What is the treatment for giant cell arteritis?

Treatment of Giant Cell Arteritis

Immediate Treatment Initiation

Start high-dose oral glucocorticoids (prednisone 40-60 mg/day or 1 mg/kg/day, maximum 60 mg) immediately upon clinical suspicion of GCA, even before biopsy confirmation, to prevent irreversible vision loss. 1, 2

• Do not delay treatment while awaiting temporal artery biopsy—the risk of permanent blindness is too high, and biopsy remains diagnostic for up to 2 weeks after starting steroids 2, 3
• Daily dosing is superior to alternate-day regimens, achieving higher remission rates (85-90% vs 30% with alternate-day therapy) 1, 4

For Patients with Threatened Vision Loss or Active Visual Symptoms

• Administer intravenous methylprednisolone 500-1000 mg/day for 3 consecutive days immediately, followed by high-dose oral prednisone (1 mg/kg/day) 1, 2, 3
• This represents a neuro-ophthalmic emergency requiring same-day treatment 5
• Without treatment, the risk of vision loss in the second eye approaches 50% if one eye is already affected 2, 3

First-Line Adjunctive Therapy

Add tocilizumab (162 mg subcutaneously weekly) to glucocorticoids as first-line therapy for all patients with newly diagnosed GCA. 1, 2, 6

• Tocilizumab significantly reduces relapse rates and minimizes cumulative steroid exposure, which is critical given that 86% of patients develop glucocorticoid-related adverse events with long-term therapy 1, 2
• The 2021 ACR guidelines conditionally recommend tocilizumab plus glucocorticoids over glucocorticoids alone based on strong evidence from randomized trials 1
• Tocilizumab is FDA-approved specifically for GCA treatment 6

Alternative Steroid-Sparing Agents

• Consider methotrexate (15-25 mg weekly) if tocilizumab is contraindicated due to recurrent infections, history of gastrointestinal perforations, diverticulitis, or cost concerns 1, 2
• Methotrexate has moderate evidence for efficacy but is less effective than tocilizumab 1, 7, 8
• Abatacept may be considered if both tocilizumab and methotrexate are ineffective 1

Glucocorticoid Tapering Protocol

• Maintain initial high-dose glucocorticoids (40-60 mg/day) for approximately 1 month until symptoms resolve and inflammatory markers (ESR, CRP) normalize 2, 3
• Begin gradual taper after disease control is achieved, aiming for 10-15 mg/day by 3 months 1, 2, 3
• Target ≤5 mg/day after 1 year of treatment 1, 2, 3
• Guide tapering by clinical symptoms and normalization of ESR/CRP, not by inflammatory markers alone 1, 2
• Avoid rapid steroid withdrawal as it leads to disease exacerbation 2

Aspirin Therapy

• Prescribe low-dose aspirin (75-150 mg/day) for all patients with GCA unless contraindicated, to reduce cardiovascular and cerebrovascular ischemic complications 2, 7, 8
• For patients with critical or flow-limiting involvement of vertebral or carotid arteries, adding aspirin is conditionally recommended 1

Management of Large Vessel Involvement

• Obtain noninvasive vascular imaging (ultrasound, CT, MRI, or PET-CT) at diagnosis to evaluate for large vessel involvement 1, 2
• For patients with active extracranial large vessel involvement (limb claudication, imaging findings), combine oral glucocorticoids with a non-glucocorticoid immunosuppressive agent (preferably tocilizumab) rather than glucocorticoids alone 1, 2

Relapse Management

For relapses with cranial ischemic symptoms, add a non-glucocorticoid immunosuppressive agent (preferably tocilizumab) and increase glucocorticoid dose. 2, 3

• For relapses with polymyalgia rheumatica symptoms only, increasing glucocorticoid dose alone may be sufficient 2
• For asymptomatic elevation of inflammatory markers without clinical symptoms, clinical observation and monitoring without escalation of therapy is recommended 2, 3

Diagnostic Confirmation

• Arrange temporal artery biopsy as soon as possible, ideally within 2 weeks of starting glucocorticoids 2, 3
• Obtain a long-segment biopsy specimen (>1 cm) to improve diagnostic yield 3
• If temporal artery biopsy is negative but clinical suspicion remains high, obtain noninvasive vascular imaging to evaluate for large vessel involvement 2

Monitoring and Prophylaxis

• Monitor ESR and CRP regularly to guide treatment decisions, though clinical symptoms should take precedence 1, 2
• Implement long-term clinical monitoring for all patients, even those in apparent remission, to detect relapses 2, 3
• Provide bone protection therapy (calcium, vitamin D, bisphosphonates as indicated) to prevent glucocorticoid-induced osteoporosis 3, 8
• Monitor for glucocorticoid-related adverse effects including hypertension, hyperglycemia, infections, and weight gain 3

Critical Pitfalls to Avoid

• Never delay treatment while awaiting biopsy confirmation—vision loss occurs in 15-35% of patients, primarily before treatment initiation, and is often irreversible 2, 3
• Do not use infliximab for GCA as it is associated with recurrent ocular symptoms and disease activity 2
• Do not routinely use statins specifically for GCA treatment, as they provide no clinically significant immunosuppressive effect 1
• Avoid alternate-day glucocorticoid regimens, which achieve remission in only 30% of patients compared to 85-90% with daily dosing 4

Special Considerations

• The optimal duration of glucocorticoid therapy varies by patient and should be guided by clinical manifestations, toxicity, number of flares, and patient preferences 1
• Most patients require 1-2 years of treatment, though some with chronic-relapsing disease may need low-dose glucocorticoids for several years 7, 5
• Induction therapy with high-dose IV methylprednisolone (15 mg/kg/day for 3 days) in addition to oral prednisone allows for more rapid tapering and higher rates of sustained remission 9