Test Value Of (1,3)-β-D-glucan In BALF In The Early Diagnosis Of Invasive Pulmonary Fungal Infections

Objective To explore the test value of (1,3)-β-D-glucan in bronchoalveolar lavage fluid (BALF) in the early diagnosis of invasion pulmonary fungal infections(IPFI).Methods 1.We selected 172 patients admitted to the Lu’An Hospital Affiliated to Anhui Medical University from June 2011 to December 2013,32 patients of which enrolled in the confirmed IPFI group, 32 patients in simple pneumonia infection group who were just with bacteria pneumonia, and 32 patients in non-infection group who without any signs of infections and factors to be infected fungi, both the two groups were as the control group.76 patients who had high risk factors of fungi infection but no evidence of confirmed IPFI were named as uncertain group when they charged in hospital were studied further. This group of patients were detected by etiology, microscopic examination, examined by real time polymerase chain reaction(PCR)and imaging examination to determine whether they had fungal infection daily,before assigned into confirmed group or no-infection group in 5days. After 5 days the patients with infection pathogen are still not clear will be removed from the study, if the patients did not accepted antifungal treatment, but the clinical symptom had improvement,then,those patients were defined as non-fungal infection group.2.A11 patients underwent BAL.We obtained the BALF and plasma from all the patients.3.All the patients were took G test of BALF and plasma.4. The data were analyzed statistically by single factor analysis of variance to test the BALF and the plasma BG levels in each three group whether had no statistical difference,and independent sample T test to test the BALF and the plasma BG levels in both confirmed and exclusion group.The area under the receiver operating characteristics (ROC) curve was established to derive the best threshold of the 2 G test.Results 1.Level of G test in BALF:the mean of IPFI group was 589.94 pg/ml, simple bacteria pneumonia group was 112.28 pg/ml and non-infection group was 28.78pg/ml, the IPFI group was significantly higher than simple bacteria pneumonia group and non-infection group(F=84.03,P<0.001), Level of G test in plasma:the mean of IPFI group was 346.13 pg/ml, simple bacteria pneumonia group was 70.88 pg/ml and non-infection group was 13.56pg/mL, the IPFI group was significantly higher than the other groups (F=75.60,P<0.001).2.29 cases in the 76 patients were diagnosed as IPFI in the subsequent 5 days b> examination.29 cases removed from the study as can not be diagnosed its identified pathogen. The remaining 18 cases were excluded from the fungal infection. The maximum concentration of (1,3)-β-D-glucan of alveolar lavage fluid came earlier than the plasma in confirmed IPFI patients, including 13 cases of early 24 hours, while 7 cases of early 48 hours.3.When the glucan concentration in bronchoalveolar lavage fluid is 149.5pg/mL had the maximum Youden’s index for diagnosis of IPFI which is 0.982 (P<0.001),at this cutoff, the Sensitivity and Specificity are 96.6% and 90.48% for IPFI diagnose. While the glucan concentration in plasma is 81pg/mL had the maximum Youden’s index for diagnosis of IPFI is 0.982, at this cutoff, the sensitivity and specificity are 96.6% and 85.7% for IPFI diagnose.4.The maximum concentration of (1,3)-β-D-glucan of alveolar lavage fluid came earlier than the plasma and the Specificity of BALF is higher than plasma.Conclusion 1.BG in BALF and plasma are both significantly high in IPFI,while BG in BALF was higher than plasma,and G test of BALF had more value in distinction between simple bacteria pneumonia and invasive pulmonary fungal infection than G test of plasma.2. The specificity and sensitivity of BALF and plasma G test were both high, but G test of BALF higher than plasma, and the peak BG concentration appeared earlier than plasma, suggesting that G test of BALF had more clinical value than G test of Plasma in the diagnosis of IPFI and to be more valuable compared to the plasma in the early diagnosis.3. The best threshold of G test of BALF for the diagnosis of IPFI is 149.5pg/mL, whose sensitivity and specificity in diagnosis of IPFI is higher.