Renal Amyloidosis Presenting as Water Losing Syndrome

Abstract

In two patients with polyuria and polydipsia, renal biopsy revealed amyloidosis. Renal function studies showed specific disturbance of water conservation, with relatively intact diluting, acidifying and ammonium excreting capacity. In addition, the second patient had a nephrotic episode which completely disappeared within some months. It is suggested that the observed abnormalities result from selective impairment of water back-diffusion from the collecting ducts, in the presence of a relatively intact glomerular filtration.