Interleukin-37 at the 2017 EULAR Annual Meeting in Madrid

Interleukin-37 (IL-37)? You might ask, why I have looked, if there has been anything on this lesser known cytokine at the 2017 EULAR Annual Meeting in Madrid.

M.F.Nold and colleagues had written in 2010 [1]: „The function of interleukin 37 (formerly IL-1 family member 7) remains elusive. Expression of IL-37 in macrophages or epithelial cells imparted near complete suppression of pro-inflammatory cytokines, …”. IL-37 suppresses pro-inflammatory cytokines and may act to stop excessive inflammation. Therefore IL-37 is interesting for further research in rheumatology.

Ping-Wei Zhao and colleagues evaluated rheumatoid arthritis patients in a relatively small study and found “that IL-37 production is most likely induced by pro-inflammatory cytokines during an active disease such as RA”. [2]

Now, G. Cavalli and colleagues presented the following study [3]: “INTERLEUKIN 37 REVERSES THE METABOLIC COST OF INFLAMMATION, INCREASES OXIDATIVE RESPIRATION AND IMPROVES EXERCISE TOLERANCE”. In is a study on mice. The authors looked at wild type mice or expression in mice transgenic for human IL-37. One of the result reads like this: “Treatment with 8 daily doses of IL-37 resulted in a further 326% increase in endurance running time compared to the performance level of mice receiving vehicle (p=0.001).” Conclusions: “These effects of IL-37 to limit the metabolic costs of chronic inflammation and to foster exercise tolerance provide a rationale for therapeutic use of IL-37 in the treatment of inflammation-mediated fatigue.”

Five years ago I’ve written: “fatigue is the most intriguing symptom in rheumatology. It has attracted far less attention than pain. Yet sometimes nearly every patient is complaining about fatigue and it doesn’t matter if the underlying disease is inflammatory or not, in remission or flaring (e.g. rheumatoid or psoriatic arthritis, ankylosing spondylitis, fibromyalgia, …). And I think at times every patient has reported fatigue.” [4] And lately I’ve looked at fatigue in fibromyalgia patients [5].

As fatigue often plagues patients more than pain, I think it’s good idea to follow any lead to curb fatigue. IL-37 might be such a lead!

Links:

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3537119/

[2] http://brainimmune.com/blood-levels-of-the-new-anti-inflammatory-cytokine-il-37-are-increased-in-rheumatoid-arthritis-patients/

[3] DOI: 10.1136/annrheumdis-2017-eular.1789

[4] http://rheumatologe.blogspot.de/2012/08/fatigue.html

[5] http://rheumatologe.blogspot.de/2017/02/reducing-fibromyalgia-fatigue.html

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