Evaluation of the Aspergillus Western Blot IgG Kit for Diagnosis of Chronic Aspergillosis

Abstract

Immunoprecipitin detection (IPD) is the current reference confirmatory technique for anti-Aspergillusantibody detection; however, the lack of standardization is a critical drawback of this assay. In this study, we evaluated the performance of theAspergillusWestern blot (Asp-WB) IgG kit (LDBio Diagnostics, Lyon, France), a recently commercialized immunoblot assay for the diagnosis of various clinical presentations of chronic aspergillosis. Three hundred eight serum samples from 158 patients with aspergillosissensu lato(s.l.) were analyzed. More specifically, 267 serum samples were derived from patients withAspergillusdisease, including 89 cases of chronic pulmonary aspergillosis, 10 of aspergilloma, and 32 of allergic bronchopulmonary aspergillosis, while 41 samples were from patients withAspergilluscolonization, including 15 cystic fibrosis (CF) and 12 non-CF patients. For blood donor controls, theAsp-WB specificity was 94%, while the kit displayed a sensitivity for the aspergillosis s.l. diagnosis of 88.6%, with a diagnostic odds ratio (DOR) of 119 (95% confidence interval [CI], 57 to 251). The DOR values were 185.22 (95% CI,78.79 to 435.45) and 43.74 (95% CI, 15.65 to 122.20) for the diagnosis ofAspergillusdisease andAspergilluscolonization, respectively. Among the patients, the sensitivities of theAsp-WB in the diagnosis ofAspergilluscolonization were 100% and 41.7% in CF and non-CF patients, respectively. TheAsp-WB yielded fewer false-negative results than did IPD. In conclusion, theAsp-WB kit performed well for the diagnosis of various clinical presentations of aspergillosis in nonimmunocompromised patients, with an enhanced standardization and a higher sensitivity than with IPD, which is the current reference method.