Th17 CD4 T cells are characterized by production of the cytokines interleukin (IL)-17A (IL-17) and IL-17F, and IL-21 and IL-22. Since their discovery in 2003, there have been numerous studies on Th17 cells, and they have emerged as key players in the pathogenesis of some autoimmune neuroinflammatory diseases and other autoimmune disorders traditionally attributed to Th1 cells.
Children with autism had significantly higher serum IL-17A levels than healthy controls (P <0.001), with increased serum levels of IL-17A found in 48.9% of the autism group. Patients with severe autism had significantly higher serum IL-17A levels than those with mild to moderate autism (P=0.01), and raised serum IL-17A levels were significantly more common in children with severe autism (67.9%) than in those with mild to moderate autism (17.6%), P=0.001.
Serum IL-17A levels were raised in the group with autism, and the levels correlated significantly with the severity of autism. This is the first study to measure levels of IL-17A in relation to the severity of autism, to our knowledge. Further research, with a larger subject population, is warranted to determine whether the increase of serum IL-17A levels plasma has a pathogenic role in autism, and whether anti- IL-17A therapy could be useful
From: J Neuroinflammation. 2012 Jul 2;9:158. doi: 10.1186/1742-2094-9-158. Elevated serum levels of interleukin-17A in children with autism. Al-Ayadhi LY1, Mostafa GA.