Serum Interleukin - 17A in Juvenile Idiopathic Arthritis

Juvenile Idiopathic Arthritis (JIA) is a group of chronic heterogenous disorders that manifests as joint inflammation in patients aged <16 years and lasts longer than 6 weeks. Globally, approximately 3 million children and young adults are suffering from JIA with prevalence rates consistently higher in girls. The prevalence of JIA in Africa and Middle East was observed to be towards the lower range of the global estimate. (1) The precise cause and pathogenesis of JIA are unknown; however, genetic, environmental, and autoimmune factors are hypothesized to play a role in its development. (2) The condition can affect one or more joints and cause systemic symptoms such as fever or rash, as well as extra-articular inflammatory signs such as uveitis.(3)

The IL-17 cytokine superfamily is composed of 6 structurally related cytokines, namely IL-17A-F. The most investigated member of the family is IL-17A. It is synthesized by Th17 cells, γδ-T cells, NK T cells, lymphoid tissue inducer-like cells, Paneth cells, and neutrophils. IL-17A plays important roles in protection from bacterial and fungal infections and in the development of autoimmune diseases (4)

Recently, a number of studies have been conducted on the role of IL-17A in the development of chronic arthritis. It has a role both at the initial stages of joint inflammation and in the destruction of joint cartilage and bone structures.(5) It binds to its receptors on synoviocytes, endothelial cells, fibroblasts and osteoblasts and stimulates production of pro-inflammatory cytokines, chemokines and other inflammatory mediators, and also, interacts synergistically with other pro- inflammatory cytokines such as IL-1, IL-6, and tumor necrosis factor alpha.(6)