Blood pressure related separately to parenchymal fibrosis and vasculopathy of the kidney.

The term nephrosclerosis is customarily used to designate a pathological entity that tends to characterize subjects with high blood pressure; it refers to a condition of diffuse fibrous replacement of renal substance secondary to ischemia from hypertension-related vascular injury. The features of parenchymal fibrosis can be distinguished from those of vasculopathies in tissue sections, parenchymal fibrosis being measured by assessing the degree of interstitial fibrosis and by counting obsolete glomeruli, while vasculopathies are measured by determining arterial intimal fibroplasia and by counting hyalinized arterioles. A series of 166 autopsies in subjects aged 25 to 92 years, selected because ample documentation of blood pressure was available, was assessed. One form of vasculopathy, arterial fibroplasia, is a better correlate of high blood pressure than is parenchymal fibrosis in this body of data. Cases with much vasculopathy and little parenchymal fibrosis occurred frequently, and these subjects were usually hypertensive. Cases with little vasculopathy and much parenchymal fibrosis were also encountered, but these subjects were usually not hypertensive. The suggested conclusion is that blood pressure relates less to the renoprival state of nephron loss than it does to renal ischemia in patients with nephrosclerosis.