RT Journal Article SR Electronic T1 Chronic hypersensitivity pneumonitis - how to predict the treatment success? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 3131 DO 10.1183/13993003.congress-2022.3131 VO 60 IS suppl 66 A1 K B Lewandowska A1 I Baranska A1 M Sobiecka A1 P Radwan-Rohrenschef A1 M Dybowska A1 M Franczuk A1 A Rozy A1 A Skoczylas A1 I Bestry A1 J Kus A1 W Tomkowski A1 M Szturmowicz YR 2022 UL http://erj.ersjournals.com/content/60/suppl_66/3131.abstract AB Introduction: Hypersensitivity pneumonitis (HP) is the interstitial lung disease with clearly established diagnostic criteria but without pharmacologic treatment recommendations. Most specialists use steroids as first-line drugs, sometimes combined with an immunosuppressive agent.Methods: We analyzed the treatment outcome defined as a combination of radiologic and functional variables (chest X-ray, VC max, TL,co) and survival in consecutive chronic HP patients treated with prednisone alone or in combination with azathioprine.Results: The study group consisted of 93 consecutive patients with HP symptoms lasting more than 6 months, of whom 54 (58%) presented with fibrosis in HRCT scan. 49 patients (53%) improved during treatment, 16 (17%) were stable and progression was observed in 28 (30%). Among those with fibrotic HP, progression was noted in 24 cases (45%), whereas among non-fibrotic in 4 (10%) – p=0.00069. Fever after antigen exposure, lymphocyte count in BALF>54%, RV/TLC>120% pred. and ill-defined centrilobular nodules in HRCT were positive treatment outcome predictors (OR 11.8, 8.3, 3.35, 3.1, respectively). Increased eosinophil count in BALF and fibrosis in HRCT predicted negative treatment outcome. Positive response to treatment and preserved baseline VC (% pred.) and TLC (% pred.) predicted longer survival, whereas fibrosis in HRCT was related to a worse prognosis.Conclusion: Immunomodulatory treatment was effective in significant portion (70%) of patients with chronic HP, including 35% of those with fibrotic changes in HRCT. Lung fibrosis was the strong indicator of bad prognosis in the whole group. Future trials are needed to establish the role of immunosuppressive treatment in cHP.FootnotesCite this article as Eur Respir J 2022; 60: Suppl. 66, 3131.This article was presented at the 2022 ERS International Congress, in session “-”.This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).