Thread by @AdamJBrownMD

INTRAVENOUS IMMUNOGLOBULIN

Or IVIG as the 😎 cool kids call it

⭐️ What is it?

⭐️How did we first start using it?

⭐️How was it accidentally found to treat autoimmune conditions?

A thread 🧵

#meded #rheumtwitter @HRheuminations #immunodeficiency

Immunoglobulin is another way of saying antibodies (Abs)

Abs are what your immune system produces after being exposed to an infection or what you produce in response to a vaccine to protect you long term

IVIG is “pooled” antibodies (Ab)

Originally made to treat people who can’t make Ab

(More on this soon)

⭐️ Why pooled?

If you took Ab from just me, then you would be immune to just what I’m immune to

If you take antibodies from 1000s of people, you’re immune to much more

The story begin..

1952 Dr Bruton a peds immunologist

Saw a kiddo with recurrent infections

What was the cause?

Sent off serum electrophoresis

The kiddo had no gamma (Y) globulins!!!

Bruton knew this is where the Abs lived

Realized the kid made no Abs

⬇️⬇️⬇️ immunity

So how can Dr Bruton help the kid?

By giving the kid antibodies!!!

But wait, how does one collect antibody and give it to someone else?

Buckle your seat belt, let’s talk about Cohn fractionation!!!

Dr Cohn from Harvard

Figured out a way to separate albumin from blood and concentrate it

Why do this?

During WW2, needed to figure out new ways to save soldiers bleeding rapidly

Albumin gives volume quickly AND easier to transport than blood ie doesn’t have to be frozen

Realized with this Cohn method you can separate out whatever protein you want, not just albumin

So, antibodies could ALSO be separated and then pooled together with much greater ease

So people who couldn’t make antibodies could be GIVEN antibodies to reduce risk of infection!!!

Yaaaaaay!!!!

⭐️ But wait, why did Rheumatologists starting using IVIG?

A combination of chance and observation!

1981

2 kids: recurrent infections, found to have low Abs

ALSO had IMMUNE MEDIATED low platelets (ITP)

Kids were given IVIG to ⬆️ Abs and ⬇️ infections

…docs noticed their platelet count ⬆️⬆️⬆️

What?!

Did larger study of ITP and IVIG, showing good platelet response.

This opened the door for using IVIG in autoimmune conditions.

Notably Kawasaki disease and inflammatory myopathy

Does it work in everything? No.

But it’s a rare treatment modality for autoimmune conditions that doesn’t suppress the immune system.

Summary:

IVIG is Ab pooled from 15,000-60,000 people.

Given to patients with low or absent Ab to help protect from infections

Also given in certain autoimmune conditions

But the Mechanism isn’t fully understood of why it works in autoimmunity

There is a lot more to learn in this story.

Take a listen for a deeper dive!!!

podcasts.apple.com/us/podcast/hea…

References:

See references in podcast links: there are a lot of them!