Efficiency of A fumigatus-specific IgG and galactomannan testing in the diagnosis of simple aspergilloma

Background An early diagnosis of chronic pulmonary aspergillosis (CPA) at the stage of simple aspergilloma (SA) remains a challenge in low- and middle-income countries, where imaging may not be routinely available. Objective We investigate the role of Aspergillus fumigatus-specific IgG in serum, and galactomannan (GM) in bronchoalveolar lavage fluid (BALF) and serum for the diagnosis of SA. Methods We included 46 consecutive treatment-naïve subjects with SA. The 81 controls were subjects of treated pulmonary tuberculosis with residual radiological abnormality and minimal symptoms; and subjects with pulmonary disorders other than CPA who underwent bronchoscopy. The diagnosis of SA was based on consistent clinical features along with radiological manifestations (cavity with fungal ball). Results Using receiver operating characteristic (ROC) curve analysis, the best cut-off value for A fumigatus-specific IgG was 27.3 mgA/L (AUROC, 0.839; sensitivity, 63.5%; specificity, 98.3%). The best cut-off value for serum and BALF-GM was 0.7 (AUROC, 0.636; sensitivity, 32%; specificity, 96.2%) and 2.5 (AUROC, 0.833; sensitivity, 63.7%; specificity, 97.1%), respectively. A combination of A fumigatus-specific IgG (>27 mgA/L) or serum GM (≥0.7) or BALF-GM (≥2.5) had a sensitivity and specificity of 82.6% and 96%, respectively. Conclusions A combination of serological tests has the best sensitivity in diagnosing SA. More studies are needed to confirm our findings.