- • Subacute–acute onset.
- • Anorexia.
- • Fever.
- • Multisystem involvement.
The pulmonary vasculitides are a heterogeneous group of systemic
disorders (Table 20–1) characterized by vascular
inflammation leading to tissue necrosis and subsequent end-organ
dysfunction. Pulmonary vasculitis may be a manifestation of an underlying
connective tissue disease, such as systemic lupus erythematosus,
or may occur in the absence of any other associated, underlying
disease, as is the case in microscopic polyangiitis or Goodpasture’s
Systemic Vasculitides. |Favorite Table|Download (.pdf)
|Small-diameter vessel vasculitis|
|Collagen vascular diseases|
|Isolated pauci-immune capillaritis|
|Medium-diameter vessel vasculitis|
|Giant cell arteritis|
|Large-diameter vessel vasculitis|
|Giant cell arteritis|
In general, the systemic vasculitides are uncommon and involve
the lung with variable frequency. Pulmonary involvement occurs in
up to 70–90% of patients with Wegener’s
granulomatosis (WG) but is rare in several other disorders such
as giant cell arteritis, Behçet’s syndrome, polyarteritis nodosa,
cryoglobulinemia, and Kawasaki’s disease. The incidence
varies from two to three cases per million people per year for microscopic
polyangiitis to 12–13 cases per million people per year
for vasculitis associated with the collagen vascular diseases. Recent
studies suggest that the incidence of systemic vasculitis is increasing.
However, this increase likely reflects the recent availability and
widespread use of testing for antineutrophil cytoplasmic antibodies
(ANCAs), autoantibodies commonly found in WG, microscopic polyangiitis,
polyarteritis nodosa (PAN), and Churg–Strauss syndrome
Vasculitis is defined as inflammation of a vessel involving small,
medium, or large arteries or veins. If medium- or large-diameter
vessels are involved, infarction, necrosis, and end-organ dysfunction
result. In contrast, involvement of small-diameter vessels (ie,
capillaries, arterioles, and venules) results in the loss of vascular
integrity and leakage of blood into the tissue. Small-diameter vessel
involvement in the lung is termed pulmonary or alveolar capillaritis
and manifests as diffuse alveolar hemorrhage (DAH). The analogous
lesions in the skin and kidney appear as leukocytoclastic vasculitis
with visible, raised palpable purpura, and sometimes as petechiae
and focal, segmental, necrotizing glomerulonephritis. Although the
focus of this chapter is on the pulmonary manifestations of vasculitides,
it should be noted that any organ system can be affected.
Several of the systemic vasculitides can be further subclassified
based on their histopathology. WG, CSS, necrotizing sarcoid granulomatosis,
giant cell arteritis, and Takayasu’s arteritis all share
the similar histological features of granulomatous inflammation.
Granulomatous inflammation involving small- and medium-diameter
blood vessels is characteristic of WG. Concomitant with vascular
inflammation and tissue necrosis, a necrotizing granulomatous process
is present in the tissue adjacent to and within the wall of the
affected blood vessel. An area of central necrosis, surrounded by
mixed acute and ...