Clinical distinctions of anti-topoisomerase positive limited cutaneous systemic sclerosis in early disease: results from the early Systemic sclerOsis Longitudinal Assessment Registry from Turkey

Creative Commons License

YAYLA M. E., Okyar B., Ersözlü E. D., Özgür D. S., Bes C., ÇEFLE A., ...Daha Fazla

Clinical and Experimental Rheumatology, cilt.44, sa.8, ss.1562-1569, 2026 (SCI-Expanded, Scopus)

Özet

Anti-topoisomerase I antibody (ATA) is typically associated with diffuse cutaneous systemic sclerosis (dcSSc). However, subset of limited cutaneous SSc (lcSSc) patients also present with ATA positivity. Emerging data suggest that ATA-positive lcSSc may represent a distinct or intermediate clinical phenotype. This study aimed to compare the demographic, clinical, and treatment features of early ATA-positive lcSSc patients with those of ACA-positive lcSSc and ATA-positive dcSSc patients. Patients were recruited from the multicentre Turkish SOLAR cohort (Systemic sclerOsis Longitudinal Assessment Registry). Among 295 SSc patients screened, 172 were included: 74 ACA-positive lcSSc, 55 ATA-positive lcSSc, and 43 ATA-positive dcSSc. Demographic, clinical, and treatment-related variables were analysed and compared across groups. ATA-positive lcSSc patients were younger at the onset of Raynaud's phenomenon (RP) (p=0.042), the first non-RP symptom (p=0.016), and at diagnosis (p=0.018) compared with ACA-positive lcSSc patients. Interstitial lung disease (ILD) was significantly more frequent in ATA-positive lcSSc (74.5%) than ACA-positive lcSSc (8.1%, p<0.001) and was comparable to ATA-positive dcSSc. Modified Rodnan skin scores were highest in ATA-positive dcSSc but were also significantly elevated in ATA-positive lcSSc (p<0.001). Pitting scars were more frequent in dcSSc. Among patients with ILD, ATA-positive lcSSc and ATA-positive dcSSc showed similar HRCT patterns. ATA-positive lcSSc patients were more frequently treated with glucocorticoids and mycophenolate mofetil than ACA-positive lcSSc, whereas cyclophosphamide was highest in dcSSc. ATA-positive lcSSc patients exhibit a clinically distinct phenotype characterized by a substantial risk of internal organ involvement, despite having less extensive skin disease. Their overlap with dcSSc and divergence from ACA-positive lcSSc highlight the importance of incorporating both skin involvement and serologic subtyping into the early management and risk stratification of SSc.