ESPE Abstracts

Introduction: In the literature, there are reports about nephrocalcinosis (NC), hypercalcemia, and hypercalciuria risk in patients with congenital adrenal hyperplasia (CAH). The prevalence and background of nephrocalcinosis is not established. Nephrocalcinosis refers to diffuse calcification in the renal parenchyma, generally in renal pyramids.

Aim of the study: The study aimed to evaluate the prevalence of nephrocalcinosis and nephrocalcinosis risk factors such as hypercalciuria, hyperphosphaturia, hyperuricosuria, hyperoxaluria, hypomagnesuria, and hypocitraturia among patients with CAH due to 21 hydroxylase deficiency.

Results: In 53 patients with confirmed 21 hydroxylase deficiency, an abdominal ultrasound was performed, and excretion of electrolytes, uric acid, oxalates, and citrates was analyzed twice. A retrospective chart review was conducted for all patients. In 10 out of 53 (18,8%) patients with confirmed 21 hydroxylase deficiency nephrocalcinosis was described in the abdominal ultrasound. All ten patients have salt-wasting CAH. The nephrocalcinosis was found in most cases accidentally during ultrasound examination due to different issues. The medium age of the diagnosis was two years six months (2 months - 7 years). In two patients, the vanishing of the nephrocalcinosis features in the ultrasound was observed after a couple of years. All patients were treated with hydrocortisone, fludrocortisone, and salt supplementation during the 1^st year of life. In 4 out of 10 patients with described NC, transient episodes of hypercalcemia during the 1^st year of life were observed. In 5 out of 10 patients, hypercalciuria and 6 out of 10 increased calcium/creatinine ratio were identified. In 7 out of 10 patients, hyperphosphaturia was observed, and in 8 out of 10, hyperuricosuria was noted. In 4 out of 10 patients, hyperoxaluria was found. In 1 out of 10 patients, hypocitraturia was described, and in 5 out of 10 patients, a decreased magnesium/creatinine ratio was observed.

Conclusion: According to our research, children with salt-wasting congenital adrenal hyperplasia are at high risk of nephrocalcinosis development. In our study group also, the prevalence of nephrocalcinosis or nephrolithiasis risk factors such as hypercalciuria, hyperphosphaturia, hyperuricosuria, hyperoxaluria, hypomagnesuria, and hypocitraturia was high. The background, etiology, and natural history remain unclear. The impact of nephrocalcinosis on renal function in this group of patients lasts inexplicitly. Further studies are needed to determine the prevalence, etiology, impact, and natural history of nephrocalcinosis in CAH.