Background Use of biologic therapy (BT) has been determinant in Rheumatoid Arthritis' (RA) change of management and outcomes improvement for the last decade. Classic extraarticular manifestations are now uncommon, except for the pulmonary involvement, which can occur due to different causes and can complicate our patients' treatment and prognosis.

Objectives The aim of this study is to evaluate the presence of pulmonary complication in RA patients under BT in our hospital, and assess its severity and the modifications required.

Methods Review of clinical records of 208 RA patients receiving BT in the last 5 years (January 2012 to December 2016). 23 cases of preexisting lung disease for other causes have been excluded and finally 26 patients have been finally included. Demographic data, characteristics of RA, types of pulmonary involvement, evolution and changes in treatment have been collected. Statistical analysis were performed using SPSS v22.

Results 73.1% are women, mean aged 59 years (31–80); 53.8% never smokers. They suffer from long term RA (median 176.92 months, SD 199.34); only 2 patientes have been recently diagnosed (less than a year). They are mainly seropositive (85% RF positive) with positive CCP antibodies in 69.2%, and with erosive disease in 70%. 25% have other extraarticular manifestations (3 rheumatoid nodules, 4 cardiac involvement).

Half of the patients were in remission or low activity (DAS 28) at the time of pulmonary disease diagnosis, and the median of CRP was 0.52 mg/dL (SD 1.72). 90% had received Methotrexate and almost half of them Leflunomide; 30% had been treated with BT (50% TNF alpha inhibitors).

Intersticial lung disease (ILD) was the most frequent pulmonary involvement (57.7%) and non-specific intersticial pheumonia (NSIP) the most prevalent pattern (>60%). We also found obstructive pulmonary disease (11.5%) and vascular involvement (7.7%). 40% of the patients had a normal radiograph (all of them a pathological CT).

Treatment was modified in 53.8% of the cases (synthetic DMARD was kept in 68% and BT in 64%).

The average time of evolution of pulmonary involvement is 37.85 months (1–156). 80% of the patients kept stable or improved from their arthritis and also from respiratory disease. Only one received a lung trasplant and another one died.

We haven't found an association between different types of pulmonary involvement and the different variables analyzed in the study. We didn't show significant differences in prognosis related to pulmonary disease distinct patterns; up to 80% of patients with ILD stabilize or improve.

Conclusions Prevalence of pulmonary disease in our experience in RA patients under BT is similar to prevalence in other observational studies (10–20%), because diagnosis here is due to casual detection in a routine chest X-ray or for clinical suspicion for respiratory symptoms (cough, dyspnea, ...). The evolution has been good perhaps for the high prevalence of NSIP, which requires less therapeutic intervention. Protocols for systematic search of lung disease in RA patients seem essential for its proper diagnosis, and there is a need for further research in pathogenesis and management of this complication.

Disclosure of Interest None declared