Changes in serum chondroitin sulphate epitopes 3-B-3 and 7-D-4 in early rheumatoid arthritis

Objectives. The aims of the present rheumatoid arthritis (RA) study were (1 ) to examine the levels of serum 3-B-3 and 7-D-4 to find out whether they a re different from controls, (2) to find out whether the concentrations of t hese epitopes change with disease duration in early RA and (3) whether the serum concentrations of 3-B-3 and 7-D-4 in early RA are prognostic for subs equent disease progression. Methods. The concentrations of 3-B-3 and 7-D-4 in sera were quantitated by immunoassays. Results. The levels of 3-B-3 and 7-D-4 were significantly lower in RA than in controls (3- to 30-fold, P < 0.001). Changes in 3-B-3 and 7-D-4 were app arent with disease duration. At first presentation, the 3-B-3 concentration was lowest and increased at 12 months (3-fold, P < 0.001). This increase w as transient since by 24 and 36 months the concentrations were not differen t to those at first presentation. The level of 7-D-4 was also lowest when t he patients first presented at clinic and increased with lime at 6 months ( 2-fold, P < 0.001). The increase was more prolonged for 7-D-4, remaining el evated at 12, 24 and 36 months. The lack of correlations of serum 3-B-3 and 7-D-4 with clinical measurements showed that these markers were not progno stic for disease severity. Conclusions. The levels of 3-B-3 and 7-D-4 differed between RA and control sera, and changed with disease duration. These markers were not prognostic in predicting disease outcome.