What is the recommended treatment for an older adult, likely over 50 years old, with a possible history of autoimmune or inflammatory conditions, diagnosed with giant cell arteritis?

Treatment of Giant Cell Arteritis

Immediately initiate high-dose oral glucocorticoids (prednisone 40-60 mg daily) as soon as giant cell arteritis is suspected, without waiting for biopsy confirmation, and add tocilizumab as adjunctive therapy to reduce glucocorticoid requirements and prevent disease relapse. 1

Immediate Management

Initial Glucocorticoid Therapy

• Start high-dose oral prednisone (40-60 mg daily or 1 mg/kg/day, maximum 60 mg) immediately upon clinical suspicion, even before diagnostic confirmation 1, 2
• For patients with visual symptoms or threatened vision loss, use IV pulse methylprednisolone (1000 mg daily for 3 days) before transitioning to oral glucocorticoids 1, 3
• Maintain the initial high dose for at least one month before beginning taper 1
• Do not delay treatment to obtain temporal artery biopsy—biopsy can be performed up to 1-2 weeks after starting glucocorticoids without affecting diagnostic yield 1, 2

Critical pitfall: Vision loss in the contralateral eye can occur despite treatment, most commonly within the first 2 days but potentially up to 12 days after treatment initiation 3. This underscores the urgency of immediate high-dose therapy.

Adjunctive Tocilizumab Therapy

• Add tocilizumab (IL-6 receptor inhibitor) to glucocorticoids for all newly diagnosed patients to reduce cumulative steroid exposure and prevent relapses 1, 2
• This combination is strongly preferred over glucocorticoids alone for patients without visual symptoms or critical cranial ischemia 1
• Tocilizumab has FDA approval for GCA and demonstrated efficacy in reducing glucocorticoid requirements and flare rates 1, 4

Aspirin Therapy

• Initiate low-dose aspirin (75-150 mg daily) for all GCA patients to reduce cardiovascular and cerebrovascular events 2, 5, 6

Diagnostic Confirmation (Parallel to Treatment)

Temporal Artery Biopsy

• Obtain biopsy specimen ≥1 cm in length from an experienced surgeon, evaluated by an experienced pathologist 1, 2
• Perform within 1-2 weeks of starting glucocorticoids 1
• Look for arterial wall thickening, narrowed lumen, mononuclear inflammatory cell infiltration of the media, and multinucleated giant cells 2, 7

Vascular Imaging

• Obtain baseline noninvasive vascular imaging (MR or CT angiography of neck/chest/abdomen/pelvis) to evaluate large vessel involvement 1
• Ultrasound showing "halo sign" around temporal artery supports diagnosis 1
• PET-FDG can demonstrate increased tracer uptake in arterial walls 2

Glucocorticoid Tapering Strategy

• Maintain initial high dose (40-60 mg daily) for one month 1
• At 3 months, target dose should be 10-15 mg daily 1
• Use daily dosing, never alternate-day dosing—alternate-day schedules increase relapse risk 1
• Taper gradually over months to years, guided by clinical symptoms and inflammatory markers (ESR/CRP) 1, 2, 6
• Target dose ≤5 mg/day after one year if disease controlled 1

Common pitfall: Rapid tapering leads to disease relapse. Many patients require 1-2 years of therapy and some cannot completely discontinue glucocorticoids 1, 2.

Alternative Immunosuppressive Agents

When tocilizumab is unavailable or contraindicated:

• Methotrexate can be considered as steroid-sparing agent 1, 6
• Abatacept is reasonable as adjunctive therapy 1
• Azathioprine or leflunomide may be used for Takayasu arteritis but have limited evidence in GCA 1
• Never use infliximab—it is associated with recurrent ocular symptoms and disease activity 1

Monitoring and Follow-up

Clinical Monitoring

• Monitor primarily with clinical symptoms plus ESR and CRP levels to guide treatment decisions 2, 5
• Do not use IL-6 measurement for monitoring 2
• Assess for glucocorticoid-related complications: hypertension, diabetes, osteoporosis, infection, peptic ulcer disease 6

Imaging Surveillance

• Periodic vascular imaging is necessary for patients with known large-vessel involvement to assess for aneurysms, stenoses, and stability of existing lesions 1, 2, 5
• Patients without large vessel involvement may not require routine repeated imaging 1

Glucocorticoid Complication Prevention

• Initiate bone protection therapy (calcium, vitamin D, bisphosphonates) for all patients unless contraindicated 1, 6
• Consider proton pump inhibitor or H2-receptor antagonist for GI protection 6
• Provide antimicrobial prophylaxis when appropriate 6

Management of Relapse

• Disease relapse is common and requires escalation of glucocorticoid dose 6
• If relapse occurs despite adequate glucocorticoid therapy, add or change non-glucocorticoid immunosuppressive agent (e.g., switch from methotrexate to tocilizumab or add abatacept) 1

Key nuance: The 2021 ACR/Vasculitis Foundation guidelines 1 represent the most current evidence and strongly favor tocilizumab as adjunctive therapy, marking a significant shift from older guidelines that relied primarily on glucocorticoid monotherapy 1. This reflects the FDA approval of tocilizumab and high-quality trial data demonstrating superior outcomes with combination therapy.