Pulmonary calcinosis after renal transplantation in pediatric patients

Pulmonary calcinosis is a recognized complication of renal failure. The resulting pulmonary compromise may be severe or even fatal. The potential contribution of hypercalcemia, hyperphosphatemia, and increased calcium-phosphorus product to the development of pulmonary calcinosis has been controversial. We describe four patients (ages 2 1/4 to 18 years) who had severe pulmonary calcinosis and respiratory failure within three to five days after renal transplantation. Initial clinical and roentgenographic findings suggested noncardiogenic pulmonary edema. Marked pulmonary hypertension was present in the two patients in whom pulmonary artery pressure data were available. Other clinical features in common included poor allograft function with persistent uremia requiring dialysis and evidence of moderate to severe secondary hyperparathyroidism. In three of the patients, the calcium-phosphorus product increased markedly after transplantation, to peak values of 122 to 147. This increase occurred at the same time as the onset of respiratory failure. Peak serum calcium levels were 10.0 to 11.0 mg/dL and peak serum phosphorus levels were 9.2 to 13.5 mg/dL. All patients died of respiratory failure five to 58 days after transplantation. The posttransplantation period may be a time of increased risk of potentially fatal pulmonary calcinosis in pediatric renal transplant recipients. The diagnosis should be considered in any patient with respiratory failure of unknown cause following renal transplantation.