Allergy in IgG4-related disease

RATIONALE: IgG4-related disease (IgG4-RD) is a systemic disorder, which is characterized by elevated serum IgG4 concentrations and infiltration of abundant IgG4 positive plasma cells in the multiple lesions. It has been reported the lesions of IgG4-RD present Th2 dominant immunity. And the patient often shows allergic history and/or symptoms. The aim of this study is to investigate allergic involvement in patients with IgG4-RD.

METHODS: A retrospective study on patients with IgG4-RD in Toyama University Hospital was performed. The diagnosis of IgG4-RD was made based on the comprehensive diagnostic criteria. We analyzed allergic history of rhinitis, and bronchial asthma, serum IgG4, IgE and Specific IgEs to 16 aeroallergens (CAP RAST).

RESULTS: Sixty-seven patients with ‘definite’ IgG4-RD were analyzed. Twenty patients (29.9%) had allergic rhinitis, 18 patients (26.9%) bronchial asthma, and 9 patients (13.4%) skin allergy in their past or present history. Serum IgG4 (> 135mg/dl) and IgE (> 170 U/ml) at the diagnosis were elevated in 97.0% and 89.4%, respectively, and the median serum levels of IgG4 and IgE were 485 mg/dl and 500 U/ml, respectively. There was no significant correlation between IgG4 and IgE. Specific IgEs were available in 48 patients, and 79% of them showed positive one or more specific IgEs to 16 aeroallergens.

CONCLUSIONS: Our study suggests that the patients with IgG4-RD show various allergic involvements, presenting rhinitis and/or bronchial asthma. However, we observed no IgEs directed against any specific aeroallergen in these patients. Further analysis of allergic manifestations might be helpful in elucidating the pathogenesis of IgG4-RD.