Parasitic worms can trigger a specific immune response that counteracts rheumatoid arthritis in mice, a study in Nature Communications reveals.

The researchers from Germany infected mice with the parasitic worms (Nippostrongylus brasiliensis) and compared them with control groups.

They discovered that the worm infections activated a Th2 immune response that protected the mice from arthritis.

According to the authors their findings provide “solid evidence” that activation of the Th2 responses by N. brasiliensis infection counteracts arthritis.

“Mechanistically, this protective effect is dependent on IL-4/IL-13-induced STAT6 pathway” they wrote.

The authors also found that the cellular components of the Th2 responses and eosinophils were present in the synovial membrane of people with RA.

This finding suggested that even in the absence of worm infection these responses were already engaged in suppressing the pathology.

“These findings are interesting to shape new approaches to rebalance immune homeostasis in arthritis,” they said.

Previous data had shown a Th2 cytokine pattern in very early forms of human RA, when the disease may still be reversible, they noted.

“Activation of Th2 responses and eosinophils in both early and established disease may emerge as a new strategy to treat arthritis,” they concluded.