PracticeUpdate Conference Series: ERS 2018

ANA Prevalent in Idiopathic Pulmonary Fibrosis Circulating ANA is prevalent among patients with IPF, though its overall clinical significance is uncertain.

C irculating antinuclear antibody (ANA) is prevalent among patients with idiopathic pulmonary fibrosis, and patients with high-titer ANA likely represent a unique subset of the overall population with idiopathic pulmonary fibrosis. This finding of an analysis of data from the recently completed, phase IIb Efficacy and Safety of SAR156597 in the TreAtment of Idiopathic pulmonary fibRosis (ESTAIR) study was reported at ERS 2018. Peter K. Wung, MD, MHS, of the Johns Hopkins Medical Institutions in Baltimore, Maryland, and colleagues set out to address these deficiencies by examining the data from a large cohort of patients with idiopathic pulmonary fibrosis. ESTAIR assessed the safety and efficacy of SAR156597 in idiopathic pulmonary idiopathic pulmonary fibrosis with high-titer ANA likely represent a unique subset of the overall population with idiopathic pulmonary fibrosis. " PRACTICEUPDATE CONFERENCE SERIES • ERS 2018 " ...patients with

ANA is used to evaluate patients with suspected idiopathic pulmonary fibrosis to exclude conditions that mimic fibrotic lung disease, but its clinical significance in patients with confirmed idiopathic pul- monary fibrosis remains to be elucidated. The significance of circulating autoan- tibodies in patients with idiopathic pulmonary fibrosis has been of clinical and scientific interest for many years. The primary concern is that these idiopathic pulmonary fibrosis autoantibody-positive patients do not suffer from idiopathic pulmonary fibrosis, but rather from some unrecognized and occult connective tis- sue disease. Surprisingly, few studies have systemat- ically examined the clinical relevance. In a cohort of 285 patients with idiopathic pulmonary fibrosis, 34% were positive for ANA (defined as ≥1:40), but no survival difference was reported between ANA- positive vs -negative patients. In another cohort of 58 patients with idiopathic pulmonary fibrosis, 41% had an ANA titer ≥1:160, and other circulating autoantibodies were found, including 7% with rheumatoid factor and 5% with anti- Sjögren's syndrome-related antigen A. No survival difference based on ANA titer was reported. SAR 156597 is an inhibitor of the interleukin-4 and -13 pathways that failed to demonstrate efficacy in a phase II,

fibrosis. The diagnosis of idiopathic pul- monary fibrosis was confirmed by central review of chest high-resolution computed tomography and lung biopsy (if per- formed). ANA was obtained at baseline. The prevalence of ANA, with its associ- ated baseline demographics and disease characteristics, was analyzed from the modified intention-to-treat population. A total of 325 patients were included in the modified intention-to-treat population. Of the 325 patients, 171 (52.6%) were ANA-negative and 105 (32.3%) harbored low-titer ANA (1:40 or 1:80). Overall, 48 (14.7%) exhibited high-titer ANA (≥1:160) at baseline. Patients with high-titer ANA were more likely to be female (35.4% vs 23.4%) and white (100% vs 91.8%), to have been diag- nosed earlier (1.68 ± 1.46 vs 1.82 ± 1.27 years), to suffer symptoms of idiopathic pulmonary fibrosis, to never have smoked (56.3% vs 32.3%), to have greater history of acute exacerbations (12.5% vs 4.7%), to require supplemental oxygen (22.9% vs 11.7%), and to demonstrate more definite features of usual interstitial pneumonia on high-resolution computed tomogra- phy (41.7% vs 31.0%) than ANA-negative patients. Dr. Wung explained that the prevalence of ANA is not well characterized in idiopathic pulmonary fibrosis.

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