Anti-immunoglobulin E antibodies may improve remodeling in a mouse model of asthma

Recent studies have confirmed that omalizumab, an anti-immunoglobulin E (IgE) antibody, has a high response rate in patients with severe asthma who satisfy conditions such as the use of high-dose inhaled steroids and poor respiratory function. However, the effect of omalizumab on airway remodeling, a characteristic feature of chronic severe asthma, remains to be confirmed. In this study, we compared the effect of omalizumab with that of steroids in a mouse model of remodeling. BALB/c mice were continuously sensitized to ovalbumin to produce a model of remodeling. After the remodeling model had been prepared, four groups were studied: an IgE neutralizing antibody group (A), a steroid group (B), an IgE neutralizing antibody plus steroid group (C), and an untreated control group (D). Basement membrane thickening, used as a marker of remodeling, was found to be significantly inhibited in the group A, as compared with the other groups. The group B showed a trend toward inhibition of basement membrane thickening, but the effect was weaker than that in the group A. In the group C, basement membrane thickening was significantly suppressed in a synergistic fashion. Airway remodeling, a characteristic of chronic severe asthma, was significantly inhibited by treatment with IgE neutralizing antibodies. Concurrent treatment with steroids was markedly effective. On the basis of these results, omalizumab is expected to be therapeutically effective for severe refractory asthma. The finding that treatment with steroids alone was less effective than combined treatment suggested that IgE neutralizing antibodies might also have a steroid-sparing effect.