A new treatment route for inflammatory rheumatism
Researchers have been successful in showing a link between macrophages, a type of white blood cells which attack foreign micro-organisms and expel harmful substances within the body and development of certain types of inflammatory rheumatism.
The findings could lead to new treatments for certain types of inflammatory rheumatism, according to research carried out by Professor Dirk Elewaut in collaboration with Professor Geert van Loo at VIB’s inflammation research center (IRC).
Enthesitis is a common problem which underlies various forms of inflammatory rheumatism with approximately 1% of the population being affected. The mechanism behind this has not been clearly understood.
As per Prof. Dirk Elewaut, “Achilles enthesitis is one of the most typical forms of chronic tendinitis. Our research demonstrates that macrophages which lack the anti-inflammatory protein A20 develop early on in their disease an enthesitis of the Achilles tendon. We were also able to demonstrate the underlying cause: A20 suppresses the activation of STAT1, a signaling molecule which seems to be key in initiating this inflammation. The absence of A20 therefore leads to a significant increase in STAT1, which promotes the development of enthesitis.”
JAK is one of the key molecules that controls STAT1. A study showed that by blocking this molecule using a so-called JAK inhibitor, the researchers were able to prevent the increase of STAT1 and treat Achilles enthesitis successfully. Prof. Elewaut said, “Our findings underline the importance of macrophages in the development of enthesitis and the possibility of treating these conditions using JAK inhibitors. In several countries, this type of inhibitors is already available for the treatment of rheumatoid arthritis."
He also conveyed that, “Our research opens up new prospects for patients in whom the existing TNF inhibitors offer no relief. In the first place, we wish to check whether this mechanism also plays a role in other places in the body, such as the spine. If so, the discovery may offer new options for patients with other forms of inflammatory rheumatic diseases such as spondyloarthritis, an umbrella term for several diseases characterized by inflammation of the spine and joints. It may also offer new treatment options for psoriatic arthritis, a very common form of joint inflammation in patients with psoriasis.”