Exacerbation of Alphaviral Arthritis and Myositis in a Mouse Model after Etanercept Treatment is due to Diminished Levels of Interferon a/b

Little is known about the possible use of TNF-α inhibitors for treating viral arthritis and myositis caused by mosquitoborne arthritogenic alphaviruses such as Ross River virus (RRV), chikungunya virus (CHIKV), and Barmah Forest virus. Emerging alphaviruses such as CHIKV, Mayaro virus and O’nyong-nyong virus are now considered significant public health threats by the World Health Organisation (WHO), with reports of severe cases of debilitating arthritis and arthralgia due to these agents in numerous regions of the world [1]. Although alphavirus-induced arthritis is generally self-limiting, the disease can be severe and the virus can persist and establish chronic infection [1]. For example, Hourau et al. recently showed the persistence of CHIKV antigen in perivascular synovial macrophages in a patient 18 months after infection [2]. At present, there are no alphavirus vaccines or antiviral drugs available for humans. The current treatments available for symptoms caused by alphavirus disease consist of non-steroidal anti-inflammatory drugs such as aspirin or ibuprofen.