The effect of serum autoantibody profile on clinical follow up of systemic sclerosis patients

Purpose: The aim of this study was to evaluate the effect of autoantibodies on the course of the disease in patients with systemic sclerosis(SSc). Method: Two-hundred and six SSc patiens (189 females) who had a follow-up period of >12 months were enrolled into this retrospective study. Autoantibody status (anti-nuclear antibody (ANA), anti-Scl70 ve anti-centromere(ACA)), clinical, laboratory and radiologic findings of the patients were recorded into a predefined protocol. The effect of autoantibody profile on the progress of disease severity over time (Medsger Severity Index), new or worsening organ developement and disease free survival (cox regression) were evaluated. Results: Autoantibody profile were as follows; %2,9(n=6) ANA(-), %27,7 (n=57) ANA(+)(ENA neg), %47,1(n=97) anti-Scl70(+) and %22,3(n=46) ACA(+). Anti-Scl70 was found to be associated with diffuse skin involvement, interstitial lung disease (ILD) and digital gangrene(p<0,001, p=0.006 and 0.009). ACA was associated with PAH(p=0,040) and found to be protective against diffuse skin involvement, ILD and flexion contractures (p=0.001, p=0.012 and p=0.008). General, vascular, skin, joint, GIS, lung severity scores were worsened during follow-up period in all auto-antibody (+) groups. Cardiac severity scores were worsened in only anti-Scl70(+) group. Time to new organ developement was found to be longer in ACA(+) patients. ACA positives more frequently developed PAH (p=0.007) and less frequently new or worsened ILD (p=0.012 and p=0.001). At 5.year of the follow-up, half of the ACA(+) patients did not have new or worsening organ involvement and at 8.year >80% of the ACA(+) patients developed worsening organ involvements. In ACA(-) groups, >67% and >%80 of the patients were found to have both new or worsening organ involvements at 5. and 8. years. Conclusion: Although ACA(+) SSc patients are considered to have a better prognosis, these results demonstrated that some of these patients may have worsening disease severity and develope new involvements particularly after 8.year of the disease. ANA (+) or anti-scl70 (+) patients were found to have more severe disease and develope new or worsening organ involvements within first 5 years of follow up, these group of patients should be carefully monitored and intensely treated at early couse of the disease. Key Words: systemic sclerosis, autoantibody, anti-centromere antibody, anti-Scl70