Hypercalcemia and pneumocystis Pneumonia after kidney transplantation: report of an exceptional case and literature review

Pneumocystis jirovecii remains an important pathogen in solid organ transplant recipients. Although the overall incidence may be decreasing, after the adoption of effective prophylactic measures, the risk has not been abolished, and pneumocystis pneumonia (PCP) can be observed even many years after successful transplantation. Hypercalcemia develops frequently after renal transplantation and is commonly associated with preexisting secondary hyperparathyroidism. But the pathogenesis of hypercalcemia occurring later in the course of transplantation may be different, and other disease states, such as malignancy and opportunistic infections, must be considered. Hypercalcemia in conjunction with PCP is being increasingly reported in renal transplant patients. In all the cases, respiratory symptoms were prominent, hypercalcemia was of mild-to-moderate severity, parathyroid hormone concentration was decreased, and 1,25(OH)(2) D levels were extraordinarily or inappropriately high. We report the first case to our knowledge of severe hypercalcemia accompanying PCP, in a patient with previous total parathyroidectomy.