This is a case of a young man who had a long history of drug use who suffered a single vehicle car crash. He came to the ED with a large laceration that was stitched up. He was given antibiotics and sent home. At home, he declined to take his antibiotics, but did take methamphetamine. A week and a half later he showed up to the ED again with fever, icterus, and purpura. He grew Staph. aureus from his blood. He declined rapidly with multiorgan failure and died.
Examination of this kidneys revealed classic simplification and flattening of the proximal tubule epithelium with loss of brush border associated with acute kidney injury . Here’s a couple of pics:
You can see how the epithelial cells are flatter and have smooth apices. To remind you, here’s a couple of pics from a more normal case:
… and a side-by-side
Somewhere along the line, I saw this called “distalization” of the proximal tubules — because they start looking like distal tubules. However apparently, that’s not a real descriptor. Too bad. I kinda like it.
I recently read an interesting article about this. It turns out that this change represents dedifferentiation of the proximal tubular cells into a more primitive form that can replicate. When the tubules are injured and have to fill in the empty spots left by dead cells, the remaining cells dedifferentiate and replicate rather than recruiting stem cells. Cool. See:
https://www.pnas.org/doi/10.1073/pnas.1310653110
Also, of interest, it turns out that methamphetamine use is a risk factor tor cellulitis following injury. Turns out that meth makes recovery more difficult by two mechanisms. First, as expected, it is a vasoconstrictor that decreases blood flow to the injury. Second, it is a direct immunomodulator that iincreases IL-6 and decreases phagocytosis. It also stimulates biiofilm formation. Who knew.
https://journals.asm.org/doi/full/10.1128/mbio.01622-15
As always, free for use with or without attribution, though attribution is always appreciated. If you need higher resolution images, contact me.