Renal calcifications in patients with autosomal recessive polycystic kidney disease: prevalence and cause.

OBJECTIVE: We investigated the prevalence of renal calcifications in children with autosomal recessive polycystic kidney disease and studied the metabolic changes that could cause this complication. SUBJECTS AND METHODS: Nine patients with known autosomal recessive polycystic kidney disease were examined with sonography and CT and screened for biochemical evidence of metabolic causes of nephrocalcinosis. RESULTS: CT showed bilateral renal calcifications in seven of the nine patients. The two patients without renal calcifications were less than 1 year old. Four patients had only a few calcifications and three patients had many. The severity of the renal calcifications correlated with the degree of kidney failure. All patients with kidney failure were found to have urine acidification defects. Hypocitraturia was present in all patients. CONCLUSION: Our results show that renal calcifications are common in older children with autosomal recessive polycystic kidney disease. Hypocitraturia and the urine acidification defect resulting from kidney failure are the leading factors in the pathogenesis of the calcifications.