Tests to diagnose invasive aspergillosis

The fungal infection invasive aspergillosis (IA) can be life threatening, especially in patients whose immune systems are weakened by chemotherapy or immunosuppressive drugs. IA is difficult to diagnose and it is caused by the fungus Aspergillus fumigatus.

A recent study compared three diagnostic tests and found that the combination of nucleic acid sequence-based amplification (NASBA) and real-time quantitative PCR (qPCR) detects aspergillosis with a high degree of accuracy.

For this, researchers evaluated the diagnostic performance of two nucleic acid amplification assays (qPCR and NASBA) and one antigen detection method (galactomannan enzyme-linked immunosorbent assay [GM-ELISA]) using blood samples collected from 80 patients at high risk of IA.

Data analysis showed that the combination of NASBA and qPCR led to 100% specificity and 100% positive predictive value (the probability that subjects truly have the infection).

The reference is:

Lipeng Wang, Yunyan He, Yun Xia, Xiaoyan Su, Huijuan Wang, Shumei Liang. Retrospective Comparison of Nucleic Acid Sequence-Based Amplification, Real-Time PCR, and Galactomannan Test for Diagnosis of Invasive Aspergillosis. The Journal of Molecular Diagnostics, 2014; DOI: 10.1016/j.jmoldx.2014.05.001

Posted by Tim Sandle