From the Guidelines
The workup for vasculitis should begin with a thorough history and physical examination, focusing on organ systems affected and constitutional symptoms, and should include initial laboratory tests such as complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), urinalysis, and rheumatoid factor, as well as specific autoantibody testing, including antineutrophil cytoplasmic antibodies (ANCA) 1. The diagnosis of vasculitis relies on the combination of clinical findings and results of imaging studies and laboratory tests.
- Initial laboratory tests should include:
- Complete blood count
- Comprehensive metabolic panel
- Erythrocyte sedimentation rate (ESR)
- C-reactive protein (CRP)
- Urinalysis
- Rheumatoid factor
- Specific autoantibody testing is essential, including:
- Antineutrophil cytoplasmic antibodies (ANCA)
- Anti-nuclear antibodies (ANA)
- Anti-double-stranded DNA
- Complement levels Imaging studies such as chest X-ray, CT scans, MRI, or angiography may be necessary depending on suspected organ involvement.
- Tissue biopsy from affected organs remains the gold standard for definitive diagnosis. Additional tests may include hepatitis B and C serologies, cryoglobulins, and serum protein electrophoresis.
- For suspected large vessel vasculitis, vascular imaging with CT angiography, MR angiography, or PET scans is recommended.
- Lumbar puncture may be indicated if central nervous system involvement is suspected. This comprehensive approach is necessary because vasculitis presents with varied manifestations depending on the vessels affected, and early diagnosis is crucial to prevent irreversible organ damage, as highlighted in the 2024 KDIGO clinical practice guideline for the management of ANCA-associated vasculitis 1. The workup should be tailored to the patient's specific symptoms and suspected vasculitis type, with consultation from rheumatology specialists recommended to guide appropriate testing and interpretation, as suggested by the EULAR recommendations for the management of primary small and medium vessel vasculitis 1.
From the Research
Workup for Vasculitis
The workup for vasculitis involves a combination of clinical evaluation, laboratory tests, and imaging studies. The following are some of the key components of the workup:
- A detailed history and physical examination to determine the type of onset, course of illness, organ systems affected, and extent of involvement 2
- Laboratory tests, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), to assess inflammation 2, 3
- Serologic tests, such as antineutrophil cytoplasmic antibodies (ANCA), to help confirm the diagnosis 4
- Imaging studies, such as angiography, computed tomographic angiography, magnetic resonance angiography, and positron emission tomography/computed tomography, to visualize the blood vessels and assess the extent of involvement 5, 6
- Biopsy of involved tissue to confirm the diagnosis and assess the extent of inflammation and damage 2, 4, 6
Laboratory Tests
Laboratory tests play a crucial role in the workup for vasculitis. Some of the key laboratory tests include:
- ESR and CRP to assess inflammation 2, 3
- ANCA to help confirm the diagnosis of certain types of vasculitis, such as Wegener's granulomatosis and microscopic polyangiitis 4
- Blood biomarkers, such as IL-6, S100 proteins, pentraxin-3, and osteopontin, to monitor disease activity and predict outcomes 3
Imaging Studies
Imaging studies are essential in the workup for vasculitis to visualize the blood vessels and assess the extent of involvement. Some of the key imaging studies include:
- Angiography to visualize the blood vessels and assess the extent of involvement 2, 5
- Computed tomographic angiography and magnetic resonance angiography to visualize the blood vessels and assess the extent of involvement 5
- Positron emission tomography/computed tomography to visualize the blood vessels and assess the extent of involvement 5, 6
- Magnetic resonance imaging, including ADC maps, diffusion, and gradient echo sequences, to detect and monitor cerebral involvement 6
Biopsy
Biopsy of involved tissue is essential to confirm the diagnosis and assess the extent of inflammation and damage. The type of biopsy performed depends on the suspected type of vasculitis and the organ systems involved 2, 4, 6