SESSION TITLE: Occupational and Environmental Lung Diseases Posters
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: Diagnostic evaluation of patients with ILD often involves serologic testing including those for hypersensitivity pneumonitis (HP). However, the clinical significance of positive HP serology in this clinical context has not been well defined. The purpose of this study is to evaluate the clinical significance of positive avian serology in the diagnosis of ILD.
METHODS: This retrospective observational cohort study evaluated the presence of positive avian serology in 91 individuals with ILD evaluated at Mayo Clinic, Rochester, MN from 2009 - 2012. Positive avian serology was defined as precipitin titer > 53.3 mg/L. Medical records and chest imaging studies were evaluated by two expert clinicians to determine final diagnosis of these patients. Diagnosis of HP required the following: (1) respiratory symptoms , (2) radiologic evidence of diffuse lung disease, and (3) no other identifiable cause for lung disease; in addition to at least one of the following: (a) lung biopsy with features of HP, (b) BAL lymphocytosis >15%, or (c) HRCT findings typical for hypersensitivity pneumonitis. The relationship between the avian precipitin titer and the diagnosis of HP was analyzed.
RESULTS: Of 91 patients with positive avian serology, 49 (54%) received a final diagnosis of HP. Those diagnosed to have HP had a mean avian serology titer of 95.0 mg/L (SD 38.7, range 53.4-197.0), while those with alternative diagnoses had a mean of 68.3 mg/L (SD 16.7, range 54.3-124.0). Higher serology was associated with increased likelihood of HP diagnosis (P<0.0001, OR 1.03 (1.02-1.07). Fifty-five patients (60%) reported clinical exposure history, of which 42 (76%) were diagnosed to have HP.
CONCLUSIONS: This study demonstrated that a positive avian serology reflecting sensitization to avian antigens may be a relatively common finding in patients with ILD, but higher serologic titers were associated with an increased likelihood of HP diagnosis.
CLINICAL IMPLICATIONS: The results of this study may help guide the usage and interpretation of avian serology result in the evaluation of patients with ILD.
DISCLOSURE: The following authors have nothing to disclose: Matthew Woge, Teng Moua, Jay Ryu
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