A special issue has been released focusing on biomarkers and diagnostics in respiratory diseases, emphasizing their potential for early and accurate diagnosis that can lead to improved patient outcomes.

Researchers at Johns Hopkins Hospital have developed a breath assay sensor capable of detecting human neutrophil elastase (HNE), a protease linked to lower respiratory tract infections (LRTIs), using samples from ICU patients and healthy volunteers.

This novel assay demonstrated impressive diagnostic capabilities, achieving 100% sensitivity and 86.7% specificity, with a detection threshold for HNE set at 0.2 picomolar.

Results indicated a significant increase in HNE activity among LRTI patients, with an area under the curve (AUC) value of 0.987, showcasing the assay's high diagnostic accuracy.

The study suggests that measuring protease activity, such as HNE, can provide insights into the stage and severity of LRTIs, thereby enhancing diagnosis and patient management.

Utilizing MALDI-TOF mass spectrometry, the assay is non-toxic and user-friendly, with the potential to evolve into a point-of-care diagnostic tool for LRTIs.

Traditional diagnostics for LRTIs often depend on lengthy microbiological methods and sensitive molecular techniques, which can struggle to distinguish between infection and colonization.

LRTIs, including bronchitis and pneumonia, are a significant global health concern, being the fifth leading cause of death worldwide, with over 2.74 million deaths reported in 2015.

In related research, Carpagnano et al. explored the role of impulse oscillometry in severe asthma patients, highlighting the advantages of single-inhaler triple therapy.

Future studies across various clinical settings are essential to validate the effectiveness of the breath assay, with potential for developing multiplexed protease panels to further enhance diagnostic accuracy.

The study also investigated the feasibility of using breath sampling to detect host response factors, particularly proteases that are often dysregulated during LRTIs.

Additionally, Hansen et al. introduced the biomarker CPa9-HNE, which effectively differentiates between chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis, and healthy individuals, outperforming traditional calprotectin measurements.