What is Giant Cell Arteritis (Temporal Arteritis)?
Giant cell arteritis (GCA) is a long-term inflammation of large to medium-sized blood vessels, most commonly in people over 50 years old. This complicated condition often affects the carotid arteries, which are found in the neck. This kind of inflammation can lead to the loss of certain cells and fibers in the blood vessels, which in turn could lead to the formation of aneurysms, or blood-filled bulges in artery walls, and changes to the blood vessels. The inflammation can also cause the artery walls to thicken and the inner part of the artery to narrow, which can lead to problems with blood flow.
The symptoms of GCA can vary, but may include general symptoms like fatigue and fever, a headache, or jaw pain during chewing, to the swelling of larger vessels which could be seen on medical imaging. Loss of vision, which often starts as temporary vision loss in one eye, is a serious outcome of this condition and requires immediate treatment with strong medication. This can sometimes be combined with a type of medication that blocks the inflammatory protein Interleukin-6 (IL-6) to boost effectiveness. Sometimes, GCA may require surgical treatment if there are issues related to the blood vessels. This condition is often linked to another inflammatory disease known as polymyalgia rheumatica, and a doctor will often consider this when planning treatment.
Treating GCA, especially in cases where it has affected large blood vessels, usually follows the same basic plan as when smaller vessels are affected. However, some patients might also need to use medication to prevent blood clots from forming. Taking into account the varying ways in which GCA can affect patients and the range of treatment options, a comprehensive approach is necessary to deal with its complexities effectively.
What Causes Giant Cell Arteritis (Temporal Arteritis)?
The exact cause of this disease is still unknown, but scientists believe that it has links to certain genes and environmental influences. Large-scale genetic studies show a strong connection between the disease and certain genetic traits in the area of the major histocompatibility complex, a part of the immune system. These traits include the human leukocyte antigen (HLA)-DRB1*04:04, HLA-DQA1*03:01, and HLA-DQB1*03:02.
On top of that, researchers have also found variations in genes that are linked to different types of T helper (Th) cells; these are important cells in our immune system that help control our body’s immune response. These include Th1, Th17, and regulatory T-cell genes.
Risk Factors and Frequency for Giant Cell Arteritis (Temporal Arteritis)
Giant Cell Arteritis (GCA) is a health condition that tends to affect older people, particularly those of Northern European ancestry. It’s also more common in women, though why this is the case is not fully understood. Its occurrence varies among different nationalities, with the highest rates among Scandinavians and the lowest rates in people of African American, Asian, Arabic, or Japanese descent.
- In the United States, about 1% of women and 0.5% of men will develop GCA in their lifetime.
- GCA mainly affects people over 50, with the majority of cases happening between the ages of 70 and 79. The average age at which it starts is 75.
- Scandinavians or those with Scandinavian ancestry are most likely to have GCA.
- People of African American, Asian, Arabic, or Japanese descent are less likely to get GCA.
- Somewhere between 40% and 60% of people with GCA also have a condition called polymyalgia rheumatica.
- On the other hand, about 16% to 21% of those with polymyalgia rheumatica also have GCA.
Signs and Symptoms of Giant Cell Arteritis (Temporal Arteritis)
Giant Cell Arteritis (GCA) is a medical condition that should be suspected in people over 50 years old who have new or changing headaches. Additional symptoms that may lead to suspicion of GCA include jaw clenching, unexplained fever or other generic symptoms, sudden vision changes or loss, and signals of vascular problems. In case of uncommon tongue pain, the chances of GCA are significantly increased. Vascular issues can show up as limb claudication, uneven blood pressures, an abnormal pulse at the wrist, vascular bruits, and peculiarities in the temporal artery.
- New or changing headaches in individuals over 50
- Jaw clenching
- Unexplained fever or other generic symptoms
- Sudden vision changes or loss
- Signals of vascular problems
- Uncommon tongue pain
- Limb claudication
- Uneven blood pressures
- An abnormal pulse at the wrist
- Vascular bruits
- Peculiarities in the temporal artery.
Individuals previously diagnosed with polymyalgia rheumatica are also at risk of GCA. So, anyone with a diagnosis of polymyalgia rheumatica should be checked for GCA by looking for signals such as headaches, jaw or arm claudication, visual symptoms, and unusual facial, throat, or tongue pain. As a baseline, these patients should also have their carotid and subclavian arteries heard for bruits and have their blood pressure measured on both sides.
