Role of Serum IL-33 in Bothrops Snakebite Victims: Linking Inflammation and Endothelial Dysfunction

<i>Bothrops</i> snakebites pose a significant public health challenge in low- and middle-income regions, often resulting in inflammation, coagulopathy, and renal complications even after antivenom therapy. This study investigated the role of interleukin-33 (IL-33) and endothelial biomarkers in patients with <i>Bothrops</i> envenoming to better understand the mechanisms associated with bleeding and kidney dysfunction. In a prospective cohort of 31 patients from Northeast Brazil, serum levels of IL-33, von Willebrand factor A2 (vWF-A2), angiopoietin-1, angiopoietin-2, syndecan-1, and VCAM-1 were measured at admission and at 10 and 20 h after antivenom administration. Fourteen patients (45%) presented with bleeding at baseline. Traditional clinical and laboratory parameters did not differ between the bleeding and non-bleeding groups on admission; however, IL-33 levels were significantly higher in patients with bleeding. Elevated IL-33 on admission correlated positively with vWF-A2 and estimated glomerular filtration rate, and negatively with angiopoietin-1, suggesting links between inflammation, endothelial dysfunction, and early renal involvement. IL-33 showed a good performance in bleeding patients (AUC = 0.739; IC 95% 0.562-0.917). These findings identified the link between IL-33, early hemorrhage, endothelial dysfunction, and renal involvement in acute <i>Bothrops</i> envenoming. After antivenom therapy, IL-33 levels presented dynamic changes in all patients and require further studies.