Giant Cell Arteritis

The exact cause of Giant Cell Arteritis remains unknown, but it is recognized as an autoimmune disease. In GCA, the body's immune system mistakenly attacks the healthy lining of the arteries. Research published in The Lancet (2022) suggests that the process begins when dendritic cells in the arterial wall become activated, triggering a cascade of inflammatory proteins like Interleukin-6 (IL-6).

This inflammation causes the 'tunica media' (the middle layer of the artery) to thicken and the 'internal elastic lamina' (a supportive membrane) to break down. This results in the narrowing of the vessel lumen (the opening), which restricts oxygen-rich blood from reaching tissues.

Non-Modifiable Risk Factors

• Age: The single greatest risk factor. GCA almost never occurs in people under 50; the average age of onset is 72.
• Sex: Women are approximately 2 to 3 times more likely to develop GCA than men.
• Ethnicity: People of Northern European descent, particularly those of Scandinavian ancestry, have the highest rates globally.
• Genetics: Specific variations in the Human Leukocyte Antigen (HLA) genes, particularly the HLA-DRB1*04 cluster, have been linked to increased susceptibility.

Modifiable Risk Factors

• Smoking: Some studies suggest that smoking may increase the risk of GCA, particularly in women, potentially by damaging the vascular endothelium (vessel lining).
• Environmental Triggers: While not fully proven, some researchers have noted seasonal peaks in GCA diagnoses, suggesting that certain viral or bacterial infections might trigger the immune response in genetically predisposed individuals.

The 'typical' patient is a female over the age of 70 of Northern European heritage who may also have a history of Polymyalgia Rheumatica. According to the National Institute of Allergy and Infectious Diseases (NIAID), individuals with a history of other vascular or autoimmune issues are not necessarily at higher risk, as GCA appears to be a distinct immunological event.

Currently, there are no known ways to prevent Giant Cell Arteritis because the primary risk factors—age, sex, and ethnicity—cannot be changed. There are no specific dietary or lifestyle interventions proven to stop the onset of the disease. However, early detection is the best 'prevention' against the condition's most severe complication: permanent blindness. Screening is generally not recommended for the general population but should be considered for patients with new-onset PMR symptoms.

Diagnosing GCA is often a race against time to prevent vision loss. The diagnostic journey typically begins with a clinical evaluation of symptoms, followed by blood tests and imaging, and is confirmed via a biopsy.

A healthcare provider will check for tenderness or swelling of the temporal arteries. They may also use a stethoscope to listen for 'bruits' (abnormal sounds caused by turbulent blood flow) in the neck or arms and check for diminished pulses in the wrists.

• Blood Tests: Providers look for markers of systemic inflammation. The Erythrocyte Sedimentation Rate (ESR) is typically very high (often over 50 mm/hr or even 100 mm/hr). C-Reactive Protein (CRP) is also usually elevated and is considered a more sensitive marker for GCA.
• Temporal Artery Biopsy (TAB): This is the gold standard for diagnosis. A small section of the temporal artery is surgically removed under local anesthesia and examined under a microscope for the presence of giant cells and inflammation.
• Color Doppler Ultrasound: This non-invasive test looks for the 'halo sign,' a dark ring around the artery indicating wall swelling. According to the 2023 EULAR guidelines, ultrasound is increasingly used as the first-line imaging test.
• MRI or PET/CT: These may be used to detect inflammation in the aorta or other large vessels that a biopsy cannot reach.

The American College of Rheumatology (ACR) established criteria for GCA diagnosis, which include: age ≥50, new-onset headache, temporal artery tenderness or decreased pulsation, elevated ESR, and abnormal artery biopsy.

Because GCA symptoms are diverse, doctors must rule out other conditions, including:

• Migraine or Tension Headaches: Usually lack the high inflammatory markers of GCA.
• Temporomandibular Joint (TMJ) Disorder: Can cause jaw pain but not vision loss.
• Trigeminal Neuralgia: Causes sharp, stabbing facial pain.
• Other Vasculitides: Such as Takayasu arteritis (usually in younger patients).

The primary goals of GCA treatment are to prevent permanent organ damage (especially blindness), induce clinical remission, and gradually taper medications to the lowest effective dose while avoiding relapses.

Standard clinical guidelines from the American College of Rheumatology (2024) mandate that treatment must begin immediately—often before a biopsy confirms the diagnosis—if GCA is strongly suspected. High-dose systemic therapy is the cornerstone of initial management to rapidly suppress inflammation.

