Assessment of circulating FCεRIa in Chronic Spontaneous Urticaria patients and its correlation with clinical and immunological variables.

Chronic spontaneous urticaria (CSU) is a chronic type characterized by episodes of wheals with or without angioedema. Autoantibody against the alpha subunit of Fc epsilon receptor (FcεRIa) was detected in CSU patients' sera. The study aims to evaluate the clinical utility of skin tests in CSU patients. In addition, it assesses the presence of circulating FcεRIa in CSU patients and their correlation with other clinical and immunological variables. The study includes 40 healthy controls and 40 CSU patients who had urticaria symptoms for at least 8 weeks. All subjects underwent the following tests: autologous serum skin test (ASST), autologous plasma skin test (APST), immunoglobulin E (IgE), antinuclear antibodies (ANA), antithyroid antibodies (ATA). An in-house enzyme-linked immunosorbent assay was used for FcεRIa detection. The prevalence of ANA and ATA in CSU was 7.5% and 20% respectively. Total IgE was significantly higher in CSU than in controls (p < 0.0001). The study detected circulating antibody to FcεRIα in 2.5% of controls and 52.5% of CSU patients (p < 0.0001). The prevalence of antibody to FcεRIa was 27.3% and 83.3% of ASST negative and positive patients respectively (p = 0.0004). But the prevalence was 17.6% and 78.3% of APST negative and positive patients respectively (p = 0.0002). In conclusion, Circulating antibody to FcεRIa has a role in the pathogenic mechanisms of CSU.