This is a fluff piece. We've known for decades that the thymus is an important part of the immune system. It's not an organ that's been believed to be vestigial, like the appendix.
> For the study, Kooshesh mined data from 1,146 adult patients who had undergone thymus removal, alongside demographically matched control patients who had undergone similar surgeries but kept their thymus
Sure, you can demographically match all you want, but I don't think this is a research question that can be answered with a retrospective analysis. The problem is that you haven't controlled for why surgeons decided to remove the thymus in some cases and not in others. Was the disease more severe in patients who got thymectomies? Was it differences in training between the surgeons? Was it just an arbitrary decision on the part of the surgeons? This is a critical confounder regardless of whether you've matched the demographics. You really need a randomized control study to answer this sort of question.
> Although the risk of autoimmune disease did not differ substantially between the groups in the overall primary cohort (relative risk, 1.1; 95% CI, 0.8 to 1.4), a difference was found when patients with preoperative infection, cancer, or autoimmune disease were excluded from the analysis (12.3% vs. 7.9%; relative risk, 1.5; 95% CI, 1.02 to 2.2)
What? What is this? Was this subgroup analysis preregistered, or did they just go fishing when their primary hypothesis didn't pan out?
I'd categorize this study as mildly interesting, but not groundbreaking the way the press statement is selling it.
I believe that the appendix is now understood to be a store for gut flora so that the microbiome can regrow after an infection or bad episode of diarrhoea etc.
I believe it’s only posited to be useful for isolated small groups where everyone might get the same stomach bug at the same time, and have no other humans around with a healthy gut biome to “re-infect” them. Which explains why in dense modern society we couldn’t find a difference that the appendix makes, because we get reinfected with healthy microbiome from sharing germs with all the other humans in our big cities - some of whom didn’t just get a terrible stomach bug at the same time as us.
> Which explains why in dense modern society we couldn’t find a difference that the appendix makes, because we get reinfected with healthy microbiome from sharing germs with all the other humans in our big cities - some of whom didn’t just get a terrible stomach bug at the same time as us.
Do you have any citations for that? Perhaps it differs by city and region, but many modern cities with good sanitation systems are exceptionally clean - you're not getting frequently reinfected by others' gut flora unless there is a catastrophic problem with the sewer system. People with things like C. difficile infection can have chronic disease for years, and fecal transplants have only recently been recognized as a good treatment in those cases - point being you have to have an actual fecal transplant, you're not just going to "get reinfected with healthy microbiome from sharing germs with all the other humans".
If true, lockdowns would have had an effect on those without an appendix?
It would be interest to see how historically contact with X other people has changed over time. I don’t think you need a big city to mix with a lot of people. I imagine in older times there are fewer people but likely to be closer to each other - people sharing beds (not stupidly associating bed with sex) and tribes of families mingling close lower instead of nuclear family. By contrast the city apartment is the hermetic seal around a small number of people choosing to live together. But a modern concept: corporations, jobs and careers ensure people keep mixing up with people outside.
Fully anecdotal, but I got my appendix removed at 19. After 2-3 years i started to have problems and found out that I can no longer process milk(protein), not allergy but intolerance and I started to have issues with "quality". I get bloated and my stomach hurts. Before that I had no issues and had perfect movement. So yeah I didn't "needed it" but quality of my life went down.
In your case I would really doubt if apendix was the cause. As a teen I also loved milk, pancakes, pasta, etc, but around early 20s started to notice that they are bad for me. Now if I eat a lot of milk and glutamine I get digestive issues, skin rashes, etc. My apendix (afaik) is intact.
Milk allergies are different from being lactose intolerant. I developed a mild allergy to dairy in my 30 or so - or so it was discovered then. With lactose intolerance, you can at least take a pill - not so much for an actual allergy. My one child has a much more severe dairy allergy and will get a very upset stomach even with a little dairy.
We both have our appendix.
