Background: Interleukin-37 is a novel cytokine emerging as a natural suppressor of inflammatory responses. Inflammation and the immune response play important roles in acute ischemic stroke. This study aimed at evaluating the plasma levels and the association with 3-month outcomes of interleukin-37 in acute ischemic stroke patients.
Patients and Methods: In total, 152 consecutive patients with acute ischemic stroke and 45 healthy controls were included. Plasma interleukin-37 levels were determined in the first morning after admission using an enzyme-linked immunesorbent assay. The primary outcome was the 3-month functional outcome (modified Rankin Scale score > 2). Logistic regression was used to evaluate the risk and 3-month outcome of stroke according to plasma interleukin-37 level.
Results: Plasma interleukin-37 levels were significantly higher in the patients with acute ischaemic stroke than in the healthy controls (182.26 versus 97.89 pg/mL, p < 0.001). Patients with large-artery atherosclerosis had significantly higher IL-37 levels than those with small-artery occlusion (202.12± 35.82 versus 175.67± 33.71pg/mL, p < 0.001). Plasma interleukin-37 levels were positively correlated with National Institutes of Health Stroke Scale scores (r=0.521, p < 0.0001) and lesion volume (r=0.442, p < 0.0001). Ninety-four and 58 patients had favourable and unfavourable 3-month outcomes, respectively. Elevated plasma interleukin-37 levels were independently associated with unfavourable 3-month outcomes (adjusted odds ratio=1.033, p=0.001, 95% confidence interval: 1.015– 1.056).
Conclusion: Admission plasma interleukin-37 levels were significantly increased after acute ischemic stroke. Elevated interleukin-37 levels were independently associated with unfavourable 3-month prognoses in acute ischemic stroke patients. Further studies with other populations are needed.
Keywords: interleukin-37, acute ischemic stroke, functional outcome, prognosis