The combination of reduced levels of AA and DHA in the active phase of poly-JIA with the increased concentration of IL-10, the inverse relationship of the two trails (n-6 and n-3), PUFA with classic markers of inflammation (CRP, ESR), and positive correlation with platelet count had indicated participation of PUFAs in the early stages of poly-JIA pathogenesis. This evidence concerns the gene IL10 and juvenile idiopathic arthritis.