Definition

• CKD in patients with hypertension.

 Epidemiology

 • A common cause of CKD.

Aetiology

 • Hypertension.

 Pathogenesis

 • Two pathophysiological theories have been suggested, which may not be mutually exclusive.

• The first suggests that narrowing of arteries and arterioles causes glomerular ischaemia and global glomerular scarring.

 • The second suggests that glomerular hypertension leads to glomerular haemodynamic stress, leading to focal and segmental glomerulosclerosis.

Presentation

• Renal dysfunction and proteinuria in a long- standing hypertensive patient, in the absence of other causes of renal disease.

• Other signs of hypertension may be present (e.g. left ventricular hypertrophy).

 Macroscopy

 • Both kidneys are shrunken with finely granular cortical surfaces.

Histopathology

 • Hyaline deposits are seen in the walls of afferent arterioles.

• Interlobular and larger arteries show medial hypertrophy and fibrous intimal thickening (Fig. 1).

• Glomeruli may show wrinkling and shrinkage (due to ischaemia), followed by scarring of the whole tuft (global sclerosis; see first pathogenetic mechanism) and/ or enlargement of glomerular tufts with focal and segmental glomerular sclerosis (see second pathogenetic mechanism).

 • This constellation of pathological features is often referred to as hypertensive nephrosclerosis, a term meaning scarring of the kidney due to hypertension.

* Note that hypertension develops as a consequence of renal failure of any cause. Therefore before attributing CKD to hypertensive nephrosclerosis in patients with hypertension, other causes of renal disease should be considered, excluded and treated.

Fig1. Fibrous arterial intimal thickening. Hematoxylin and eosin stain. A thick layer of fibrous tissue is present under the endothelium and above the duplicated layers of elastic lamina, which appear as thin wavy dark pink lines. In a normal artery, the endothelium is much more closely apposed to the elastic lamina, with only a thin intervening layer of matrix (see Plate 19).

Prognosis

• Patients with persistent poorly controlled hypertension progress to renal failure, which may result in the need for renal replacement therapy.

 • The decline in renal function can be slowed by aggressive control of blood pressure.