ALTERED EXPRESSION OF IGG AND COMPLEMENT RECEPTORS INDICATES A SIGNIFICANT ROLE OF PHAGOCYTES IN ATOPIC-DERMATITIS

Background: Strict dietary precautions against allergic sensitization may benefit a group of predisposed children. Objective, To develop new strategies for identifying these children, a better understanding of the processes that initiate sensitization and regulate and perpetuate the inflammatory response is needed, Methods: We measured the expressi on of the receptors for the constant (Fc) region of IgG (Fc gamma RI, Fc gamma RII, and Fc gamma RIII) and that for the complement fragments C3b and C3bi (CRI and CR3) in neutrophils and monocytes from 39 child ren with atopic dermatitis, 17 disease control patients with acute inf ections, and 17 healthy control subjects. The capacity of phagocytes t o produce reactive oxygen species was also determined, To find the bes t way of discriminating the patients with atopic dermatitis from contr ol subjects, a stepwise logistic binary regression model was made, Res ults: The stepwise logistic regression analysis was based on differenc es in individual receptor expression between the study groups, Because acute infections strongly affected receptor expression in both neutro phils and monocytes, to avoid diagnostic bias, children with acute inf ections were excluded from the analysis, The combination of the recept ors CR1 in neutrophils and Fc gamma R1 and Fc gamma RII in monocytes w as the best indicator of atopic dermatitis. A significant correlation between the expression of CRI in neutrophils and in monocytes, as well as reactive oxygen species production of phagocytes, and the severity of the eczema was detected, Conclusions: These results suggest that a distinct receptor profile of phagocytic cells can be characterized in patients with atopic dermatitis, providing a new direction to the sea rch for early identification of children predisposed to allergic sensi tization.