Safety and tolerability of immunosuppression in non-IPF ILD: clinical experience from a tertiary ILD centre

Introduction: Immunosuppression plays an integral role in treatment of non-idiopathic pulmonary fibrosis (IPF) interstitial lung disease (ILD), however use may be limited by side effects. Aim: To report the safety and tolerability of second-line immunosuppression use in non-IPF ILD at a tertiary centre. Methods: Patients with an MDT diagnosis of ILD other than IPF who had received at least one course of second-line immunosuppression between December 2009 and May 2018 were identified. Retrospective case note review was performed to identify adverse events (AEs). Results: 99 patients (45% male, mean age 60±10) received treatment with at least one second-line immunosuppressant. Diagnoses were; nonspecific interstitial pneumonia (28.3%), hypersensitivity pneumonitis (22.2%), sarcoid (17.2%), connective tissue disease related ILD (18.2%), unclassifiable ILD (11.1%), cryptogenic organising pneumonia (2.0%), acute interstitial pneumonitis (1.0%). Table 1 details the immunosuppressants used, number of patients reporting AEs and discontinuation rate. A total of 95 AEs were reported. The most commonly reported AEs across all treatments were abnormal liver function tests (18.9%), infection (15.8%) and tiredness (13.7%). Conclusion: Tolerability of immunosuppression was variable with a higher discontinuation rate amongst patients treated with azathioprine compared to other forms of immunosuppression.