Clinical manifestations and long-term outcome of anti-Jo1 antisynthetase patients in a large cohort of Spanish patients from the GEAS-IIM group.

OBJECTIVE: To evaluate the clinical manifestations, long-term clinical outcome and longitudinal pulmonary function in a large cohort of Spanish patients with anti-Jo1 antibodies.
METHODS: We retrospectively analyzed the clinical data and lung function parameters of 148 anti-Jo1 patients recruited from a multicentre registry including 18 Spanish hospitals. A composite endpoint was defined, comprising death due to respiratory failure directly related to antisynthetase syndrome (ASS), the need for long-term oxygen therapy or lung transplantation.
RESULTS: Median follow-up was 78.3 months. Clinical presentation patterns at onset are as follows: isolated interstitial lung disease (ILD) (32.4%), isolated myositis (26.9%), concomitant myositis and ILD (22.8%), and isolated polyarthritis (17.9%). Myositis with ILD was the most frequent final clinical phenotype (67.6%). In most ASS patients, ILD was a non-progressive disease, tending to stabilize with therapy. The endpoint was reached in a significantly larger number of ILD patients with dyspnea at onset than those with paucisymptomatic or asymptomatic forms (p = 0.01). A steady FVC decrease was the hallmark of patients with end-stage lung disease. Estimated survival rates were 87.7% and 75.4% at 5 and 10 years, respectively. Cancer (p = 0.02) and advanced age at ASS diagnosis (p < 0.0001) were related to poorer survival. Mortality was significantly higher than in the general Spanish population, with a standardised mortality ratio (95% CI) of 4.03 (2.79-5.64).
CONCLUSIONS: Anti-Jo1 ASS is a heterogeneous syndrome. ILD in ASS under immunosuppressive therapy is mainly a non-progressive disease. Dyspnea at ILD onset and a steady FVC decrease over time were related to a poorer respiratory prognosis.