Mechanisms of orthostatic proteinuria: lessons from a transplant donor.
Orthostatic proteinuria accounts for 60% of all children and 75% of adolescents with proteinuria. Despite its frequent occurrence, the underlying pathophysiologic mechanisms remain unclear. The following three possibilities have been reviewed: (1) a normal variant; (2) a glomerular abnormality; (3) a hemodynamic abnormality. On the basis of the experience with an individual who had orthostatic proteinuria and who was a donor of a living-related kidney transplant, novel insights and a potentially unifying hypothesis for the pathogenesis of this condition are presented. It is suggested that individuals with orthostatic proteinuria may be predisposed by a subtle glomerular abnormality. However, a precipitating factor, in the form of an exaggerated response to the upright position, appears to be essential to unmask the condition.
Devarajan
P
P
Yale University, New Haven, CT.
D000328:Adult; D002648:Child; D005260:Female; D006439:Hemodynamics; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology; D016030:Kidney Transplantation; D008297:Male; D011187:Posture; D011507:Proteinuria / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D014019:Tissue Donors