The clinical phenotype of systemic sclerosis patients with anti-PM/Scl antibodies: results from the EUSTAR cohort.

OBJECTIVE: To evaluate clinical associations of anti-PM/Scl antibodies in patients with SSc in a multicentre international cohort, with particular focus on unresolved issues, including scleroderma renal crisis (RC), malignancies, and functional outcome of interstitial lung disease (ILD). METHODS: (1) Analysis of SSc patients from the EUSTAR database: 144 anti-PM/Scl+ without SSc-specific autoantibodies were compared with 7202 anti-PM/Scl-, and then to 155 anti-Pm/Scl+ with SSc-specific antibodies. (2) Case-control study: additional data were collected for 165 anti-PM/Scl+ SSc patients (85 from the EUSTAR registry) and compared with 257 anti-PM/Scl- SSc controls, matched for sex, cutaneous subset, disease duration and age at SSc onset. RESULTS: Patients with isolated anti-PM/Scl+, as compared with anti-Pm/Scl-, had higher frequency of muscle involvement, ILD, calcinosis and cutaneous signs of DM, but similar frequency of SRC and malignancies (either synchronous with SSc onset or not). The presence of muscle involvement was associated with a more severe disease phenotype. Although very frequent, ILD had a better functional outcome in cases than in controls. In patients with both anti-PM/Scl and SSc-specific antibodies, a higher frequency of typical SSc features than in those with isolated anti-PM/Scl was observed. CONCLUSION: The analysis of the largest series of anti-PM/Scl+ SSc patients so far reported helps to delineate a specific clinical subset with muscle involvement, cutaneous DM, calcinosis and ILD characterized by a good functional outcome. SRC and malignancies do not seem to be part of this syndrome.

Evolution of Pulmonary Function in a Cohort of Patients with Interstitial Lung Disease and Positive for Antisynthetase Antibodies.

OBJECTIVE: To describe the evolution of the pulmonary function in patients with interstitial lung disease (ILD) who are positive for at least 1 of the antisynthetase antibodies (ASAB) after medical treatment, and to compare whether the evolution of pulmonary function is associated with the type of ASAB. METHODS: Patients with ILD and positive for at least 1 of the ASAB (anti-Jo1, anti-PL7, anti-PL12, anti-EJ, or anti-OJ) were included. The clinical evolution, time until death or censoring, and improvement of lung disease were registered. RESULTS: The study included 118 patients. Most of the patients had a high extent of ground glass opacities in high-resolution computed tomography (HRCT) and low extent of fibrosis. In the final evaluation of pulmonary function (median 749.5 days of followup), 67% of the patients had lung disease improvement. The improvement occurred within the first 6 months after initiating medical treatment; thereafter, pulmonary function remained stable in most of the patients. A decrease of the extent of ground glass opacities was demonstrated in HRCT at followup in those patients with pulmonary improvement. No differences were observed in the percentage of patients who achieved improvement between the ASAB groups, or in survival. CONCLUSION: Improvement of pulmonary function was observed in 67% of the patients. Improvement was observed in all ASAB groups and occurred within 6 months after initiating medical treatment.