Refractory hypercalcemia in an infant secondary to talc pleurodesis resolving after renal transplantation

Talc pleurodesis is the definitive therapy of recurrent pneumothorax and has not been associated with metabolic complications. We report an anephric male infant who developed severe hypercalcemia 6 months following talc pleurodesis for recurrent peritoneal dialysis-related hydrothorax. The etiology of hypercalcemia was related to persistently elevated 1,25-dihyroxyvitamin D ₃ (1,25[OH]₂D) levels. The source appeared to be the extrarenal production of 1,25(OH)₂D from macrophages in a large thoracic talc granuloma. Hypercalcemia was controlled with a combination of a low calcium diet, low calcium dialysis, ketoconazole and hydroxychloroquine, but elevated 1,25(OH)₂D levels persisted. At 32 months of age the child underwent renal transplantation with alemtuzumab pre-conditioning. The hypercalcemia resolved immediately, with normalization of serum 1,25(OH) ₂D levels and without hypercalciuria. This case demonstrates that hypercalcemia is a potential complication of talc pleurodesis from the extrarenal production of 1,25(OH)₂D and that alemtuzumab, a monoclonal antibody directed against the CD52 antigen (which is expressed on almost all macrophages), may have a role in the treatment of hypercalcemia associated with granulomatous conditions.