Expression of sTREM-1 and other biomarkers in Candida albicans pneumonia in rabbits / 中国免疫学杂志

ABSTRACT

Objective:To identify a suitable biomarker for early diagnosis and prognosis of Candida albicans pneumonia ( CAP) ,we investigated the expression of several biomarkers,such as soluble triggering receptor expressed on myeloid cells-1 ( sTREM-1),soluble hemoglobin-haptoglobin scavenger receptor (sCD163),C-reactive protein (CRP),and procalcitonin (PCT),in rabbits with CAP. Methods:A rabbit model was established after immunosuppression of 40 rabbits,randomly divided into 2 groups of 20 each. The experimental group received 1 ml injection of 5×107 cfu/ml C. albicans solution via percutaneous tracheal puncture,while the control group received normal saline. Rabbit blood samples were collected on days 2,3,4,5,6 and 9 post-inoculation and examined for levels of sTREM-1,sCD163,CRP,PCT,interleukin-6 (IL-6),IL-8,IL-10 and tumor necrosis factor-α (TNF-α). Other tests included routine blood examination,arterial blood gas test,chest thin-layer computed tomography on days 3 and 9 post-inoculation,lung tissue biopsy, and blood culture to confirm C. albicans infection. Results:The levels of sTREM-1,SCD163,PCT,and TNF-αwere higher in the exper-imental group as compared to control. Additionally,sTREM-1 and CRP indices showed an upward trend during 9 days of observation period in the experimental group,while others showed a short-term increase after inoculation and then declined gradually. Areas under the receiver operating characteristic curve for CAP diagnosis were calculated as 0. 882,0. 814,0. 685 and 0. 55 for sTREM-1,SCD163, PCT and CRP,respectively. Conclusion: The diagnostic value of biomarkers,sTREM-1 and SCD163,is superior to that of CRP and PCT in the diagnosis of CAP.