Turns out lowly thymus may be saving your life
news.harvard.edu
news.harvard.edu
> 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.
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.
But that's exactly what we did with the appendix, multiple times [1, 2].
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.
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".
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.
[0]: https://en.wikipedia.org/wiki/Appendix_(anatomy)#/media/File...
We both have our appendix.
Though to your point, whether you can develop a milk allergy later in life I am not sure.
If so a confidence interval of 1.02 to 2.2 after arbitrarily excluding some data is not exactly ground breaking.
Not vestigial evolutionary speaking, but doesn't it get less and less functional over a person's lifespan and gets replaced with fat tissue?
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.”
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
Good practice in general but particularly so when you find a heisenbug that must be exterminated.
I just get mad tonsil stones now. lol
After I had my tonsils removed, even the thought of solid food was out of the question. It was just too painful.
You can have as much ice cream as you want. What they don't tell you is you won't want any. :P
Anyway, the relationship of tonsils and ice cream was established by Richard Scarry in "What do people do all day?" [0]
https://en.wikipedia.org/wiki/Eosinophilia%E2%80%93myalgia_s...
Yeah, kids don’t get tonsils removed anymore either. Just antibiotics.
Anyway, I offer my patients a choice. Most choose surgery. Those conscientious enough without insurance usually choose nonoperative management because it's much cheaper.
Are we to pretend all diets are the same?
Am I to pretend it is a religious mystery/miracle and no ones knows? Or genetics? Please, enlighten us...
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.
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.
Add circumcisions to the list.
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.
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.
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.
> 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.
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.
Edit:
Wikipedia on it: https://en.wikipedia.org/wiki/Thymic_involution#Unknown_sele...