Elevated serum and cerebrospinal fluid levels of Interleukin-4 related to poor outcome of Aneurysmal subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a hemorrhagic cerebrovascular disease that seriously jeopardizes human life and health. Some studies have shown that although Interleukin-4 (IL-4) acts as an anti-inflammatory factor, IL-4 levels are elevated when the disease occurs. This study focuses on exploring the relationship between IL and 4 concentrations in the serum and cerebrospinal fluid (CSF) and poor outcome in patients with aSAH. This study was a prospective observational study and 210 aSAH patients who met the inclusion criteria were divided into two groups according to the mRS score at 3 months after discharge, and 210 healthy people were selected as controls. The IL-4 concentrations were quantitatively determined with enzyme-linked adsorption assay (ELISA). We can draw a conclusion that Serum and CSF IL-4 concentrations are generally elevated in patients with poor outcome(P < 0.05), and the CSF IL-4 concentration decreased gradually over the progress of time (P < 0.05). The IL-4 concentration in the CSF was positively correlated with age, platelet-lymphocyte ratio (PLR), C-reactive protein (CRP), Hunt-Hess grade, mRS score, and World Federation of Neurological Surgeons score (WFNS) (P < 0.0001). Additionally, IL-4 concentrations in the CSF were correlated with complications such as intracranial infection (P = 0.01), cerebral edema (P < 0.01), hydrocephalus (P = 0.02), and complications by DCI (P = 0.02). Elevated serum and CSF concentrations of IL-4 may associated with the outcome of aSAH and may be a candidate early biomarkers for outcome of aSAH.