Increased seroprevalence of Enterovirus 71 IgE antibodies in asthmatic compared with non-asthmatic children.

Abstract

Asthma is a common pediatric chronic inflammatory airway disease. Respiratory viral infections are frequent infectious triggers for exacerbations of asthma. We sought to determine whether Enterovirus 71 (EV71), a ubiquitous virus that causes systemic inflammatory responses in children but is not a known respiratory pathogen, can also serve as an infectious trigger for asthma. Specific EV71 IgE and IgM antibodies (Abs), total serum IgE, and IL-2 and IL-4 cytokine levels in serum of asthmatic and non-asthmatic children (N=42, ages 5-19; N=35, ages 1-20, respectively) were measured (ELISA). Asthmatic children had higher EV71 IgE Ab levels than non-asthmatic (P<0.001). Non-asthmatic children had significantly higher EV71 IgM Ab levels than asthmatic (P<0.001). Despite low serum IgE levels of non-asthmatic, compared with asthmatic (P<0.001), the non-asthmatic children produced significantly more IL-2 and IL-4 than asthmatic (P<0.001; P<0.001). The ages of the asthmatics, but not the non-asthmatics had a significant effect on the levels of EV 71 IgE Abs (P=0.02; P=0.356). A test of difference between these two slopes was significant. However, the ages of the non-asthmatic, but not the asthmatic children had a significant effect on the levels of EV 71 IgM Abs; a test of difference between these two slopes was significant. Increased specific EV71 IgE Ab responses may indicate that EV71 infection may also be an infectious trigger in asthma. However, the role of specific EV71 IgM Abs, Th2 cytokines, and age in non-asthmatic children should be further studied.