RESUMO
BACKGROUND: IL-4 receptor (IL-4R) overexpression on immunoregulatory/effector cells was found in allergic patients. However, its role in allergy development remains unclear. The aim of this study was to assess the correlation between IL-4R expression and allergy development within the first year of life. MATERIAL/METHODS: IL-4R expression on monocytes and Th lymphocytes of 43 newborns was analyzed using flow cytometry. Plasma levels of IL-4, -12 and IFN-gamma were also measured using ELISA. The same parameters were assessed one year later. Furthermore, clinical evaluation was performed every three months for one year. RESULTS: Mean IL-4R expression on monocytes and Th lymphocytes did not differ at birth. After one year it increased on Th-lymphocytes and decreased on monocytes. However, among 10 children with severe atopy during the observation period, 8 displayed IL-4R above the mean value for the group on both monocytes and Th cells at birth as well as one year later. No correlation was found between IL-4 or IFN-gamma and IL-4R expression at birth. After one year, significant IL-4 increases and IFN-gamma decreases were observed which correlated with IL-4R expression. IL-4R expression on the newborns' monocytes correlated negatively with IL-12 plasma level; however, it was statistically significant only in the children developing allergy. Moreover, only in these patients was a significant decrease in IL-12 found after one year. CONCLUSIONS: IL-4R-dependent over-signaling in newborns' monocytes and Th lymphocytes could contribute to Th1/Th2 imbalance. IL-4R overexpression on newborns' monocytes and lymphocytes could be an early risk marker of allergy development.
