IgG4 Related Disease

The clinical manifestations, diagnosis, differential, and treatment or IgG4-related disease.
Structure of IgG on thumbnail adapted from IgG.png by user Ikacskovics, made available under CC BY-SA 2.5, downloaded from Wikimedia Commons September 2022.
#rheumatology

[@proudmom3971]

Insane how these things get dismissed gaslighted

[@no_country_for_real_men]

Exactly

[@cornelbacauanu1544]

Amazing Lecture. Better, than a textbook, for a quick orientation. Thank you. Coincidentally, a few weeks ago I came across an elderly patient who presented to ER with severe abdominal pain with radiation to the back associated with weight loss, nausea, and vomiting, and the CT showed a pancreatic tumor. The immediate Dx was a strong suspicion of Pancreatic Cancer and a Whipple procedure was performed. The pathology report turned out to be Ig G4 disease with Pancreatitis. A course of steroids was started and currently, the patient reminded asymptomatic however testing of possible other organs affected is underway.

[@malaikamaqsood6529]

Hello ap bta sakhti hen k igg4 hota kia hai or yeah positive ho toh kia hota

[@bhuvandocz1778]

Superb lecture 👍😌

[@andersstorgaard6828]

Hey Dr. Strong. Wonderful lecture. I did a review of Igg4-RD as part of my pathology rotation i 2015. Only ad would be that refractory/ relaps after steroid treatment would be Rituximab, as it seems to have the best long term remission effect. I always enjoy your videos. keep up the good work. Cheers fra Scandinavia ;)

[@jinggoy9062]

i was reading your slide on the related diseases for fun and it looks like you listed IgG4-related sclerosing cholangitis twice... literally unwatchable video, jk love your work boss! thanks for making this video!! :)

[@StrongMed]

Argh! I can't believe I did that.

[@carinaekstrom1]

Very interesting lecture. Would lichen sclerosis also be an IgG4 related disease?

[@smsladen6568]

Fantastic teaching

[@ramacokari9318]

Not related to this video, just recently started following you, but decided I’d have a better chance of you answering on a more current video…. Can ACNES develop after years with CRPS and/or would there be any correlation between the two??? Any email we could contact you directly?

[@StrongMed]

I am unaware of any relationship between CRPS and ACNES. Sorry, I don't respond to unsolicited emails asking medical questions - I get far too many to even read them all.

[@ramacokari9318]

@@StrongMed thank you for even responding to this question.

[@sunving]

Thank you very much.

[@byzaldiv]

I understand that high serum Igg4 is not enough to diagnose Igg4-RD as biopsy would be needed. You also mentioned in another comment that the vast majority of patient's with high serum levels are probably not Igg4-RD. What are other diseases that can cause elevated serum Igg4 for cases that do not present with fibrosis or tumors but are symptomatic?

[@StrongMed]

Chronic and/or recurrent infections and autoimmune disease are the most common causes of elevated IgG4. In this study of 59 patients with elevated IgG4 levels, only 6 were due to IgG4-RD: www.ncbi.nlm.nih.gov/pmc/articles/PMC3433130/ However, the more abnormal the level, the more likely it's due to IgG4-RD.

[@Receipt1705]

MDS

[@agd712]

Love this from an aspiring pulm doc! Currently IM categorical intern.

[@strongDr]

Where?

[@hisham148]

God save you king 👑

[@TheNheg66]

What implications can the finding that the mRNA vaccines can cause a highly elevated IgG4 levels after third dose have on manifestations of IgG4 RD? Are high IgG4 levels sufficient to cause IgG4 RD or is some kind of comorbidity required for IgG4 RD to manifest? If the IgG4 levels alone are enough to cause IgG4 RD, would the hightened IgG4 levels observed post 3rd dose of mRNA vaccines be sufficient to cause IgG4 RD? Thank you kindly for your answer.

