Giant Cell Arteritis: Difficult to diagnose, eminently treatable
Giant Cell Arteritis (GCA) is the most common form of vasculitis that occurs in adults. Almost all patients who develop giant cell arteritis are over the age of 50. GCA commonly causes headaches, joint pain, facial pain, fever, and difficulties with vision, and sometimes permanent visual loss in one or both eyes. Because the disease is relatively uncommon and because the disease can cause so many different symptoms, the diagnosis of GCA can be difficult to make. With appropriate therapy, GCA is an eminently treatable, controllable, and often curable disease.
“My general practitioner called me up and he said ‘I think it’s giant cell arteritis, you could go blind’. I’ve told doctors I can handle a lot of stuff but I can’t handle going blind.” says Richard Higgins Giant cell arteritis (GCA) patient from Schenectady, New York, USA.
This is the reality of giant cell arteritis – GCA – a ‘silent’ disease of the immune system that most people have never heard of, which can strike without warning and rob people of their sight in days.
According to a report by Roche, for decades, patients, doctors and scientists have been waging a war against this little-understood condition, which remains incurable. Its exact cause is still not yet known and because it triggers a host of non-specific symptoms – from severe headaches and scalp tenderness to jaw pain and visual problems – it is difficult to diagnose. If left untreated, GCA can lead to blindness, aortic aneurysm or stroke. When it is finally diagnosed, it is a medical emergency and patients are treated with high-dose steroids for a number of months to bring it under control and prevent sight loss.
The report established that despite the disease’s complexity, continuing research has substantially increased Roche’s overall understanding of the chronic and potentially life-threatening condition. Yet for almost 70 years, the only treatment option for GCA sufferers has been long-term steroids, which commonly cause severe side effects.2
“It can be difficult to diagnose because there are lots of other competing illnesses that a doctor has to think about in order to tease out a diagnosis of GCA.” Says Neil Collinson, Senior Clinical Development Scientist at Roche.
Roche further revealed that there have been several attempts in the past to identify a new treatment option which could not only control the disease, but spare patients from the high doses of steroids. Unfortunately these have all failed, showing conflicting results or negative data.
But the fight continues, as researchers discover more and more about GCA and its complex causes within the body.
“I was always in good health. I never missed work and then all of a sudden it was like my world came undone. I could tell it was something bad. Judy Murphy GCA patient and registered nurse from Everett, Massachusetts, US said.
According to Roche, depending on which arteries are affected, GCA reveals itself in many ways, which is why it is so tough to diagnose. Immune system cells invade the walls of arteries, setting off a chain reaction of inflammation. Inflammation thickens the artery walls, causing them to narrow and reducing the flow of blood. This in turn causes the devastating symptoms suffered by patients – severe headaches, scalp tenderness, jaw pain and sight problems. In some cases the blood vessel can close completely and when this happens to the arteries serving the eye, sudden blindness can occur. What is still not known is what triggers this immune attack.
The report further states that steroids have been the mainstay of treatment for GCA for almost 70 years with little progress discovering effective, but less toxic, ways of tackling it. Steroids suppress the immune system, and block the inflammatory process, but how exactly they tackle GCA is not known. Trying to unravel the mechanism by which steroids treat GCA is leading the way to potentially discover new GCA treatment options. The aim is to find a treatment that could break the devastating inflammatory cascade triggered by the disease to get people into remission quickly without needing to resort to steroids.
For Roche, progress is already being made to work out the complex role of all the different immune cells and biological pathways that are implicated in the disease. As more is understood about the immune system it will hopefully reveal not only why GCA develops, but more importantly how it can be stopped.
They share that GCA can trigger inflammation inside a number of different arteries in the body. This means it reveals itself in different ways in different people, causing a complex range of symptoms – from headaches and jaw pain to scalp tenderness. This is also why it is typically diagnosed by one of a range of medical professionals – from rheumatologists, neurologists and ophthalmologists to general practitioners. It is this range of ambiguous symptoms that means it is often misdiagnosed, or diagnosed late.
Missing the warning signs can have a devastating impact on a patient’s life, including permanent sight loss. Despite the urgency to treat GCA, it is not usually until it is too late that a patient’s individual symptoms get pieced together.
Kemi Ajumobi with wired reports