Seronegative LEMSPosted by ashley-gregory on January 31, 2023 at 2:00 pm
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!
MemberFebruary 4, 2023 at 7:40 am
I am P/Q positive – negative SFEMG
MemberFebruary 4, 2023 at 12:26 pm
Same here on my original testing, P/Q positive.
My new neurologist just decided to “retest”. I don’t know the results yet.
MemberFebruary 4, 2023 at 8:05 am
I am type N.
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>
MemberFebruary 4, 2023 at 12:27 pm
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.
MemberFebruary 6, 2023 at 3:15 pm
Thanks for sharing with us!
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!
MemberFebruary 6, 2023 at 3:24 pm
Here are two that talk about it. Ill try to do some more digging too!
MemberFebruary 6, 2023 at 4:18 pm
Thank you Ashley. These two articles are very helpful for my Advocacy. I’ll keep everyone posted on what happens.
MemberFebruary 10, 2023 at 9:31 pm
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!!!
MemberFebruary 11, 2023 at 9:15 am
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.
MemberFebruary 14, 2023 at 4:42 pm
<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
MemberFebruary 14, 2023 at 6:12 pm
That’s a very good question. I don’t have the answer with a quick Google search, but perhaps someone else will know.
MemberFebruary 14, 2023 at 6:10 pm
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)
MemberFebruary 14, 2023 at 6:16 pm
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!
MemberFebruary 17, 2023 at 9:51 am
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.
MemberFebruary 17, 2023 at 9:56 am
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.
MemberFebruary 17, 2023 at 3:52 pm
I am negative for all antibodies. My diagnosis was based on SFEMG and symptoms.
MemberFebruary 18, 2023 at 9:54 am
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!
MemberFebruary 23, 2023 at 2:15 pm
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
MemberMarch 14, 2023 at 4:04 pm
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.
MemberMarch 28, 2023 at 9:40 am
I’m interested in your testing. I recently got a new neurologist who wanted to retest antibodies. My original Mayo Clinic Lab results at my diagnosis were Positive for PQ. On my retest they were negative, though this was done at Quest Diagnostics who do not report numbers, only Positive/Negative. I made sure my neurologist got a copy of my original test results. He did not seem to question my diagnosis.
Anything further on your testing?
MemberMarch 28, 2023 at 5:01 pm
Yeah the neurologist wasn’t worried about retesting the results. Once initial results are positive and EMGs are positive, they don’t question the LEMS diagnosis. But issue is, with LEMS we often have other concomitant rare diseases that might be present with new symptoms. So something to be on the lookout for is what I was told.
MemberMarch 29, 2023 at 4:47 pm
I totally agree, once you have the diagnosis on solid testing results, it should be good. And with autoimmune, they often do have others follow. In my case two. But I know other patients who have several more, all going along with LEMS and autoimmune.
I’m sure you and your team will remain watchful.
MemberMarch 28, 2023 at 10:00 am
My neurologist is ready to dismiss my LEMS diagnosis because of negative test results from Mayo Clinic. He did refer me for a consult and SFEMG scheduled for April 26th.
I sent him the articles that Ashley referenced in this thread and my neurologist responded, “not true in my experience”
MemberMarch 29, 2023 at 4:44 pm
Okay, well good luck in your diagnostic journey and continue to press for a solid diagnosis. Neuromuscular disorders are difficult to diagnose, often showing similar symptoms. The VGCC blood test is a good one for a differential diagnosis, but so too is the single fiber EMG. If it turns up positive for muscle facilitation, that could make your diagnosis clearer.
Keep us posted!
MemberMarch 29, 2023 at 5:04 pm
Sorry I was unclear. I have Been positively diagnosed With LEMS. There’s no doubt about it. But I also have other diagnosis on top of LEMS that confound symptoms. I have positive SFEMG’s & P/Q & N type antibodies, muscle weakness & atrophy. Finding effective treatment that I’m not allergic to or that works is my challenge sadly.
MemberMarch 31, 2023 at 8:12 am
Ah okay! For LEMS the usuals are Mestinon, Firdapse, IVIG. Often, if those don’t work, not indicated due to other issues, or not tolerated, I hear of good results with Cellcept and Rituxan (immunosuppressants). And of course there are steroids which are great at reducing inflammation, but come with their own problems if used long term. Argenx is currently in preclinical studies for another drug that works above the antibody level, but it is not close as of yet. Stay with it and work with your neurologist! Keep us posted.
MemberMarch 31, 2023 at 3:34 pm
So I’m currently on mestinon. But it only helps with my POTS symptoms only. Nothing for the muscle pain/weakness. Firdapse didn’t work & caused seizure. IVIG caused aseptic meningitis & SCIG contraindicated because I also have IgA deficiency. Cellcept, methotrexate, Sulfasalazine, Rituxan infusion didn’t work. On plaquenil but need stronger immune suppression. Awaiting approval to restart Humira. Plasmapharesis worked but it only lasted a week before I needed it again, so they thought that wasn’t a long term option. But may have to go back to that if Humira doesn’t work.
Steroids make my symptoms worse so that’s definitely not an option for me.
I haven’t heard anything about argenx preclinical trials ??
can you send me some info. On it ??
If I can get into their early human trials I’d definitely look into !!
super desperate as I’m almost completely bedbound at this point! Neurologist has run out of LEMS treatment options.
MemberMarch 31, 2023 at 3:53 pm
i posted a response, but now I can’t find it? Not sure where it went? But in case it got deleted, I’ll re add it.
already on mestinon but it helps only with my POTS symptoms not LEMS muscle weakness/pain/cramping.
Firdapse didn’t work & caused seizure. IVIG caused aseptic meningitis & SCIG is also contraindicated due to my IgA deficiency. I’ve tried all the immunosuppressive you mentioned and then some and didn’t help. Trying to go back on Humira. Plasmapharesis helped but symptoms only stayed at bay for a week before returning, so Drs didn’t think it was a long term option. But may have to go back to it unfortunately.
i hadn’t heard about the argenx clinical trials. So I’m so happy you brought this up!! I will definitely look into this to see if I can participate in an upcoming clinical trial. I’m basically bed bound at this point since I’ve failed all other standard LEMS treatments, neuro doesn’t know what more to do. So I’ll definitely bring up this argenx trial at my next visit!!
MemberApril 1, 2023 at 4:31 pm
Yes many of us use Mestinon with success, though often it is not enough.
We don’t have much yet on the Argenx effort yet, but hope to get more details soon. They manufacture a MG drug, Vyvgart.
MemberApril 1, 2023 at 5:34 pm
Yes, please please keep us updated as soon as you get any updates from Argenx. I had heard about Vyvgart but unfortunately I test AChr Antibody negative, so not a candidate. But I get these antibodies tested every year just in case. My neuro says your AChr Antibody level normally never changes but has had one patient that did so I still get checked just in case. Never know.
MemberApril 11, 2023 at 3:16 pm
I am seronegative
MemberApril 12, 2023 at 9:38 am
Were you always seronegative, or just tested so after getting on your treatment regimine?
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