[A case of mesangial proliferative glomerulonephritis with endothelial damage].

We describe a 71-year-old man, who had been treated for hypertension, myocardial infarction and abdominal aortic aneurysm, and was admitted to our hospital because of proteinuria(3.9 g/day at the outpatient clinic and 1.5 g/day at the time of admission) and edema in the extremities. Light microscopic study of the kidney biopsy specimen revealed mesangial proliferative glomerulonephritis and glomerular paralysis. Electron microscopic findings showed endothelial damage, including widening of the subendothelial space and detachment of endothelial cells from the glomerular basement membrane. Deposition of immunoglobulins and complement was not detected by immunofluorescence studies. These pathological findings resemble the findings of thrombotic microangiopathy, but there were no clinical pictures of HUS/TTP. These findings suggest that hypertension, atherosclerosis and circulating turbulence caused by an aortic aneurysm induced severe glomerular endothelial damage leading to mesangial proliferative glomerulonephritis without an immune response.