Evaluation of the Aspergillus Western Blot IgG kit for the diagnosis of chronic aspergillosis.
[allergic bronchopulmonary aspergillosis]
Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillus antibody detection; however, lack of standardisation is a critical drawback of this assay. In this study, we evaluated the performance of the Aspergillus Western Blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialised immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight sera from 158 patients with aspergillosis sensu lato (s.l.) were analysed. More specifically, 267 sera were derived from patients with Aspergillus disease, including 89 chronic pulmonary aspergillosis, 10 aspergilloma and 32 allergic bronchopulmonary aspergillosis cases, while 41 sera were from patients with Aspergillus colonisation, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, Asp-WB specificity was 94%, while the kit displayed a sensitivity for aspergillosis s.l. diagnosis of 88.6%, with 119 (95%CI[57-251]) Diagnostic Odds Ratio (DOR). The DOR values were 185.22 (95%CI[78,79-435,45]) and 43.74 (95%CI[15.65-122.20]) for the diagnosis of Aspergillus disease and Aspergillus colonisation, respectively. Among the patients, the sensitivity of Asp-WB in the diagnosis of Aspergillus colonisation was 100% and 41.7% in CF and non-CF patients, respectively. Asp-WB yielded fewer false-negative results than IPD. In conclusion, the Asp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in non-immunocompromised patients, with an enhanced standardisation and higher sensitivity compared with IPD, the current reference method.