Intracranial infection is a commonly observed complication following neurosurgery and is primarily caused by the invasion of pathogens into the central nervous system. These pathogens include bacteria, fungi, viruses, and Mycobacterium tuberculosis, with bacterial infection being the most prevalent. The occurrence of intracranial infections after neurosurgery is an important cause of reduced surgical outcomes, prolonged hospital stays, and increased morbidity and mortality [1], [2]. Due to poor clinical outcomes [3], [4], [5], empirical antimicrobial treatment is usually started in the absence of bacteriological results. Traditional laboratory indexes, including total protein (TP), neutrophils, and white blood cell count (WBC) in cerebrospinal fluid (CSF), suffer from a lack of specificity, and Gram staining sensitivity is very low. The current gold standard for the diagnosis of intracranial infections is CSF pathogenic testing; however, it is time-consuming, has a low positive culture rate [6], and cannot rapidly diagnose the occurrence of intracranial infections, while early and rapid diagnosis and treatment are important to increase patient survival and improve patient prognosis. Therefore, finding more objective, scientific, and simple markers has become an important issue facing diagnosis [7].

Heparin-binding protein (HBP) is a granular protein that is rapidly released upon stimulation from mature neutrophils. When bacterial infection occurs in the body, substances such as toxins released by bacteria stimulate neutrophils to release HBP, resulting in increased HBP levels in the blood. Studies have shown that HBP can be used as an early marker of bacterial infections and can also be rapidly detected in plasma when local or mild bacterial infections occur, which has attracted increasing attention in the early diagnosis of infectious diseases [8]. Interleukin-6 (IL-6) is a proinflammatory cytokine mainly produced by mononuclear macrophages, Th2 cells, endothelial cells, and among others, which has important clinical value for the early diagnosis of infectious diseases. Interleukin-10 (IL-10) is a representative anti-inflammatory cytokine that is sensitive to inflammatory reactions. Procalcitonin (PCT) is a polypeptide hormone synthesized and secreted by thyroid parafollicular cells. When the body is infected with bacteria, fungi, or parasites, the levels of serum PCT increase [9]. The combined detection of these four indicators may be an effective method for diagnosing post-neurosurgical intracranial infection. Therefore, in this paper, we retrospectively analysed the CSF HBP, IL-6, IL-10, and PCT levels in patients admitted to our hospital with post-neurosurgical intracranial infection to provide reference values for the early identification, monitoring, and prognosis of post-neurosurgical intracranial infection.