Browsing by Author "Puar, Akshan"

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    Hyperphosphatemic Tumoral Calcinosis With Pemigatinib Use
    (Elsevier, 2022-07-16) Puar, Akshan; Donegan, Diane; Helft, Paul; Kuhar, Matthew; Webster, Jonathan; Rao, Megana; Econs, Michael; Medicine, School of Medicine
    Background/objective: Pemigatinib, a fibroblast growth factor receptor (FGFR) 1-3 inhibitor, is a novel therapeutic approach for treating cholangiocarcinoma when an FGFR fusion or gene rearrangement is identified. Although the most reported side effect of pemigatinib is hyperphosphatemia, tumoral calcinosis with soft tissue calcifications is not widely recognized as a complication. We report a case of patient with hyperphosphatemic tumoral calcinosis on pemigatinib. Case report: A 59-year-old woman with progressive metastatic cholangiocarcinoma, despite receiving treatment with cisplatin and gemcitabine for 7 months, was found to have an FGFR2-BICC1 fusion in the tumor on next-generation sequencing. Pemigatinib was, therefore, initiated. Four months into the therapy, multiple subcutaneous nodules developed over the lower portion of her back, hips, and legs. Punch biopsies revealed deep dermal and subcutaneous calcifications. Investigations revealed elevated serum phosphorus (7.5 mg/dL), normal serum calcium (8.7 mg/dL), and elevated intact fibroblast growth factor-23 (FGF23, 1216 pg/mL; normal value <59 pg/mL) levels. Serum phosphorus levels improved with a low-phosphorus diet and sevelamer. Calcifications regressed with pemigatinib discontinuation. Discussion: Inhibition or deficiency of FGF-23 results in hyperphosphatemia and can lead to ectopic calcification. Pemigatinib, a potent inhibitor of FGFR-1-3, blocks the effect of FGF-23 leading to hyperphosphatemia and tumoral calcinosis as observed in our case. Treatment is aimed primarily at lowering serum phosphate levels through dietary restriction or phosphate binders; however, the regression of tumoral calcinosis can occur with pemigatinib cessation, as seen in this case. Conclusion: As the use of FGFR 1-3 inhibitors becomes more prevalent, we aim to raise attention to the potential side effects of tumoral calcinosis.
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    Prolonged Hypocalcemia After a Single Dose of Denosumab in Chronic Kidney Disease
    (Endocrine Society, 2021-05-03) Puar, Akshan; Saeed, Zeb Ijaz; Medicine, School of Medicine
    Introduction: Denosumab, a monoclonal antibody that inhibits RANK L (receptor activator nuclear factor-kappa beta ligand), is one of the few medications that can be used to treat osteoporosis in patients with chronic kidney disease (CKD). However, its use is associated with a much higher incidence of hypocalcemia in this patient population. What remains unclear is the duration of hypocalcemia after denosumab use. We describe a case of prolonged hypocalcemia of 9 months in a patient with CKD after a single dose of denosumab. Case: A 64-year-old Caucasian man with a history of bilateral lung transplant for interstitial pulmonary fibrosis and CKD Stage IV was referred to the Endocrinology clinic for evaluation of steroid-induced osteoporosis. Bone density scan was consistent with osteoporosis with the lowest T-score of -2.8 at the left femoral neck, which showed a 25.3% decline from a previous one two years prior. His labs upon initial visit: 25 hydroxy Vitamin D: 36.5 ng/mL (30–100), 1, 25 hydroxy vitamin D 32 pg/ml (19.9–79.3), corrected Serum Calcium 8.9 mg/dL (8.5–10.5), Serum Cr 4.38 mg/dL (0.6–1.4), PTH 157 pg/mL (10–65), Serum Alkaline Phosphatase 61 Units/L (25–125), Urine NTX 39 nM BCE/mM creatinine (21–83). After discussing risks and benefits, he was given a dose of subcutaneous denosumab 60 mg. He had been started on Calcium/Vitamin D (600 mg/400 IU BID) prior to receiving his dose. Keeping in mind the increased risk of hypocalcemia given his history of CKD, his corrected serum calcium was checked one week later, and it was 6.5 mg/dL. The patient was asymptomatic. However, given the severity of his hypocalcemia, he was started on calcitriol 0.25 mcg oral BID and calcium carbonate 1200 mg daily. He did show mild improvement in three days to a corrected calcium of 7.0 mg/dL. His calcitriol was briefly increased to 0.5 mcg BID and calcium carbonate was increased to 1800 mg daily. The regimen was weaned to calcitriol 0.25 mcg daily and previous calcium/Vitamin D dosing later that month. Thereafter, his labs were monitored regularly and there were several unsuccessful attempts made to decrease the calcitriol/calcium carbonate. Given persistent hypocalcemia, other bloodwork including a bone specific alkaline phosphatase and celiac screen were checked which were unremarkable. Finally, nine months after his denosumab dose, calcitriol was discontinued safely. Serum calcium levels have remained stable thereafter. Given prolonged hypocalcemia, it was decided not to administer another dose of denosumab. Conclusion: Patients with CKD who receive denosumab are not only at risk for developing severe, but also prolonged hypocalcemia. Therefore, it is imperative to monitor serum calcium levels, not only immediately after receiving a dose, but serially.