Serum complement levels in anti-N-methyl-d-aspartate receptor encephalitis

Eur J Neurol. 2018 Jan;25(1):178-184. doi: 10.1111/ene.13495. Epub 2017 Nov 17.

Abstract

Background and purpose: This study aimed to evaluate the relationship between serum complement and anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis.

Methods: Serum complement (C3, C4 and CH50), immunoglobulins (IgG, IgM and IgA) and C-reactive protein (CRP) were evaluated in 40 patients with anti-NMDAR encephalitis and 40 controls. Follow-up evaluations of 11 of the 40 patients with anti-NMDAR encephalitis were conducted 6 months after admission. Modified Rankin Scale (mRS) scores and clinical and cerebrospinal fluid parameters were evaluated in patients with anti-NMDAR encephalitis.

Results: Serum C4 levels were significantly higher in patients with anti-NMDAR encephalitis than in controls (P = 0.003), especially in female patients (P = 0.001) and those with severe impairment (mRS ≥ 4; P < 0.001). Serum CH50 levels were significantly higher in patients with severe impairment (P = 0.007) and limited treatment responses (P = 0.007). Serum C4 was associated with C3 (r = 0.506, P = 0.001), CH50 (r = 0.478, P = 0.002) and mRS score (r = 0.607, P < 0.001). Serum C3 was associated with CH50 (r = 0.339, P = 0.032) and cerebrospinal fluid white blood cells (r = 0.351, P = 0.026). Serum CH50 was associated with age, mRS score and CRP. Follow-up evaluations revealed that mRS scores were significantly lower than those before treatment, and a significant negative correlation was observed between the change in C3 levels and the change in mRS score.

Conclusion: Our results demonstrated that serum C4 levels were elevated and associated with C3, CH50 and CRP levels, and disease severity in patients with anti-NMDAR encephalitis.

Keywords: anti-N-methyl-d-aspartate receptor encephalitis; immune effects; serum complement.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / blood*
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / cerebrospinal fluid
  • Anti-N-Methyl-D-Aspartate Receptor Encephalitis / therapy
  • C-Reactive Protein / analysis
  • Child
  • Complement System Proteins / analysis*
  • Female
  • Follow-Up Studies
  • Humans
  • Immunoglobulins / blood
  • Leukocyte Count
  • Male
  • Middle Aged
  • Nerve Tissue Proteins / analysis
  • Receptors, N-Methyl-D-Aspartate / analysis
  • Treatment Outcome
  • Young Adult

Substances

  • GRIN1 protein, human
  • Immunoglobulins
  • Nerve Tissue Proteins
  • Receptors, N-Methyl-D-Aspartate
  • Complement System Proteins
  • C-Reactive Protein