Interstitial Pneumonia With Autoimmune Features: Clinical, Morphological, and Serological Features

Abstract

SESSION TITLE: Connective Tissue-Associated Interstitial Lung Disease SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: To determine the frequency and characteristics of interstitial pneumonia with autoimmune features (IPAF) in a group of patients evaluated in two different centres specialized in interstitial lung diseases (ILD). As secondary objective we compared the clinical, morphological and laboratory features of patients with IPAF, idiopathic pulmonary fibrosis (IPF) and ILD associated with connective tissue diseases (CT-ILD). METHODS: Analytic retrospective study. Data were collected from the medical records of all patients diagnosed with ILD in two specialized centers. For the statistical analysis we used Kruskal-Wallis test RESULTS: 199 patients with ILD were evaluated, 121 (60.8%) of who were female. Of them 116 presented some of the tree categories like IPAF (n=28: 14.07%), IPF (n=43: 21.60%) and CTD-ILD (n=45: 22.61%), so they were included in the analysis. The mean age in the group of IPAF was 63.28±11.09, versus 70.32±6.62 in IPF and 62.35±13.95 in CTD (p=0.006). Unlike IPF, where 58.14% were males, there was a predominance in females both in IPAF and CTD (82.14% and 77.77% respectively). Mean forced vital capacity (FVC) expressed in percentage of predicted value in IPAF was 69.21±15.21, 64.17±16.67 in IPF and 77.14±18.79 in CT-ILD (p=0.011). Remarkably, 100% of the patients with IPF, 82.14% of IPAF and 21% of CT-ILD patients presented “velcro” at auscultation (p<0.001), and the clubbing was more frequent in IPF (62.79%), followed by CT-ILD (26.66%) and IPAF (14.28%) (p<0.001). The frequency of gastro-esophageal reflux symptoms was 57.77% in CT-ILD, 44.18% in IPF and 42.58% in IPAF (p=0.335). Within the extra-articular symptoms, arthralgia and gastro-esophageal reflux were the more frequent features in IPAF (67.85% and 42.85% respectively). In the case of CT-ILD, were arthralgia and arthritis (88.88% and 71.11% respectively). Regarding auto-antibodies, the most frequently found in IPF patients was the antinuclear (ANA), which was positive in 64.28%. Only 2 patients with IPAF had antibodies negatives. In the group of IPF 27.90% had some autoantibody positive. In reference to computed tomography, the pattern most frequently found in both the IPAF as in the CT-ILD group was nonspecific pneumonia (NSIP) unlike what happened in the IPF group were 83.72% had UIP pattern. What concerns to prognosis, the mean %FVC at six months of the diagnosis in patients with IPAF were lower than baseline. The same was seen in IPF and CT-ILD. Moreover, in the group of IPAF, fewer exacerbations were observed (7.14% versus 15.55% in CT-ILD and 23.25% in IPF; p=0.332) CONCLUSIONS: In our serie of 199 patients with ILD we found a frequency of IPAF of 14.07%. Of them, the most frequent tomographic and histological pattern was NSIP. The vast majority of patients had a positive autoantibodies. IPAF patients showed lower values of FVC than CT-ILD, but higher than those with IPF. CLINICAL IMPLICATIONS: The term IPAF describes a group of ILD with specific clinical, morphological and laboratory features that suggest an autoimmune condition but are not enough to full fit the established criteria of a specific CTD. Early referral to rheumatology and interdisciplinary discussion is key to the best approach to this group of patients. DISCLOSURE: The following authors have nothing to disclose: Gabriela Tabaj, Brenda Varela, Maria Victoria Gallardo, Cecilia Gonzalez Ginestet, Georgina Gramblicka, Mariana Salomon, Carlos Nigro, Patricia Malamud No Product/Research Disclosure Information