HDCN Abstract:  Am Soc Nephrol Ann Mtg -- Toronto  

Kleta R, Candan B, Tanja F, Stefan F, et al

Physiologic treatment of Bartter syndrome

Am Soc Nephrol Ann Mtg -- Toronto
J Am Soc Nephrol (Sep) 11:107A 2000

Bartter syndrome (BS) is a major reason of congenital renal saltwasting. Even though BS was revealed as being caused by a hindered NaCl reabsorption in the thick ascending limb of Henle's loop, current treatment options do not take these findings into account.

Therefore, we treated a 7 year old boy with BS type III with a balanced NaCl diet. The idea was to suppress the elevated aldosterone and thereby to reduce the renal potassium loss. The treatment consisted of the administration of a high-salt containing mineral water (NaCl content 180 mmol / l). The urinary excretion rates of Na+, K+, aldosterone-18-glucuronide (A-18-G), and creatinine were measured by 24 hours specimens. By simultaneous serum measurements urinary fractional excretion rates for Na+ (FeNa) and K+ (FeK) were determined.

The elevated FeNa after starting the NaCl diet indicates an adequate salt supply. BS patients exhibit furosemide treated signs, therefore the FeNa has to become pathologic. As a result of the adequate salt supply A-18-G became normal, FeK was lowered markedly. The elevated and not changing renin concentration indicates part of the pathophysiology, because the renin producing macula densa is also affected by either NKCC2, ROMK, or (in this case) ClC-Kb mutations which result in elevated renin.

In summary, we suggest to give BS patients a (high) NaCl diet which should result in an elevated FeNa.

before NaCL diet after NaCl diet ref. values
K+ supply 9 6 1 mmol/kg die
NaCl supply ad libitum 9 3 mmol/kg die
serum K+ 3.4 3.8 3.5-5.0 mmol/l
FeNa 0.5 3.5 < 1 %
FeK 500 60 15+/-10 %
A-18-G 17.7 4.1 < 8 mg/die
Renin 145 144 < 50 mU/ml

Copyright 2000, American Society of Nephrology