"But looking more closely at the increased deaths, they were mostly from autoimmune diseases that couldn’t plausibly be related to their donations."
Kidneys make calcitriol. One kidney means you'll make less, and if you don't supplement, you'll become deficient. Deficiency would (possibly) lead to autoimmune diseases.
Also EPO (erythropoietin). One kidney means less, and less (possibly) means fewer new red blood cells, then (possibly) anemia. Anemia wreaks havoc.
And bicarbonate.
To be clear, if you want to donate a kidney, then do it if it's the right choice. It's very kind. Just know what to pay attention to to keep yourself in good health.
One small advantage of kidney donation is that it comes with lifetime screening without some of the gatekeeping normally attached to that. I dunno exactly how it works in the US, but here in Canada you can't just really demand blood tests purely for screening reasons, there needs to be a reason for it. But if you're a donor, your transplant clinic will insist on periodic screening both to monitor for GFR dropping as well as other issues like the ones you mention.
Transplant centres vary for sure (to a surprisingly huge degree), but at least where I am if you do donate the clinic will be watching out for this stuff on your behalf.
About erythropoietin (EPO), I understand it's a hormone whose amount is regulated by the need for oxygen in the blood (i.e. a feedback loop which regulates the amount of red blood cells to be just what is needed to satisfy the oxygen needs of the body).
So EPO is not limited by the ability of the kidneys to produce it (I expect, by a large margin). So one kidney would just as well be able to produce all the EPO you may need, the kidney is not the limiting factor.
Cyclists who dope with EPO are raising their levels far beyond what is healthy in order to get their red blood cell count to superhuman levels. It has the side effect of massively raising your risk of stroke
My point is that cyclists dope with EPO precisely because the body doesn't produce enough for your oxygen needs. There is a cap, probably for good reasons as you say.
>they were mostly from autoimmune diseases that couldn’t plausibly be related to their donations
Sounds extremely brittle logic. Why couldn't they be "related to their donations"?
For starters, the donations could make their immune system weaker (and thus make any autommune diseases they already have more impactful) or make it go haywire to combat the post-operation stress...
The idea "the donations could make their immune system weaker" seems pretty brittle. Why? What biological mechanism would support that hypothesis? What kidney function that would be halved (assuming the remaining kidney wouldn't "step up" to fill the gap) that could lead to an autoimmune disorder?
Not saying there's nothing, but you haven't provided any more evidence or logic than OP has provided.
Kidneys make calcitriol. One kidney means you'll make less, and if you don't supplement, you'll become deficient. Deficiency would (possibly) lead to autoimmune diseases.
Also EPO (erythropoietin). One kidney means less, and less (possibly) means fewer new red blood cells, then (possibly) anemia. Anemia wreaks havoc.
And bicarbonate.
To be clear, if you want to donate a kidney, then do it if it's the right choice. It's very kind. Just know what to pay attention to to keep yourself in good health.