Changes of NLRP3 in serum and cerebrospinal fluid of patients after moderate to severe traumatic brain injury and their predictive values for prognosis

Background: Traumatic brain injury (TBI) remains a major concern for global health. Recent studies have suggested the role of NOD-like receptor pyrin domain-containing protein 3 (NLRP3), an inflammatory marker, in the cerebrospinal fluid (CSF) and serum as potential indicators of TBI prognosis. The objective of the study was to characterize NLRP3 as a clinically applicable tool for predicting the outcomes of TBI patients. Methods: A total of 270 patients with moderate to severe TBI were included in this retrospective analysis. Serum and CSF samples were collected at 1-, 3-, 7-, and 21-day post-injury to measure NLRP3 levels. The prognosis of patients was evaluated after 3 months using the Glasgow Outcome Scale (GOS). Patients were categorized into good prognosis (GOS score >3) and poor prognosis (GOS score <= 3) groups. The relationship between NLRP3 levels and prognosis was analyzed. Results: Patients with poor prognosis had significantly elevated NLRP3 levels in their serum on days 1 and 3 post-injury compared with those with a good prognosis. The difference was more pronounced during these early days compared with days 7 and 21. However, NLRP3 levels in CSF consistently showed a large difference between the two groups throughout the observation period. Receiver operating characteristic analysis revealed that the level of NLRP3 in the CSF on day 3 post-injury had the highest predictive value for prognosis, with an area under the curve of 0.83, followed by the level of NLRP3 in the serum on day 3 post-injury. Conclusions: The levels of NLRP3, especially in the CSF on day 3 post-injury, can serve as a potential biomarker for predicting prognosis in moderate to severe TBI patients. Early measurement of NLRP3 levels can provide valuable insights into patient outcomes and guide therapeutic strategies.