VGKC Voltage Gated Potassium Channel Complex Antibodies Including LG1 and CASPR2

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I have VGKC antibody and I'm compiling research. The VGKC-complex antibodies are VGKC, LG1, and CASPR2 and it is believed based on research and case studies that there are more not discovered yet.
A substantial number of VGKC-antibody positive cases are negative for LGI1 and CASPR2 IgG autoantibodies, not all VGKC complex antigens are known. The clinical significance of this test can only be determined in conjunction with the patient's clinical history and related laboratory testing.
Vgkc antibody ARUP labs
We will review all the major neurological conditions associated with VGKC complex-IgG. These include Isaacs’ syndrome, Morvan syndrome, limbic encephalitis, facio-brachial dystonic seizures, chorea and other movement disorders, epilepsy, psychosis, gastrointestinal neuromuscular diseases, a subacute encephalopathy that mimics Creutzfeldt-Jakob prion disease both clinically and radiologically and autoimmune chronic pain.
VGKC complex-IgG are now part of the investigation of patients with unexplained subacute onset of epilepsy, memory or cognitive problems, or peripheral nerve hyperexcitability syndromes.
(highlighting what would be more common to people on this site)Neurological diseases associated with autoantibodies targeting the voltage-gated potassium channel complex: immunobiology and clinical characteristics
 

nerd

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There are so many candidate antibody and protein tests that would give us more insight if every CFS/ME patient had them tested. You can't do large observational studies when most patients don't have much more than their basic blood profile. It's so frustrating because such tests aren't difficult to implement. Somebody has to do them, that's all. I wish there was one laboratory that could do all of the CFS/ME-associated biomarkers altogether.
 
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Great!

And here's a link to a thread that about VGKC-related disease that @ChookityPop created earlier this year.

https://forums.phoenixrising.me/thr...tassium-channels-ana-dysautonomia-ivig.82981/
I saw that zebra thanks. I'm gunna be compiling my research here so other people can see it too. I wanted to help you figure out what's causing your fasciculations because you tested negative. You can talk about that on this thread if you want, I want it to be research as well as discussion. I started getting muscle twitches two days ago. So I'm really trying to understand what syndromes I might have and might be developing now. I'll be evaluated of course. Things are rapidly progressing after a brief period of improvement after immunotherapy because it's wearing off and I didn't have enough of it all due to it being a stop gap measure I paid for out of pocket. Can we compare? Do you have insomnia? Have you ever had a seizure? Memory issues? Do your muscles cramps up? Burn?
 

ChookityPop

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Can we compare? Do you have insomnia? Have you ever had a seizure? Memory issues? Do your muscles cramps up? Burn?
Are seizures connected to VGKC antibodies? I have had seizures since I was a kid. They only appeared at night and I was conscious during them but past out right after and often didn't remember it happening the day after.

have a history with seizures, insomnia at times, memory issues, my muscles twitches, burns and cramps up.

Edit: I wrote about my history with seizures here: https://forums.phoenixrising.me/thr...-a-severe-seizure-what-could-that-mean.84352/
 
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Theoretically, they can. But CFS/ME pathology itself without these antibodies could do as well.
Yes but I'd like to keep this thread about vgkc complex antibodies so people can have an avenue to investigate and treat if they are found. Thanks :)
I hope you can find answers for your seizures if they are still happening
 
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Exact quotes bulleted by me
Insights From LGI1 and CASPR2 Potassium Channel Complex Autoantibody Subtyping

• Herein we report clinical correlations and other autoantibody accompaniments of VGKC complex IgG detected in nonselected patients undergoing comprehensive autoimmune serologic evaluation for unexplained neurologic symptoms as well as the frequency of LGI1 IgG and CASPR2 IgG in these patients.

• The study was approved by the Mayo Clinic institutional review board. Subjects were Mayo Clinic patients who were identified as VGKC complex autoantibody positive in serologic evaluation

• Because our study's design did not restrict antibody testing to patients prejudged to have a pertinent syndromic presentation, it permitted broader determination of the neurologic spectrum of VGKC autoimmunity. Study patients were identified through comprehensive neural autoantibody testing of thousands of patients undergoing service evaluation for any suspected autoimmune neurologic disorder, generally of subacute onset, with or without historic or familial stigmata of autoimmunity and not readily explained by alternative diagnoses.

• During the 25-month study, 54853 patients had a comprehensive neural autoantibody evaluation in the Mayo Clinic Neuroimmunology Laboratory. Voltage-gated potassium channel complex IgG was detected in 1992 patients (4%)

This large clinicoserologic study of VGKC complex autoimmunity makes several important observations.

First, both LGI1 IgG and CASPR2 IgG are associated with diverse neurologic manifestations that commonly overlap.

Second, only a minority of seropositive patients have antibodies that recognize LGI1 and/or CASPR2.

