Author(s)

Jiancong Lin, Wenming Xu, Ming Li, Yanli Xin, Yuanyuan Niu, Changran Zhang, Zelong Guo

Department of Internal Medicine, Huang Pu Hospital of the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
Department of Internal Medicine, Huang Pu Hospital of the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China..

Background: Consensus on the most reliable assays to detect invasive aspergillosis from minimally or noninvasive samples has not been reached. In this study, we compared the efficacy of an enzyme-linked immunosorbent assay (ELISA) for galactomannan (GM) detection and quantitative real-time PCR assay (qRT-PCR) for the diagnosis of invasive pulmonary aspergillosis in a rat model. Methods: Neutropenic, male Sprague-Dawley rats (specific pathogen free; 8 weeks old; weight, 200 ± 20 g) were immunosuppressed with cyclophosphamide and infected with Aspergillus fumigatus intratracheally. Tissue and whole blood samples were harvested on days 1, 3, 5, and 7 post-infection and examined with GM ELISA and qRT-PCR. Results: On day 7, A. fumigatus DNA was amplified from 14 of 48 whole blood samples from immunosuppressed infected rats: day 1 (0/12), day 3 (0/12), day 5 (6/12), day 7 (8/12) post infection. The sensitivity and specificity of the qRT-PCR assay were 29.2% and 100%, respectively. Receiver operating characteristic curve (ROC) analysis indicated a Ct cut-off value of 15.35, and the area under the curve (AUC) was 0.627. The GM assay detected antigen in sera obtained on day 1 (5/12), day 3 (9/12), day 5 (12/12), and day 7 (12/12) post-infection, and thus had a sensitivity of 79.2% and a specificity of 100%. The ROC of the GM assay indicated that the optimal cut-off value was 1.40 (specificity, 100%; AUC, 0.919). Conclusions: The GM assay was more sensitive than qRT-PCR assay in diagnosing invasive pulmonary aspergillosis in rats.

Invasive Pulmonary Aspergillosis; Aspergillus; Galactomannan Antigen; Quantitative Real-Time PCR; Receiver Operating Characteristic Curve; Rat Model

J. Lin, W. Xu, M. Li, Y. Xin, Y. Niu, C. Zhang and Z. Guo, "The Effect Analysis of Different Experimental Methods for the Diagnosis of Invasive Pulmonary Aspergillosis in a Rat Model," International Journal of Clinical Medicine, Vol. 4 No. 10, 2013, pp. 472-478. doi: 10.4236/ijcm.2013.410083.