Cartilage Proteoglycan Aggrecan: Potential as Serum Marker of Cartilage Destruction in Juvenile Rheumatoid Arthritis

El-Sayed ZA , Saleh MT, Al-Wakkad AS, Sherief L, Al-Dien AM

Faculty of Medicine, Ain Shams University, Cairo, Egypt


Objective: To investigate whether aggrecan is a predictor of cartilage destruction in juvenile rheumatoid arthritis patients (JRA).

Methods: Aggrecan was quantified (ELISA) in sera from 31 children with JRA and synovial fluid (SF) in 10. Patients were evaluated at baseline and 3 mo later: Clinically (overall articular severity score), laboratory (ESR, CRP, total leucocytic and platelet counts, hemoglobin and rheumatoid factor), Radiologically (baseline and after a year by modified Larsen, malalignment and vanRossum’s scores).Fifteen healthy children and 10 with arthritis due to other collagen vascular diseases were studied for comparison.

Results: Baseline serum aggrecan was significantly higher in JRA patients as compared to controls and to patients with other collagen vascular diseases with 93% sensitivity and 100% specificity at a cut off level of 18.6 ng/ml (control mean + 3 SD). On reevaluation, a significant drop of serum aggrecan was noticed (p < 0.01) coinciding with a significant drop in clinical and laboratory indices of active inflammation. Serum aggrecan levels correlated significantly with SF protein concentration. Lower levels of serum aggrecan were observed in patients with radiographic evidence of joint destruction and in those with evidence of deterioration one year later.

Conclusion: Serum aggrecan can help to assess the extent of cartilage destruction and to predict joint damage in JRA.