Acid-Base Imbalance in Pseudohypoaldosteronism Type 1 in Comparison With Type IV Renal Tubular Acidosis

Masanori Adachi; Keiko Nagahara; Ayako Ochi; Junya Toyoda; Koji Muroya; Katsumi Mizuno

doi:10.1210/jendso/bvac147

Acid-Base Imbalance in Pseudohypoaldosteronism Type 1 in Comparison With Type IV Renal Tubular Acidosis

J Endocr Soc. 2022 Sep 27;6(12):bvac147. doi: 10.1210/jendso/bvac147. eCollection 2022 Oct 26.

Authors

Masanori Adachi¹, Keiko Nagahara¹, Ayako Ochi¹, Junya Toyoda¹, Koji Muroya², Katsumi Mizuno¹

Affiliations

¹ Department of Pediatrics, Showa University School of Medicine, Shinagawa-ku, Tokyo, 142-8555, Japan.
² Department of Endocrinology and Metabolism, Kanagawa Children's Medical Center, Yokohama, Kanagawa, 232-8555, Japan.

Abstract

Context: Pseudohypoaldosteronism type 1 (PHA1) has been treated as a genetic variant of type IV renal tubular acidosis (RTA), leading to the conception that PHA1 develops hyperchloremic acidosis with a normal anion gap (AG).

Objective: To delineate the acid-base imbalance in PHA1A (dominant type) and PHA1B (recessive type).

Methods: We conducted the following: (1) a retrospective chart review of our patient with PHA1B, and (2) a literature search of PHA1 cases focusing on acid-base balance. The main outcome measures were the incidence and nature of acidosis, including chloride levels and AG.

Results: In our patient with PHA1B, 7 salt-wasting episodes were analyzed. Acidosis was ascertained each time, and it was accompanied by hypochloremia except in 1 episode. AG was elevated in 5 episodes, while hyperlacticaemia was present in 3. In the literature, 41 cases of PHA1A and 65 cases of PHA1B have been identified. During salt-wasting crises, acidosis developed in 85% of PHA1A cases and 87% of PHA1B cases. Hypochloremia was present in 69% of PHA1A cases with available data (n = 13) and 54% of eligible PHA1B cases (n = 13), with mean chloride levels of 96 mEq/L and 95 mEq/L, respectively. Increased AG was less frequently reported (14% in PHA1A and 44% in PHA1B).

Conclusions: Patients with PHA1 frequently presented with metabolic acidosis. However, hyperchloremia may not be a universal finding, whereas hypochloremia and increased AG may occur in a substantial proportion of the patients.

Keywords: acidosis; anion gap; hyperkalemic RTA; hypochloremia; hyporeninemic hypoaldosteronism.