Diagnostic Value of Galactomannan Antigen Test in Serum and Bronchoalveolar Lavage Fluid Samples from Patients with Nonneutropenic Invasive Pulmonary Aspergillosis

Abstract

ABSTRACT The objective of this study was to compare the diagnostic value of galactomannan (GM) detection in bronchoalveolar lavage fluid (BALF) and serum samples from nonneutropenic patients with invasive pulmonary aspergillosis (IPA) and determine the optimal BALF GM cutoff value for pulmonary aspergillosis. GM detection in BALF and serum samples was performed by enzyme-linked immunosorbent assay (ELISA) in 128 patients with clinically suspected nonneutropenic pulmonary aspergillosis between June 2014 and June 2016. On the basis of the clinical and pathological diagnoses, 8 patients were excluded because their diagnosis was uncertain. The remaining 120 patients were diagnosed with either IPA ( n = 37), community-acquired pneumonia (CAP; n = 59), noninfectious diseases ( n = 19), or tuberculosis ( n = 5). At a cutoff optical density index (ODI) value of ≥0.5, the sensitivity of BALF GM detection was much higher than that of serum GM detection (75.68% versus 37.84%; P = 0.001), but there was no significant difference between their specificities (80.72% versus 87.14%; P = 0.286). At a cutoff value of ≥1.0, the sensitivity of BALF GM detection was still much higher than that of serum GM detection (64.86% versus 24.32%; P < 0.001), and their specificities were similar (90.36% versus 95.71%; P = 0.202). Receiver operating characteristic (ROC) curve analysis showed that when the BALF GM detection cutoff value was 0.7, its diagnostic value for pulmonary aspergillosis was optimized, and the sensitivity and specificity reached 72.97% and 89.16%, respectively. BALF GM detection was valuable for the diagnosis of IPA in nonneutropenic patients, and its diagnostic value was superior to that of serum GM detection. The optimal BALF GM cutoff value was 0.7.