[@StrongMed]

While elevated IgG4 levels in IgG4-related disease is involved in the pathogenesis of the disease, they are neither necessary nor sufficient for a patient to develop it. In other words, there are people with IgG4-RD who have normal IgG4 levels; and the majority of people with elevated IgG4 levels do not have any clinical evidence of IgG4-RD. I just rewatched my video and I think I may have casually overemphasized the centrality of the IgG4 antibodies to the disease in the sense that experts currently think they are not pathogenic in themselves, but rather are caused by the same processes that lead to the disease manifestations (i.e. an "epiphenomenon"; like a fever in patients with pneumonia). So to answer the question that I think you're asking ("Could the mRNA vaccines cause IgG4-RD?"), my answer would be I don't know, but the finding of higher IgG4 levels following vaccination would not significantly point in that direction (based on medicine's current understanding of the disease).

[@TheNheg66]

@@StrongMed thank you for adressing my question with a clear and understandable answer and i also praise you for not pretending to know things that we don't yet have answers to (because sadly this is a thing that's worthy of praise in today's world).

[@Noneatall246]

We are f…

[@sugabay]

What is the reason for having no igg4 subclass ? And how can I rebuild it?

[@StrongMed]

I'm sorry but I can't give specific, individualized medical advice here, and I recommend speaking with your own physicians about your concerns. However, here is a scientific paper that summarizes the more common explanations: www.karger.com/Article/FullText/503967 The paper isn't amazing per se, and isn't layperson friendly, but there is little information out there on this issue for patients.

[@sugabay]

@@StrongMed ok Thank you

[@antjan6716]

Hello, so I have extreme flushing/rashes and a allergic reaction to sunlight/heat. My igg4 is insanely high 118.4. Is this a normal reaction, where should i go from here?

[@StrongMed]

I'm sorry, but I can't offer specific, individualized medical advice here. I recommend you speak with your doctor in person regarding your symptoms and lab results.

[@buhaysajapanvlog622]

I have a high igg4 what does it means pls help me

[@Sohailali1]

Same here with many symptoms.

[@StrongMed]

Elevated IgG4 levels are neither sensitive nor specific for this disease. IgG4-related disease is rare. The majority of people (perhaps vast majority of people) who have elevated IgG4 levels do *not* have IgG4-RD.

[@Sohailali1]

@@StrongMed Agreed. But I had autoimmune pancreatitis and I am now developing other symptoms while being on immunosuppressant... so I'm guessing I'm the zebra I never wanted to be.

[@ellennaj3382]

@@Sohailali1hey. I need to ask you something. Does it mean you have adverse side effects from almost every medication?

[@jz5005]

Isn’t this the primary outcome of the Vax?

[@StrongMed]

No. There has been a single case report of IgG4 related disease occurring in the weeks after the patient received an mRNA COVID vaccine, which is most likely coincidence. Given that billions of people have received the mRNA vaccines, and IgG4 RD is relatively rare, if the vaccine caused IgG4 RD with any notable frequency, the cases of IgG4 RD would have skyrocketed beyond their baseline, which has not been observed.

[@Goldbergeri]

I just listened study that the covid vax increases the igG4 production by over 40% if i recall with 3 shots. But thats different than this video is talking about. As i searched from youtube what is igG4 youtube wanted to recommend this video several days later. Even though its not good to be producing that much IgG4 at least its not nearly as serious as the topic in this video.

[@StrongMed]

@@marc-io No, there is still no convincing data that the COVID vaccine causes IgG4-RD

[@StrongMed]

I just discovered some viewers are wondering about a possible connection between IgG4 levels and mRNA-based COVID vaccines, likely on account of research like this: www.science.org/doi/10.1126/sciimmunol.ade2798 . Class-switching to IgG4 type antibodies is not thought to trigger IgG4-RD in itself, and there is no evidence that the mRNA vaccines are associated with the subsequent development of IgG4-RD.

[@steven4776]

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