1. Corticosteroids (Glucocorticoids)

• How it works: These are powerful anti-inflammatory agents that quickly reduce the swelling in the arterial walls.
• When it is preferred: This is the universal first-line treatment for all GCA patients.
• Common side effects: Weight gain, increased blood sugar (diabetes risk), bone thinning (osteoporosis), mood changes, and increased risk of infection.
• Typical duration: Patients usually start on high doses, which are slowly tapered over 12 to 24 months.

2. Interleukin-6 (IL-6) Inhibitors

• How it works: These are biologic medications that block IL-6, a key protein that drives the inflammatory process in GCA.
• When it is preferred: Often used in combination with corticosteroids to help patients taper off steroids faster (steroid-sparing effect) or for patients who experience relapses.
• Common side effects: Injection site reactions, upper respiratory infections, and changes in liver enzymes.

3. Conventional Synthetic DMARDs (Immunosuppressants)

• How it works: These medications suppress the immune system through various metabolic pathways.
• When it is preferred: Sometimes used as a second-line 'steroid-sparing' option if biologics are not suitable.

While medication is the only way to treat the underlying inflammation, supportive care is vital. This includes regular ophthalmological exams to monitor vision and bone density scans (DEXA) to monitor the impact of long-term steroid use. Surgery is rarely used for GCA itself but may be necessary to repair an aortic aneurysm caused by the disease.

Treatment is a marathon, not a sprint. Most patients require medication for at least one to two years. Monitoring involves regular blood tests (ESR and CRP) and frequent clinical check-ups to watch for signs of a 'flare' (return of symptoms).

In the elderly, doctors must be extremely cautious with steroid dosing due to the high risk of cataracts, glaucoma, and brittle bones. For patients with pre-existing diabetes or heart disease, the side effects of treatment may require additional medications to manage blood pressure or glucose levels.

> Important: Talk to your healthcare provider about which approach is right for you.

Dietary adjustments are primarily focused on mitigating the side effects of corticosteroid treatment. Research suggests that a 'bone-healthy' diet is essential. Patients should prioritize:

• Calcium and Vitamin D: Essential to prevent steroid-induced osteoporosis. Sources include dairy, leafy greens, and fortified cereals.
• Low-Sodium Intake: Steroids cause fluid retention; reducing salt can help manage blood pressure and swelling.
• Low-Glycemic Index Foods: To help stabilize blood sugar levels, which often rise during treatment.

Weight-bearing exercises, such as walking, jogging, or using resistance bands, are highly recommended to maintain bone density and muscle strength. However, during an active flare, patients should avoid high-intensity exercise and focus on rest. Once remission is achieved, the American College of Rheumatology suggests moderate activity for at least 150 minutes per week.

Corticosteroids often cause insomnia. Establishing a strict sleep hygiene routine—such as avoiding screens an hour before bed and keeping the bedroom cool—is vital. If GCA causes scalp tenderness, using a silk pillowcase or a specialized neck pillow may reduce discomfort.

Chronic illness is a significant stressor. Evidence-based techniques such as Mindfulness-Based Stress Reduction (MBSR) or cognitive-behavioral therapy (CBT) can help patients cope with the anxiety of potential vision loss and the mood-altering effects of medications.

There is no evidence that herbal supplements can treat the inflammation of GCA. However, acupuncture may help manage the secondary muscle pain associated with PMR. Always consult a doctor before starting supplements, as some (like St. John’s Wort) can interfere with conventional medications.

Caregivers should monitor the patient for 'steroid psychosis' or significant mood swings, which can occur with high-dose treatment. Helping the patient track their tapering schedule and attending appointments to report any new visual symptoms are critical roles for family members.

The prognosis for Giant Cell Arteritis is generally excellent if the condition is diagnosed and treated before vision loss occurs. Most patients achieve complete remission and can eventually stop taking medication. According to a study in Arthritis & Rheumatology (2022), the life expectancy of individuals with GCA is similar to that of the general population, provided the disease is well-managed.

• Permanent Blindness: The most feared complication, occurring in about 15-20% of untreated or late-treated cases.
• Aortic Aneurysm: Inflammation can weaken the wall of the aorta, leading to a bulge that could potentially burst years after the initial diagnosis.
• Stroke: If the inflammation affects the arteries supplying the brain.

Because the risk of relapse is high (estimated at 40-60% within the first two years), long-term management involves 'tapering'—very slowly reducing the steroid dose. Patients will need periodic blood tests and imaging for several years to ensure the disease remains inactive.

Living well requires a partnership with a rheumatologist. Joining support groups, such as those offered by the Vasculitis Foundation, can provide emotional support and practical tips for managing long-term treatment.

Contact your healthcare provider immediately if you experience:

• A return of headaches or jaw pain.
• Any new visual disturbances.
• New pain in the chest or back (which could indicate an aortic issue).
• Signs of infection, such as fever or chills, while on immunosuppressants.