Primary Distal Renal Tubular Acidosis: Towards an Optimal Correction of Metabolic Acidosis

Clin J Am Soc Nephrol. 2024 Jul 5. doi: 10.2215/CJN.0000000000000535. Online ahead of print.

Abstract

The term classic, type I renal tubular acidosis (RTA) or primary distal RTA is used to designate patients with impaired ability to excrete acid normally in the urine as a result of tubular transport defects involving type A intercalated cells in the collecting duct. The clinical phenotype is largely characterized by the complications of chronic metabolic acidosis, stunted growth, bone abnormalities, as well as nephrocalcinosis and nephrolithiasis that develop as the consequence of hypercalciuria and hypocitraturia. All these manifestations are preventable with early and sustained correction of metabolic acidosis with alkali therapy. The optimal target for plasma bicarbonate should be as close as possible to the range considered normal by current standards (between 23 and 28 mEq/l.). Most of the benefits of alkali therapy are tangible early in the course of the disease in childhood, but life-long treatment is required to prevent the vast array of complications attributable to chronic metabolic acidosis.