Elliot Tapper Profile picture
Oct 15, 2021 19 tweets 10 min read Read on X
The hepatitis B vaccine is amazing.

It also has a wild backstory
Want to hear it?

A #tweetorial

1/

#livertwitter #MedTwitter Image
First:

Hepatitis B sucks
1⃣About 3-4 in every 100 people have it
2⃣It causes liver cancer, #cirrhosis

But the vaccine rocks!
1⃣Prevents liver cancer!
2⃣Was first recombinant vaccine!

So let's get into it

2/ ImageImageImage
Did you know that the discovery of hepatitis B was recognized with the 1976 @NobelPrize for Dr. Baruch Blumberg?

His studies over the course of 5 years 1964-1969 changed the world.

Let's take a look

3/ Image
Hep B discovery

1⃣Looking for new blood antigens, Blumberg finds a weird one. It reacts with an 🇦🇺man's serum
2⃣The '🇦🇺antigen' is found in people with leukemia, hemophilia, & living in institutions (e.g. Down's)
3⃣🇦🇺antigen pops up during viral hepatitis

4/ Image
Why did Blumberg even think that 🇦🇺 antigen (hepatitis B) could cause hepatitis?

A technician working in his lab - Dr. Barbara Werner - got sick with jaundice and hepatitis. She tested herself for Australia antigen...and it was positive. She recovered. Rest is history
5/ Image
Funny thing about hep B

1⃣Multiple hep B particles are found in the blood
2⃣One - surface (🇦🇺) antigen - exceeds the other - core antigen - by 100,000:1
3⃣The surface (🇦🇺) antigen alone is NOT infectious!

6/ Image
Why can we see surface antigen separate from the infectious viral particles (surface coating the core) in the blood of people with hepatitis B?

This has to do with how HBV DNA is transcribed in the liver cell. The parts get made separately and then assembled.

7/ Image
But WHY would there be massive surface antigen overproduction relative to the other parts of the virus?

Only hep B knows!

It is thought that this influences our immune system in a way that is advantageous for the virus

But we can fight back!
Next slide please

8/
An idea is born:
If hep b makes a ton of surface antigen, we can separate it from the infectious parts and use it to generate an antibody against the virus

Blumberg develops the method to purify surface antigen from infected plasma and files a patent in 1969

9/ Image
But are antibodies against surface antigen protective against infection?

In this study of patients receiving dialysis - where there was a crazy high rate of hep B infections - it sure looked like having antibodies against surface antigen was good

10/ Image
Now if we gave surface antigen injections, would we make antibodies? And would antibodies prevent infection with hep B?

In 1976, chimpanzees were enrolled in 'challenge trials' - some were given a surface antigen injection before being infected. It worked!

11/ Image
So where are we getting all of this surface antigen from?

We are getting it from volunteers with hep B who donated their plasma!

BONUS: Not only can we get antigen from infected people, we can get antibody from exposed people!

12/ Image
Looks like we have 2 tools in the box
1⃣Antibody (HBIG, hepatitis B immune globulin)
2⃣Antigen (to train our body to make antibody)

HBIG is best for clear exposure like, say, a baby on their birthday when mom has HBV

RCT: HBIG works great at birth, 3, and 6 months

13/ ImageImage
Between 1980-1982 the world would see the results of a plasma-derived hepatitis B vaccine

These trials showed that the vaccine was >90% effective, >98% if 3 doses were given and the patient made surface antibodies

Game. changed.

14/ ImageImage
Hold up!

Despite the success of the plasma-derived vaccine, the 80's brought awareness that plasma could transmit viruses like HIV, even with safety precautions

Enter the mighty yeast!
1⃣Yeast can make surface antigen
2⃣It's effective as vax in trial of chimps
PHEW!
/15 ImageImage
The recombinant vaccine made in yeast was proven to be just as effective as the plasma vaccine, even for newborns!

And it has CRUSHED Hep B and liver cancer. See Figure 3 from Taiwan

/16 ImageImageImage
SUMMARY

1⃣HBV causes liver cancer, #cirrhosis
2⃣HBV has a non-infectious surface antigen which is made 100000x more than the infectious core. We use antigen for the vax
3⃣HBV vaccine was 1st recombinant DNA vax. Made by yeast
4⃣HBV vax has⬇️liver cancer

/17
This concludes a #tweetorial on the HBV vaccine. I hope you enjoyed the story of HBV discovery and its super effective, cancer preventing vaccine. I would like to thank my boss, mentor, and Queen of HBV, Dr. Anna Lok for her peer review and contributions.

