Long-term follow-up of a girl with the neonatal form of Bartter's syndrome.

We followed up a girl with the neonatal form of Bartter's syndrome for sixteen years and determined the sensitivity to angiotensin II before and during the indomethacin treatment. A 4-month-old girl was admitted to our hospital, because of severe hypokalemia and growth retardation. Initially we treated her with spironolactone and potassium supplements. This treatment increased plasma potassium levels and her growth. At the age of one year she was diagnosed as having Bartter's syndrome. Since then she has been treated with indomethacin at an initial dose of 3 mg/kg/day combined with spironolactone and potassium. After the start of the indomethacin treatment, her growth increased dramatically, and her final height was normal adult height. Her puberty developed normally and menarche occurred at the age of 12 years. Levels of serum sodium, chloride, plasma aldosterone and urinary prostaglandin E2 were also normalized. Levels of angiotensin I and II were improved but not within the normal range, but plasma potassium levels slightly decreased after plasma aldosterone levels were normalized and did not change during the treatment period. Plasma renin activity remained high until about the age of 8 years, after which it decreased to almost within the normal range. At 5 months after the start of indomethacin (3 mg/kg/day), her vascular sensitivity to angiotensin II had been improved, and after 2 years and 5 months, her vascular sensitivity was further improved. At this time renin activity had decreased after angiotensin II infusion, but plasma aldosterone did not change. At the age of 16 years (dose of indomethacin: 0.5 mg/kg/day), plasma aldosterone increased after angiotensin II infusion. These data suggest that indomethacin and spironolactone are effective treatments for the neonatal form of Bartter's syndrome, especially during childhood.