2a) Welcome to a🆕#accredited #tweetorial brought to you by the collaboration of @ckd_ce & @KIReports.
— @CKD_ce (@ckd_ce) April 30, 2024
Our guest author is Ali W. Rizvi @AWRizviDO of @OhioStateNeph
Our topic for 🆓CE/#CME : #KidneyStones #Recurrentstones as a journal club on a paper by @amyaimei titled . . . pic.twitter.com/BYT56j8rAE
3) This article is a part of our new @KIReports series the Stone Chronicles, led by the emerging stone expert @amyaimei with expert reviewers @Goldfarbdavid and John Asplin. Stay tuned for more in the months to come!
— @CKD_ce (@ckd_ce) April 30, 2024
4b) Please note there was no industry support for this accredited program. FOLLOW US at @ckd_ce and @KIReports for more expert #MedEd in #kidneydisease.
— @CKD_ce (@ckd_ce) April 30, 2024
6) Quiz answer: ⬇️Urine pH. Higher the urine pH ➡ more likely scenario for CaPO4 stones to form. The phosphate in CaPO4 stones has a dissociation constant (pKa2) of 6.8, which causes crystal formation at urine pH closer to this value. Let’s 👀 at the presented case @amyaimei!
— @CKD_ce (@ckd_ce) April 30, 2024
8) He underwent bilateral percutaneous #nephrolithotomy and #ureteroscopy w/stent placement. Stone analysis showed 90% calcium phosphate (#brushite) & 10% calcium phosphate (#apatite)
— @CKD_ce (@ckd_ce) April 30, 2024
10) This patient had recurrent calcium phosphate stones. The urinary metabolic work-up revealed the following risk factors for stone formation:
— @CKD_ce (@ckd_ce) April 30, 2024
– ⬇️urine volume
– Hypercalciuria
– Hypocitraturia pic.twitter.com/zOXszPtjKY
12) He also had a ⬆️urinary #supersaturation (SS) of calcium salts. Urine SS is based on acid dissociation constants (pKa) of urinary salts & stability of all ion pairs. This concept + stone analysis gives us a clearer picture ✨ of why these stones form
— @CKD_ce (@ckd_ce) April 30, 2024
14) But why is metabolic acidosis a known player in stone formation? pic.twitter.com/3dYx64o4Gf
— @CKD_ce (@ckd_ce) April 30, 2024
16) Normally, majority of Ca++ is reabsorbed paracellularly in PCT & TAL, whereas 10% is reabsorbed in DCT by Transient Receptor Potential Vanilloid Subgroup 5 (TRPV-5)- an epithelial Ca++ channel that is ⛔ in metabolic acidosis ➡⬆️relative calciuria (Yau AA, KI Reports, 2023) pic.twitter.com/3HJvGIXOaM
— @CKD_ce (@ckd_ce) April 30, 2024
18) Here’s the evidence so far:
— @CKD_ce (@ckd_ce) April 30, 2024
● Large reviews found CaOx stones that 🔀to CaPO4 stones had 🔺 in urine pH 6.2➡️6.7
● But these studies didn’t show an increase in urine SS of CaPO4 (1.9 ▶️1.6) & unclear if they received alkali therapy as well. Maybe other factors are at play?
20) Our patient was started on sodium bicarbonate as he could not tolerate K-citrate. He also had hypokalemia of 3.3 mEq/l, so was started on potassium supplementation. Urine citrate was still low but modest urine volume mitigated stone formation risk.
— @CKD_ce (@ckd_ce) April 30, 2024
22a) Let’s try another quiz: In chronic metabolic acidosis (MA), which of the following malfunctioning channels in DCT contribute to⬆️risk of Ca++ stone formation?
— @CKD_ce (@ckd_ce) April 30, 2024
A) Citrate uptake via NADC1
B) Calcium uptake via TRPV5
C) Na/Cl uptake via NCC
D) H/K ion transport via H/K ATPase
22c) These two combined make an environment conducive to stone formation. See 🔓 https://t.co/9mk6TXDVsl
— @CKD_ce (@ckd_ce) April 30, 2024
23) And you just earned 0.5hr 🆓CE/#CME! Claim your certificate at https://t.co/nuRF1cYZbg. THANK YOU to @AWRizviDO and @sophia_kidney. FOLLOW US for more #MedEd all about the 🫘 !!
— @CKD_ce (@ckd_ce) April 30, 2024