Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 0 0 2026 02 14 1 11 Abbas Khalili Department of Pediatrics, Shahid Sadoughi Hospital, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Zahra Estakhri Department of Pediatrics, Shahid Sadoughi Hospital, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. Ali Shams Department of Immunology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran. Yeganeh Lalehzari Department of Immunology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran. 2025 08 12 2025 12 01   Chronic Spontaneous Urticaria (CSU) patients’ responses to regular therapeutic options are different. While some of the patients are treated by these methods but many of they do not respond successfully. Despite several studies that have been conducted to find out which immunologic and inflammatory biomarkers of the patients could be used to predict responding patients but our knowledge are not sufficient. The present study aimed to determine the effective biomarkers that may contribute in predicting of the therapeutic response. The present interventional study evaluated 61 moderate to severe CSU patients aged 20 to 50 years who presented to our clinic from January 2024 and January 2025. A peripheral blood sample, serum and plasma were collected for measuring inflammatory and immunological parameters and were analyzed at a reference laboratory. Subsequently, patients were treated with Cetirizine 10 mg every 12 hours and Famotidine 40 mg every night and after one month, urticarial severity was reassessed using the same questionnaire. Severity scores were compared between patients with elevated biomarkers and those with normal levels. Sixty-one patients with chronic spontaneous urticaria were enrolled; 77% were female and 23% were male. Forty-two patients had a good response to treatment, while 20 patients did not have a response. The average UAS7 scores before and after treatment were 27.72 and 12.67, respectively. Among the serum biomarkers evaluated, only the Neutrophil-to-Lymphocyte Ratio (NLR) and serum eosinophil count showed a significant relationship with treatment response.  To conclude, a high Eosinophil count and NLR may serve as predictors of a poor clinical response to antihistamine therapy. However, further clinical trials are needed to confirm these findings.   https://ijaai.tums.ac.ir/index.php/ijaai/article/view/4550 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/4550/2310