To investigate the diagnostic value of serum Aspergillus immunoglobulin G (IgG) antibody combined with bronchoalveolar lavage fluid (BALF) galactomannan (GM) detection for pulmonary aspergillosis.

From September 2016 to September 2018, a total of 99 patients with suspected pulmonary Aspergillus infection admitted to Yanda Hospital in Hebei Province were selected, and were divided into control group (38 cases), invasion group (24 cases) and chronic group (37 cases) according to the diagnostic criteria. The diagnostic results of serum Aspergillus IgG antibody and GM antigen were recorded, respectively.

Among the patients with pulmonary aspergillosis, the proportion of old tuberculosis patients was 26.23% (16/61), followed by 18.03% (11/61) of chronic obstructive pulmonary disease, 9.84% (6/61) of lung malignant tumors and 9.84% (6/61) of bronchial asthma. The proportion of old tuberculosis in chronic group (40.54%, 15/37) was significantly higher than that of invasion group (4.17%, 1/24) (χ² = 9.954, P = 0.002). The main clinical symptoms of the patients were cough, expectoration, dyspnea, fever and hemoptysis; while the main manifestations of CT were cavity, Aspergillus ball, multiple or diffuse lesions. The proportion of cough (100.00%, 37/37), expectoration (97.30%, 36/37), hemoptysis (54.05%, 20/37), cavity (83.78%, 31/37), Aspergillus (59.46%, 22/37) in chronic group were significantly higher than that in invasion group [(75.00%, 18/24), 75.00% (18/24), 20.83% (5/24), 45.83% (11/24), 16.67% (4/24)], with significant differences (χ² = 7.634, 5.099, 6.642, 9.776, 10.900; P = 0.006, 0.024, 0.010, 0.002, 0.001) ]; while multiple or diffuse lesions (13.51%, 5/37) and halo sign (0.00%, 0/37) were significantly lower than those of the invasion group [ (75.00%, 18/24) and 41.67% (10/24)], with significant differences (χ² = 23.431, 15.525; all P < 0.001). BALF GM antigen [(0.88 ± 0.13, 0.98 ± 0.24) kiU/L] and serum Aspergillus fumigatus IgG antibody levels [(121.96 ± 42.03, 153.42 ± 49.67) kAU/L] in the invasion and chronic groups were higher than those of the control group, with significant differences (t = 6.422, 9.389, 17.395, 14.436; all P < 0.001). The serum Aspergillus fumigatus IgG antibody level in the invasion group (121.96 ± 42.03) kAU/L was lower than that in the chronic group [(153.42 ± 49.67) kAU/L], with significant difference (t = 2.563, P = 0.013), and there was no difference in BALF GM antigen level between the two groups [(0.88 ± 0.13, 0.98 ± 0.24) kiU/L], with significant difference (t = 1.868, P = 0.067). The sensitivity of serum Aspergillus fumigatus IgG antibody with a critical value of 120 kAU/L was 62.30%, the specificity was 81.58%, and sensitivity was determined at a critical value of 140 kAU/L. When the threshold value was 140 kAU/L, the sensitivity was 52.46%, and the specificity was 94.74%. When the BALF GM antigen was 0.5, the sensitivity was 73.77%, and the specificity was 81.58%. The sensitivity [(73.77%, 45/61)] of BALF GM antigen at the critical value of 0.5 was significantly higher than that of serum Aspergillus fumigatus IgG antibody at the critical value of 140 kAU/L (52.46%, 32/61), with significant difference (χ² = 5.950, P = 0.015). The area under the diagnostic curve of BALF GM antigen and serum Aspergillus fumigatus IgG antibody were 0.812 and 0.771, while the area under the diagnostic curve of combined detetion was 0.898.

The detection of serum Aspergillus fumigatus IgG antibody combined with BALF GM could greatly improve the diagnosis rate of patients with pulmonary aspergillosis.