Evaluation of CSF albumin quotient in neuronal surface antibody-associated autoimmune encephalitis

Abstract

Background and Objectives Disruption of brain barriers is considered to be involved in the pathogenesis of neuronal surface antibody-associated autoimmune encephalitis (NSAE), but few studies have focused on their relationship. We aimed to explore the association between the integrity of brain barriers and clinical and paraclinical characteristics in patients with NSAE. Methods This retrospective study consecutively recruited patients with NSAE. The cerebrospinal fluid (CSF) / serum albumin quotient (Qalb) was used to evaluate the function of brain barriers. The data on demographic information, clinical manifestations, magnetic resonance imaging (MRI), CSF findings and prognosis were collected and analyzed. Results Of the 93 patients included, 33 (35.5%) patients were assigned to the elevated Qalb group and 60 (64.5%) patients to the normal Qalb group. Males and prodromal symptoms were more common in elevated Qalb group (both P < 0.05). The CSF white blood cell, protein, immunoglobulin G and albumin were significantly higher in elevated Qalb group (all P < 0.05). Patients with elevated Qalb were more likely to have brain lesions on MRI (60.6% versus 33.3%, P = 0.011). The modified Rankin Scale (mRS) scores at discharge and at last follow-up were significantly higher in patients with elevated Qalb than those with normal Qalb (both P < 0.05). After univariate and multivariate analyses, Qalb elevation (adjusted odds ratio = 3.96, 95% confidence interval = 1.15–13.59, P = 0.029) was demonstrated as the only independent risk factor for a poor prognosis. Discussion Males, prodromal symptoms, brain lesions on MRI, CSF pleocytosis, and elevated CSF protein were more common in NSAE patients with increased Qalb. Qalb elevation was an independent prognostic indicator for a poor prognosis in NSAE.

Elevated blood and cerebrospinal fluid biomarkers of microglial activation and blood‒brain barrier disruption in anti-NMDA receptor encephalitis

“…The cerebrospinal fluid (CSF)/plasma albumin ratio (Qalb) is believed to reflect the integrity of the blood‒brain barrier (BBB) [ 26 ]. As Qalb is age dependent, the individual age-related reference value was defined as Qalb* = (4 + Age/15) × 10 −3 .…”

Editorial: Biomarkers in autoimmune diseases of the central nervous system

“…Autoimmune encephalitis is an umbrella term for the non-infectious, immune-mediated inflammation of the brain parenchyma, in which neural antibodies can be found in a large proportion of patients ( 4 ). Neuronal surface antibody-associated autoimmune encephalitis is the most common subgroup, mainly including anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis and anti-leucine-rich glioma-inactivated 1 (LGI1) encephalitis ( 5 ). Shao et al.…”