RTA-3

Q: What is TYPE-3 renal tubular acidosis (RTA)?

Answer: Mix of RTA-1 and RTA-2

Academic books describe in detail Type I, 2 and 4 RTAs, but RTA-3 is rarely mentioned.

The term RTA-3 is used when both proximal and distal acidification defects coexist. It is a failure to reabsorb bicarbonate and an inability to acidify urine properly, resulting in systemic metabolic acidosis. 

In the pediatric population, it is associated with growth hormone deficiency.

#nephrology

#acid-base

References:

1. Goswami RP, Mondal S, Karmakar PS, Ghosh A. Type 3 renal tubular acidosis. Indian J Nephrol. 2012 Nov;22(6):466-8. doi: 10.4103/0971-4065.106058. PMID: 23439805; PMCID: PMC3573491.

2. Reddy P. Clinical approach to renal tubular acidosis in adult patients. Int J Clin Pract. 2011 Mar;65(3):350-60. doi: 10.1111/j.1742-1241.2009.02311.x. PMID: 21314872.

3. Liew YP, Rogers TA, Garb JL, Allen HF, Reiter EO, Campfield TJ, Dharnidharka VR, Braden GL. Type 3 renal tubular acidosis associated with growth hormone deficiency. J Pediatr Endocrinol Metab. 2017 Oct 26;30(10):1047-1053. doi: 10.1515/jpem-2016-0460. PMID: 28888090.