Abstract: PO2190
Hypercalcemia Associated with Immune Checkpoint Inhibitors
Session Information
- Onco-Nephrology - 2
October 22, 2020 | Location: On-Demand
Abstract Time: 10:00 AM - 12:00 PM
Category: Onco-Nephrology
- 1500 Onco-Nephrology
Authors
- Obole, Eshetu L., The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Ayoub, Isabelle, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
Introduction
Immune checkpoint inhibitors revolutionized treatment of many cancers with marked improvement in prognosis. They target CTLA-4, PD-1/PD-L1 pathways. However immune related adverse events complicate their use. Here we present the first reported case of hypercalcemia as a result of immune checkpoint inhibitors
Case Description
A 68-year old man with metastatic renal cell carcinoma underwent right nephrectomy followed by immunotherapy with ipilimumab and nivolumab. Two weeks after his second cycle of immunotherapy, he presented with inflammatory arthritis and pruritis. Work up was significant for sCa 12.8 mg/dl and Scr 3.6 mg/dl. Hypercalcemia was suspected to be malignancy related from bone metastasis or humoral stimulation. He received fluids, calcitonin and Zoledronic acid. Further investigations showed a suppressed iPTH<6.3 pg/ml, normal PTrP, low TSH 0.04 uU/ml, free T4 1.91, normal 25-OH vitamin D, elevated 1,25dihydroxy vitamin D 142 pg/ml and normal ACE level. No monoclonal proteins were detected in serum. CRP and interleukin 6 were elevated to 80 mg/dl and 176 pg/ml respectively. PET scan showed diffuse hypermetabolic lymph nodes in mediastinum, neck, and abdomen. Transbronchial needle aspiration was negative for malignancy. Inflammatory arthritis, pruritis, hyperthyroidism, nonmalignant diffuse lymphadenopathy, and 1.25 dihydroxyvitamin D induced hypercalcemia are suggestive of immune related adverse effects rather than disease progression. Patient was started on prednisone 1mg/kg/d. Hypercalcemia, AKI, pruritis and inflammatory arthritis resolved. Repeat 1,25 dihydroxy vitamin D and CRP levels were back to normal
Discussion
Hypercalcemia related to checkpoint inhibitors was previously described in setting of increased PTrP. Our patient had hypercalcemia directly related to immunotherapy likely through increased alpha hydroxylation.