Soft tissue calcification in pediatric patients with end-stage renal disease

Soft tissue calcification is a recognized complication of uremia in adult patients and has been implicated as a cause of ischemic necrosis, cardiac arrhythmias, and respiratory failure. However, soft tissue calcification has been regarded as rare in pediatric renal patients. Following a sudden death due to pulmonary calcinosis in an adolescent after renal transplantation, we retrospectively reviewed clinical, biochemical and autopsy data of 120 patients with uremia, on dialysis, or following renal transplantation cared for at Childrens Hospital of Los Angeles from 1960 to 1983. Soft tissue calcification was found in 72 of 120 patients (60 percent). Forty-three patients (36 percent) had systemic calcinosis (Group A); the most frequent sites of mineral deposition were blood vessels, lung, kidney, myocardium, coronary artery, central nervous system, and gastric mucosa. Vascular calcification was uniformly accompanied by deposits in other organs. Twenty-nine patients had small amounts of focal calcification (Group B) and 48 patients had no soft tissue calcification (Group C). By multiple logistic regression analysis, the use of vitamin D or its analogues, the form of vitamin D medication prescribed, the peak calcium x phosphorus product, the age at onset of renal failure, and male sex were jointly associated with calcinosis (Group A). Vitamin D therapy showed the strongest independent association with calcinosis and the probability of calcinosis was greater in patients receiving calcitriol when compared with dihydrotachysterol and vitamin D₂ or D₃. The duration of renal failure, peak serum calcium, serum calcium at death, serum phosphorus at death, and primary renal diagnosis, were not statistically associated with calcinosis. The data from this series confirm that soft tissue calcification is a significant problem in young patients with advanced renal disease. Lung, myocardium, and coronary arteries were frequent sites of calcium deposition, with clinically significant, and in some cases fatal consequences.