Construction and Efficacy Evaluation of a Highly Efficient Diagnostic Model for Neurosyphilis Driven by the Cerebrospinal Fluid/Serum Free Light Chain Index

ObjectiveTo determine free light chains (FLC) in cerebrospinal fluid (CSF) and serum, calculate the FLC index, and establish a model to evaluate its application value in diagnosing neurosyphilis. MethodsThis study included 87 syphilis patients, comprising 48 neurosyphilis patients (NS group) and 39 non-neurosyphilis patients (n-NS group). CSF and serum samples were collected from all patients to measure kappa free light chains (FLC-κ) and lambda free light chains (FLC-λ). The FLC index, FLC-κ index, and FLC-λ index were calculated. Receiver operating characteristic (ROC) curves were used to evaluate these indices. A neurosyphilis diagnostic model based on the FLC index was established and its visualization was verified.ResultsStatistically significant differences were observed between the two groups in serological syphilis screening, CSF nucleated cell count, CSF microprotein, CSF IgG, IgG synthesis rate, IgG index, and albumin quotient (P P P ConclusionFLC-κ and FLC-λ have high diagnostic performance for neurosyphilis, and the FLC index has certain application value in the diagnosis of neurosyphilis.