Severity of atopic dermatitis and Ascaris lumbricoides infection: an evaluation of CCR4+ and CXCR3+ helper T cell frequency.

Introduction: Ascaris lumbricoides-infected patients present lower prevalence of severe atopic dermatitis. Methods: Peripheral blood of infected children with atopic dermatitis was assessed by flow cytometry of the frequency of Th1 and Th2 cells through the expression of CXCR3 and CCR4 chemokine receptors, respectively. Results: Helminth-free patients with atopic dermatitis presented a high frequency of CCR4+Th2 cells. Parasitized patients with atopic dermatitis showed a lower frequency of CXCR3+Th1 cells compared to infected individuals only. Conclusions: Ascariasis modifies the blood traffic of Th2 cells in atopic dermatitis patients, while the allergic disease down-regulates the traffic of Th1 cells in parasitized patients.