Lactate dehydrogenase and caspase activity in nasopharyngeal secretions are predictors of bronchiolitis severity

Mehta, Reena; Scheffler, Margaret; Tapia, Lorena; Aideyan, Letisha; Patel, Kirtida D; Jewell, Alan M; Avadhanula, Vasanthi; Mei, Minghua; Garofalo, Roberto P; Piedra, Pedro A

Viruses in NPAs were identified by two methods: isolation from culture in four cell lines (rhesus monkey kidney, HEp-2, WI-38, and LLC-MK2), and real-time PCR (rt-PCR). For rt-PCR, specific primers and fluorescent probes were used to identify the following common viruses: RSV (A and B) rhinovirus (RV), parainfluenza viruses (1, 2, and 3), human metapneumovirus (HMPV), adenovirus (AD), influenza viruses (B, H3N2, and novel H1N1), enterovirus, and coronaviruses (229 E, OC43, NL63, and HKU1). 12 Amplification of the gene for RNase-P, a ribonuclease enzyme, served as a positive internal control assessing the quality of samples. NPA samples with a cycle threshold value for RNase-P of less than 30 were considered optimal quality specimens; those between 30 to <35 were considered reasonable quality and those with ≥35 were of poor quality. Only two of the NPA samples were of poor quality for rt-PCR; the remaining were either optimal (n = 84) or reasonable (n = 45) quality specimens.