Objectives. Evaluation of chondroitin sulfate (CS), as an early marker of aggrecan degradation, and chondroitin sulfate 846 epitope (CS846), as a biomarker of CS synthesis, is an attempt at answering the question whether the therapy used in juvenile idiopathic arthritis (JIA) patients contributes to the normalization of biochemical changes in aggrecan. Methods and Results. Here, ACAN is linked to juvenile idiopathic arthritis.