THE EUROPEAN DRTA REGISTRY: AN INITIAL DATA ANALYSIS

BACKGROUND AND AIMS: Distal renal tubular acidosis (dRTA) is a rare disorder characterised by an inability of the distal tubule to secrete acid, leading to metabolic acidosis. Clinical consequences typically include hypokalaemia, hypercalciuria with nephrocalcinosis and/or urolithiasis, as well as bone disease. Treatment with adequate alkali supplementation corrects the acidosis and hypercalciuria, but there are few data on long-term outcome. In 2018, a registry for dRTA was established by the European Society for Paediatric Nephrology, hosted by the European Rare Kidney Disease Reference Network. Here, we present an initial analysis of data in the registry. METHOD: Analysis of data entered into the registry by the cut-off data of 18/11/2020. RESULTS: A total of 135 patients had been entered, of which 106 had additional data from an annual follow-up visit. Median age at last visit was 10 years (range 0-54), including 16 adults (>17y). Genetic testing had been performed in 91 subjects and causative variants were reported in 74 (81%). Pertinent clinical details according to genetic group are listed in table 1. Treatment was provided with at least 15 different preparations, containing citrate or bicarbonate, given in 1-10 (median 3) daily doses. Adequate treatment at last follow-up, as judged by a plasma bicarbonate level >21 mmol/l and a urine calcium-creatinine ratio in the age-specific normal range was present in 46% of subjects. There was a trend for higher eGFR and height SDS in subjects with adequate treatment compared to those without, but this was not statistically significant. CONCLUSION: Currently available data demonstrate the difficulties in treating dRTA, with less than half of subjects achieving adequate control of their acidosis. By collecting long-term data, the registry will provide important information on the prognosis and complications of dRTA and to what degree these can be prevented with treatment. Enrollment of further, especially adult patients will contribute to our understanding of this rare disorder

A Nationwide Retrospective Study in Turkish Children With Nephrocalcinosis.

Background/aim: Nephrocalcinosis (NC) is defined as calcium deposition in the kidney parenchyma and tubules. This study aims to determine the etiology, risk factors, and follow-up results of patients with NC in Turkey. Materials and methods: Patients diagnosed with NC in the pediatric nephrology Department Units of 19 centers from all geographical regions of Turkey over a 10-year period (2010-2019) were included in the study. The medical records from the centers were reviewed and demographic data, admission complaints, medical history, systemic and genetic disorders, risk factors for NC, treatment details, and presence of NC after one-year follow-up, were recorded retrospectively. Results: The study sample included 195 patients (88 females, 107 males). The mean age at diagnosis was 39.44 +/- 47.25 (0.5-208) months; 82/190 patients (43.2%) were diagnosed incidentally; 46/195 patients (23.6%) had an underlying disease; idiopathic hypercalciuria was detected in 75/195 (38.4%) patients. The most common systemic diseases were distal renal tubular acidosis in 11/46 patients (23.9%), primary hyperoxaluria in 9/46 patients (19.6%) and Bartter syndrome in 7/46 patients (15.3%). After one year of follow-up, NC resolved in 56/159 patients (35.2%) and they all did not have an underlying systemic disease. Conclusion: The most common presentation of NC was incidental. Distal renal tubular acidosis and primary hyperoxaluria were the main systemic diseases leading to NC, while hypercalciuria was the most common metabolic risk factor. Nephrocalcinosis was found to remain in most of the patients at a one-year follow-up. It may resolve particularly in patients with no underlying systemic disease

COVID-19 in pediatric nephrology centers in Turkey

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