Page 186 - The Vasculitides, Volume 1: General Considerations and Systemic Vasculitis

162 Lindsay Lally and Stephen A. Paget

(SVV) includes granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA),
and eosinophilic granulomatosis with polyangiitis (EGPA), known collectively as the anti-
neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV). Medium vessel
vasculitis (MVV) is exemplified by polyarteritis nodosa (PAN). Large vessel vasculitis
includes giant cell arteritis (GCA), and Takayasu arteritis (TAK). Vascular inflammation
confirmed to a single organ system such as the kidney, peripheral nerves, brain or vessel such
as the aorta, is deemed single organ vasculitis (SOV).

This chapter provides an overview of the clinical approach and management of patients
with primary systemic vasculitis including aspects of the clinical presentation, differential
diagnosis, imaging, histopathologic evaluation, and short- and long-term treatment-related
complications.

Clinical Diagnosis

While it may seem obvious, the first challenge in the management of the vasculitis
patient is considering vasculitis as a possible diagnosis. Heterogeneity of presentation
accompanied by nonspecific constitutional symptoms may hinder prompt diagnosis.
The diagnosis of primary systemic vasculitis is often delayed as more common causes of
multi-system disease like infections and malignancies are investigated. One population-based
study reported a median time interval between the onset of symptoms and diagnosis of 11
months (range, 1 to 50 months) in TAK [2]. The past decade has witnessed a decrease in the
time to diagnosis of AAV from a mean of 17 months to 4 months; however delays in
diagnosis occur in subgroups of patients with flu-like prodromal and upper respiratory
symptoms [3, 4]. Failure to make a timely diagnosis can have devastating consequences such
as blindness due to unrecognized GCA, renal failure caused by untreated AAV, and death due
to a rupture of an unrecognized mesenteric aneurysm caused by PAN.

Despite significant overlap, vasculitic disorders generally manifest characteristic patterns
of organ involvement. Fever, weight loss, fatigue, arthritis, skin rash, peripheral (PNS) and
central nervous (CNS) manifestations are common symptoms and signs of systemic
vasculitides. In spite of expected disparities in vessel involvement and resultant end-organ
damage, in one cohort of 800 patients with AAV, PAN, GCA, and TAK [5], greater than 30%
of those with LVV, and more than 70% of patients with SVV and MVV experienced
constitutional symptoms at the time of diagnosis. Certain clinical presentations should prompt
swift evaluation for systemic vasculitis such as mononeuritis multiplex, pulmonary-renal
syndrome with a rapidly progressive glomerulonephritis, alveolar hemorrhage and infarction
in multiple vascular beds. Clinical acumen combined with a thorough history and physical
exam is essential to making the diagnosis and defining the correct testing to complete the
diagnosis and assess the extent of disease. Accurate diagnosis depends upon familiarity with
the myriad of clinical features of the various vasculitides together with results of carefully
selected laboratory studies including autoimmune and infectious serology, vascular imaging
studies and tissue biopsy. The resulting laboratory data will often reflect the immunological
storm, easily ascertained by preliminary elevations in the erythrocyte sedimentation rate
(ESR) and C reactive protein (CRP), presence of anemia and thrombocytosis. Management of
these disorders requires close collaboration between medical and surgical specialists to

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