/end
Here is a picture of Blumberg (who discovered Hep B) and Dr. Lok, on the occasion of her Distinguished Scientist Award from @HepBFoundation. Also, inscription from Blumberg to Lok inside his memoir.

The anti-HBV force in that picture is off the charts Image

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More from @ebtapper

Jun 9, 2023
WHAT is the deal with Milk Thistle?
WHY is it used to treat liver disease?
HOW does it work?
DOES it work?
ARE you ready for a #tweetorial?
🧵
#medtwitter #livertwitter Image
Milk Thistle, a history:
1⃣Use to treat snake bites (Dioscorides)
2⃣To carry off bile (Pliny the Elder)
3⃣Great for liver disease (1500's: Otto Brunfels)
4⃣In 19th Century 🇺🇸, the 'Eclectics' popularized herbology, especially milk thistle, for the liver ImageImageImageImage
Fast forward to today:
1⃣Herbal supplements are a multibillion dollarindustry
2⃣A quarter of the population takes an herbal supplement
3⃣~5% of the US population is using Milk Thistle, including 12% of people with liver disease

What do they get out of it? ImageImage
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Jun 4, 2023
I once did a cost effectiveness analysis comparing shotgun vs deliberate testing for elevated ALT

pubmed.ncbi.nlm.nih.gov/27717864/ @JHepatology

We found that broad testing didn’t add much costs but increased false positives, especially when pretest probability of NAFLD was high
Then, In this RCT, John Dillon comparing usual care to broad evaluation of elevated liver enzymes, the cost per incremental diagnosis was 284💷 but was def cost-effective

pubmed.ncbi.nlm.nih.gov/31226388/
I don’t know of many examples of RCTs that confirm or support cost-effectiveness analyses so

A) cool!
B) understanding the differences in the results hinges on the assumptions in the model and the design of the RCT
Read 4 tweets
Jun 4, 2023
How to read a cost-effectiveness paper

This is a powerful method. But poorly understood, often maligned. My goal is to improve critical appraisal and help good analyses get the appreciation they deserve

🧵#MedTwitter CEA: cost-effectiveness analysis
A decision must be made!

All CEA begins with a clinical decision where we are uncertain about the best path forward. Nevertheless, when we face patients we must do something, even if that something is nothing. CEA brings our dilemma to life. Helping us quantify trade offs
Usually we compare a fair description of usual care to an alternative - make sure you agree the choice is fair, realistic, and represents an actual clinical dilemma
Read 20 tweets
Jun 2, 2023
An older man comes to the ED with abrupt onset nausea, & diarrhea

He is joined by her daughter whom he is visiting from abroad

Testing is below
The diagnosis is unclear
Until his daughter got just as sick too
🧵
#livertwitter #liverstory #MedTwitter Image
ALT >1000 has a narrow differential diagnosis



There's lots of tests you can order.
But most diagnoses are made in the H+P

Like this one

In fact, in this case, my attending said the diagnosis was obvious from the beginning

Just not to me
When I meet someone with ALT>1000, I think:

1⃣Ischemic hepatitis. Right 🫀failure? 🫀-genic shock? Cool legs?
2⃣Biliary 🪨. Pain? imaging!
3⃣Drug induced liver injury. Tylenol? Run every med through livertox.gov
4⃣Viral hep. Hep A/B/C

But these weren’t the answers
Read 16 tweets
Feb 6, 2023
The correct answer is variceal bleeding

First, the lactate is up. Take this patient seriously
Second, the obvious clues are lower hemoglobin, platelet consumption.
Third, the ammonia is crazy high. This seals the deal for variceal bleeding.

Why is that?

next slide please
Ammonia is a biomarker of badness

1. Liver dysfunction
2. Portosystemic shunting
3. Dehydration, renal injury (🫘eliminates nh3)
4. Sarcopenia (💪eliminates nh3)
5. Malnutrition

6. And upper GI bleeding
Where is all that ammonia coming from?

The answer is hemoglobin and albumin are isoleucine-poor. This means that when our blood enters the gut, it is not a nutritious source of protein. It gets broken down for waste. That waste, my friends, is ammonia
Read 9 tweets
Oct 12, 2022
5 steps toward a killer talk
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1️⃣practice by recording yourself on the memo app. Listen next day while walking. Refine. Repeat.
2️⃣stay on time, preferably under. If 10 min slot, 9. If 15, 12. If 30, 25.
Read 6 tweets

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