Pathologic Findings Light Microscopy

The arterial lesion is the cardinal feature of chronic rejection (Fig. 20.11)

(52). The arteries show pronounced fibrous intimal thickening with myo-intimal cells, collagen fibrils, focal calcification, a variable infiltrate of T cells (often subendothelial), and lipid-filled, foamy macrophages disposed characteristically against the external elastica, which is duplicated and disrupted. The adventitia also often has an infiltrate of mononuclear cells, sometimes invading and destroying the outer media. Marked duplication of the internal elastica, a normal or thickened media, and relative sparing of the larger arteries (arcuate and larger) are more typical of hypertension

(53). The arterioles are relatively spared in chronic rejection, compared with chronic cyclosporin A (CsA) toxicity, thrombotic microangiopathy/

Figure 20.11. Chronic allograft arteriopathy. Expansion of the intima with foam cells and scattered infiltrating mononuclear cells are shown in a nephrectomy 2 years after transplantation (elastin stain).

hemolytic uremic syndrome, and systemic sclerosis. These processes do not cause a mononuclear infiltrate in the vessels. However, the healing phase of hemolytic uremic syndrome and systemic sclerosis may leave intimal fibrosis that resembles chronic rejection.

The glomerular features are not specific for chronic graft rejection, but are typical. The glomeruli have an increase in mesangial cells and matrix and thickening and duplication of the GBM, with various degrees of scarring and adhesions (Fig. 20.12). This lesion has been shown to derive from acute allograft glomerulopathy in a few cases (10,14). Extensive crescents, diffuse granular or linear deposits of IgG, or subepithelial deposits are unusual and suggest recurrent or de novo glomerulonephritis.

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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