What is the initial workup and treatment for a patient suspected of having vasculitis?

From the Guidelines

The initial workup for suspected vasculitis should include a comprehensive clinical evaluation, laboratory tests, and imaging studies to confirm the diagnosis and determine the extent of organ involvement, with a focus on testing for antineutrophil cytoplasmic antibodies (ANCA) and considering a tissue biopsy for definitive diagnosis, as recommended by the most recent guidelines 1.

The workup should begin with a complete blood count, comprehensive metabolic panel, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), urinalysis, and specific autoantibody tests such as ANCA, antinuclear antibodies (ANA), and rheumatoid factor.

• A positive biopsy is strongly supportive of a diagnosis of vasculitis and is recommended to assist in establishing a new diagnosis and for further evaluation for patients suspected of having relapsing vasculitis 1.
• Imaging studies, such as CT of the chest, can help detect organ involvement and identify potential biopsy sites 1.
• The use of plasma exchange may be considered for selected patients with rapidly progressive severe renal disease, but its routine use is not recommended 1.

Treatment typically involves immunosuppression with corticosteroids like prednisone (starting at 50-75 mg prednisolone equivalent/day) as first-line therapy, with a stepwise reduction in glucocorticoids according to clinical response 1.

• For severe or organ-threatening disease, add rituximab or cyclophosphamide, with rituximab preferred in relapsing disease 1.
• Once remission is achieved, transition to maintenance therapy with less toxic agents such as azathioprine, methotrexate, or mycophenolate mofetil, with treatment duration varying by vasculitis type but typically continuing for at least 12-24 months 1.
• Prophylaxis against Pneumocystis jirovecii pneumonia with trimethoprim-sulfamethoxazole is recommended during intensive immunosuppression 1.

This aggressive approach is necessary because vasculitis causes inflammation of blood vessels that can lead to tissue ischemia, organ damage, and potentially life-threatening complications if left untreated.

• The treatment should be individualized based on the severity of the disease, the presence of organ-threatening manifestations, and the patient's overall health status 1.
• Regular monitoring of disease activity, organ function, and treatment side effects is crucial to adjust the treatment plan as needed and minimize the risk of complications 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Initial Workup for Vasculitis

The initial workup for a patient suspected of having vasculitis involves a combination of laboratory tests, physical examination, and medical history. The following tests are recommended:

• Serial measurements of acute phase reactants, complete blood cell count with differential, biochemistry profiles, urinalysis, and C3 and C4 levels should be obtained in all patients 2
• Antineutrophil cytoplasmic antibodies (ANCA) determination provides valuable information and is highly specific for the diagnosis of small-vessel vasculitides, particularly Wegener's granulomatosis and microscopic polyangiitis 2, 3
• Hepatitis-B and hepatitis-C testing is extremely useful, particularly in the presence of liver involvement and associated risk factors 2
• Angiographic studies may confirm the diagnosis, particularly if there is laboratory and clinical evidence of specific organ involvement 2
• A definite diagnosis is provided by a tissue biopsy, which should be performed whenever there is access to clinically affected tissue 2

Laboratory Tests

Laboratory tests play a crucial role in the diagnosis and management of vasculitis. The following tests are recommended:

• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are often helpful for the diagnosis of vasculitis, but they are nonspecific and do not help in distinguishing between vasculitis disease activity and a concomitant infection or another source of inflammation 3
• Autoantibodies such as ANCA, anti-glomerular basement membrane (GBM) antibodies, and anti-C1q antibodies are helpful for diagnosis 3
• Urinalysis, including tests for hematuria, proteinuria, and red cell casts, is essential for assessing renal involvement 4
• Blood tests, including full blood screen, erythrocyte sedimentation rate, CRP, creatinine, urea, and glucose, are also necessary 4

Treatment

The treatment of vasculitis depends on the severity and type of disease. The following treatments are recommended:

• ACE-inhibitors, angiotensin receptor-blockers, aldosteron antagonists, and renin-inhibitors are the mainstay in the therapy of arterial hypertension with proteinuria 4
• Immunosuppressive drug regimens, including glucocorticoids, cyclophosphamide, and azathioprine, are used to treat certain types of glomerulonephritis and vasculitis 4
• Rituximab is a new and less toxic alternative to cyclophosphamide for the treatment of severe forms of glomerulonephritis and vasculitis 4, 5, 6
• Plasma exchange may be useful in certain cases, such as Goodpasture's syndrome or severe ANCA-positive vasculitis 4