Supplementary Material for: Clinical and Immunological Features of Bronchial Asthma Comorbid Chronic Urticaria: A Retrospective Study

Introduction: Asthma and chronic urticaria (CU) are two high prevalent diseases and often coexist. The underlying relationship and potential immunological mechanism between the two diseases are still unclear. To investigate the clinical and immunological feature of asthma comorbid with CU.
Methods: A retrospective study was conducted. 50 patients with asthma comorbid CU,50 patients of with asthma, 50 patients of with CU alone. Age and sex of the patients enrolled were matched. Data of demographic characteristics, clinical manifestations including disease severity (frequency of symptoms, age of onset, disease duration, symptom score, complication with allergic rhinitis) as well as serum immunological index including total IgE(tIgE), allergen specific IgE (sIgE) and food specific IgG4 (FS-IgG4), were collected and analyzed.
Results: No significant differences in the frequency of symptoms, age of onset and disease duration were found among the three groups. The score of asthma control test (ACT) in patients with asthma comorbid CU was significantly lower than that of asthma (p=0.005), however, compared with patients with CU, the 7-day urticaria activity score(UAS7) of patients with asthma comorbid CU didn’t show obvious differences. Immunological index showed that the positive rate of tIgE, house dust mite (HDM)-sIgE, and FS-IgG4 were different among the three groups (p<0.05). Patients with asthma comorbid CU had the highest rate of positive tIgE, moderate and severe positive sIgE to HDM. Egg specific IgG4 (egg-sIgG4) had the highest positive rate in all groups.Patients of asthma comorbid CU obtained the highest rate of severe positive of egg-sIgG4.
Conclusion: Our results demonstrated that patients with asthma comorbid CU has lower control level of asthma symptoms, higher tIgE and HDM-sIgE level, and highest rate of severe positive egg-sIgG4. These results indicate that comorbidity of CU in asthma obviously increases the severity of allergens.