Early signs of lung involvement in seropositive rheumatoid arthritis is associated with reduced exercise capacity

In asymptomatic seropositive and ACPA positive Rheumatoid Arthritis (RA) patients, we used a novel screening protocol for early detection of pulmonary involvement (interstitial lung disease (ILD) based on lung function testing (PFT), lung ultrasound (LUS) and cardiopulmonary exercise test in (CPET) (Reichenberger et al ERS 2023). We included 67 patients (78% female, mean age 61+/−12, 48% active or previous smokers) without symptoms of pulmonary disease. In 11 patients (16%) early ILD was suspected based on reduced DLCOc-SB</=80% pred and noticeable changes in LUS. These patients showed a reduced exercise capacity during CPET with a significantly reduced VO2 at anaerobic threshold and peak exercise. There were no significant differences between both groups in respect to age, gender, BMI, disease activity of RA (DAS28-CRP Score), CCP titer, use of DMARDs and biologicals for treatment, but smoking habits. <table-wrap><object-id>erj;64/suppl_68/PA4270/T1</object-id><object-id>T1</object-id><object-id>t1</object-id><table><colgroup><col></col><col></col><col></col></colgroup><tbody><tr><td>mean (SD), *p<0,05</td><td>No ILD signs (n=56)</td><td>With ILD signs (n=11)</td></tr><tr><td>Female</td><td>77%</td><td>82%</td></tr><tr><td>Age</td><td>60 (11,3)</td><td>64,8 (13,1)</td></tr><tr><td>DLCOc-SB (%pred)</td><td>80 (17)</td><td>66 (15)*</td></tr><tr><td>FVC (%pred)</td><td>106 (17)</td><td>97 (17)</td></tr><tr><td>smoking</td><td>33%</td><td>73%*</td></tr><tr><td>VO2 max ml/kg/min CPET</td><td>23,6 (8,4)</td><td>18,3 (5,8)*</td></tr><tr><td>VO2 AT ml/kg/min CPET</td><td>17,5 (7,0)</td><td>13,5 (5,3)*</td></tr><tr><td>EqCO2 slope</td><td>26,7 (5,6)</td><td>29,9 (5,2)</td></tr></tbody></table></table-wrap> <bold>Conclusion:</bold> In asymptomatic RA-patients, signs of ILD based on PFT and LUS were associated with reduced exercise capacity but not with serological or clinical parameters. This is an independent, investigator-initiated study supported by Boehringer Ingelheim, Germany. Boehringer Ingelheim has no role in the design, analysis or interpretation of the results in this study;