RESUMO
INTRODUCTION: The optimal pharmacological management of chronic hypersensitivity pneumonitis (cHP) is unknown. Corticosteroids are often used as first line therapy but can be associated with side effects. There is a paucity of data examining the role of steroid-sparing agents in cHP. We aimed to determine the effect of mycophenolate mofetil (MMF) and azathioprine (AZA) on lung function and prednisolone dose in cHP patients. METHODS: Retrospective analysis of patients initiated on either MMF or AZA following a multidisciplinary team diagnosis of cHP. Changes in lung function and prednisolone dose up to 12 months before and after MMF/AZA initiation were analysed. RESULTS: Twenty two out of 30 patients remained on treatment at 12 months (18 MMF, 4 AZA). Steroid-sparing therapy resulted in a significant reduction in prednisolone dose from 16.2 ± 9.7 to 8.2 ± 4.2 mg daily (P = 0.002). Treatment with MMF or AZA for 12 months was associated with a significant improvement in carbon monoxide diffusing capacity (TLCO) (-0.55 ± 0.96 vs. +0.31 ± 0.58 mmol/kPa/min, P = 0.02). Although treatment reduced the rate of forced vital capacity decline (-111 ± 295 vs. +2.3 ± 319 mL), it was not significant (P = 0.22). CONCLUSION: MMF or AZA therapy in cHP is associated with an improvement in TLCO and reduction in prednisolone dose. There is a need for prospective trials.