Diagnostic Value Of Detecting (1â†'3)-β-D-glucan In Invasive Pulmonary Fungal Infections

The diagnosis of invasive pulmonary fungal infections, according to the criteria as defined by the European Organization for the Research and Treatment of Cancer/Mycoses Study Group (EORTC/MCS), is difficult to establish in organ transplant recipients. During the recent years, researchers all over the world have been working on the subject of detecting the antigens of fungus from the body fluid. Our study is to investigate the diagnostic value of detecting the (1→3)-β-D-glucan (BG) in invasive pulmonary fungal infections.Part 1 Diagnostic value of detecting the (1→3)-β-D-glucan in rat's invasive pulmonary fungal infectionsObjective: To evaluate the diagnostic value of detecting (1→3)-β-D-glucan in rat's invasive pulmonary fungal infections.Methods: The models of immunosuppressive rats with pulmonary aspergillosis and pulmonary candidiasis were established. MB-80 Microbiology Kinetic Rapid Reader was used to detect the plasma contents of BG (G test). And the serum circulating galactomannan was measured by ELISA (GM test, Platelia Aspergillus) when necessary.Results: (1) The average value of the groups of IPA and IPC was 56pg/ml and 61pg/ml, respectively. They both had significant meanings compared to the control groups. (2) The sensitivity and specificity for G test and GM test diagnosing IPA were different, namely, 60%, 97%, 73% and 91%, respectively. The sensitivity and specificity for G test diagnosing IPC was 53% and 100%, respectively. (3) A combination of the two different tests improved the sensitivity and specificity of diagnosing IFA, namely, 86% and 98%, respectively.Conclusion: Using MB-80 Microbiology Kinetic Rapid Reader to detect BG is a new and noninvasive method to diagnose the IPFI with high specificity. The combined detection of G test and GM test can improve the sensitivity and specificity of IPA diagnosing. In conclusion, the results presented in this study encourage a prospective evaluation of the G test to assess its role in the diagnosis of IPFI. Part 2 Diagnostic value of detecting (1→3)-β-D-glucan in organ transplant recipients'invasive pulmonary fungal infectionsObjective: To evaluate the diagnostic value of detecting the (1→3)-β-D-glucan in organ transplant recipients'invasive pulmonary fungal infections.Methods: All organ transplant recipients with pulmonary infections between January 2006 and February 2008 were studied in Shanghai First People's Hospital. Fugal infections were assessed according to the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG). G test was performed to plasma screen for (1→3)-β-D-glucan.Results: When setting one positive sample as the diagnostic foundation, the sensitivity, specificity, and positive and negative predictive values of IPFI was 62.5%, 89.7%, 76.9% and 81.3%, respectively. The accuracy was 90.0%. When setting two or more samples as the diagnosit foundation, the sensitivity, specificity, and positive and negative predictive values of IPFI was 43.8%, 98.3%, 93.3% and 76.6%, respectively. And the accuracy was 78.9%. G test is a early diagnosing index which makes results 8.2 days earlier than sputum cultivation and 3 days earlier than radiography. When diagnosing IPA, G test and GM test had a good consistency. Conclusions: MB-80 Microbiology Kinetic Rapid Reader is an early diagnosing method for IPFI. It has a good reliability when the results turn positive. Patients in high risk with positive results warrant immediate investigations for IPFI and the initiation of antifungal therapy.