Pathogenesis of chronic chikungunya arthritis: resemblances and links with rheumatoid arthritis

Chikungunya virus (CHIKV) infection results from transmission by the mosquito vector. Following an incubation period of 5-7 days, patients develop an acute febrile illness, chikungunya fever (CHIKF), characterized by high fevers, maculopapular rash, headaches, polyarthritis/arthralgias, myalgias, nausea, vomiting, and diarrhea. Joint pain is often severe, and most often involves the hands, the wrists, the ankles, and the metatarsal-phalangeal joints of the feet. Many patients recover within several weeks, but up to 50% develop chronic joint pain and swelling for more than 12 weeks, then we refer to these symptoms as chronic chikungunya arthritis (CCA). The pathogenesis of CCA is not well understood. In this article, we suggest that mesenchymal stem cells (MSCs) may play an important role in this pathogenesis. This heterogeneous group of multipotent cells, morphologically similar to fibroblasts, may undergo epigenetic changes capable of generating aberrant progenies. However, we believe that there is no need for a latent infection. In our pathogenic hypothesis, CHIKV infection of MSCs would cause epigenetic changes both in MSCs themselves and in their progenies, without the need for reactivation of dormant viruses.