POS0688 SCREENING OF INTERSTITIAL LUNG DISEASE IN PATIENTS WITH RHEUMATOID ARTHRITIS: WHICH TOOLS TO USE?
Authors: H. Boussaa, J. Soua, A. Fazaa, S. Miladi, Y. Makhlouf, K. Ben Abdelghani, A. Laatar
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Interstitial lung disease (ILD) remains underestimated in patients with rheumatoid arthritis (RA). Despite the increased mortality associated with RA-ILD, guidelines on optimal tools for early screening and regular follow-up are lacking. <h3>Objectives:</h3> The aim of this study was to evaluate the different screening tools for RA-ILD. <h3>Methods:</h3> We conducted a cross-sectional study including patients diagnosed with RA according to the ACR/EULAR 2010 criteria between 2018 and 2023. RA patients who had respiratory symptoms were excluded. Sociodemographic and clinical data were collected: age, gender, smoking status, disease duration, presence of erosions, rheumatoid factor (RF) and ACPA positivity and levels, erythrocyte sedimentation (ESR) and C-reactive protein (CRP) rates, disease activity score 28 (DAS28) and ongoing treatments. All patients underwent pulmonary examination, pulmonary function tests (PFT), chest x-ray and high-resolution computed tomography (HRCT) at inclusion. HRCT was taken as the gold standard for assessment of the other screening tools. We used Cohen's kappa (κ) to determine the agreement between ILD screening tools. The κ result was interpreted as follows: values ≤ 0 as indicating no agreement and 0.01–0.20 as none to slight, 0.21–0.40 as fair, 0.41– 0.60 as moderate, 0.61–0.80 as substantial, and 0.81–1.00 as almost perfect agreement. A "p" value inferior to 0.05 was considered significant. <h3>Results:</h3> We included 48 RA patients (37 women and 11 men) with a mean age of 60 ±13 years old. Seven patients (16.3 %) were active smokers. The mean disease duration was 1.6 ± 1.5 years. RA was erosive in 79.5% of cases. RF was positive in 83.3% of cases at a mean level of 180 UI/mL. ACPA were positive in 88.4% of cases at a mean level of 211 UI/mL. The mean rates of ESR and CRP were 50.9 mm and 37.18 mg/L, respectively. The main DAS28 ESR was 5.96. Corticosteroids were prescribed in 77.5% of cases, with a mean daily dose of 8.87 ± 3.34 mg. 68.3% of patients were on Methotrexate, with a mean dose of 16.33±3.75 mg per week. Pulmonary auscultation showed crackles in 3 patients (7.1%) and wheezes in one patient (2.4%). Oxygen saturation values were normal in all patients. No digital clubbing was identified. PFT showed an impaired forced vital capacity (FVC) in 17.6% of cases. Diffusing capacity of the lungs for carbon monoxide (DLCO) was low in 25% of cases. Chest x-rays showed interstitial syndrome in 55.6% of cases. The described abnormalities were located in the bases in the majority of cases (81.8%). HRCT screened the presence of ILD in 30.8 % of patients. The following subtypes were identified: non-specific interstitial pneumonia (NSIP) in 90% of cases and usual interstitial pneumonia (UIP) in 10 % of cases. A fair agreement was noted between chest x-rays and HRCT (κ=0.235), but the result was not statistically significant (p&lt;0.138). Sensitivity and specificity of chest x-rays were 72.7% and 80%, respectively. Sensitivities and specificities of crackles, FVC and DLCO were 16.7% and 96% (κ=0.157; p=0.186), 28.6% and 100% (κ=0.299; p=0.104), and 50% and 100% (κ=0.500; p=0.248), respectively. <h3>Conclusion:</h3> Pulmonary auscultation, PFT and chest x-rays showed low sensitivities in the detection of RA-ILD. HRCT remains the gold standard for RA-ILD screening and its implementation should be encouraged at an early stage of the disease. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>