Hypercalcemia in a renal transplant recipient suffering with Pneumocystis carinii pneumonia.

Hypercalcemia occurs frequently after renal transplantation. Preexisting hyperparathyroidism is the most common cause of post-transplantation hypercalcemia. We describe a renal transplant recipient infected with Pneumocystis carinii pneumonia (PCP) who developed hypercalcemia, elevated 1,25-dihydroxyvitamin D, and suppressed parathyroid hormone levels. This phenomenon mimics the extrarenal production of 1,25-dihydroxyvitamin D by activated alveolar macrophages in granulomatous diseases with hypercalcemia. To the best of our knowledge, this is the first report of 1,25-dihydroxyvitamin D-mediated hypercalcemia caused by PCP in a renal transplant recipient. This entity should be included in the differential diagnosis for renal transplant recipients with hypercalcemia, especially in patients who develop lung infections. Copyright 2002 by the National Kidney Foundation, Inc.