AB1057 Multidisciplinary approach for diagnosing connective tissue disease-related lung disease: is it useful for rheumatologists?

Background Many patients with idiopathic interstitial pneumonia (IP) have certain clinical, serological and/or pulmonary morphologic features suggesting an underlying autoimmune disease (AD), but without meeting established criteria for connective tissue disease (CTD), a situation labelled as “IP with autoimmune features” (IPAF) 1 . To identify an underlying aetiology is important because it may impact on treatment and prognosis, and could be optimised by multidisciplinary approach. Objectives 1.To identify prevalence of IPAF in routine practice. 2. To determine the value of lung biopsy to diagnose underlying AD.3. To describe the course of IPAF. Methods Observational, longitudinal retrospective study in a tertiary hospital specific outpatient clinic for IP patients with cough and dyspnea as dominant symptoms requiring co-evaluation by rheumatologists in 2010–2016. Variables included: clinical, serologic and morphological findings by High-Resolution Computed Tomography of lungs assessed by 2011 current guidelines 2 and open lung biopsy. Statistical analysis:SPSS 17.0. Results Of 410 patients evaluated for IP, 93 had rheumatologist assessment, 70 F (75.3%), mean age at diagnosis 62.6 years (SD12.13), of whose 48 had no previous diagnosis. Mean follow-up 3.54 (SD2.77)years in undiagnosed patients. The most frequent radiological patterns were: inconsistent with usual interstitial pneumonia (UIP) (67.7%), UIP (22.6%), Possible UIP (4.3%), others (4.3%). Lung biopsy was performed in 15 patients (16%),11 without previous diagnosis. Histopathology patterns: 8 non-specific interstitial pneumonia (NSIP) in whom final rheumathologic clinical diagnosis was IPAF in 6 and UCTD in 2; 1 UIP (Sjogren); 1 vasculitis (p-ANCA) and 1 lymphoid interstitial pneumonia (LIP) corresponding to IPAF. We found lymphoid aggregates in one patient diagnosed as a IPAF. Overall new diagnostics were: IPAF 43.8%, UCTD 4.2%, CTD 52.1%.14/93 (15%) patients died, of whom 6 had IPAF (43%). Conclusions 1. Of patients with IP referred for rheumatologist assessment, 31% has no established CTD, with IPAF as clinical diagnosis in 24.7% of overall patients. 2. Surgical lung biopsy allowed to diagnose AD in 23% of unlabelled patients. 3. After a follow-up time of 3.5 years,43% of patients that died had been diagnosed as a IPAF. References Fischer A,et al. Er Respir J 2015. Raghu G, et al.Am J Respir Crit Care Med 2011. Disclosure of Interest None declared