Diagnostic accuracy of specific IgG antibodies for bird fancier's lung: a systematic review and meta-analysis.

BACKGROUND: Serologic assays for specific immunoglobulin G (IgG) antibodies are available for diagnosing the condition of bird fancier's lung, however, their usefulness is controversial. This systematic review was aimed at investigating the diagnostic accuracy of specific IgG antibodies used for avian antigens. METHODS: Medline, Embase, the Cochrane Library, the International Clinical Trials Registry Platform, and the Web of Science were searched for studies performed to evaluate the diagnostic accuracy of the Ouchterlony method, enzyme-linked immunosorbent assays (ELISAs), electrosyneresis, and ImmunoCAP assays for diagnosing bird fancier's lung. Nine articles were included in the meta-analysis. The pooled sensitivity and specificity were summarized using a bivariate mixed-effects model, and a hierarchical summary receiver operating characteristic curve was rendered to determine the diagnostic accuracy of the antibodies. RESULTS: The pooled sensitivities and specificities of each specific IgG antibody were 82.9% (95% confidence interval, 71.1-90.5%) and 93.0% (95% confidence interval, 74.4-98.4%) for the Ouchterlony method, 92.5% (95% confidence interval, 71.3-98.4%) and 90.8% (95% confidence interval, 72.1-97.4%) for ELISAs, 90.0% (95% confidence interval, 55.5-99.7%) and 84.6% (95% confidence interval, 73.5-92.4%) for the electrosyneresis method, and 43.5% (95% confidence interval, 35.3-52.1%) and 100% (95% confidence interval, 0-100%) for ImmunoCAP assays. The overall quality of the collective evidence was low, primarily due to the high risk of bias, indirectness, and imprecision of the included studies. CONCLUSIONS: The Ouchterlony method demonstrated high specificity, the ELISA method showed high sensitivity, and the diagnostic utilities of electrosyneresis and ImmunoCAP assay testing remain unclear.