Initial serum thyroid peroxidase antibodies and long-term outcomes in SREAT

Acta Neurol Scand. 2016 Dec;134(6):452-457. doi: 10.1111/ane.12556. Epub 2016 Jan 12.


Objective: To quantify clinical outcome in patients with steroid-responsive encephalopathy and associated autoimmune thyroiditis (SREAT) after the acute phase and explore potential associations of initial serum thyroid peroxidase antibody titers (TPO-Abs) with outcome.

Materials and methods: Retrospective chart review of patients diagnosed with SREAT between 01/2005 and 05/2014 in a tertiary care center and followed in an affiliated autoimmune outpatient clinic. Outcome was quantified using the extended Glasgow Outcome Scale (GOS-E). We calculated Pearson's correlation coefficients to quantify associations with clinical outcome at follow-up.

Results: Among 134 patients with encephalopathy of unknown etiology, we identified 13 patients diagnosed with SREAT. In two patients, the diagnosis was revised at subsequent hospitalization (NMDA-R encephalitis and adult-onset Still's disease). The median follow-up time was 11 months, and the median GOS-E was 6 (range 3-8). Higher serum TPO-Ab-titers correlated with more favorable outcomes (Pearson coefficient 0.65, P = 0.03).

Conclusion: A correlation between TPO-Ab-titers and outcome has not been reported previously and challenges the notion of a mere bystander role of TPO-Abs in SREAT.

Keywords: SREAT; autoantibodies; autoimmune diseases; encephalitis; hashimoto encephalopathy; steroid-responsive encephalopathy; thyroid microsomal antibodies; thyroid peroxidase antibodies.

MeSH terms

  • Adult
  • Aged
  • Anti-Inflammatory Agents / therapeutic use
  • Autoantibodies / analysis*
  • Encephalitis / blood
  • Encephalitis / immunology*
  • Encephalitis / therapy*
  • Female
  • Follow-Up Studies
  • Glasgow Outcome Scale
  • Hashimoto Disease / blood
  • Hashimoto Disease / immunology*
  • Hashimoto Disease / therapy*
  • Humans
  • Immunosuppressive Agents / therapeutic use
  • Iodide Peroxidase / blood
  • Iodide Peroxidase / immunology*
  • Magnetic Resonance Imaging
  • Male
  • Methotrexate / therapeutic use
  • Middle Aged
  • Retrospective Studies
  • Steroids / therapeutic use
  • Thyroiditis, Autoimmune / blood
  • Thyroiditis, Autoimmune / immunology*
  • Thyroiditis, Autoimmune / therapy*
  • Treatment Outcome


  • Anti-Inflammatory Agents
  • Autoantibodies
  • Immunosuppressive Agents
  • Steroids
  • Iodide Peroxidase
  • Methotrexate

Supplementary concepts

  • Hashimoto's encephalitis