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.