To investigate the predictive value of early expression levels of plasma pyruvate kinase M2 (PKM2) for the severity and prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH).

A total of 95 aSAH patients admitted to Neurosurgery Department of China Resources Wuhan Iron and Steel General Hospital from September 2021 to May 2023 were prospectively enrolled as aSAH group, while 100 healthy individuals who underwent physical examination in the hospital during the same period were selected as the control group. Enzyme-linked immunosorbent assay (ELISA) was used to measure the PKM2 levels of patients in the aSAH group 12 h after admission, as well as the PKM2 levels of the control group on the day of admission physical examination, and general data and early plasma PKM2 levels were collected and compared between the two groups. The aSAH group was further stratified by disease severity (mild: Hunt-Hess grade Ⅰ-Ⅱ, moderate: Hunt-Hess grade Ⅲ, severe: Hunt-Hess grade Ⅳ) and surgical approach (craniotomy clipping subgroup and endovascular embolization subgroup), with their prognosis evaluated using the modified Rankin scale (mRs) at 90 d after discharge, patients with an mRs score>2 were assigned to the poor prognosis group, and those with an mRs score≤2 to the good prognosis group, and clinical data differences among these subgroups were compared. Additionally, the aSAH patients were divided into the high-expression group (plasma PKM2 level≥190.0 ng/L) and the low-expression group (plasma PKM2 level<190.0 ng/L), and the clinical data of aSAH patients with different plasma PKM2 levels were compared. Receiver operating characteristic (ROC) curve was plotted to assess the predictive value of early plasma PKM2 levels for poor prognosis in aSAH patients.

Early plasma PKM2 levels were significantly higher in the aSAH group than in the control group (P<0.05). Furthermore, significant differences in maximum diameter of aneurysms, plasma PKM2 expression levels, modified Fisher grading, and GCS scores among patients with mild, moderate, and severe aSAH (P<0.05), and the more severe the condition, the higher the plasma PKM2 expression level. In contrast, no statistically significant differences in plasma PKM2 levels or clinical outcomes were found between the different surgical groups (P>0.05). The differences in hypertension history, Hunt-Hess grading, GCS score, modified Fisher grading, and plasma PKM2 expression levels between patients with favorable and unfavorable outcome were statistically significant (P<0.05). The differences in Hunt-Hess grading, GCS score, and modified Fisher grading between patients with high PKM2 expression and those with low PKM2 expression were statistically significant (P<0.05). ROC curve analysis demonstrated that early plasma PKM2 levels effectively predicted unfavorable outcomes in aSAH patients, with an area under the curve of 0.846 (95%CI: 0.764-0.928), a sensitivity of 80.60%, and a specificity of 81.40% at the optimal cut-off value of 190.0 ng/L.

The early expression level of plasma PKM2 is related to the severity and prognosis of aSAH patients, providing certain diagnostic value for predicting disease progression and potentially serving as a new marker for predicting the outcome of aSAH patients.