GCA comes with a variety of symptoms and findings. Most people with typical GCA (around 2/3) complain initially of a new headache. While traditionally linked with a temporal headache and tenderness of the scalp, it could also be frontal, at the back of the head, one-sided, or generalized. The headache may fluctuate, fade, worsen, or even disappear before any treatment starts.
Classic signals of GCA include enlargement, nodular swelling, tenderness, and loss of pulse of the temporal artery, either on one or both sides. No physical temporal artery findings decrease the chances of GCA.
Furthermore, many patients with cranial GCA have nonspecific constitutional symptoms like fever, malaise, depression, loss of appetite, and weight loss. The fever is usually low-grade and is seen in 40% of patients going up to nearly 40°C in 15% of patients. Of all fevers where the cause is unknown in patients aged 65 or older, GCA accounts for more than 15% of them.
Jaw claudication, seen in nearly 50% of GCA patients, presents as pain or fatigue in the jaw, sometimes the tongue, triggered by chewing but usually goes away when chewing stops. About 20% to 30% of patients experience visual disturbances. Sight loss associated with GCA can be momentary or permanent. Overall, around 8.2% of patients with GCA suffer from permanent vision loss.
It’s also not uncommon for GCA patients to have polymyalgia rheumatica, characterized by pain, stiffness, and limited movement in the muscles around the neck, shoulders, and hips. This makes it hard to do simple actions such as get up from a chair or comb their hair. Plus, this condition is present in the initial diagnosis of 45% to 61% of GCA cases.
Large blood vessels, mainly the aorta and its major nearby branches, can also be affected by GCA. These cases often have symptoms ranging from upper extremity claudication, back or chest pain due to aortitis, or aortic dissection. Aortic aneurysms, often in the thoracic area, may be present.
Cerebrovascular events or strokes, particularly involving the posterior brain circulation, can be associated with GCA. However, these are lesser observed potential symptoms of GCA. Altogether, if you experience any combination of these symptoms, please consult a healthcare professional urgently.
Testing for Giant Cell Arteritis (Temporal Arteritis)
If your doctor suspects Giant Cell Arteritis (GCA), a condition that causes inflammation in large blood vessels, they’ll use a variety of tools to confirm it. As the signs of GCA can mimic other diseases, further tests beyond just looking at symptoms are needed.
Lab Tests
There are a number of laboratory tests that your doctor may use to explore the possibility of GCA. These tests include a routine blood test, an Erythrocyte Sedimentation Rate (ESR) test, a C-Reactive Protein (CRP) test, and tests for liver enzymes, blood sugar levels, and muscle enzymes. Your doctor might also recommend other tests for kidney and liver function and levels of minerals, proteins, and vitamins in your blood.
Indicators of GCA usually include a significant increase in ESR, CRP, and platelet levels. While most patients with confirmed GCA show higher levels of ESR, there can be exceptions. Also, those with other health conditions such as anemia and kidney disease may have elevated ESR levels as well. Thus, CRP is considered to be a more reliable marker for inflammation in GCA. However, having normal CRP or ESR levels does not necessarily rule out GCA.
Temporal Artery Evaluation
If GCA is suspected, your doctor may perform a biopsy or a type of ultrasound called Color Doppler Ultrasound (CDUS) on your temporal artery, which is located in your temples.
The biopsy involves removing a small sample of the artery to be looked at under a microscope. Despite being the traditional ‘gold-standard’ test for GCA diagnosis, it has some limitations. For instance, it only has a diagnostic sensitivity of about 77%, meaning it could miss GCA in about 23% of affected patients. Also, taking steroids – which are usually started as soon as GCA is suspected – limits the effectiveness of the biopsy.
If a biopsy can’t be done or its results are unclear, a CDUS might be used. This ultrasound checks for a ‘halo sign’, which is an area of inflammation or swelling around your arteries. If this sign is seen on both sides of your temporal arteries, it is highly specific for GCA.
Other Imaging
If the first biopsy or ultrasound doesn’t provide a clear result and GCA is still suspected, other forms of imaging might be used. These include more detailed scans like high-resolution Magnetic Resonance Imaging (MRI) with Magnetic Resonance Angiography (MRA), Positron Emission Tomography (PET), and Computed Tomography (CT) with angiography (CTA).
