Abstract: SA-PO1163
Severe Hypercalcemia as the Presenting Feature of Pneumocystis jirovecii Pneumonia in a Kidney Transplant Recipient
Session Information
- Transplantation: Clinical - Infectious Diseases
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Transplantation
- 2002 Transplantation: Clinical
Authors
- Mohan, Pankhuri, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Kleman, Mark A., The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Kotzen, Elizabeth, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
Introduction
Hypercalcemia is a common complication following kidney transplant with the most common cause being hyperparathyroidism. This case demonstrates a lesser-known, PTH-independent etiology of hypercalcemia with a specific infectious presentation.
Case Description
A 66-year-old female with history of deceased donor kidney transplantation 6 years prior and parathyroidectomy 9 years prior (on daily calcitriol) presented with hypertensive urgency and was found to have new hypercalcemia. Laboratory evaluation revealed normal WBC, baseline creatinine 2.2 (from baseline 1.8-2.0 mg/dL), hypercalcemia (initial total calcium of 11.0 mg/dL with peak to 13.5 mg/dL), suppressed PTH levels (<6.3 pg/mL), low 25-OH vitamin D (24 ng/ml), normal PTH-related peptide, and elevated 1,25-OH vitamin D level (111 pg/mL). Chronic medications of calcitriol and chlorthalidone were held but the hypercalcemia persisted and worsened. Patient received IV fluids and calcitonin without improvement. On hospital day 3 she developed new acute hypoxic respiratory failure. Chest radiograph revealed bronchial wall thickening, respiratory virus panel was negative, and she had no improvement with diuresis. CT chest was obtained which revealed ground-glass opacities in bilateral lungs with relative sparing of bilateral lung bases, concerning for Pneumocystis jirovecii pneumonia (PJP). Induced sputum was positive for PJP PCR. Due to a sulfa allergy, the PJP infection was treated with primaquine, clindamycin and corticosteroids with clinical improvement. From the time of PJP treatment initiation, the oxygen requirement resolved in 6 days and total serum calcium normalized in 8 days.
Notably, bisphosphonates and denusomab were avoided due to history of parathyroidectomy, to mitigate risk of prolonged hypocalcemia.
Discussion
This case highlights the importance of considering PJP (and other granulomatous infections) as a cause of PTH-independent hypercalcemia in an immunosuppressed renal transplant patient with elevated 1,25-OH vitamin D. In this case, the hypercalcemia preceded the development of respiratory symptoms. The proposed mechanism for hypercalcemia in PJP is extrarenal 1-a-hydroxylase activity from activated alveolar macrophages. Early identification and treatment of the underlying infection are key to resolving hypercalcemia and improving patient outcomes.