Contribution to the aetiopathogenesis of orthostatic proteinuria in children: relation to the upper calyx syndrome.

The authors discuss the correlations between the upper calyx syndrome and proteinuria. The syndrome was demonstrated in 33.6 per cent of all children with orthostatic proteinuria hospitalized at the Paediatric Clinic, Martin (Czechoslovakia) during 1978-1985. They consider the possible relations between these conditions that could be mediated by the activation of the renin/angiotensin II system. The direct stimulus of this system could rest in local ischaemization of parenchyma in the region of the proximal pole of the kidney or its partial passive congestion. They assume that these changes become more marked in the standing position and may cause proteinuria of orthostatic character. The inhibition of the renin/angiotensin II system may obviously lead to decreased proteinuria.