Expression of TSLP Isoforms in Asthma

Condition(s) studied

Investigational drug(s) / intervention(s)

No Intervention: Observational Cohort: This study is designed as a cross-sectional, observational investigation. No therapeutic or diagnostic interventions beyond routine clinical care will be introduced as part of the study. All procedures performed are limited to standard, minimally invasive sample collection and data acquisition for research purposes. Clinical management of participants will remain unchanged and will be conducted entirely at the discretion of the treating physicians. Participation in the study will not influence treatment decisions or patient care.

Study summary

Asthma is a heterogeneous disease characterized by chronic airway inflammation, leading to variable airflow obstruction, bronchial hyperresponsiveness, excessive mucus secretion, and, consequently, structural airway remodeling. Asthma is defined by the presence of symptoms such as wheezing, dyspnea, chest tightness, and cough, with variable intensity and frequency.

Thymic stromal lymphopoietin (TSLP) is a cytokine produced primarily by epithelial cells in the lungs. Two distinct isoforms of TSLP have been identified: a long form (lfTSLP) and a short form (sfTSLP). The long isoform is induced during inflammatory conditions and promotes a T2-dependent immune response. In contrast, the short isoform is believed to exert homeostatic and anti-inflammatory functions and exhibits antimicrobial properties.

Studies have demonstrated an association between elevated serum and airway TSLP levels and increased disease severity, as well as reduced spirometric parameters. However, the literature contains limited data regarding the expression of TSLP isoforms across different asthma phenotypes and their relationship with the degree of disease control.

The goal of this study is:

1. To assess the expression of TSLP protein and TSLP mRNA, including its isoforms (sfTSLP and lfTSLP), in serum and in airway-derived samples (nasal epithelial cells),
2. To compare these levels among patients with different asthma phenotypes (allergic and non-allergic asthma; eosinophilic, neutrophilic, and paucigranulocytic asthma; early-onset and late-onset asthma; obesity-associated asthma; cough-variant asthma), as well as between patients with asthma and healthy controls.
3. To analyze the correlations between the expression of TSLP isoforms (sfTSLP and lfTSLP) and asthma severity, level of disease control (as measured by the Asthma Control Questionnaire \[ACQ\]), pulmonary function parameters, blood eosinophil count and other clinical parameters.

Eligibility

Primary outcome measure(s)

• TSLP mRNA expression, including the sfTSLP and lfTSLP isoforms in nasal epithelial cells and TSLP protein expression in blood and nasal epithelial cells — This is cross-sectional studies; blood and nasal epithelial cells (nasal swab) will be taken from each study participant at one study point - through study completion, an average of 2 years
  The primary endpoint of the study is the quantitative assessment of TSLP protein expression and TSLP mRNA expression, including the sfTSLP and lfTSLP isoforms, in biological material obtained from serum and nasal epithelial cells. Peripheral venous blood samples will be collected and centrifuged to obtain serum, which will be aliquoted and stored at -80°C until analysis. Nasal epithelial cells will be collected using sterile cytology brushes. All biological samples will be processed promptly and stored under appropriate conditions prior to laboratory analysis. TSLP protein concentrations will be measured using commercially available enzyme-linked immunosorbent assay (ELISA) kits in accordance with the manufacturer's instructions. Measurements will be performed in duplicate, and optical density will be determined using a microplate reader. Concent

Trial sites (1)

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