The Value Of G Test And GM Test Of Bronchoalveolar Lavage Fluid In The Early Diagnosis Of Invasive Pulmonary Fungal Infection

Objective To study the early diagnostic value of(1,3)-?-D-glucan and galactomannan in alveolar lavage fluid for invasive pulmonary fungal infection(IPFI).Methods A prospective study was conducted to collect 95 patients admitted to the intensive care department of t the Second Hospital of Anhui Medical University from January from January 2017 to March 2018 with IPFI risk factors.Each patient had a high risk factor of invasive pulmonary fungal infection(IPFI),and alveolar lavage was performed after the improvement of chest CT to find the target segment of lavage or the segment or subsegment of bronchus with the most severe lesions.While alveolar lavage and alveolar lavage fluid(BALF)were performed in all patients,serum specimens were collected and tested for(1,3)-?-D glucan content(G test)and galactomannan content(GM test).According to expert consensus on diagnosis and treatment of pulmonary mycosis,all patients were divided into IPFI group(observation group)with 43 cases,and non-IPFI group(control group)with 52 cases.Patients were divided into invasive pulmonary aspergillosis(IPA)group and non-IPA group according to whether they had aspergillosis.All patients underwent serum,BALF G and GM tests.The differences of BALF G and GM test results between the two groups were compared with those of serum G and GM test results,and the diagnostic value of the above indicators was analyzed by drawing subject operating characteristic curve(ROC curve).Results 1.BALF G test results of the IPFI group and the non-IPFI group were294.07±137.78ng/L and 94.74±46.21ng/L,respectively,with statistically significant differences(P=0.000).The results of serum G test in IPFI group and non-IPFI group were 25.26±12.17ng/L and 15.02±6.05ng/L,respectively,with statistically significant difference(P=0.036).BALF GM test results of IPA group and non-IPA group were 2.68±1.98 and 0.53±0.40,respectively,and the difference was statistically significant(P=0.001).The results of serum GM test in IPA group and non-IPA group were 0.63±0.21 and 0.25±0.17,respectively,and the difference was statistically significant(P=0.030).2.The area under the ROC curve in BALF G test for the early diagnosis of IPFI was 0.900(P=0.000),the 95% confidence interval was 0.841-0.960,the optimal diagnostic threshold was 157ng/L,and the Youden Index,sensitivity and specificity were 0.64,81.2% and 83.1%,respectively.The area under the curve of serum G test for early diagnosis of IPFI was 0.556(P=0.35),the optimal diagnostic threshold was 22ng/L,and the Youden Index,sensitivity and specificity were 0.11,37.2% and 73.1%,respectively.3.The area under the curve of BALF GM test for the early diagnosis of pulmonary aspergillus infection was 0.99(P=0.000),the 95% confidence interval was 0.936-1.000,the optimal threshold was 1.08,and the Youden Index,sensitivity and specificity were 0.918,99% and 92.8%,respectively.The area under the curve corresponding to the serum GM test was 0.732(P=0.025),and the 95% confidence interval was 0.590-0.875.With 0.5 as the diagnostic threshold,the Youden Index,sensitivity and specificity were 0.443,88.9% and 55.7%,respectively.Conclusions The sensitivity and specificity of BLAF G test and GM test for the diagnosis of IPFI and IPA are significantly better than serum,which is conducive to the early diagnosis and treatment of IPFI and IPA.The threshold of BALF G test for IPFIprediction is 157ng/l,and the threshold of BALF GM test for IPA prediction is 1.08.