These scans can provide a detailed view of larger vessels such as those in the neck, chest, stomach, or pelvic areas, and are particularly useful in assessing for inflammation in these regions.
If GCA is diagnosed, you will also need scans to check if large vessels are involved. This can include CT, CTA, and PET scans for the aorta and its branches.
Again, these different imaging modalities have pros and cons – some reveal more detailed information, others involve contrast dyes or radiation, and costs vary. The choice will depend on your individual case.
Overall, diagnosing GCA involves a combination of clinical evaluation, laboratory testing, and imaging studies. This comprehensive approach helps doctors to make an accurate and timely diagnosis.
Treatment Options for Giant Cell Arteritis (Temporal Arteritis)
If you’re diagnosed with Giant Cell Arteritis (GCA), a condition that causes inflammation in the arteries, your first treatment will usually involve high-dose steroids. The exact dosage and how the steroids are administered can depend on different factors, especially if you’re at risk of vision loss.
No Vision Loss at Diagnosis:
Patients with GCA but no symptoms of vision loss are usually given high-dose steroids orally. Steroids are generally effective in inflammation reduction. Once you start to feel better, your doctor will gradually reduce the amount of steroids you’re taking. Some patients, particularly those at risk of complications from the steroids or those who have had a relapse of GCA, may also be given another medicine like tocilizumab, an IL-6 inhibitor. This is to help reduce the amount of steroids needed, limiting potential side effects. Tocilizumab has been shown to keep more patients in remission compared to treatment with just steroids alone. However, because of its cost and limited long-term use data, it’s often reserved for certain cases.
Threatened or Established Visual Loss at Diagnosis:
If vision loss is a risk or has already occurred from GCA, steroids are given intravenously (directly into a vein) instead of orally. The steroid treatment is often more intense to prevent further vision loss. If steroids aren’t enough, other therapies may be required.
Large Vessel Involvement:
If GCA has spread to major blood vessels outside of the head (known as large vessel involvement), a combination of steroids and other immune-suppressing drugs may be used. These might include medications like tocilizumab or methotrexate if tocilizumab isn’t suitable. The aim is to control the inflammation as effectively as possible.
Additional Recommendations:
As well as medications to combat the underlying inflammation, patients might be given aspirin. Although it’s not of benefit to all patients with GCA, aspirin has been found to reduce the risk of vision loss and stroke in those who have narrowing of the vertebral or carotid arteries.
Management of Relapses:
Relapses, where the symptoms of GCA return, occur in nearly half of all patients. If this happens, it may be necessary to increase the steroid dosage or to add or switch to another treatment like tocilizumab or methotrexate. The approach is different if the relapse comes with evidence of cranial ischemia (insufficient blood flow to the brain), in which case the steroid dose is increased and an immune-suppressant drug is added.
The diagnosis and treatment of GCA can be complex and individual to each patient, accounting for personal circumstances, the specifics of the condition, and any other medical issues. Regular check-ups will be required to make sure the treatment is working and to adjust any medications as necessary.
What else can Giant Cell Arteritis (Temporal Arteritis) be?
When diagnosing Giant Cell Arteritis (GCA), the doctor will consider various conditions that may present similar symptoms. These conditions include:
- Takayasu arteritis
- Microscopic polyangiitis
- Granulomatosis with polyangiitis
- Polyarteritis nodosa
- Primary angiitis of the central nervous system
- Vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome
- Idiopathic aortitis
- Nonarteritic ischemic anterior optic neuropathy
- Infections like endocarditis
It’s vital for doctors to consider these possible conditions and carry out the necessary tests to confirm the correct diagnosis.
What to expect with Giant Cell Arteritis (Temporal Arteritis)
GCA, or Giant Cell Arteritis, is a health condition that can last for different lengths of time. Most patients can gradually reduce and eventually stop using corticosteroids, a type of medicine often used for inflammatory conditions, after a few years. However, some may need to stay on a low-dose of these medicines for a longer period.
It’s important to note that having GCA does not typically affect a person’s overall lifespan. The main exception is those patients who experience aortitis, a condition that can weaken the wall of the aorta, the main blood vessel in the body. This can sometimes lead to serious complications, such as aortic dissection, a life-threatening condition where there is a tear in the wall of the aorta.
