ChatGPT 4.0 - Immunoglobulin edition
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I do IVIg infusions quarterly, to guard against antibody-mediated rejection.
They almost always cause me a night of flu-like symptoms. Sometimes really bad, but usually tolerable. I had one today and the symptoms have started.
So I was curious about the exact mechanism by which this occurs.
Me: IVIg infusions can cause fever and chills. By what mechanism does this occur?
ChatGPT:
Intravenous immunoglobulin (IVIg) infusions can cause fever and chills through several mechanisms. The primary mechanisms are:
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Cytokine Release: IVIg can stimulate the release of pro-inflammatory cytokines such as interleukins (IL-1, IL-6) and tumor necrosis factor-alpha (TNF-α). These cytokines can act on the hypothalamus, the body's temperature regulation center, causing an increase in body temperature and resulting in fever and chills.
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Immune Complex Formation: During IVIg therapy, immune complexes can form, which can activate the complement system. This activation leads to the generation of anaphylatoxins (C3a, C5a) that can trigger inflammatory responses, including fever and chills.
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Direct Effects of IVIg Components: Some components or impurities in IVIg preparations might directly trigger an immune response, leading to the release of pyrogens, which are substances that can induce fever.
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Activation of Macrophages: IVIg can activate macrophages, leading to the release of endogenous pyrogens such as IL-1 and TNF-α, which can induce fever and chills as part of the body's immune response.
These responses are generally more common in the initial infusions and may decrease with subsequent treatments as the body adjusts to the therapy. It's also important to monitor patients closely during infusions for any adverse reactions.
For more detailed information on the mechanisms and management of IVIg-related side effects, you can refer to medical literature or specific guidelines provided by health organizations.
Pretty impressive response. I suspect the percentage of MDs (that don’t specialize in immunology) who could give that complete an answer is a rounding error off of zero.
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Interesting stuff. At some level, it's going to evolve (devolve?) into a decision-making tree. We were taught to come up with a differential diagnosis. For example the patient has chest pain. The student has to have, in his head, a list of all the things that can cause chest pain. By ordering appropriate studies and a physical exam, you narrow the DD to, hopefully, one possibility.
But, when it comes to AI, there's one thing missing - the ability to do a physical exam. The ability to feel a liver, evaluate the strength of a reflex, or look into an ear isn't something that AI can do...yet.
WOn't be long before AI is taught to intubate. After that, heart surgery!
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I’m treating my symptoms with Tylenol, which works pretty well (though it runs out before I’m supposed to take more). So I was curious.
Me: By what mechanism does acetaminophen reduce fever and chills and body aches
ChatGPT:
Acetaminophen, also known as paracetamol, reduces fever, chills, and body aches through several mechanisms:
- Inhibition of Cyclooxygenase (COX) Enzymes: Acetaminophen primarily works by inhibiting the cyclooxygenase (COX) enzymes, particularly COX-2, in the brain. This enzyme is involved in the synthesis of prostaglandins, which are chemicals that promote inflammation, pain, and fever. By reducing the production of prostaglandins in the central nervous system, acetaminophen lowers the body’s temperature set point in the hypothalamus, effectively reducing fever.
- Action on the Hypothalamus: The hypothalamus is the part of the brain that regulates body temperature. Acetaminophen acts directly on the hypothalamic heat-regulating center to induce peripheral vasodilation and sweating, which helps dissipate heat and lower body temperature.
- Analgesic Effect: For body aches, acetaminophen’s analgesic (pain-relieving) effect is also due to its action in the central nervous system. By inhibiting COX enzymes and reducing prostaglandin synthesis, acetaminophen decreases the sensation of pain.
- Central Serotonergic Pathways: There is also some evidence suggesting that acetaminophen might exert its analgesic effects through serotonergic pathways in the brain, which influence pain perception and modulation.
These combined actions make acetaminophen effective at reducing fever, alleviating chills, and relieving body aches associated with various conditions, such as infections and inflammatory disorders.
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I usually take two extra strength. Last night at my worst I took three.
I have stage 3 CKD thanks to tx meds, so I need to be careful. But in this case I knew it would pass in an evening so I took three just once. When I had covid, I was very strict with the dosing and intervals thinking it could be two weeks I’d be taking it. In the event, I was only on them for about three days, thanks to the antivirals I took.
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