Though to your point, whether you can develop a milk allergy later in life I am not sure.
It’s been conjectured by some researchers that maybe this is the case, particularly for infants. But there’s very little evidence for it. As far as I’m aware there have been no studies that are able to statistically distinguish between people with and without an appendix in terms of actual heath outcomes
Otoh, I wouldn't say that dismisses the appendix having a potential role. Part of the problem is we barely have a grasp on gut flora and it's full impact on human health, and several studies show that impact can be over years including potentially being one cause of dementia.
Yes, but some believed this function was most relevant in adolescence, with the importance fading in adulthood. The purpose of the research is to understand the role of the organ in later age.
Recently, while on my usual documentaries watch, I learnt that the appendix may no longer be considered appendix.
From Wikipedia[1], “The appendix was once considered a vestigial organ, but this view has changed since the early 2000s. Research suggests that the appendix may serve an important purpose as a reservoir for beneficial gut bacteria.”
This is a research question you can't answer with a prospective analysis either, because it's not ethical in most cases to randomize whether you're removing a body part.
The best we're going to do is a careful case control study (and research in animal models). And the evidence is enough to imply strongly that we should expend a little more effort to avoid removing the thymus.
> This is a research question you can't answer with a prospective analysis either, because it's not ethical to randomize whether you're removing a body part.
But that's exactly what we did with the appendix, multiple times [1, 2].
I had thought about this and had amended this to "in most cases" before you posted.
If the standard of care is removing the appendix, and you have a strong reason to believe that something less may be superior, you may be able to conduct a randomized trial.
But any other combination of facts is going to be hard for an IRB to swallow.
Yes. This is why T cell activity decreases as one ages. The thymus is where naive T cells are generated, and the output dramatically slows after adolescence.
I've always felt us removing things like tonsils and appendix without a high barrier was always premature. I remember kids wanting to have their tonsils removed to eat ice cream for a few weeks. lol.
Even if we have legacy parts in out body, I'm fine just letting it fester in my body as long as it's not trying to kill me.
Feels very similar to thinking farming just needs 3 nutrients. Turns out better farming requires a lot more.
I am just a plain old bozo though so I could be talking out me ass
I think we're getting better about non-surgical interventions when it's not necessary. Appendicitis can, and is, treated with antibiotics, but the timing has to be spot on otherwise it needs to come out. I had to have mine removed because by the time I was seen in the hospital it had already burst. I think the only time that people pre-emptively remove appendixes is when you can't risk the chance of a burst; like if you're the over-winter physician at Amunden Scott South Pole station
surgeon here:
antibiotic treatment works great as long as there's no peritonitis and/or no appendicolith seen on CT. However, statistics show that 30% of successfully treated patients go on to get appendicitis again within 1 year.
Anyway, I offer my patients a choice. Most choose surgery. Those conscientious enough without insurance usually choose nonoperative management because it's much cheaper.
I had chronic strep and had mine removed at the recommendation of my MD Aunt and Uncle who both practice in Germany. I flew in and immediately got sick at their house. The flight must have wrecked havoc on my immune system. I could feel myself getting progressively sicker during the flight but I was completely fine at the start.
You literally imply there is one and describe it in the sibling comment reply.
Interestingly you present the possibility of a falsifiable hypothesis. Unfortunately due to the highly variable accuracy of diagnosis and propensity to treat (source: I was on The path to surgical training and now routinely diagnose appendicitis in my role as an emergency doctor) depending on health system capacity and availability to acute care the existing retrospective data doesn’t provide a satisfying result - what it does suggest is illuminating however; with a suggestion of a decrease in rate of incidence over the second half of the 20th century in industrialised countries, and a suggestion of increase in some developing countries. This would be more in keeping with an improvement in diagnostic capacity in both industrialised (less false positives) and developing (more false negatives) countries.
Very applicable to programming too. I'm pretty conservative as a programmer and I've had coworkers want to completely change a segment but you never know why some weird programming was done. There be dragons sometimes.
