Renal Tubular Acidosis Syndromes

, Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock

South Med J. 2000;93(11) 

In This Article

Abstract and Introduction

Renal tubular acidosis is a constellation of syndromes arising from different derangements of tubular acid transport. Recent advances in the biology of urinary acidification have allowed us to discern various molecular mechanisms responsible for these syndromes. This report relates clinical disorders of acidification to the underlying defective mechanisms responsible for them. A clinical classification of these disorders is presented, integrating each disorder with the prevailing serum potassium concentration. That renal tubular acidosis can be associated with low, normal, or high serum potassium concentration is now explainable by identifying the specific defect in transport causing each syndrome.

Renal tubular acidosis (RTA) syndromes are nonuremic defects of urinary acidification. Renal tubular acidosis is characterized by a normal anion gap and hyperchloremic metabolic acidosis; plasma potassium may be normal, low, or high, depending on the type of RTA. These syndromes differ from uremic acidosis, which is associated with a high anion gap and with enhanced proton secretion by each remaining nephron. As new technologies have been applied to biology, we now better understand the basic lesions of these important syndromes.