Pt in 40s thin, new poorly controlled DM, severe HTN, nephrotic proteinuria, retinopathy, hypercalcemia 12-13. Cr 1.0 Previously healthy but not seeing doc regularly. PTH 40s after repleting vit D. 24 hr urine ca anywhere from undetectable to <150. Pth-rp nl, Pan CT negative for cancer. Calcium still 12s after IVFs in hospital briefly improved it. Pt a little dizzy in general. Has orthostasis, BP 150s sitting to 120s standing. Next steps for hypercalcemia??
All just opinions and thoughts
Total zebra, but pheo is sometimes associated with orthostasis and with hypercalcemia through PTH-dependent and independent mechanisms.
Much more likely I would think would be secondary hyperpara from diabetic kidney disease (which is severe, evidenced by the proteinuria, though his GFR is well preserved). PTH 40 is WNL in your units, is that right? Should be suppressed by hypercalcemia and isn't.
Practically, 13 (3.24) is around the zone where i might consider empirically using a bisphosphonate for control. Or sensipar if it is covered for him, based on the hyperparathyroid idea.
What are you thinking? I'll boost in the hope of getting other people's ideas.
PS do an intro tweet and write your bio. Lots of hashtags so you start seeing what you love. Welcome to mastodon!
@alexchangmd @hswapnil I guess I'd call this tertiary hyperparathyroidism, because of the hypercalcaemia. PTH should be suppressed for any other cause of hypercalcaemia, though that isa pathophysiology argument not one I can support with evidence. I think you've done due diligence for now diagnostically. Are you thinking of using bisphosphonate IV or only of hypercalcaemia worsens?
PS for others to have a chance of seeing and weighing in, which would be great, would value other #nephpearls #kidneyverse opinions, on Mastodon you have to reblog/boost. Unlike the birdsite, there's no algorithm that responds to likes, it just tells the person posting that you liked it.
Very nice to meet you and what an interesting post!
@cmclase @hswapnil thanks Catherine
For the input and tips on using mastodon!
I didn’t mention that this patient was heterozygous for a SLC34A3 variant Ser192Leu on the genetic testing. This causes increased risk of hypercalciuria (which are pt doesn’t have) due to low serum phos stimulating calcitriol synthesis. Bialleic cases have been described w/hypercalcemia but not monoalleic cases. I don’t feel this pts case is explained by that mutation but may be contributing https://www.medrxiv.org/content/10.1101/2023.01.21.23284856v1
@alexchangmd @hswapnil
Really interesting! & you are welcome! ♥️
@cmclase @hswapnil pts 1,25 dihydroxyvit D was 40s so I figure can try to suppress that with either fluconazole or hydroxychloroquine off-label for more “targeted” treatment than bispnosphonates. Side note: she has excellent bone density…again would have been great to have a dx of FHH. Checked a ACE level (high of course w/no evidence of disease anywhere…why did I check it??) She agreed to give hydroxychloroquine a shot as a next step... will see if any response. Still needs a cscope done.
@cmclase thanks! Trying to see if I’m missing any zebras. With low calcium excretion I thought I’d pick up FHH. Genetic testing neg for FHH. Thought of the pheo zebra (some secrete calcitonin)…plasma metanephrines wnl. Parathyroid scan neg (I know it’s not 100%), i empirically gave cinacalcet and no improvement in calcium. Vit A wnl. Cystatin c eGFR is lower at 38 but don’t think would have hypercalcemia w/secondary hyperpara…