30 April 2021
This month’s focus for eLearning is giant cell arteritis (GCA). We speak to Dr Sarah Mackie, Associate Professor and Consultant Rheumatologist at the University of Leeds. Dr Mackie talks about the recent GCA guidelines, how her team diagnose GCA and why small changes can make a big difference when treating patients.
When did you become interested in GCA?
When I moved to the University of Leeds, I first became interested in polymyalgia rheumatica (PMR) because my supervising consultant, Dr Colin Pease, was looking at long term patient outcomes. Little had been published in this area and I worked with him to analyse these patients over five years. Some of them developed GCA.
This next led to work on GCA, which was the focus of my PhD. During this I recruited hundreds of patients and realised there was so much more to these two diseases than what’s written in textbooks.
GCA is a difficult area; do you have some overall tips?
GCA can be hard to diagnose, even if you’re an expert. What we’ve found useful in Leeds is to set up a monthly GCA diagnostic multidisciplinary team (MDT) meeting, where we get together and discuss our cases. That supports the trainees, helps our learning and lets us discuss tricky cases.
You recently updated our guideline on GCA, what’s new that we need to be aware of?
One of the key advances is the evidence for tocilizumab, which is the first biologic therapy to be approved for GCA. Previously, the only licensed therapy was steroids. The guidance details the trial evidence for using tocilizumab in GCA and signposts to the funding decision from NHS England. It provides context on the kind of patients who might benefit.
The other important advance is the usefulness of ultrasound as a tool for diagnosing GCA. We cover how to integrate the ultrasound result into your diagnostic thinking. We acknowledge that ultrasound is not available in every centre right now, but we hope that by providing guidance on how it might be used, this will help people implement it in their area.
How does it currently work with tocilizumab funding?
The original guidance issued by NHS England was that patients with GCA should take tocilizumab for one year and then stop. During the pandemic it was judged that stopping treatment wasn’t the right thing to do, so a short-term extension to the end of June 2021 was issued. We don’t yet know what will happen after that, as it’s an evolving area.
Why are co-morbidities so important in GCA?
Patients with GCA are typically older – the average age of onset being 75. This means that most patients will have some form of co-morbidity. Also, we tend to prescribe high-dose steroids which can lead to issues like diabetes, high blood pressure, vision problems and infections. So, it’s important to evaluate patients at an early stage for co-morbidities and we provide a suggested checklist in the guideline. We specifically advise monitoring patients for hyperglycaemia after starting high-dose steroids.
What allied health professional input did you have when writing the guidelines?
We were fortunate to co-write the guidelines with a very experienced rheumatology specialist nurse, so that helped us to consider the role of the entire MDT when looking after patients with GCA. Nurses have a key role in helping patients to understand their condition and its treatment in the context of their lives, and to support them through the process of tapering their steroids.
Our eLearning platform contains your article on pre-test probability, what got you interested in this area?
When we were writing about the role of ultrasound in diagnosing GCA in the guideline, we said that the result of any test needs to be considered in light of the pre-test probability. The challenge for GCA was how to quantify that pre-test probability in order to know how to act on the ultrasound result.
So, in this new study we meta-analysed the published literature to derive likelihood ratios for each individual symptom, sign or laboratory feature of GCA. We hope this article could be used to teach students and trainees what things to look for when evaluating a patient for GCA.
What’s your key message to members?
If you manage GCA well, there’s a huge amount you can do to help patients. Even a small change in the way the clinical pathway works, or the way patients are looked after, can make a big difference. The resources on the eLearning platform will give you ideas and I hope that everyone can learn something that will help improve patient care.
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Many thanks to Dr Mackie for sharing her GCA expertise. Improve your knowledge on the condition by visiting our eLearning platform. This month's spotlight features a clinical update and podcast from Dr Vanessa Quick, a patient perspective podcast as well as an interactive case which you can use to test your knowledge of GCA.