Satoshi Izaki1, Shota Toyoshima2, Takahiro Endo1, Kazuko Kanegae2, Satoshi Nunomura3, Jun-Ichi Kashiwakura4, Tomomi Sasaki-Sakamoto2, Ryosuke Nakamura5, Haruyo Akiyama6, Chisei Ra7, Koremasa Hayama1, Tadashi Terui8, Yoshimichi Okayama9. 1. Allergy and Immunology Research Project Team, Nihon University School of Medicine, Tokyo, Japan; Department of Dermatology, Nihon University School of Medicine, Tokyo, Japan. 2. Allergy and Immunology Research Project Team, Nihon University School of Medicine, Tokyo, Japan; Center for Institutional Research and Medical Education, Nihon University School of Medicine, Tokyo, Japan. 3. Division of Medical Biochemistry, Department of Biomolecular Sciences, Saga Medical School, Saga, Japan. 4. Department of Immunology, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan. 5. Division of Medicinal Safety Science, National Institute of Health Sciences, Kawasaki, Japan. 6. Division of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Tokyo, Japan. 7. Department of Microbiology, Nihon University School of Medicine, Tokyo, Japan; Department of Clinical Laboratory, Asahi General Hospital, Chiba, Japan. 8. Department of Dermatology, Nihon University School of Medicine, Tokyo, Japan. 9. Allergy and Immunology Research Project Team, Nihon University School of Medicine, Tokyo, Japan; Center for Institutional Research and Medical Education, Nihon University School of Medicine, Tokyo, Japan. Electronic address: okayama.yoshimichi@nihon-u.ac.jp.
Abstract
BACKGROUND: The reported prevalences of IgG autoantibodies (AAbs) to FcεRIα and IgE in sera from patients with chronic spontaneous urticaria (CSU) have varied, and these AAbs are also often observed in healthy control subjects. Regarding the histamine release activity of purified IgG from patients with CSU, the number of examined patients has been small. Thus, we sought to determine the prevalence and FcεRI crosslinking ability of these AAbs in a large number of patients with CSU and non-atopic control (NC) subjects. METHODS: We compared the concentrations of anti-IgE and anti-FcεRIα AAbs and the abilities of these AAbs to cause FcεRI aggregation in patients with CSU (n = 134) and NC subjects (n = 55) using ELISA and an in vitro elicitation test, respectively. RESULTS: The concentration of anti-IgE AAbs was significantly different between the NC subjects and the CSU patients (P < 0.0001, cutoff value: 0.558 μg/mL), whereas the concentration of anti-FcεRIα AAbs was not. A significant difference in the duration of illness was noted between patients with lower and those with higher concentrations of anti-IgE AAbs relative to the cutoff value. The abilities of anti-IgE AAbs, but not anti-FcεRIα AAbs, to induce FcεRI crosslinking were significantly higher in CSU patients than in NC subjects (P = 0.0106). CONCLUSIONS: In the Japanese population of CSU patients studied, the ability of the anti-IgE AAbs to induce FcεRI crosslinking differed significantly between NC subjects and CSU patients, suggesting the involvement of anti-IgE AAbs in the pathogenesis of CSU in the Japanese population.
BACKGROUND: The reported prevalences of IgG autoantibodies (AAbs) to FcεRIα and IgE in sera from patients with chronic spontaneous urticaria (CSU) have varied, and these AAbs are also often observed in healthy control subjects. Regarding the histamine release activity of purified IgG from patients with CSU, the number of examined patients has been small. Thus, we sought to determine the prevalence and FcεRI crosslinking ability of these AAbs in a large number of patients with CSU and non-atopic control (NC) subjects. METHODS: We compared the concentrations of anti-IgE and anti-FcεRIα AAbs and the abilities of these AAbs to cause FcεRI aggregation in patients with CSU (n = 134) and NC subjects (n = 55) using ELISA and an in vitro elicitation test, respectively. RESULTS: The concentration of anti-IgE AAbs was significantly different between the NC subjects and the CSU patients (P < 0.0001, cutoff value: 0.558 μg/mL), whereas the concentration of anti-FcεRIα AAbs was not. A significant difference in the duration of illness was noted between patients with lower and those with higher concentrations of anti-IgE AAbs relative to the cutoff value. The abilities of anti-IgE AAbs, but not anti-FcεRIα AAbs, to induce FcεRI crosslinking were significantly higher in CSU patients than in NC subjects (P = 0.0106). CONCLUSIONS: In the Japanese population of CSU patients studied, the ability of the anti-IgE AAbs to induce FcεRI crosslinking differed significantly between NC subjects and CSU patients, suggesting the involvement of anti-IgE AAbs in the pathogenesis of CSU in the Japanese population.