Thymic stromal lymphopoietin (TSLP), a pro-inflammatory cytokine produced by the epithelium, stimulates both immune and non-immune cells. It’s been discovered that it’s a master regulator of type 2 immune responses. On TSLP and childhood asthma, there is very little information. Researchers wanted to see if there was any link between TSLP levels and asthma phenotypes or disease activity in the investigation. The study included 207 asthmatic children and 100 healthy children aged 1 to 13. Investigators used an ELISA kit to look at blood TSLP concentrations in asthma patients and controls, and then looked at how these related to asthma phenotypes and pulmonary function. TSLP concentrations were also measured in 23 patients with stable asthma and acute asthma exacerbations. 

TSLP blood concentrations were considerably higher in asthma patients than in healthy controls (P<0.05), however, there was no significant difference in TSLP concentrations between three asthma phenotypes (P>0.05) (allergic asthma, virus-induced asthma, and nonallergic asthma). TSLP concentrations and FEV1pred% had no significant relationship (r=0.01, P>0.05). TSLP concentrations in acute asthma exacerbation were not substantially different from those in the stable phase of illness (P>0.05). When compared to healthy controls, children with asthma had greater blood TSLP concentrations. In children, TSLP did not appear to be a biomarker of illness aggravation. Different asthma phenotypes had identical TSLP concentration profiles in peripheral blood, suggesting that TSLP is not a viable biomarker for phenotyping asthma in children.