The following are true for renal tubular acidosis (RTA) except:a. Type 1 RTA is the failure of H+ secretion in the distal nephron tubules
Renal tubular acidosis (RTA) is a family of diseases characterised by failure of tubular H+ secretion and urinary acidification. Type 1 RTA is the failure of H+ secretion in the distal nephron tubules and is characterised by hyperchloraemic metabolic acidosis (normal anion gap), a high urinary pH (>5.5, alkaline urine) and low serum bicarbonate. The disease also has low sodium levels, there is a female predominance and due to the low citrate they are predisposed to calcium stones and in particular calcium phosphate stones. The condition is treated with potassium citrate solution. In Type 2 RTA, there is a failure of bicarbonate reabsorption (loss) in the proximal tubule of the nephron with similar characteristics to Type 1 RTA except citrate levels are normal therefore no stones form. The ammonium chloride acidification test (100 mg/kg) is one of the tests used to diagnose RTA with a urinary pH of >5.5 indicative of a failure of urinary acidification, and supportive of the diagnosis of dRTA.
Treatment of distal RTA include correction of the metabolic acidosis, with potassium citrate being one of the treatment options.