Diagnostic and clinical associations of serum Isthmin-1 in acute ischemic stroke

This study aimed to evaluate the diagnostic value of serum Isthmin-1 levels and their associations with radiological severity, vascular territory involvement, and clinical outcomes in patients with acute ischemic stroke. This prospective, single-center study was conducted between January 1 and June 30, 2024. Serum Isthmin-1 levels were measured at admission. Clinical characteristics, radiological findings, and stroke-related scores were recorded. Radiological severity was assessed using the Alberta Stroke Program Early CT Score (ASPECTS), and functional outcomes were evaluated at 90 days using the modified Rankin Scale (mRS). The median age of stroke patients was 71 years (IQR 63–79), and the median serum Isthmin-1 level was 393.72 ng/mL (IQR 326.34–477.22). Serum Isthmin-1 levels were significantly higher in patients with acute ischemic stroke compared with healthy controls (p < 0.001). Patients with anterior cerebral artery infarction had significantly lower Isthmin-1 levels than those with other vascular territory involvement (p = 0.005). A weak but significant positive correlation was observed between Isthmin-1 levels and ASPECTS scores (r = 0.252, p = 0.007). No significant association was found between Isthmin-1 levels and 90-day functional outcomes or early mortality. Serum Isthmin-1 levels are elevated in acute ischemic stroke and are associated with vascular territory involvement and radiological severity. Although not predictive of functional outcomes or early mortality, Isthmin-1 may reflect hypoxia-related endothelial and inflammatory processes and could serve as an adjunctive biomarker in the acute evaluation of ischemic stroke.