Recent Developments in the Treatment of Pediatric Distal Renal Tubular Acidosis

Distal renal tubular acidosis (dRTA) is characterized by a primary defect in proton secretion by alpha-intercalated cells of the collecting duct, leading to impaired urine acidification and resulting in metabolic acidosis, hypokalemia, and hypercalciuria. Inherited forms of dRTA are currently associated with variants in five genes (SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, and WDR72), each being associated with specific extra-renal manifestations. Acquired forms can result from autoimmune diseases or drug side effects. Classical complications include nephrolithiasis, nephrocalcinosis, reduced glomerular filtration rate (GFR), bone demineralization, and growth failure. Treatment focuses on correcting the acid-base imbalance through alkali supplementation (potassium, sodium, or magnesium bicarbonate or citrate) to reduce renal disease progression and promote normal growth and mineralization. Traditional treatments (alkali and potassium supplementation) often suffer from poor adherence due to frequent day and night administrations, gastrointestinal discomfort, and unpleasant taste. A novel investigational drug, ADV7103, which contains potassium citrate and potassium bicarbonate in an extended-release formulation, has recently been approved by the European Medicine Agency (EMA) for dRTA. Recent studies support its use as a first-line treatment, given its efficacy and safety profile.