The Diagnostic Value Of Bronchoalveolar Lavage Fluid (1,3) -?-D-glucan And Galactomannan Assay For Invasive Pulmonary Fungal Infection

Objective: To explore the significance of combined detection of bronchoalveolar lavage fluid 1,3--d-glucan(G test)and galactomannan antigen assay(GM test)in the early diagnosis of invasive pulmonary fungal infection(IPFI)patients.Methods: We selected 155 patients who were suspected as IPFI and were tested with G and GM test during hospitalization in Nanjing Chest Hospital from October 1,2015 to February 28,2019.Their Medical records including course of disease,prescribed medication,imaging images and results of various laboratory tests were collected.The patients were divided into the diagnosis group,clinical diagnosis group,quasi diagnosis group and non-fungal infection group according to the diagnostic criteria of pulmonary fungal infection in the consensus of experts on the diagnosis and treatment of pulmonary fungal infection formulated by the infection group of the respiratory medicine branch of the Chinese medical association in 2007.The first three groups were included in the IPFI group,and the non-fungal infection group was the non-IPFI group.We compared the levels of 1,3-?-D-glucan and galactomannan in the two groups,and analyzed the diagnostic efficacy of G and GM test when they were separated and combined.According to the pathological and cultural results,patients with aspergillus infection were included in the IPA group to analyze and compare the diagnostic efficacy of IPA in the detection of G test and GM test alone and in combination(parallel/series).Among the 155 study subjects collected,143 patients were tested for both serum and BALF G test and GM test.The diagnosis,clinical diagnosis,quasi diagnosis patients were included in the case group,and patients with non-IPFI were included in the control group.The diagnostic values of G and GM tests of the two specimens were compared.Results:1.There were no statistically significant differences in age and gender between the IPFI group and the non-IPFI group,and the clinical and imaging manifestations of IPFI patients were lack of specificity.2.The BG level in BALF in IPFI group was significantly higher than that in non-IPFI group(P < 0.05),and the difference was statistically significant.When BALF G test was positive with 100pg/m L,the sensitivity,specificity,positive predictive value and negative predictive value of BALF G test were 64.29%,88.89%,76.60% and 81.48%,respectively.Area under ROC curve 0.786;When BALF BG value 46.35pg/m L is taken as the boundary value,the Jordan index is at its maximum,with a sensitivity of 80.40% and a specificity of 68.70%.3.The GM level in BALF in IPFI group was significantly higher than that in non-IPFI group(P < 0.05),and the difference was statistically significant.When BALF GM test was positive with > 0.5,the sensitivity,specificity,positive predictive value and negative predictive value of BALF GM test were 62.50%,84.85%,70.00% and 77.40%,respectively.Area under ROC curve 0.781;When BALF GM value 0.51 was taken as the boundary value,the Jordan index reached the maximum,and the sensitivity and specificity were 64.30% and 89.90% respectively.4.The sensitivity,specificity,negative predictive value and negative predictive value of BALF G test in IPA group were 46.67%/88.89%/56.00%/84.62% and 73.33%/84.84%/59.46%/91.30%,respectively.5.The sensitivity(98.21%)and negative predictive value(98.70%)in parallel analysis of BALF G test and GM test in IPFI group were improved compared with that in single test,and the specificity(96.97%)and positive predictive value(85.00%)in series analysis were higher than that in single test.6.BG and GM levels in BALF,serum BG and GM levels in the case group were significantly higher than those in the non-IPFI group(all P< 0.05),and the difference was statistically significant.The BG and GM levels of lavage solution were significantly higher than those of the same group(P < 0.05),and the difference was statistically significant.The sensitivity of G test and GM test in BALF was higher than that in serum (p < 0.05),and the difference was statistically significant.The specificity of G test and GM test in serum was higher than that in BALF(P < 0.05),and the difference was statistically significant.GM level and BG level in BALF in IPFI group were significantly higher than those in non-IPFI group(P < 0.05),and the difference was statistically significant.Conclusion:1.The values of G test and GM test in BALF were higher than those in serum G test and GM test,and their sensitivity was better than serum samples,suggesting that G test and GM test in BALF had advantages in the early diagnosis of invasive pulmonary fungal infection.2.BALF G test and GM test have high sensitivity and specificity for IPFI,and have important diagnostic value.GM test has more significance for IPA diagnosis.The sensitivity and negative predictive value in parallel analysis of G test and GM test were improved compared with that in separate detection,and the specificity and positive predictive value were higher in series analysis.