If Giant Cell Arteritis isn’t treated, the condition can become severe. The main reasons people with untreated GCA may pass away include having a heart attack or stroke. The chance of dying due to these complications in patients with GCA is around 1% to 3%.
Certain signs point to a strong inflammatory response and are linked to prolonged treatment and higher chances of the disease coming back. These signs include having a fever, losing weight, having an erythrocyte sedimentation rate (which measures inflammation) that’s equal to or greater than 85 mm/h, and having a hemoglobin level (a protein in red blood cells that carries oxygen) that’s equal to or less than 11 g/dL.
Patients with large blood vessels outside the brain involved with GCA may also need a longer course of treatment with glucocorticoids (another type of anti-inflammatory medication), and have greater chances of the disease returning, and a possibly shorter lifespan. These patients also have a higher chance of getting aortic aneurysms, which is a bulge in the wall of the aorta. Large blood vessels affected by GCA increases the risk of aortic aneurysms to 14% within 4 years, compared to 5% in patients where the disease only affects the arteries in the brain. Overall, the chance of getting an aortic aneurysm is twice as high in patients with GCA compared to people of the same age who don’t have the disease.
Possible Complications When Diagnosed with Giant Cell Arteritis (Temporal Arteritis)
Giant Cell Arteritis (GCA) may cause several complications, such as
- Vision loss
- Aortic aneurysm and dissection
- Stroke
- Tongue necrosis
There might also be side effects from the use of glucocorticoids including:
- Cataract formation
- Fragility fractures
- Infections
- High blood pressure (hypertension)
- Adrenal Gland issues (Adrenal insufficiency)
- Diabetes
- Thinning of the bones (osteoporosis)
- Bone death (osteonecrosis)
- Weight gain
Additionally, the use of tocilizumab can also have side effects, like:
- Opportunistic infections
- Neutropenia (low neutrophil count)
- Raised liver enzyme levels (Elevated transaminase levels)
- High lipid levels (hyperlipidemia)
- Disease of the pouches on the colon (diverticulitis)
- Rupture in gastrointestinal tract (Gastrointestinal perforation)
Not only this, patients with GCA are at an increased risk of diseases affecting the heart and blood vessels such as coronary artery disease, heart attack, and cerebrovascular disease. They are four times more likely to have a heart attack and 2.5 times more likely to have a cerebrovascular stroke compared to people of similar age.
Preventing Giant Cell Arteritis (Temporal Arteritis)
Understanding how to manage Giant Cell Arteritis (GCA), a type of blood vessel inflammation, is crucial for patients. Part of the treatment for GCA often includes high-dose medicines called glucocorticoids. Though these medicines are necessary, they can come with complications that can occur in nearly 90% of people taking them for about 2 to 3 years. These issues can include weight gain, cataracts (clouding in the eye’s lens), bone loss (osteopenia or osteoporosis), fractures, high blood sugar or diabetes, and adrenal insufficiency (a condition where the adrenal glands don’t produce enough hormones).
Doctors need to assess the chances of these problems and put steps in place to lessen them. For patients who are most at risk of facing these complications, combining glucocorticoid with other therapies that can reduce the total amount of glucocorticoid used is essential. Tools like the Fracture Risk Assessment Tool can help doctors see how high a patient’s bone loss risk is. Patients should also make lifestyle changes like doing weight-bearing exercises, strength training, stopping smoking, and ensuring their diet includes enough calcium. If needed, they should take calcium and vitamin D supplements and have their bone strength monitored regularly. Patients may also need to start bisphosphonate treatment if their bones are becoming too weak.
Regular glucose checks for high blood sugar before and during glucocorticoid therapy are also vital. Patients should also make lifestyle changes such as a balanced diet, regular exercise, and losing weight if necessary. Doctors will also slowly reduce the amount of corticosteroid medicine patients are taking to lessen the risk of adrenal insufficiency.
Finally, sudden vision loss can be an early sign of permanent vision damage, requiring immediate attention for individuals diagnosed with polymyalgia rheumatica or GCA. Increasing patients’ understanding of these points can help patients take an active role in their health care and provide the best possible outcomes.
