Peritubular capillary changes in alport syndrome, diabetic glomerulopathy, Balkan endemic nephropathy and hemorrhagic fever with renal syndrome.

The morphology of peritubular capillary has been mostly studied in relation to chronic transplant rejection, where an association has been found between transplant glomerulopathy and reduplication of peritubular capillary basement membranes (PCBM). This electron microscopy study of peritubular capillaries was done on kidney biopsies performed on patients with conditions involving primarily glomeruli (diabetic glomerulopathy (23), Alport syndrome (37)) or causing more or less isolated changes of nephron structures outside the glomeruli (Balkan endemic nephropathy (15) and hemorrhagic fever with renal syndrome (19)). The aim was to explore the ultrastructural features of the PCBM. In patients with diabetic glomerulopathy, the PCBM was homogeneous, with a width ranging from normal to evidently increased (55-355 nm). In patients with Alport syndrome, the PCBM was homogeneous, with no substantial splitting or prominent thickening. Mean thickness varied between 80 (85-100) nm in children and 120 (46-250) nm in adults. Mean PCBM thickness in patients with Balkan endemic nephropathy was 209 (90-1270) nm. The thickened PCBM was also often split. In patients with hemorrhagic fever with renal syndrome, peritubular capillaries and medular vasa recta were generally extremely congested and focally ruptured, and their basal lamina showed prevailing thinning and focal discontinuities.