7 November 2021

Day 1 conference highlights

ACR Giant-cell arteritis Immune Checkpoint Inhibitors Polymyalgia Rheumatica

Early career rheumatologists Dr Bonnia Liu, Dr Kylan Pathmanathan and Dr Chris McMaster take us through some of their favourite abstracts and posters.

Dr Bonnia Liu

Concomitant polymyalgia and subclinical large vessel vasculitis – a missed diagnostic opportunity?

Oral abstract 0466, presented by Dr Eugenio De Miguel, reported a multicentre prospective study of 181 patients with newly diagnosed polymyalgia rheumatica (PMR), and utilised ultrasound investigation of cranial and extracranial arteries to identify patients with subclinical large vessel vasculitis (LVV).

Around 22% (40/180) of patients has a positive ultrasound to suggest large vessel vasculitis in either cranial or extra-cranial vessels. Cranial artery involvement was less common (9.1%) compared to extra-cranial vessel involvement (19.3%). Interestingly, no clinical sign or symptom was predictive of subclinical US-proven vasculitis, except patient age.

It is plausible that LVV has been underdiagnosed in the past due to the historical gold standard of temporal artery biopsy which only samples cranial vessels. This update suggests that 1 in 5 patients with PMR may have structural vascular abnormalities.

But we need to consider if structural changes translate to LVV which will impact on treatment. With the emerging utility of MRA and FGD-PET/CT and availability of tocilizumab for LVV, perhaps we need to start looking for the possibility of concomitant subclinical extra-cranial LVV at time of PMR diagnosis.

  • 0466 Subclinical Large Vessel Vasculitis in Polymyalgia Rheumatica

Dr Bonnia Liu is a final year rheumatology trainee pursuing dual training in rheumatology and nuclear medicine at Austin Hospital in Melbourne.

Dr Kylan Pathmanathan

As another virtual ACR conference springs into action, I thought I would focus on an entity that can induce rheumatological immune-related events: oncologists!

Of course, immune checkpoint inhibitors (ICIs) have transformed the oncology landscape and survival rates have drastically improved. It’s fair to say ICIs are well and truly here to stay.

Dr Kristen Mathias and colleagues (#0440) retrospectively assessed 152 patients and demonstrated that pre-ICI autoantibody testing led to an increased risk of immune-related adverse events (OR 17.5, CI 1.76-174.1). Interestingly, pre-ICI testing for RF and anti-CCP revealed a high specificity (90 and 98% respectively) for the development of a post-ICI arthritis.

Dr Amy Cunningham-Bussel and colleagues (#0439) identified risk factors for the development of rheumatic immune-related side effects using case-control methodology. These included combination ICI therapy, melanoma and genitourinary cancer, pre-existing autoimmune disease and glucocorticoid use within one year prior to ICI introduction.

Finally, Dr Alicia Rodriguez-Pla (#0438) studied 11,203 rheumatological side effects reported to the FDA. Unsurprisingly, non-specific symptoms such as arthralgia, myalgias and muscle weakness were most common. Intriguingly, atezolizumab and avelumab appeared to be associated with Sjogrens’s and sarcoidosis. Myositis was also relatively frequent.

Rheumatological side effects of ICI-therapy are increasingly commonplace. Our understanding, risk stratification and treatment paradigms are likely to evolve in the near future.

  • 0440 Association Between Rheumatic Autoantibody Positivity and Immune-related Adverse Events
  • 0439 Predictors of Rheumatic Immune-related Adverse Events and de Novo Inflammatory Arthritis After Immune Checkpoint Inhibitor-treatment for Cancer
  • 0438 Rheumatological Immune-Related Adverse Events of Immune Checkpoint Inhibitors Based on the FDA Adverse Event Reporting System

Dr Kylan Pathmanathan is an advanced trainee in rheumatology based in Perth.

Dr Chris McMaster

We’re only one day into the official ACR 2021 program and already there is much to ponder.

I particularly enjoyed looking at the poster sessions – there are a lot of interesting emerging lines of research in those sessions.

On the PMR front, we have more evidence of subclinical LVV in 22.1% of PMR patients without GCA features, this time on ultrasound (#0466).

On that topic, ultrasound performed well at picking up extracranial GCA (#0151), although it did miss two cases that were picked up on PET-CT. There’s still a long way to go to settle the USS vs PET-CT vs both discussion, but this certainly helps to seal one debate for me: we should probably be doing at least one of these to look for LVV in our PMR patients.

On the geeky side of things, there were some interesting uses of machine learning. In particular, Professor Phil Conaghan and colleagues (#0211) looked at unsupervised phenotyping of OA patients based on baseline clinical characteristics. They then looked at how these phenotypes fared over time, with respect to disease progression.

As we discover more about the biology of rheumatic diseases, we appreciate that the heterogeneity we have always observed in the clinic is reflected by heterogeneity in the pathophysiology. Unsupervised learning is an important knowledge-discovery tool that we should be using to study that heterogeneity to better guide prognosis and treatment.

All in all, it was an interesting night of research to digest. Time for the next course!

  • 0466 Subclinical Large Vessel Vasculitis in Polymyalgia Rheumatica
  • 0151 Usefulness of Ultrasound and (FDG) PET/CT to Detect Cranial and Extracranial Artery Involvement in Patients with Suspected Large Vessel Vasculitis
  • 0211 Unsupervised Machine-learning Algorithms for the Identification of Clinical Phenotypes in the Osteoarthritis Initiative Database

Dr Chris McMaster is a Melbourne-based final-year rheumatology and clinical pharmacology trainee.