Serum TNF-α levels and indicators of disease activity in children with oligoarticular juvenile idiopathic arthritis (oJIA) in the first year of the disease.

Background: Juvenile idiopathic arthritis is the most common arthropathy in childhood. Clinical assessment in JIA patients is based on clinical examination and conventional parameters of inflammation. Regardless of the JIA form, a distinctive characteristic of JIA is joint inflammation, which is sustained by an imbalance between pro- and anti-inflammatory factors. A significant amount of research has confirmed elevated levels of TNF-alpha in the serum and synovial fluid of JIA patients. The aim of the study was to compare serum TNF-alpha levels and indicators of disease activity in children with newly diagnosed oJIA in the first year of the disease and to assess the diagnostic value of TNF-alpha.

Methods: In a 1-year prospective study, TNF-alpha levels were measured using ELISA in serum samples for 22 oJIA patients. The control group consisted of 16 healthy children. The data were correlated with disease activity indicators and CHAQ score.

Results: Concentrations of TNF-alpha were significantly higher in the study group than in the control group at time 0 [10.03 pg/mL (2.16 - 15.53) vs. 0.00 pg/mL (0.00 - 0.12); p < 0.001] and at time 2 [0.00 pg/mL (0.00 - 9.26) vs. 0.00 pg/mL (0.00 - 0.12); p = 0.014]. The analysis of changes in TNF-alpha concentrations in the study group over time showed no statistically significant differences. No correlation between concentrations of TNF-alpha and any of the analyzed indicators of disease activity and CHAQ was found.

Conclusions: Assessment of TNF-alpha concentration in blood serum in children with oJIA has no diagnostic value in monitoring the severity of the disease and the effectiveness of treatment.