Diagnostic Biomarkers in Cerebrospinal Fluid in Primary Central Nervous System Lymphoma: A Protocol for Systematic Review and Meta-analysis

Background: Primary central nervous system lymphoma (PCNSL) is a highly aggressive non-Hodgkin's lymphoma with an unfavorable prognosis. Currently, the diagnosis of PCNSL relies on brain excisional biopsy, which is an invasive procedure that carries the risk of complications such as intracranial hemorrhage and functional impairment. Finding effective biomarkers will help us to diagnose PCNSL faster and safer. Methods: A systematic review and meta-analysis will be conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocol (PRISMA-P) 2015 guidelines. We will search databases including PubMed, Cochrane Library, Medline, Web of Science, EMBASE, and CNKI. Studies that demonstrated the diagnostic value of certain biomarkers in cerebrospinal fluid (CSF) in PCNSL will be included. The standardized mean difference (SMD) and their 95% confidence intervals (CI) will be calculated for quantitative values. The outcomes are the mean difference in biomarker levels in CSF between PCNSL patients and controls. Discussion: In this systematic review and meta-analysis, we will analyze biomarkers in cerebrospinal fluid for the diagnosis of PCNSL. This research can help us to identify biomarkers with diagnostic value for PCNSL, making the diagnosis of PCNSL easier, faster, and safer.