1. Objectives
Giant cell arteritis (GCA) also referred to as temporal arteritis is a condition that induces the inflammation of large arteries mainly in the heat and neck areas. Symptoms associated with the disease include manifestations such as headaches, joint and facial pain, fever, and vision problems that may cause a permanent sight loss in one or both eyes.
There are various GCA treatments aiming at e.g. relieving the symptoms associated with the disease and preventing visual loss often accoutered by many patients
2 Therapeutic options
2.1. Non-pharmacological therapy
The practice of a healthy lifestyle including physical exercises, smoking termination, and a decrease in the daily alcohol intake can induce a regression of the condition. When vision problems occur, it is recommended to initiate rehabilitation and supportive programs including physical and occupational therapies to prepare the patient for a life without vision. Patients may require training such Braille reading, use of a cane or a voice-activated or Braille computer.
The non-pharmacological therapies are usually performed in addition to the use of medicines.
2.2. Pharmacological therapy
2.2.1 Glucocorticoids
This is the first-line treatment that should be administrated as soon as a development of GCA is suspected. Although there is a need to confirm the disease by temporal and artery biopsies, it is recommended not to withhold the treatment the results waiting time. This is due to the fact that a sight loss occurs quite early and is almost irreversible.
In the case where the biopsies results are negative, but a development of GCA strongly suspected, it is advised to sustain the glucocorticoid treatment as false-negative results occur in at least 9% of GCA cases.
Depending on the level of the condition when diagnosed, different doses are administrated. For a primary GCA where occurrence of a jaw or tongue claudication or visual problems is observed, 40-60 mg of Prednisolone is administrated until complete regression of the symptoms and acceptable laboratory results are obtained. For advanced GCA cases involving a progressing visual loss or history of amaurosis fugax, a daily dose of 500 mg-1 g of i.v. Methylprednisolone is provided. For advanced cases where a complete sight loss has happened at least 60 mg/day of Prednisolone should be administrated.
The duration of treatment is variable according to the patient, the evolution of the disease and other triggering factors. It can last for a few days only or many years or even a lifetime. The dose can also be readjusted at any time.
A reduction of the daily dose is considered when the clinical symptoms have regressed significantly, and the results of the laboratory assessments (e.g. erythrocyte sedimentation rate, and C-reactive protein) are normal. A steroid tapering program can be applied as follows: 1-2 weeks after the start of the treatment, Prednisolone can be reduced to 10 mg/1-2 weeks. A reduction to 2.5 mg/2 weeks can be considered when the initial daily dose is less than 30 mg. A decrease by 1 mg/month until the lowest effective dose is reached is advised once a dose of 10 mg/day is tolerated. For patients being administrated enteric coated Prednisolone, another tapering program should be considered.
2.2.2. Methotrexate
A study conducted on 161 patients revealed that Methotrexate can decrease the risk of relapse and the need for corticosteroid intake. A reduction of the cumulative corticosteroid dose by 842 mg within 48 weeks (p < 0.001) was associated with an intake of Methotrexate. Further, a higher probability of sustained discontinuation of corticosteroids for more than 24 weeks with fewer relapses (HR 2.84, p = 0.001) was observed.
It is not recommended to administrate glucocorticoids and Methotrexate simultaneously for GCA treatment
2.2.3. Tocilizumab
A study has demonstrated that Tocilizumab is effective in inducing clinical regression in patients with relapsing or refractory GCA. Patients (10) suffering from large-vessel vasculitis and treated with Tocilizumab at a dose of 8 or 4 mg/kg/month exhibited a clinical improvement within 8-12 weeks. Further, the use of the medicine allowed a tapering of Prednisone intake to about 6 mg/day.
2.2.4. Cyclophosphamide
It is used as an alternative drug for patients who have not responded adequately to other immunosuppressive or immunomodulatory glucocorticoid therapies.
2.2.5 Associated treatments
Treatments for bone and gastrointestinal protection can be given to GCA patients. It is advised to administrate bisphosphonate, calcium or vitamin D for the protection of the bone of individual being treated with glucocorticosteroids. For gastrointestinal protection, proton pump inhibitors are used. Aspirin has been shown to lower the risk of sight loss and cerebrovascular accidents in GCA. Reduced dose can be given to patients only if no contraindications exist.
2.3. Monitoring
GCA can be monitored through the clinical symptoms associated or a laboratory assessment.
2.3.1. Symptoms
Clinical symptoms indicative of a development of GCA include manifestations such as headaches, jaw and tongue claudication, vision decrease, vascular claudication of limbs, hypertension, proximal pain, morning stiffness, osteoporotic risk factors and fractures. Manifestations related to the use of glucocorticosteroid include e.g. weight gain, hypertension, diabetes, cataract, glaucoma, and dyslipidaemia.
2.3.2. Laboratory monitoring
This includes analyzes such as full blood count, ESR/CRP, urea, electrolytes, glucose, and bone mineral measurements. Every two years a radiography of the chest is required to monitor for an aortic aneurysm. Additionally, other imaging screenings such as echocardiography, PET and MRI can be used when necessary.
2.3.3 Follow-up frequency
Monitoring of GCA patients should be performed according to a defined program. The following follow-up schedule can be adapted: during the first year, visits should be made the first, third and sixth week from the day of diagnosis then every three months. If necessary, additional visits may be considered according to the development of the disease. After the first year, the visits can be scheduled for every three months
2.4. Relapse
2.4.1. Features
Following a treatment, a disease a relapse can be suspected when some manifestations occur including e.g. a persistent fever higher than 38C, an occurrence of recurrent headaches, tenderness and or pain of the scalp or temporal artery, an optic neuropathy or visual loss not imputable to other causes, a reoccurrence of the tongue, jaw pain and extremity pain and/or claudication, angiographic abnormalities, a stroke not attributable to cardiac arrhythmias or atherosclerotic diseases, malaise and fatigue . Also, An increase of the ESR/CRP level is often observed with a relapse.
In all cases, patients in whom a relapse is suspected should be referred for a specialist assessment and treatment.
2.4.2. Treatment of relapse
Headaches can be treated with the previous higher glucocorticosteroid dosage. For headaches, jaw claudication and eye problems, a dose of 60 mg of Prednisolone or i.v. Methylprednisolone can be given. In the case of a suspected large-vessel GCA, an imaging technique should be used to confirm the diagnosis. If the reoccurrence of the disease is confirmed, a treatment involving the use of systemic vasculitis protocols should be considered.
