TSLP and TSLPR Expression Levels in Peripheral Blood as Potential Biomarkers in Patients with Chronic Rhinosinusitis with Nasal Polyps.

TSLP is an alarmin released upon activation of epithelia in response to various external stimuli and is involved in type 2 cytokine-mediated pathological disorders. The formation of a high-affinity heterodimeric receptor complex, comprising the thymic stromal lymphopoietin receptor (TSLPR) chain and IL-7Rα, is required for signaling. This study investigated whether TSLP and TSLPR expression in peripheral blood or nasal polyps could provide a valuable approach for the molecular phenotyping of patients with chronic rhinosinusitis with nasal polyps (CRSwNP). The study population comprised 156 unrelated Caucasian individuals, including 45 controls and 111 patients with CRSwNP. Quantitative PCR analysis of TSLP and TSLPR was performed on the population study's peripheral blood and nasal biopsy. The data were analyzed for potential associations, and possible use as a biomarker was studied. Significant differences were observed in TSLP and TSLPR blood expression between the control group and patients. Similarly, the expression of TSLP observed in biopsy samples was statistically significantly elevated in the polyp tissue of the patient compared with healthy controls. The combination of TSLP and TSLPR expression testing with peripheral blood eosinophils represents a more specific biomarker in patients exhibiting low eosinophil values. Further investigation of TSLP/TSLPR mRNA levels in peripheral blood may yield new minimally invasive biomarkers.