As a software engineer who has sometimes specifically specialized in handling dragons, I always try to leave (sometimes voluminous) comments about why a thing was handled that way when it's not obvious to a surface reading.
Good practice in general but particularly so when you find a heisenbug that must be exterminated.
I had my tonsils out for what at the time we thought was legitimate reasons, but well after they started phasing out the practice.
I recall when I woke up my throat didn't hurt (possibly due to painkillers), and when they brought ice cream and popsicles to sooth my pain I felt like a fraud. But the experience up to that point was traumatic to put it lightly, so you're damned right I was going to get all of the treats I could wrangle.
There was never a medical reason for those, only religious. American doctors tried to invent a medical reason, but those are the same doctors who told people that smoking is good for you because the tobacco companies paid them to.
Sorry, I forgot to mention that; you're absolutely correct, but that's for a tiny number of people who actually have some medical problem where circumcision is a viable remedy. I meant medical reasons for doing it to all male infants as some sort of preventative procedure.
Pre-puberty here, and as someone that was about 4 years old when my circumcision was done I can absolutely understand how ancient peoples would decide just to do every baby boy on the off chance they’d need it later.
True, during the healing process I had the same thought! Would have been rather more convenient to have just had it done as a baby even if I hadn’t needed it!
They did not express any indication that they didn’t understand why ice cream is often recommended, so you don’t need to be explaining it. The point of the comment is that kids don’t understand what’s going on, only hear about the ice cream thing, and then want the same procedure just so they can eat ice cream for a week.
Except they demonstrated interest in the response. Further, they are not the only person who reads the comments. Others may be interested to know the relationship between ice cream and tonsils.
My grandmother had hers taken out in the 1940's. Now she has a small pocket/hole that food gets stuck in which can cause her to gag and/or sometimes throw up.
This type article declaring a thymus revelation is published every few years.
We've known the thymus is saving our lives — it's where the t in t-Cells derives from for years. There are very old studies of removing it from older humans and statistically seeing a decline in health. Most doctors will not remove it without a decent cause in older patients (intractable infection, for example). In those cases it's not that removing the thymus was a good approach. It was just the least-bad approach the physician had on hand to help their patient.
Never forget that everything we do, medically, is a stall. I'm glad we have blood pressure pills and better health spans than our grandparents. Eat a healthy diet, run 3 times a week, manage stress and... die anyway. That's the deal we were given as living things.
I wish I could say my dad's thymus is saving his life, quite the opposite. He was discharged from the ICU/hospital yesterday after he nearly died from a "myasthenic crisis"—an event that most people with Myasthenia Gravis (MG) will experience. From what I understand, his thymus produces antibodies that destroys receptors connecting the nerves and muscles. He can't keep his head up, eyelids up, can't swallow and during the crisis could not breathe.
Interestingly, a small portion of MG patients have an enlarged/tumorous thymus and end up getting it removed, though there aren't necessarily clear benefits. It's also a quite invasive procedure they wouldn't perform on older folks like my dad (he shows no signs of it anyway).
Overall I agree with you though—this article is not saying anything new. As a concerned son who's spent more than his fair share of time trying to understand what's going on here, I wish it did. I also wish there were some treatments for my dad that worked. For now, exercising, eating healthy, lowering stress, and a healthy dose of steroids are currently keeping him with us. If anyone has advice, I'm all ears.
My mother was diagnosed with MG 25 years ago. Her first symptoms were droopy eyelid and double vision. Plasmapheresis helped, Prednisone had nasty side effects (glad to hear that sounds not to be the case for your father), prismatic glasses to un-double her vision kind of helped?
