Page 233 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

208 Loic Guillevin

Figure 3. Renal infarcts reflecting vascular nephropathy.

Renal Manifestations
Renal manifestations result from medium-sized–vessel involvement leading to renal

infarcts and microaneurysm formation. Malignant arterial hypertension [51], which occurs in
6.9% of patients [36], reflects vascular ischemic nephropathy. Renal insufficiency is an
overall poor prognostic factor [52]. Angiography shows renal parenchymal infarction (Figure
3), with characteristic multiple stenosis and microaneurysms of branches of celiac, mesenteric
and renal arteries (Figure 4). Microaneurysms can spontaneously rupture notably after renal
biopsy, the latter of which is strongly contraindicated when microaneurysms are present.
Renal hematoma can be extensive requiring embolization [53] or nephrectomy [54]. Acute
renal insufficiency can occur soon after onset or following a disease flare. Plasma exchanges
may be required initially however renal function is unpredictable. Some patients develop end-
stage renal failure decades after the first PAN flare.

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