Pneumoncystis jirovecii (PJP) is an opportunistic infection that can occur in immunosuppressed patients, including those with renal transplant. We present the case of a 63-year old male with autosomal-dominant polycystic kidney disease with renal transplant on immunosuppressive therapy who presented with cough and exertional dyspnea. He was hypoxic with coarse breath sounds bilaterally. CT chest revealed ground-glass opacities with increased interstitial markings of the left lung. Labs were significant for hypercalcemia with ionized calcium 1.53 mmol/L, parathyroid hormone 97 pg/mL, 25-hydroxy vitamin D level 30 ng/mL and increased 1,25-dihydroxy vitamin D to 156 pg/mL. He was started on intravenous normal saline, furosemide and calcitonin, however, he remained hypercalcemic. Endocrinology evaluated him and he was started on ketoconazole and received one dose of denosumab, with no improvement in calcium levels. Bronchiolar lavage cultures obtained from bronchoscopy were positive for PJP. He was started on intravenous steroids, clindamycin and primaquine due to acute kidney injury, precluding the use of Bactrim. His calcium levels improved with treatment of PJP, and he was discharged home. This case illustrates the potential for renal transplant recipients who develop PJP to develop hypercalcemia. Although the mechanism is not fully understood, it is thought to be secondary to an increase in 1,25-dihydroxy vitamin D, possibly related to a granulomatous reaction against PJP. Patients with PJP may have hypercalcemia that improves with treatment, as was seen in this patient. It is important to consider PJP as the etiology of unexplained hypercalcemia in renal transplant patients.https://scholarlycommons.henryford.com/merf2020caserpt/1113/thumbnail.jp
