Impact of Azathioprine use in chronic hypersensitivity pneumonitis patients

• Published in: Pulmonary pharmacology & therapeutics Vol. 60; p. 101878
• Main Authors: Terras Alexandre, André, Martins, Natália, Raimundo, Sara, Melo, Natália, Catetano Mota, Patrícia, Novais e Bastos, Hélder, Pereira, José Miguel, Cunha, Rui, Guimarães, Susana, Souto Moura, Conceição, Morais, António
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.02.2020
• Subjects: Adult; Aged; Aged, 80 and over; Alveolitis, Extrinsic Allergic - drug therapy; Azathioprine; Azathioprine - adverse effects; Azathioprine - therapeutic use; Carbon Monoxide; Chronic Disease - drug therapy; Female; Humans; Hypersensitivity pneumonitis; Immunosuppressive Agents - adverse effects; Immunosuppressive Agents - therapeutic use; Interstitial lung disease; Longitudinal Studies; Lung - drug effects; Male; Middle Aged; Respiratory Function Tests; Retrospective Studies; Total Lung Capacity - drug effects; Treatment Outcome; Vital Capacity - drug effects; Azathioprine; Interstitial lung disease; Hypersensitivity pneumonitis
• ISSN: 1094-5539; 1522-9629
• DOI: 10.1016/j.pupt.2019.101878

Systemic corticosteroids are widely used in chronic hypersensitivity pneumonitis (CHP); however, there is not much evidence to support their use, besides being associated with significant side effects. Azathioprine (AZA) use is common in CHP, although not prospectively tested in randomized controlled trials. Our objective was to evaluate the lung function trajectory of CHP patients after AZA initiation, as well as to assess the safety profile of this drug. Retrospective analysis of patients initiated on AZA following a multidisciplinary team diagnosis of CHP. The longitudinal trajectory of lung function in the first 2 years of treatment was assessed. Thirty-five out of 62 patients (56.5%) remained on treatment after 2 years. AZA treatment was associated with a significant improvement in forced vital capacity (FVC) at 12 and 24 months (p = 0.015 and p < 0.001, respectively). A slight increase in total lung capacity (TLC) and 6-min walking test (6MWT) were also reported, although it did not reach statistical differences at the end of 2 years. No changes in diffusion capacity for carbon monoxide (DLCO) were observed. This is the first study identifying an improvement in lung function (FVC) of CHP patients on AZA treatment for 2 years. Prospective studies are needed to confirm these results and to more adequately select CHP patients who may benefit from AZA.