What are the diagnosis and management of Giant Cell Arteritis (GCA)?

From the Guidelines

Giant cell arteritis (GCA) should be diagnosed and managed promptly with high-dose prednisone (40-60mg daily) as soon as GCA is suspected, even before confirming the diagnosis, to prevent vision loss and other complications, as recommended by the 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of giant cell arteritis and Takayasu arteritis 1.

Diagnosis

GCA is diagnosed through a combination of clinical features, laboratory tests, and temporal artery biopsy. Patients typically present with new-onset headache, scalp tenderness, jaw claudication, visual disturbances, and constitutional symptoms like fever and weight loss. Laboratory tests should include erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), which are typically elevated. Temporal artery biopsy should be performed within 1-2 weeks of starting steroids to confirm the diagnosis.

Management

For long-term management, gradually taper prednisone over 12-18 months while monitoring symptoms and inflammatory markers. Consider adding tocilizumab (162mg subcutaneously weekly or every other week) for steroid-sparing effects, especially in patients with relapsing disease or at high risk for steroid complications, as recommended by the 2021 guideline 1 and supported by previous studies 1. Patients should receive bone protection with calcium (1000-1200mg daily), vitamin D (800-1000 IU daily), and consider bisphosphonates if on prolonged steroid therapy. Regular monitoring includes checking for symptom recurrence, steroid side effects, and periodic ESR/CRP measurements.

Key Considerations

• GCA is a granulomatous vasculitis affecting large and medium-sized arteries, particularly the branches of the carotid artery, and prompt treatment is essential because inflammation of these vessels can lead to ischemic complications, most notably irreversible vision loss.
• The 2021 American College of Rheumatology/Vasculitis Foundation guideline for the management of giant cell arteritis and Takayasu arteritis provides evidence-based recommendations for the evaluation and management of GCA and TAK 1.
• Tocilizumab has been approved by the US Food and Drug Administration for the treatment of GCA, and its use is recommended for steroid-sparing effects in patients with relapsing disease or at high risk for steroid complications 1.

From the FDA Drug Label

The primary efficacy endpoint was the proportion of patients achieving sustained remission from Week 12 through Week 52 Sustained remission was defined by a patient attaining a sustained (1) absence of GCA signs and symptoms from Week 12 through Week 52, (2) normalization of erythrocyte sedimentation rate (ESR) (to < 30 mm/hr without an elevation to ≥ 30 mm/hr attributable to GCA) from Week 12 through Week 52, (3) normalization of C-reactive protein (CRP) (to < 1 mg/dL, with an absence of successive elevations to ≥ 1mg/dL) from Week 12 through Week 52, and (4) successful adherence to the prednisone taper defined by not more than 100 mg of excess prednisone from Week 12 through Week 52.

Giant Cell Arteritis (GCA) Diagnosis and Management:

• Diagnosis: The diagnosis of GCA is based on the presence of signs and symptoms, such as absence of GCA signs and symptoms, normalization of ESR and CRP, and successful adherence to the prednisone taper.
• Management: The management of GCA involves the use of tocilizumab (ACTEMRA) to achieve sustained remission, defined as the absence of GCA signs and symptoms, normalization of ESR and CRP, and successful adherence to the prednisone taper.
• Treatment: Tocilizumab (ACTEMRA) is administered intravenously at a dose of 6 mg/kg every 4 weeks to achieve sustained remission in patients with GCA 2.
• Key Considerations: Patients with GCA should be monitored for signs and symptoms of the disease, as well as for laboratory test results, such as ESR and CRP, to assess the effectiveness of treatment 2.

From the Research

Diagnosis of Giant Cell Arteritis

• The diagnosis of giant cell arteritis (GCA) is typically confirmed by a temporal artery biopsy after initiation of therapy 3.
• Patients with suspected GCA should be started on high-dose corticosteroid therapy without delay, and a temporal artery biopsy should be performed to confirm the diagnosis 3.

Management of Giant Cell Arteritis

• Corticosteroids remain the cornerstone of therapy for GCA, but relapse during dose tapering and corticosteroid-related adverse events often complicate management 4, 5, 6.
• Methotrexate has been shown to be a safe alternative to corticosteroid therapy alone in patients with GCA, reducing the proportion of patients who experience at least one relapse and the cumulative dose of prednisone 4.
• Tocilizumab, an anti-IL-6 receptor antibody, is available as an approved substance for subcutaneous application and can be used as an additive GC-sparing treatment 7.
• Aspirin may be beneficial for patients with ischemic complications or multiple cardiovascular risk factors, and prevention of osteoporosis is recommended for all patients treated for GCA 6.
• The treatment of GCA should be individualized, taking into account the patient's characteristics, disease severity, and comorbidities, as well as the efficacy, cost, and ease of follow-up of the treatment 6.

Treatment Options

• High-dose oral prednisone (80 mg per day or 1 mg/kg) is often used as the initial treatment, with tapering by 10 mg per day every month 3.
• Intravenous methylprednisolone sodium succinate (250 mg intravenously every 6 hours) may be used for patients with acute visual or neurologic symptoms, followed by oral prednisone 3.
• Methotrexate or tocilizumab may be used as GC-sparing therapies, with methotrexate preferred in most cases due to its lower cost and ease of follow-up 6.