J. Zawadzki, PERMEABILITY DEFECT WITH BICARBONATE LEAK AS A MECHANISM OF IMMUNE-RELATED DISTAL RENAL TUBULAR-ACIDOSIS, American journal of kidney diseases, 31(3), 1998, pp. 527-532
We present a 15-year-old girl with distal renal tubular acidosis (dRTA
) appearing in what is probably a very early stage of primary Sjogren'
s syndrome. On the basis of tests evaluating renal handling of H+, we
attempt to explain the mechanism of the urine acidification disorder.
The inability to decrease urinary pH during systemic acidosis, togethe
r with the normal increase of urinary carbon dioxide partial pressure
(pCO(2)) values after sodium bicarbonate and neutral phosphate loading
, suggest a gradient-type dRTA. The inability to lower urinary pH in r
esponse to furosemide, accompanied by markedly increased urinary excre
tion of NH4, HCO3, Na, and K, points to a collecting tubule permeabili
ty disorder with bicarbonate leak to the tubular lumen. This patient h
ad never been exposed to amphotericin B. To our knowledge, immune-rela
ted dRTA as a result of a gradient defect with bicarbonate leak into t
he tubular lumen has not been described. (C) 1998 by the National Kidn
ey Foundation, Inc.