Correlation between regulatory T cells and autologous serum skin test among chronic spontaneous urticaria patients

Chronic spontaneous urticaria (CSU) is considered as an autoimmune disorder in around 30-50% of cases and referred to as chronic autoimmune urticaria. T regulatory cells (Tregs) may be involved in the pathogenesis of CSU. However, their exact role has not yet been fully defined in those patients. This study aimed to investigate the possible role of Tregs cells subsets in CSU patients. In a case-control study, conducted at dermatology clinics, Suez- Canal University Hospitals, Ismailia, Egypt; 25 CSU patients and 25 apparently healthy control blood donors with matched age and gender were recruited. CSU patients were subjected to history taking, physical examination, assessment of urticaria activity score (UAS) and autologous serum skin test (ASST). Blood samples were obtained from both groups to estimate the number of Tregs cells by flow cytometric analysis. The mean values of CD4+ Fox P3+ and CD4+ FoxP3+ CD25+ Tregs in the study cases were increased significantly compared to the controls (Mean ± SD, ]73.51±26.63[ vs ]4.68±2.98[; P= 0.001 and ]0.97±0.59[ vs ]0.56±0.36 [; P =0.003), respectively. However, the mean values of CD4+ CD25+ Tregs were decreased significantly in CSU patients compared to the controls (0.27±0.38 vs 3.63±1.44, P= 0.001). Mean levels of CD4+CD25+ and CD4+ CD25+ FoxP3+ Tregs cells decreased in positive ASST group in comparison to the ASST negative group, but this decrease did not reach statistical insignificance. In conclusion, our data indicated that CSU was associated with alterations in circulating Tregs cells subsets supporting the autoimmune theory.