The Relationship Between Allergic Reactions and Serum Erythropoietin Levels: A New Biomarker Candidate in Allergic Reactions

Objective: This study aimed to compare serum erythropoietin (EPO) levels in patients admitted to the emergency department with allergic reactions who were clinically diagnosed with urticaria, angioedema, or anaphylaxis, and to evaluate the diagnostic value of EPO as a potential biomarker. Methods: The study was conducted prospectively in the Emergency Department of Atatürk University between 2013 and 2016. A total of 156 patients diagnosed with urticaria, angioedema, or anaphylaxis were included. Serum EPO levels from blood samples taken at admission were analyzed using the enzyme-linked immunosorbent assay method. Relationships between vital signs, clinical symptoms, and EPO levels were statistically evaluated. Results: No significant difference in serum EPO levels was observed among the urticaria (41.7%), angioedema (35.9%), and anaphylaxis (24.4%) groups (P = 0.799). However, patients with uvular edema had significantly higher EPO levels (6.5 ± 1.6 vs. 6.0 ± 1.7 mIU/mL; P = 0.027). In the anaphylaxis group, oxygen saturation and blood pressure were significantly lower, whereas pulse rate and respiratory rate were significantly higher. Conclusion: EPO levels alone are not sufficient for differential diagnosis of acute allergic reactions. However, when assessed alongside specific symptoms, such as uvular edema, EPO may reflect the severity of the inflammatory response and serve as a potential biomarker. Multicenter studies including tissue-level analyses are needed to better understand the role of EPO in allergic inflammation.