Proteomics of nasal mucus in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is among the three most common chronic diseases in North America. The area of proteomics research is providing tremendous insight into the mechanisms of a variety of physiological processes and disease states. The purpose of this study was to evaluate qualitative and quantitative differences in protein content of nasal mucus in patients with chronic hypertrophic sinusitis with nasal polyposis when compared with control subjects.

A case-control study was performed in a tertiary academic center. Nasal mucus was collected from four patients with CRS and nasal polyposis as well as four control subjects. The protein content was digested using proteolytic enzymes, labeled with iTRAQ reagents, and subjected to mass spectrometry (MS) analysis.

A total of 35 proteins were identified, many of which were related to innate and acquired immunity. Lysozyme C precursor was found to be down-regulated by a ratio (R) of 0.65 (p = 0.016) in CRS patients, as was Clara cell phospholipid-binding protein (R = 0.23; p = 0.0018), and antileukoproteinase 1 (R = 0.47; p < 0.0001). A detailed analysis and characterization of the protein isolates is outlined.

The field of proteomics has great potential in leading to a better understanding of the mechanism of the disease process in CRS. Differences in the expression of proteins related to regulation of immune cells and mediators merit additional investigation.