Comparing Luminex NxTAG-Respiratory Pathogen Panel and RespiFinder-22 for multiplex detection of respiratory pathogens

Abstract

Respiratory tract infection (RTI) involves a variety of viruses and bacteria, which can be conveniently detected by multiplex nucleic acid amplification testing (NAT). To compare the novel Luminex-based NxTAG-Respiratory Pathogen Panel (NxTAG-RPP) with the routine multiplex-ligation-NAT based RespiFinder-22® (RF-22), 282 respiratory specimens including nasopharyngeal swabs (71%), broncho-alveolar lavage (27%), throat swabs, tracheal secretions, and sputum (2%) from 116 children and 155 adults were extracted using a Corbett CAS1200 (Qiagen), and analyzed in parallel by the routine RF-22 and NxTAG-RPP. Concordant results were obtained in 263 (93.3%) cases consisting of concordant positives in 167 (59.2%) and concordant negatives in 96 (34%). Results were discordant in 19 (6.7%) consisting of 15 positive:negative, and 4 negative:positive results by NxTAG-RPP versus RF-22, respectively. Co-infections were observed in 10.3% with NxTAG-RPP and in 5.9% with RF-22. Most additional viral pathogens identified by the NxTAG-RPP involved dual infections with rhinovirus and RSV. Discordant samples were mainly due to low genome signals of Ct less than 36, when retested by QNAT suggesting a higher sensitivity of the NxTAG-RPP, also when detecting multiple infections. Hands-on time after extraction for 24 and 96 samples was 0.25 and <0.5 hr for the NxTAG-RPP, and 2 and 4 hr for the RF-22, respectively. The median turn-around time was 6 hr (range 5-7 hr) for NxTAG-RPP and 12 hr (range 8-16 hr) for RF-22. The NxTAG-RPP showed comparable detection rates for most respiratory pathogens, while hands-on and turn-around time were considerably shorter. The clinical significance of detecting multiple viruses needs further clinical evaluation. J. Med. Virol. 88:1319-1324, 2016. © 2016 Wiley Periodicals, Inc.

Keywords: hands-on-time; multiplex PCR; nucleic acid testing; respiratory tract infection; respiratory tract infectious disease; turn-around-time.

Figure 1

A: Specimen distribution. Distribution of 282 specimens from 116 pediatric and 155 adult patients. Blue, nasopharyngeal swabs (NPS); red, broncho‐alveolar lavage (BAL); yellow, throat swabs (ThSw); green, tracheal secretions (TS); dark blue, sputum. B: Detection rate by NxTAG‐RPP and by RespiFinder‐22. Number of pathogens detected in both cohorts of retrospective and prospective samples (n = 282). ADV, adenovirus; HBoV, human bocavirus; HCoV, human coronavirus; HMPV, human metapneumovirus; HRhV, human rhinovirus; INF, influenza; Lpneu, Legionella pneumophila; Mpneu, Mycoplasma pneumoniae; PIV, parainfluenza virus; RSV, respiratory syncytial virus. Red bars: detection by NxTAG‐RPP; blue bars: detection by RF‐22.