What is Giant Cell Arteritis (GCA)?

From the Guidelines

Giant cell arteritis (GCA) should be treated immediately with high-dose corticosteroids, typically prednisone 40-60mg daily, to prevent vision loss and other complications, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of GCA and Takayasu arteritis 1.

Key Considerations

• The treatment should begin promptly, without waiting for the results of a temporal artery biopsy, to prevent irreversible complications such as vision loss.
• For acute cases with visual symptoms, methylprednisolone 500-1000mg IV daily for 3 days may be used before transitioning to oral therapy.
• Temporal artery biopsy should be performed within 1-2 weeks of starting treatment to confirm diagnosis.
• The steroid dose is maintained for 2-4 weeks until symptoms resolve and inflammatory markers normalize, then gradually tapered over 12-24 months.
• Tocilizumab, an IL-6 receptor antagonist, may be added as a steroid-sparing agent at 162mg subcutaneously weekly, as recommended by the 2020 EULAR update for the management of large vessel vasculitis 1.

Monitoring and Adjunctive Therapy

• Patients should be monitored for disease recurrence and steroid side effects.
• Low-dose aspirin (81mg daily) is often recommended to reduce ischemic complications.
• Adjunctive therapy with tocilizumab or methotrexate should be considered in patients with refractory or relapsing disease, or those with an increased risk of glucocorticoid-related adverse effects.

Diagnosis and Imaging

• A clinical diagnosis of GCA should be confirmed by either imaging or biopsy, as recommended by the 2020 EULAR update for the management of large vessel vasculitis 1.
• Imaging modalities such as ultrasound, MRI, or PET-CT may be used to assess the extent of arterial involvement and guide treatment decisions.

Treatment Algorithm

• The 2018 EULAR algorithm for pharmacological treatment of GCA provides a framework for treatment decisions, including the use of glucocorticoids, tocilizumab, and methotrexate 1.
• The algorithm recommends tapering the glucocorticoid dose to a target of 15-20 mg/day within 2-3 months and then to ≤5 mg/day after 1 year, with faster tapering possible in patients receiving glucocorticoid-sparing therapy.

From the Research

Diagnosis of Giant Cell Arteritis

• Giant cell arteritis (GCA) is a systemic inflammatory vasculitis affecting medium and large vessels with potentially sight and life-threatening complications 2.
• Early diagnosis and prompt treatment are imperative in order to prevent vision loss and progression of the disease 2.
• Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are inflammatory markers which are elevated in the majority of patients and support the diagnosis of GCA among patients who present with typical symptoms 2.
• GCA is confirmed with superficial temporal artery biopsy which demonstrates characteristic pathological findings 2.

Treatment of Giant Cell Arteritis

• High dose corticosteroid therapy is the mainstay of treatment and is administered either intravenously or orally to prevent further vision loss and treat systemic vasculitis 2, 3.
• Oral corticosteroid therapy is required for months to years with careful follow-up and periodic laboratory evaluations with ESR and CRP 2.
• Corticosteroids are tapered gradually over months and may be associated with complications such as hypertension, diabetes mellitus, osteoporosis, psychosis, peptic ulcer disease, and infection 2.
• Supplementation with calcium, vitamin D, bisphosphonate therapy, antimicrobial prophylaxis, and initiation of a proton pump inhibitor or Histamine H2-receptor antagonist should be considered 2, 3.

Adjunctive Therapy

• Adjunctive immunomodulatory therapy may be considered in patients experiencing relapsing inflammation despite high doses of corticosteroids or those with corticosteroid-induced complications 2.
• Emerging evidence for adjunctive therapy with tocilizumab, methotrexate, aspirin, angiotensin receptor blockers, and statins is encouraging and may lead to a more mainstream role for these therapies among patients with GCA 2, 4, 5, 6.
• Methotrexate has a moderate corticosteroid sparing effect but it does not prevent cephalic complications and there is no evidence of a reduced frequency of CS adverse effects with this drug 5.
• Tocilizumab is a promising treatment option, but its benefit-to-risk ratio in old people is largely unknown 5, 6.

Prevention of Cardiovascular Events

• Prevention of cardiovascular events is an important aspect of the treatment of GCA 6.
• Aspirin (75-100mg/day) is recommended during the first month of treatment or longer in case of occurrence of an ischemic complication 6.
• Each patient treated for GCA should receive a prevention of osteoporosis with respect of usual recommendations 6.