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"Hashimoto encephalopathy (HE) is an autoimmune encephalopathy associated with autoimmune chronic thyroiditis"

pattismith

Senior Member
Messages
3,931
@Gingergrrl

Many patients here have autoimmune thyroiditis, also called Hashimoto thyroiditis (high anti TPO and TG antibodies), so I think we should pay a special attention to the HE entity

Hashimoto encephalopathy

Akiko Matsunaga

Masamichi Ikawa

Makoto Yoneda

First published: 19 September 2019


Abstract

"Hashimoto encephalopathy (HE) is an autoimmune encephalopathy associated with autoimmune chronic thyroiditis.

The clinical entity and nosology of HE have long been debated.

Recently, new autoantibodies associated with autoimmune encephalitis have been discovered.

With accumulated reported cases, and our discovery of serum autoantibody against NH2‐terminal of alpha‐enolase as a specific diagnostic marker, HE has been recognized as a distinct clinical entity.

The condition appears dominant in females. The clinical features of HE are characterized by various neuropsychiatric symptoms, such as altered consciousness, psychosis and seizures, the presence of serum anti‐thyroid antibodies, normal or non‐specific changes in brain magnetic resonance imaging, diffuse slow wave activities in electroencephalogram and responsiveness to immunotherapy.

A few pathological studies showed a lymphocytic infiltration of the small and medium‐sized vessels of the brain, which suggested vasculitis.

Non‐specific neurological symptoms, laboratory findings and neuroimaging of HE make its diagnosis an oversight and difficult, whereas antibodies against NH2‐terminal of alpha‐enolase can be useful as a diagnostic biomarker for HE.

In this review, we describe the current state of knowledge about HE and discuss progress in the diagnosis of HE."
 
Last edited:

pattismith

Senior Member
Messages
3,931
4. Exclusion of other psychiatric and neurological diseases

Differential diagnoses; viral encephalitis, autoimmune encephalitis, autoimmune limbic encephalitis, amyloid angiopathy, depression, schizophrenia, CJD, spinocerebellar degeneration etc.

Check autoantibodies associated with autoimmune encephalitis

(i.e. anti‐NMDAR, anti‐VGKC, anti‐LGI1, anti‐Caspr2, anti‐GABAA/BR, anti‐AMPAR, anti‐mGluR5, anti‐D2R, anti‐DPPX, anti‐GlyR, anti‐IgLON5, anti‐Hu, anti‐Ma1/2, anti‐amphiphysin)
 

Gingergrrl

Senior Member
Messages
16,171
@Gingergrrl Many patients here have autoimmune thyroiditis, also called Hashimoto thyroiditis (high anti TPO and TG antibodies), so I think we should pay a special attention to the HE entity

Thanks for tagging me, Patti, and I have Hashimoto's and high levels of both Hashi's autoantibodies (TPO and TG Abs). At one point they were extremely high (via blood tests) but after being on Armour and being (90%) gluten free, they are now at a more moderate level. My Endo said that I will always test positive for the Hashi's autoantibodies and that the levels do not correlate w/my thyroid symptoms (which I have found to be 100% accurate).

Recently, new autoantibodies associated with autoimmune encephalitis have been discovered.

I had heard of Hashi's Encephalopathy but had thought it was an acute episode that could be triggered and required emergency care (vs. a chronic illness due to a separate autoantibody). Is this something new or did I misunderstand it from the beginning?

With accumulated reported cases, and our discovery of serum autoantibody against NH2‐terminal of alpha‐enolase as a specific diagnostic marker, HE has been recognized as a distinct clinical entity.

How would someone test to see if they are positive for "NH2‐terminal of alpha‐enolase" autoantibodies? Is it a commercial test, or only at a specialty lab like Mayo, or only for research studies? I don't have any of the symptoms but am curious if I have the autoantibody (since I have so many others :nerd:)
 

pattismith

Senior Member
Messages
3,931
@Gingergrrl

yes you are right, HE is considered a rare and acute disease. On the other hand the entity is still not perfectly defined.
Is HE the result of direct TPO/TG antibodies in the brain, or is it just that these antibodies are frequently associated with other auto-antibodies damaging the brain? This is not yet solved.


If they find a biomarker for HE, they may be able to detect subacute or even chronic HE.

This very new study (released on 01.01.2020) suggests that TPO and TG antibodies may directly bind brain targets (beyond).
This finding mean that high intrathecal anti-TPO/TG antibodies could produce brain disturbance.




Homology between TSH-R/Tg/TPO and Hashimoto's encephalopathy autoantigens.
Benvenga S1,

Guarneri F2

Department of Clinical and Experimental Medicine - Endocrinology, University of Messina, via Consolare Valeria - Gazzi, 98125 Messina, Italy

01 Jan 2020


Abstract
Hashimoto's encephalopathy (HE) is a syndrome occurring in some patients with Hashimoto's thyroiditis or, less frequently, Graves' disease.

Three known autoantigens are involved in HE: alpha-enolase, dimethylargininase-I (DDAHI) and aldehyde reductase-I (AKRIAI).

We searched for amino acid sequence homologies between these proteins and the three classical thyroid autoantigens (thyroperoxidase (TPO), thyroglobulin (Tg), TSH-receptor (TSH-R)), which are also expressed in the central nervous system (CNS).

TSH-R shows homologies with alpha-enolase (n=4), DDAHI (n=2) and AKRIAI (n=5); of these segments, two, two and four, respectively, overlap totally or partially with epitope-containing TSH-R segments.

Tg has 10 homologies with alpha-enolase, five with DDAHI, and eight with AKRIAI; epitope-containing segments of Tg overlap four, three and four segments, respectively.

TPO has six segments homologous to alpha-enolase, three to DDAHI and seven to AKRIAI; of these segments, five, one and four, respectively, are located in epitope-containing parts.

These data suggest that cross-reactivity between CNS autoantigens and thyroid autoantigens might contribute to the HE pathogenesis, together with other proposed mechanisms, including autoimmunity involving autoantigens common to CNS and thyroid.