Quantity increase and functional affinity/avidity decrease of anti-FcεRI and anti-IgE autoantibodies in chronic...

Area of Science:

• Immunology
• Dermatology
• Allergy

Background:

• Autoimmune chronic spontaneous urticaria (aiCSU) is characterized by autoantibodies targeting the high-affinity IgE receptor (FcεRI) and IgE.
• The correlation between autoantibody presence and disease activity in aiCSU is inconsistent, suggesting functional aspects like avidity may be crucial.

Purpose of the Study:

• This study aimed to investigate the changes in quantity and avidity of autoantibodies against IgE and FcεRI over a six-month period in patients with aiCSU.
• To explore the relationship between autoantibody avidity, basophil activation, and disease activity in aiCSU.

Main Methods:

• Serum samples from 49 patients with chronic spontaneous urticaria (CSU) and 30 healthy controls were collected at baseline and after six months.
• Enzyme-linked immunosorbent assay (ELISA) was used to quantify autoantibodies against IgE and FcεRI and assess their avidity.
• Basophil activation was measured using the basophil activation test (CU-BAT).

Main Results:

• Patients with CSU showed a significant increase in the quantity of anti-FcεRI and anti-IgE autoantibodies after six months.
• Concurrently, the avidity of these autoantibodies significantly decreased over the same period.
• No significant changes in basophil activation frequency were observed, and autoantibody avidity did not correlate with basophil activation.

Conclusions:

• Both the quantity and avidity of anti-FcεRI and anti-IgE autoantibodies fluctuate over time in patients with CSU.
• The basophil activation test (CU-BAT) appears more suitable for diagnosing aiCSU than measuring autoantibody avidity.
• The lack of correlation between autoantibody avidity and basophil activation suggests other factors contribute to aiCSU pathogenesis.