Influence of antibody profile in clinical features and prognosis in a cohort of Spanish patients with systemic sclerosis.

Objectives: To assess the clinical manifestations and prognosis of Spanish patients with systemic sclerosis (SSc) according to their immunological profile.

Methods: From the Spanish Scleroderma Study Group or RESCLE (Registro de ESCLErodermia as Spanish nomenclature) Registry we selected those patients in which anti-centromere (ACA), anti-topoisomerase I (ATA), and anti-RNA polymerase III (ARA) antibodies had been determined, and a single positivity for each SSc specific antibody was detected. Demographic, clinical, laboratory, and survival data were compared according to the serologic status of these antibodies.

Results: Overall, 209 SSc patients were included. In 128 (61%) patients ACA was the only positive antibody, 46 (22%) were only positive for ATA, and 35 (17%) for ARA. Of note, the three groups were mutually exclusive. In univariate analysis, patients with ACA presented more frequently limited cutaneous SSc (lcSSc) (p<0.001), whereas diffuse cutaneous SSc (dcSSc) was the most frequent subtype in patients with ATA (54%) and ARA (62%) (both p<0.001). Positive patients for ARA showed the highest prevalence of joint involvement (p<0.001) and those from ATA group had a higher prevalence of interstitial lung disease (ILD) (p<0.001). Scleroderma renal crisis was more frequent in the ARA group (p<0.001). In multivariate analysis, ACA were associated with female gender and were protective for dcSSc and ILD. ATA were found to be protective for lcSSc and they were independently associated with interstitial reticular pattern. ARA positivity was independently associated with dcSSc. We did not find differences in mortality between the three groups.

Conclusions: In Spanish SSc patients, the presence of SSc specific antibodies conferred a distinctive clinical profile.