retinoic acid correlates with reduced serum il-10 and tgf-β in allergic rhinitis

Background: retinoic acid (ra) plays a key role in naïve t cell differentiation into foxp3+ treg cell in the respiratory airways. the present study aims to investigate ra and treg-related cytokine serum levels, salivary iga levels, foxp3 and il-4 gene expression, and the relationships between ra serum levels and treg-related cytokines in allergic rhinitis (ar) patients and healthy controls.methods: salivary iga and serum ige, ra, il-10, and tgf-β concentrations were measured by elisa in 37 ar patients and 30 age- and sex-matched healthy controls.results: il-10 and tgf-β concentrations were significantly less in ar patients than in healthy controls (p< 0.01 and p< 0.0001, respectively). salivary iga was significantly greater in patients than in controls (p< 0.05). ra was not significantly different between patients and controls (p> 0.05); however, a significant positive correlation was found between serum ra and both il-10 and tgf-β in ar patients.conclusions: our data suggest that ra may influence ar risk via affecting the tgf-β and il-10 production.