THE OFFICIAL NEWS SOURCE OF ACR CONVERGENCE 2022 • NOVEMBER 10-14



Enthesis could guide future inflammatory arthritis treatment breakthroughs

Dr. McGonagle
Dr. McGonagle

An educational session on Friday, Nov. 6, will consider the clinical relevance of enthesis in inflammatory arthritis.

Anatomy of the Enthesis will be shown for the first time on from 11 a.m. – 12 p.m. on Nov. 6 and will feature a live question-and-answer session. Registered participants can watch an on-demand replay of the session until March 11, 2021.

Dennis McGonagle, PhD, MB, FRCPI, academic rheumatologist, University of Leeds, will open his presentation with a historical review of the concept of the enthesis as a focal anchorage point for ligaments and tendons. He will follow that with an overview of the more modern concept of the enthesis organ as an integrated group of tissues functioning to minimize stress. The enthesis organ includes tissues beyond just at the attachment points and may include a synovio-entheseal complex.

Dr. McGonagle will describe how structures not attached to the skeleton have very similar microanatomy, histological composition, and similar patterns of skeletal biomechanical stressing to insertion sites. These structures, called functional enthesis, include the tendons that wrap around the ankle and hand flexor tendons and their constraining accessory pulley “mini-entheses.” Understanding how the different types of inflammatory arthritis attack the synovium (RA) or enthesis organ (SpA) will likely be increasingly important for diagnosis and could help improve specific therapy selection as the pharmacological management of inflammatory arthritis is diverging.

“I’ll also touch on the new understanding of how the immune system might become activated at the enthesis, which is a structure that has no blood vessels or immune cells at the actual insertion site,” Dr. McGonagle said. “So, I’ll be explaining why the immune system gets activated in a structure that doesn’t have an immune system, so to speak.”

Catherine Bakewell, MD
Catherine Bakewell, MD

Catherine Bakewell, MD, rheumatologist with Intermountain Healthcare, will discuss the use of ultrasound in evaluating the enthesis. She will cover how to assess enthesitis severity, the nuances and pitfalls of current enthesitis scoring systems, and how to distinguish on ultrasound the features more suggestive of underlying inflammatory disease.

Newer ultrasound machines with higher resolution can provide insight into the presence of enthesitis and may help in avoiding some of the traditional pitfalls, Dr. Bakewell said.

“Ultrasound provides objective data, rather than relying on tenderness to determine presence or absence of enthesitis.  Physical examination alone misses subclinical disease and overestimates enthesitis in patients with fibromyalgia or central sensitization,” Dr. Bakewell said. “Detection of ultrasonographic enthesitis gives us the opportunity for early diagnosis, monitoring response to treatment, and predicting flare.”

During the presentation, Dr. Bakewell will also talk about the OMERACT Ultrasound Working Group’s current enthesitis in dactylitis research to determine which enthesial sites at the digit are most commonly involved and feasible for evaluation. She also will discuss the Diagnostic Ultrasound Enthesitis Tool (DUET) being developed by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) to be a scoring system for diagnosing patients with psoriatic arthritis, in contrast to the OMERACT enthesitis scoring system, which is designed to be used in clinical trials and monitoring treatment response.