The Clinical Value Of Galactomannan Detection For Invasive Aspergillosis And Establishment Of Rat Model Of Pulmonary Aspergillosis

PARTⅠEXPLORING THE CLINICAL VALUE OF SERUM GALACTOMANNAN DETECTION FOR INVASIVE ASPERGILLOSIS PATIENTS WITH HEMATOLOGIC DISEASE/CANCERObjective:Invasive aspergillosis (IA) caused by Aspergillus is common severe opportunistic infection of patients with hematologic disease/cancer, which is difficult to diagnose early and has a higher mortality. This study is to assess the value of serum galactomannan(GM) detection for early diagnosis and therapeautic effect of IA in patients with hematologic disease/cancer.Methods:402 serum samples of 127 inpatients with high IA risk of hematology department from January 2009 to February 2010 in Shandong provincal hospital were selected according to the domestic diagnosis standard of the host factors of invasive fungus infection in patients with hematologic disease/cancer.100 serum samples of 30 other inpatients without host factors and healthy volunteer were also selected as control. The serum GM concentration was detected by platelia Aspergillus double-sandwich enzyme linked immunosorbent assay(PADSELISA).The data of clinical,pathological,laboratory manifestation,images and therapeautic effect were also collected. According to the diagnostic criteria of invasive fungal infections in China, the changes of diagnosis and GM concentration before and after antifungal treatment were evaluated and statistical analysis of the evaluation indexes were performed.Results:The sensitivity,specificity,positive predictive values and negative Predictive values of the PADSELISA were 92.3%,82.4%,57.1% and 97.7% respectively by using the serum GM cut-off value of single index≥0.7 and/or 2 consecutive index>0.5.Comparing with the given reagent serum GM cut-off index≥1.5,it had a increased sensitivity,without obvious decreased specificity, which can effectively distinguish the two IA levels between probable and possible patients. The probable IA cases were increased from 10 to 19 after the GM detection. GM test was positive 6.1±4.5d (1-11d) ahead of sputum culture,and 7.2±5.5d(1-15d) ahead of CT scan. A fluctuant reduction of GM level was found in patients sensitive to antifungal treatment, and an increased or constant GM level in insensitive patients. The GM false positive rate could become obviously high in control group patients with intravenous injection of piperacillin-Tazobactam. The GM level of IA patients after using echinocandin increased in early stage and showed a decreased trend during the whole course. The concentration of GM had a relation with the prognosis of the disease.Conclusions:Serum GM antigen detection is an effective method for early diagnosis of IA. Comparing with other diagnostic accessory examination, such as typical CT imaging and direct microbiological test, GM test had an obvious advantage on the positive rate and time. Comparing with single value, single index≥0.7 and/or 2 consecutive index≥0.5 could increase the sensitivity without obvious decreased specificity. Among patients with high risk of hematologic disease/cancer, GM test positive as a starting point to pre-empt the anti-Aspergillus treatment can reduce mortality of IA patients.The serum GM concentration decrease after effective treatment. We can estimate the anti-fungal effect by dynamic detection of serum galactomannan. PARTⅡESTABLISHMENT OF ANIMAL MODEL OF INVASIVE PULMONARY ASPERGILLOSIS IN IMMUNOSUPPRESSED RATObjective:To establish animal model of model of invasive pulmonary aspergillosis in immunosuppressed rat which would be used in preclinical and clinal research.Methods:In order to get immunosuppressed rat,SD rat were administrated different doses of cyclohosphamide(CPA) intraperitoneally or dexamethasone sodium phosphate subcutaneously,the consecutive change of leukocytes and neutrophils in rat peripheral blood were observed.Aspergillus fumigatus SL1369 was inoculated by nostril drop of each rat to generate invasive pulmonary aspergillosis.The death and behaviors of rat after infection were recorded.All rat were killed at different time points and the lung tissue was analyzed histopathologically.Results:The neutrophils counts in (75+60+60)mg/kg CPA doses group decreased to less than 200/μL and lated for 5 days.The survival rate of rat was respectively in 4d.8d.12d after inoculation concentration of fungal conidiospore suspension with concentration about 108/ml.A great deal of A.fumigatus were observed and fungal granuloma appeared at 3d in rat lung tissue. A.fumigatus multiplied to the highest density,tissue necrosis and pulmonary abscess appeared at 5-7d.Conclusions:Immunosuppressed rat were indced by CPA administration in combination, and invasive pulmonary aspergillosis were established successfully by dropping A.fumigatus SL1369 into the nares of each rat.