Renal tubular acidosis
Renal tubular acidosis is a metabolic acidosis caused by renal tubular dysfunction. It is characterized by normal glomerular filtration rate, hyperchloremia, and a normal plasma anion gap. Based on pathophysiology, location, and genetics several types may be distinguished.
The traditional classification of renal tubular acidosis (RTA) is based in pathophysiological findings and localization of the tubular defect.
|3||combined proximal and distal RTA|
Very different defects in tubular transport, metabolism and signal transduction can result in renal tubular acidosis. The filtered bicarbonate reabsorbed fundamentally in the proximal tubule. This way defects in bicarbonate reabsorption are classified as proximal tubular acidosis. The acidification occurs in the distal nephron. That's why defects in acidification are called distal tubular acidosis. Of course there can be mixed forms. Defects in the adosterone signal transduction that result in hypoaldosteronism can cause the hypokalemic form of renal tubular acidosis.
Hyperchloremic metabolic acidosis is the hallmark of RTA.
Igarashi T et al. (2002) Unraveling the molecular pathogenesis of isolated proximal renal tubular acidosis.[^]
Karet FE et al. (2002) Inherited distal renal tubular acidosis.[^]
Santos F et. al. (2017) Renal tubular acidosis.[^]
Yaxley J et. al. (2016) Review of the Diagnostic Evaluation of Renal Tubular Acidosis.[^]