Study Overview: SARS-CoV-2 RNA Detection
DEVICE-CAPTURED cough droplets detected SARS-CoV-2 RNA and inflammatory biomarkers from the lower respiratory tract in patients. Adult patients with recent nasopharyngeal PCR positivity for COVID-19 provided multiple sets of directed coughs into a collection device. The captured material was eluted and analyzed for SARS-CoV-2 RNA by PCR using three primer sets and for a panel of cytokines including IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, and TNF-α, along with amylase. Among specimens with adequate material and clinical data, 68% were PCR positive for SARS-CoV-2 RNA, 23% were negative, and 9% were indeterminate. These findings indicate that lower airway droplets can be sampled noninvasively and frequently contain detectable viral RNA.
Cytokine Signals and Symptom Correlates
Compared with control cough specimens, case specimens showed significantly higher IL-13 and TNF-α levels and lower IL-2 levels. In multivariable analyses that combined biomarker levels with reported symptoms, higher IL-10 associated with reduced fatigue, while higher IL-12p70, IL-4, and TNF-α associated with fever. These associations suggest that cough-collected lung droplets can reflect biologically meaningful inflammatory activity and may help explain symptom variability in acute COVID-19.
Clinical Implications for Respiratory Practice
The approach targets lower respiratory tract material rather than the upper airway sampled by nasopharyngeal swabs. For clinicians, this method offers a noninvasive option to detect SARS-CoV-2 RNA and characterize lung-specific inflammation using cytokine profiles. Such information could complement routine diagnostic testing, inform monitoring of disease activity, and potentially extend to other lower respiratory tract infections where bronchoalveolar sampling is impractical. While additional validation is warranted, these results support integrating device-captured cough droplets into research and, where appropriate, clinical workflows that seek lung-level signals without invasive procedures.
Reference: Steinberg RS et al. Detection of SARS-CoV-2 RNA and Biomarkers in Device-Captured Droplets From the Lung. Chest Infections. 2025;3(3):100137.
