Thread by @CharlesMilrod

Picture this:

A young woman presents with gum bleeding, and you find this 👇 on your evaluation.

Why (and how) is this an emergency? 🤔

A #tweetorial 🧵 1/6

To guide our thoughts, here are 2 acute promyelocytic leukemia (APL) facts-

1) 🔑 APL is a hematology emergency because of ⬆️ rates of DIC

2) ~10% of patients died from hemorrhage in the first 10 days 🤯 in the pre-ATRA era

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With the risk of hemorrhagic death in mind…

How does APL cause DIC? 🤔

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🔑 APL cells produce excessive procoagulants (especially tissue factor)

This 1️⃣ activates the coagulation cascade… (leads to clotting)

and then 2️⃣ consumes fibrinogen (leads to bleeding)

And we see markers of DIC quickly reverse with treatment 👇

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We’ve come a long way in treatment for APL!

👶🏻 1980s: Overall survival ~40%
with chemotherapy

🙋🏻‍♂️ 1990s: ⬆️ survival to ~70%
with addition of ATRA

👴🏻 2010s: ⬆️ survival to >97% (!)
with ATRA + arsenic

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Key takeaways:

🔑 APL cells produce excessive tissue factor, which leads to DIC and bleeding

📈 With ATRA + arsenic, overall survival is ~97% 🤯

… and food for thought:

🤔 What other fatal diseases may have great outcomes with targeted therapy?

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Thank you to @makhan1390 for the guidance 👏

For a deeper dive, here are the full articles:

pubmed.ncbi.nlm.nih.gov/2189506/
pubmed.ncbi.nlm.nih.gov/9558362/
nejm.org/doi/full/10.10…
nejm.org/doi/10.1056/NE…

And images:
imagebank.hematology.org/collection/5911
imagebank.hematology.org/imageset/689/p…