• Voltage-gated potassium channel (VGKC) complex autoimmunity was initially described with acquired neuromyotonia and hyperhidrosis (Isaacs syndrome) and subsequently with limbic encephalitis, neuromyotonia, insomnia, and autonomic dysfunction (Morvan syndrome).

The restriction of autoantibody testing to patients with defined neurologic syndromes precludes appreciation of the full phenotypic spectrum of VGKC complex autoimmunity.

• Identification of VGKC complex antibody–positive patients through comprehensive serologic evaluation for any suspected autoimmune neurologic disorder (thus avoiding prejudgment of the clinical spectrum of VGKC complex autoimmunity) has extended the clinical spectrum to include miscellaneous sleep disorders, neuropsychiatric presentations, seizures, mimics of Creutzfeldt-Jakob disease, and frontotemporal dementia.

Importantly, in these reports, robust improvement often followed immunotherapy.

• It was recently reported that VGKC complex autoantibodies detected by radioimmunoprecipitation assays generally do not bind to VGKC channel proteins per se, but they bind instead to synaptic and axonal neuronal proteins that coprecipitate with detergent-solubilized VGKCs.

• the findings support the clinical significance of relatively low VGKC complex IgG values.

• Several earlier studies have suggested that values less than 100 pM or 400 pM (ie, 0.10 nmol/L or 0.40 nmol/L) are negligible.12,16 Had we used 0.40 nmol/L as the cutoff value in this study, we would have missed detecting 61% of the patients (50 of 82) whom reflexive cell-binding assay identified as seropositive for LGI1 IgG, CASPR2 IgG, or both

• It is noteworthy that none of the 10 CASPR2 IgG–positive patients whose VGKC complex IgG values exceeded 0.40 nmol/L had Morvan syndrome

The high proportion of VGKC complex IgG–seropositive patients whose serum samples lack LGI1 IgG and CASPR2 IgG specificities suggests that other VGKC complex molecular targets remain to be discovered.

Klein CJ, Lennon VA, Aston PA, McKeon A, O'Toole O, Quek A, Pittock SJ. Insights from LGI1 and CASPR2 potassium channel complex autoantibody subtyping. JAMA Neurol. 2013 Feb;70(2):229-34. doi: 10.1001/jamaneurol.2013.592. PMID: 23407760; PMCID: PMC3895328.
https://jamanetwork.com/journals/jamaneurology/fullarticle/1397614
 
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Exact quotes bulleted by me
Outcome of limbic encephalitis with VGKC-complex antibodies: relation to antigenic specificity

• In limbic encephalitis (LE) with antibodies (Abs) to the voltage-gated potassium channel complex (VGKC), the Abs are mainly directed to the VGKC-complex proteins, leucine-rich, glioma inactivated 1 protein (LGI1) or contactin-associated protein-like 2 (CASPR-2) or neither. Eighteen VGKC-LE patients were identified: nine patients (50 %) had LGI1-Abs, three (16 %) had CASPR-2-Abs; and six (33 %) were negative for both LGI1- and CASPR-2-Abs.

At first assessment, the groups did not differ clinically or radiologically, but faciobrachial dystonic seizures were only observed in two LGI1-Ab+ patients.

All patients received monthly intravenous methylprednisolone (MP) pulses. At the most recent follow up (median 26 months), thirteen (72 %) were seizure-free, and seizure-freedom rates did not differ between the Ab groups.

• Hippocampal atrophy had developed in 7/9 LGI1-Ab+ patients, but in none of the CASPR-2-Ab+ or LGI/CASPR-2-Ab− patients (p = 0.003).

While all subgroups improved, memory scores only normalized in six patients (33 %) and LGI1-Ab+ patients were left with significantly poorer memory than the other two subgroups. Most VGKC-LE patients become seizure-free with pulsed monthly MP, but memory outcome is less favourable.

• Hippocampal atrophy and poor memory recovery is common in patients with LGI1-Abs and suggests permanent functional damage.

More intense immunotherapies could improve outcomes in LGI1-Ab+-LE.

Malter MP, Frisch C, Schoene-Bake JC, Helmstaedter C, Wandinger KP, Stoecker W, Urbach H, Surges R, Elger CE, Vincent AV, Bien CG. Outcome of limbic encephalitis with VGKC-complex antibodies: relation to antigenic specificity. J Neurol. 2014 Sep;261(9):1695-705. doi: 10.1007/s00415-014-7408-6. Epub 2014 Jun 17. PMID: 24935858.
https://link.springer.com/article/10.1007/s00415-014-7408-6
 

Zebra

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I just wanted to let folks know that -- to my astonishment -- the general VGKC antibody is available direct to consumer in the United States. Meaning, no doctor's order is required. However, it is about $600.

Note: this is only for the main voltage-gated potassium channel antibody, and not the subunits, such as LG1, CASPR2, DPPX.

Here's a link to Ulta Labs and the VGKC test:

https://www.ultalabtests.com/ultdir...-gated-potassium-channel-vgkc-antibody?q=Mg==