Page 278 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

252 Christian Pagnoux and Gerard P. Cox

development of vasculitic features primarily affecting the skin and peripheral nerves.
The preponderance of Th2 lymphocytes and eosinophils suggests their participation in the
pathogenesis of EGPA; however, ANCA production is noted in up to 40% of patients, which
suggests a role in amplifying or facilitating the development of vasculitic lesions. Asthma is a
constant feature in EGPA. Pleural effusions are noted in 29% of patients, but hilar and/or
mediastinal lymphadenopathy is less common. Lung infiltrates were reported in 72% of
patients [68], presenting as multifocal peripheral consolidation in two-thirds of patients, with
unilateral or bilateral, and symmetrical or asymmetrical appearance, devoid of lobar and
segmental location [69]. A centrilobular perivascular dense pattern with scattered
centrilobular nodules measuring 5 mm within ground-glass opacities was found in 89% of
patients [69]. Multiple large nodules occur with occasional cavitation; however, alveolar
haemorrhage is rare in EGPA. Non-compressive mediastinal hilar adenopathy may be
detected on chest CT. Pleural effusions are present in 20% to 30% of patients and are
exudative and rich in eosinophils.

Anti–Glomerular Basement Membrane Disease

Anti-GBM disease, which was included in the revised 2012 CHCC [1] under the SVV
category of IC disease, typically affects young people, aged 15 to 35 years. Isolated
glomerulonephritis occurs in 20% to 40% of patients and is combined with alveolar
hemorrhage in 60% to 70% of patients. Isolated alveolar hemorrhage is a rare but described
presenting feature of anti-GBM. Alveolar hemorrhage is strongly associated with smoking
[70, 71]. Up to one-third of patients with anti-GBM disease become ANCA-seropositive at
some time during their illness; such patients have intermediate prognosis with worse renal
prognosis than those with isolated AAV.

Other Small-Vessel Vaculitides

Alveolar hemorrhage occurs in less than 5% of patients with IgAV [29] and mixed CV.
Other lung manifestations are likely due to underlying human immunodeficiency virus (HIV)
and hepatitis C virus (HCV) infection or a lymphoproliferative disorder.

Variable Vessel Vasculitides

Behçet Disease

Lung manifestations occur in less than 10% of patients with BD [72-77]. Pulmonary
artery involvement is most common after aortic involvement in young men with aneurysms
and thrombosis, with or without associated aneurysm or vascular stenosis [78, 79].
Aneurysms can be seen on chest radiographs but are best visualized by chest CT and
magnetic resonance imaging (MRI), appearing as multiple, unilateral or bilateral, with
varying diameter of 1 to 7 cm. Pulmonary artery involvement is associated with poor

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