Circulating interleukin-6, soluble interleukin-2 receptors, tumor necrosis factor alpha, and interleukin-10 levels in juvenile chronic arthritis: correlations with soft tissue vascularity assessed by power Doppler sonography

Abstract.

Nineteen patients with juvenile chronic arthritis (JCA), ten with systemic (s)-JCA, and nine with polyarticular-onset (p)-JCA were examined for interleukin (IL)-6, tumor necrosis factor (TNF)-α, IL-2R, and IL-10 levels. Power Doppler sonography (PDS) for the more affected knee was used in all of them to evaluate soft tissue vascularity. Serum levels of IL-6 were significantly higher in JCA patients than in controls (P<0.007). Patients with p-JCA showed higher levels of IL-6 than patients with s-JCA, and the difference was statistically nonsignificant. Serum IL-6 levels in all patients correlated significantly with the degree of vascularity detected by PDS (P<0.01). This correlation was more pronounced in p-JCA patients (P<0.01 in p-JCA vs P<0.05 in s-JCA). Serum levels of TNF-α were higher in patients with JCA than in controls (P<0.0001). Serum levels of TNF-α were significantly greater in patients with s-JCA than in p-JCA (P=0.008). Soluble IL-2R levels were higher in patients with JCA than controls (P<0.0002). Serum levels of IL-2R correlated significantly with pannus thickness in p-JCA (P<0.01) and inversely with methoxetrate (MTX) duration in s-JCA (P<0.05). Serum levels of IL-10 were significantly higher in JCA patients than in controls (P<0.0008). Serum IL-10 levels in all patients correlated significantly inversely with hemoglobin levels (r=–0.50, P<0.05), total leukocytic count (TLC) (r=–0.58, P<0.01), and intra-articular steroid injection (r=+0.56, P<0.01). In s-JCA, IL-10 levels correlated significantly with MTX weekly dose (P<0.05). In conclusion, a significant correlation of serum IL-6 levels with the degree of knee joint vascularity was found, and this correlation was more pronounced in p-JCA, which may stress the role of IL-6 as an inducer of neoangiogenesis in JCA.