Autoantibody profile in a cohort of Algerian patients with systemic sclerosis.

AIM

To describe the autoantibody profile in a cohort of Algerian patients with systemic sclerosis (SSc) and to determine clinical associations between SSc-related autoantibodies, disease subtypes and specific clinical features.

METHODS

Consecutive Algerian patients with SSc were included in the present study. In addition to clinical characterization, all subjects underwent autoantibody testing using indirect immunofluorescence, immunoenzymatic, and line immunoblot assays.

RESULTS

A total of 150 patients were included in this study, 103 (68.7%) had limited cutaneous SSc (lcSSc), 42 (28%) had diffuse cutaneous SSc (dcSSc) and 5 (3.3%) had sine cutaneous scleroderma. One hundred thirty-five (90.0%) patients were positive for SSc-related autoantibodies, including 63 (42%) with more than one autoantibody. The two most frequent autoantibodies were anti-topoisomerase I (ATA) (76; 50.7%) and anti-SSA/Ro (49; 32.7%). Only 23 (15.3%) patients were positive for anticentromere; 9 (6%) were positive for anti RNA polymerase III; 5 (3.3%) for anti-U3 RNP; 3 (2%) for anti Th/To; 25 (16.7%) for anti-U1 RNP; 11 (7.3%) for anti-PM/Scl and 4 (2.7%) for anti-Ku. Anti-topoisomerase I was associated with dcSSc (p <0.0001), interstitial lung disease (ILD) (p <0.0001) and digital ulcers (p <0.0001). Anti-U3 RNP was associated with pulmonary arterial hypertension (PAH) (p=0.031).

CONCLUSION

Notable similarities and differences in the prevalence of SSc-related autoantibodies were found in our population when compared to other ethnic groups. ATA and anti-U3 RNP may be a reliable biomarker for ILD and PAH. Further studies should be conducted to better understand the ethnic influence on disease expression and autoantibody production.