As her symptoms increased—-speech delay, difficulty swallowing, eye misalignment, all stemming from fatigue-induced nerve conduction delays which can culminate in respiratory failure—-myasthenic crisis, they opted for thymectomy (open surgery). She was probably 50 and while the recovery was lengthy, it drastically improved her symptoms and the amount of activity she could do before arose symptoms appeared. No more prism glasses or multi-second speech delays, or weekly plasmapheresis visits. If she spent too much time being active or driving on a sunny day (squinting), she’d feel the ocular fatigue first and know she had to rest or take a prednisone. Now her eyes are failing for other reasons but the thymectomy bought her 25 years and counting.
I’m glad your father survived his crisis. It sounds like you’re doing all of the conservative treatments (which is good; steroid noncompliance is a risk factor for crisis).
There are new medications that directly reduce or deactivate AChR antibodies. Non-invasive video-assisted thoracoscopic thymectomy is more viable today too (and thymectomy has been shown to decrease the frequency and severity of crises even where the thymus was considered normal). Plasmapheresis remains generally effective, if time consuming.
MG sucks. From one son to another, I hope you can get a few more good decades with your parent too.
I've been doing this for some time but I replaced metformin requires RX with Berberine that is safer based on my research. less risk of lactic acidosis of the liver. I found that it's hard to find a sweet spot with DHEA. Too much leads to easy bruising.
I actually prefer pregnenolone to DHEA, I've found it to be more forgiving. I agree wrt Berberine, the lactic acidosis issue turned me off metformin as well. I believe it's the reason Peter Attia stopped using it also.
Sigh. Now I have to track down a copy of The Memluks' album Partida, so I can listen again to their classic "Joe's Thymus" (inspired, I'm sure, by the Readers' Digest "I am {Joe's, Jane's} [name of organ]" articles).
Not claiming it's wrong, especially because it looks like this is an important organ re: immune response, but
> It is typically removed due to issues with the organ itself, such as thymus cancer
> The magnitude of death and cancer in patients who had undergone thymectomy was the biggest surprise for me
Isn't having had cancer the best predictor of having cancer in the future? And so if the main cause of Thymus removal is cancer, seeing cancer after its removal is not very statistically significant?
This covers a paper that, while small in sample size, shows a reduction in age of 6 years. One of the major impacts of the drug cocktail is that it removes much of the fat that accumulates in the thymus as one ages.
There's an amino acid chain synthesized from the thymus of a cow that helped double my lymphocytes (they were low for months). Called Thymic Protein-A. Readily accessible. One of the few things that made a change. Nothing else really helped me out.
What I find interesting how the thymus becomes essentially a blog of fat as we get older and partially explains why infections tend to hit us harder as we age.
I can't remember what it was but there was a talk about some kind of tradeoff with thymus function and age that was supposed to explain its atrophy, something like pneumonia death vs auto immune or cancer or something?
#/media/File:Appendix_function_diagram.svg){kind=link}
> For the study, Kooshesh mined data from 1,146 adult patients who had undergone thymus removal, alongside demographically matched control patients who had undergone similar surgeries but kept their thymus
Sure, you can demographically match all you want, but I don't think this is a research question that can be answered with a retrospective analysis. The problem is that you haven't controlled for why surgeons decided to remove the thymus in some cases and not in others. Was the disease more severe in patients who got thymectomies? Was it differences in training between the surgeons? Was it just an arbitrary decision on the part of the surgeons? This is a critical confounder regardless of whether you've matched the demographics. You really need a randomized control study to answer this sort of question.
> Although the risk of autoimmune disease did not differ substantially between the groups in the overall primary cohort (relative risk, 1.1; 95% CI, 0.8 to 1.4), a difference was found when patients with preoperative infection, cancer, or autoimmune disease were excluded from the analysis (12.3% vs. 7.9%; relative risk, 1.5; 95% CI, 1.02 to 2.2)
What? What is this? Was this subgroup analysis preregistered, or did they just go fishing when their primary hypothesis didn't pan out?
I'd categorize this study as mildly interesting, but not groundbreaking the way the press statement is selling it.