Factors Predicting the Response to Cyclosporin Treatment in Patients With Chronic Spontaneous Urticaria: A Systematic Review

PURPOSE: This study aimed to systemically review literature relating to factors that could potentially predict a favorable response to cyclosporine A (CsA) treatment for chronic spontaneous urticaria (CSU). METHODS: A systematic literature review was done according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis recommendations. RESULTS: A total of 13 studies (404 patients with CSU and 200 healthy patients) were included. There were only 1 randomized controlled trial (RCT) and 12 non-RCTs. Our systematic review showed that positive autologous serum skin test results, positive baseline basophil histamine release assays, positive baseline basophil activation test responses, elevated baseline plasma D-dimer levels, elevated baseline serum interleukin (IL)-2, IL-5, and tumor necrosis factor-alpha (TNF-α) levels, and low baseline serum IgE levels might assist in predicting favorable CsA responses in CSU patients. Decreased plasma D-dimer levels; and decreased serum IL-2, IL-5, and TNF-α levels were reported to be correlated with clinical improvement after CsA treatment. CONCLUSIONS: Since most positive results were from non-RCT articles and some data were still inconsistent, this systematic review identified no reliable practical biomarker for predicting CsA treatment response in patients with CSU. There were no positive predictors with good consistency and mechanical plausibility.