitis in patiens with rheumatoid arthritis (RA) and CTD.
Methods Serum of 54 patients with RA and 32 with CTD were analysed for concentrations of TNF-alpha, IL-6, antinuclear antibodies (ANA) and ds-DNA using specific enzyme immunoassay. Anti-native DNA antibodies (nDNA) and anti-neutrophil cytoplasmic autoantibodies (ANCA) were assessed by indirect immunofluorescence test.
Results Fifty out of 86 patients had systemic lesions. Pathological picture of the vascular loop in nailfold capillary microscopy was found in 84 patients. In 19 patients microvascular changes were advanced, in 35-moderate and in 30-mild. Patients with advanced changes in capillary microscopy had longer disease duration (9,7; SD = 7,4 years) compared to patients with mild intensity of vasculitis (6,1; SD = 5,7 years). Significant correlation between ANA titre and disease duration, TNF-alpha serum levels and haemoglobin concentration were observed. Presence of ANCA correlated with titer of Waaler-Rose test and erythrocyte count and of dsDNA with patient age. Serum concentration of IL-6 correlated with titer of Waaler-Rose test and CRP. RA and CTD patients with clinical signs of systemic vasculitis showed significantly higher levels of TNF-alpha, IL-6 and ANA titre as compared to those without vascular involvement. ANA and ANCA were observed significantly more frequent among patients with systemic damage compare to patients without organ injury. Also ANA were twice more frequent among patients with advanced capillaroscopic abnormalities.
Conclusion These results indicate that systemic lesions in the course of RA and CTD are accompanied by abnormalities in nailfold capillary microscopy. Our findings showed correlation between presence of ANA, TNF-alpha serum levels and clinical manifestations of vasculitis. This study point to a pathogenic role of the cytokine network and autoantibodies in systemic vasculitis.