A Review Of Patients Following A Diagnosis Of Unclassified Interstitial Lung Disease (Ild) At A Tertiary Centre

Introduction: A proportion of patients with ILD remain unclassified after multidisciplinary discussion (MDD). Without a definitive diagnosis there is currently a lack of licensed treatment options for this group. We aimed to review outcomes in this cohort of patients. Method: UK single centre retrospective review of all patients with unclassified ILD diagnosis following ILD MDD between 12/11/2012 and 19/6/2017 with a minimum 2 year follow up. Data extracted from electronic records. Ethical approval obtained. Results: 145 patients included with a mean (SD) follow-up period of 3.9 years (1.2). Baseline demographics were as follows: males 62.1% with mean (SD); age 70.7 years (9.2), FVC% 81.4 (21.4) and DLCO% 55.4 (17.1). At censor, 40.7% of patients had been reclassified to an alternative diagnosis. The median time taken to re-classify patients was 90 days with a wide range (16-2052 days). Common review diagnosis were (n); idiopathic pulmonary fibrosis (29), hypersensitivity pneumonitis (10) and connective tissue disease related ILD (3). Repeat CT and MDD re-discussion led to re-classification in 23% of patients. 15% of patients had a surgical lung biopsy and this led to subsequent re-classification of ILD in 82% of people biopsied. In patients with serial FVC% (n=101), 25% had a >10% decline over a mean interval of 2.5 years. 40% of patients with >10% FVC decline remained unclassified. No baseline characteristics were found to predict progression. Conclusion: These results highlight the importance of MDD follow up of patients with unclassified ILD over time to both review diagnosis and monitor for disease progression to enable appropriate disease targeted therapy.