Seronegative LEMS

[Ashley Gregory]

Hi LEMS friends! 

Most of us that have been diagnosed with LEMS have auto-antibodies to calcium channels, either P/Q or N-type. We can also have both types of antibodies. 

Did you know there are some LEMS patients that have NO antibodies and are considered seronegative? 

“A study of 110 LEMS patients in 2002 concluded that  Anti-P/Q-type voltage-gated calcium channels (VGCC) antibodies were detected in 85% of the patients (seropositive) but not in the rest (seronegative).” Nakao YK, Motomura M, Fukudome T, Fukuda T, Shiraishi H, Yoshimura T, Tsujihata M, Eguchi K. Seronegative Lambert-Eaton myasthenic syndrome: study of 110 Japanese patients. Neurology. 2002 Dec 10;59(11):1773-5. doi: 10.1212/01.wnl.0000037485.56217.5f. PMID: 12473768.

I am curious to hear what type of antibodies you (or your family member) have. 

When I was originally tested in 2015, I had only N-type antibodies. 

I have not been re-tested since then as I was told IVIG skews levels and can cause a false negative. 

If you have calcium-channel antibodies, what type do you have?

Have you been re-tested since your original antibody titer? If so, what treatments did you try and how did your levels change?

As always, thanks for sharing with us! 

[Jan Grizzel]

I am P/Q positive – negative SFEMG

[Price Wooldridge]

Same here on my original testing, P/Q positive.
My new neurologist just decided to “retest”. I don’t know the results yet.

[David1949]

I am type N.

Ashley,

In reference to this comment, “I have not been re-tested since then as I was told IVIG skews levels and can cause a false negative”, do you know if there is documentation on the fact that being on IVIG could give a false negative?
<p style=”text-align: left;”>My neurologist has tested me twice recently and and both test were negative for LEMS. I would like to show him the information that says being on IVIG can skew the results.</p>
David

[Price Wooldridge]

I haven’t received my “retest” results from my new Neuro yet. My original antibodies test was P/Q positive for LEMS. I’m going to be curious how this comes out.

[Ashley Gregory]

Hey @blessed

Thanks for sharing with us!

 

 

Hey @dpmitnick

Thanks for sharing with us! I am going to do some digging to see if i can find an article about it! I’ll get back to you and post here!

[Ashley Gregory]

Impact of IVIG therapy on serologic testing for infectious diseases – ScienceDirect

Effects of IVIg treatment on autoantibody testing in neurological patients: marked reduction in sensitivity but reliable specificity – PubMed (nih.gov)

Here are two that talk about it. Ill try to do some more digging too!

 

[David1949]

Thank you Ashley. These two articles are very helpful for my Advocacy. I’ll keep everyone posted on what happens.

[Heather]

I have a very rare primary immune regulatory disorder in addition to LEMS. Going through all the immunological testing taught me more than I wanted to know about the impact of IVIG on antibodies.  Bottom line is that any tests done with ivig in a person’s system will be  inaccurate-you have to be off ivig for 3 months to get an accurate test. I went through that 3-month flush out…and it caused a runaway infection that nearly cost me my life, followed by myesthenic crisis. Plus side? I got a diagnosis and hopefully I’ll never go through that ever again!!!

Heather

[David1949]

Thank you for the information Heather. I have communicated with my neurologist in reference to these comments and I hope it makes an impression on him.

[David1949]

<p style=”text-align: left;”>Does anyone know if being on IVIG infusions would affect the results of a “high frequency nerve stimulation” EMG?</p>
Posted by David

[Price Wooldridge]

That’s a very good question. I don’t have the answer with a quick Google search, but perhaps someone else will know.

[Y Petrie]

P/Q negative, N positive.

3 tests over 18 months while doing IVIG (blood drawn 7-30 days after IVIG infusion) – all P/Q negative and N positive in each test result.  Not all at same lab either.  IVIG didn’t suppress my own N antibody titers enough to turn any of the three tests from positive to negative.  What did I care about? Was the test elevated above the lab reference range – how high it is above the lab reference range doesn’t change my treatment, my distinct symptoms or the diagnosis.

Fourth test 7 days after plasmapheresis – definitely both P/Q and N negative on this test, but false negative due to my total antibody level being low (tested at the same time).

Did show false positive for thyroid antibodies while I was doing IVIG – one of the most diagnosed autoimmune conditions in the world, which thankfully I do not have. The thyroid antibodies came from the immunoglobulin donors, not me.  Value of Thyroid Peroxidase Antibodies in Neuroimmune Diseases: Analysis of Interference During Treatment with Intravenous Immunoglobulins – PubMed (nih.gov)

 

 

[Price Wooldridge]

All this is very interesting! I just did an antibodies re-test on orders from my new Neuro. I’m anxious about the results.
I also believe I’m about to have a thyroid blood test from nephrology. Curious on that one too. So much to learn.
Thanks for your observations!

[Tina Sadler]

A diagnosis of LEMS was made in a woman at the age of 23 years. She had become aware of ptosis. In her late teens. she developed weakness in the limbs and had difficulty in speech. chewing and swallowing. She was noted to have bilateral ptosis facial weakness, poor palatal movements and weakness of neck flexion and tendon reflexes were absent
Anti-VGCC antibodies were positive on three occasions (titres 105-282 pmol/I:
positive >30 pmol/) and anti-AchR antibodies were negative. Neurophysiologica studies strongly supported LEMs.

[Price Wooldridge]

Yes, thanks for this report. It’s interesting that these reported symptoms are all high up. Myasthenia Gravis is generally considered a top down disorder and LEMS the opposite, a bottom up disorder. This illustrates how commonly held assumptions are not always correct.

[Bernie]

I am negative for all antibodies.  My diagnosis was based on SFEMG and symptoms.

[Price Wooldridge]

Interesting Bernie. If I recall you did not respond to IVIG antibodies therapy either. Please correct me if I’m remembering incorrectly. Just wondering out loud, would the lack of P/Q or N antibodies account for this. That might be q question I’d ask my neurologist. Thanks for responding!

[Price Wooldridge]

I just was retested by a new neurologist, even though I have been on IVIG antibodies therapy for years. My results just came back negative. Obviously, this makes me very uncomfortable, because I have my original Mayo Clinic lab results from my diagnosis, which were positive.
I’m concerned becausese I don’t know what my new neurologist is going to do with my treatment plan. TBC

[RDT]

Initially tested positive for both types (P/Q & N Type), retested a year later only P/Q type & tested again both positive again. Just got retested last week and now the Mayo autoimmune encephalopathy panel removed the P/Q & N Type from their panel??? So who knows?? Regular EMGs are negatives but SFEMG are always positive.

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