Molecular aspects and long-term outcome of patients with primary distal renal tubular acidosis.

Background: Primary distal renal tubular acidosis (dRTA) is a rare genetic disorder caused by impaired distal mechanisms of urinary acidification. Most cases are secondary to pathogenic variants in ATP6V0A4, ATP6V1B1, and SLC4A1 genes, which encode transporters regulating acid-base balance in the collecting duct.

Methods: Retrospective study of molecular and clinical data from diagnosis and long-term follow-up (10, 20, and 40±10 years) of 16 patients with primary dRTA diagnosed in childhood.

Efficacy and safety of cinacalcet for the treatment of secondary hyperparathyroidism in patients with advanced chronic kidney disease before initiation of regular dialysis.

Aim: To evaluate the compassionate use of cinacalcet for the management of secondary hyperparathyroidism in patients who are not on dialysis.

Methods: Patients with stage 4-5 chronic kidney disease (CKD) who were not on dialysis, had an intact parathyroid hormone (iPTH) level greater than 300 pg/mL, and had not responded satisfactorily to treatment with phosphate binders and vitamin D were prospectively studied. Patients received 6 months of compassionate treatment with cinacalcet, which was initiated at a dose of 30 mg/day orally and flexibly dosed thereafter based on iPTH levels.