A sensitive assay for the measurement of serum chondroitin sulfate 3B3(-) epitope levels in human rheumatic diseases

Citation
Ssl. Chan et al., A sensitive assay for the measurement of serum chondroitin sulfate 3B3(-) epitope levels in human rheumatic diseases, CLIN EXP RH, 19(5), 2001, pp. 533-540
Citations number
39
Categorie Soggetti
Rheumatology,"da verificare
Journal title
CLINICAL AND EXPERIMENTAL RHEUMATOLOGY
ISSN journal
0392856X → ACNP
Volume
19
Issue
5
Year of publication
2001
Pages
533 - 540
Database
ISI
SICI code
0392-856X(200109/10)19:5<533:ASAFTM>2.0.ZU;2-K
Abstract
Objective To develop a sensitive assay to quantitate serum 3B3(-) levels in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) as well as levels in control sera. Methods An enzyme-linked immunosorbent assay (ELISA) was developed using th e monoclonal antibody (MAb) 3B3 to detect a chondroitin sulfate (CS) epitop e in the sera and synovial fluid (SF) of RA and OA patients. Keratan sulfat e levels were measured in the same biological fluids using the 5D4 monoclon al antibody. Results The detection limit for our 3B3(-) assay was 2 mug/L. Most OA sera sample curves run on the 3B3 assay were parallel (87.5%) to the standard cu rve and detectable (90.0%). RA sera sample curves were 87.1% detectable and 85.2% parallel. The 3B3(-) epitope was detectable in 60% of control sera a nd of these 66.7% of sample curves were parallel to the standard curve. All RA and OA SF had detectable quantities of 3B3(-). For the 3B3 assay, the O A and RA sera levels were significantly higher than for control sera (P = 0 .03, P = 0.04 respectively). We found a significant correlation in a subset of paired OA sera and SF 3B3(-) concentrations. No correlation was found b etween age, joint activity scores, HAQ and CRP in RA patients and sera 3B3( -) and 5D4 levels. Conclusion We have validated this assay for the quantification of 3B3(-) ep itope in RA and OA serum. Levels of this epitope are significantly higher i n sera from RA and OA patients than controls. 3B3(-) levels in RA sera were found to correlate with disease duration.