Mt. Goodarzi et al., Sialyl Lewis(x) expression on IgG in rheumatoid arthritis and other arthritic conditions: a preliminary study, GLYCOCON J, 15(12), 1998, pp. 1149-1154
Both infiltrating leukocytes and soluble immunoglobulin form aggregates in
synovial fluid during the inflammatory process in rheumatoid arthritis (RA)
. Some of these changes are probably mediated by the adhesion molecule, E-s
electin, which increases its expression with disease activity. As glycosyla
tion changes in IgG in RA are well established, the current study was under
taken to measure the expression of the carbohydrate antigen sialyl Lewis x
(sLe(x)), on IgG in RA. sLe(x) is a major ligand for E-selectin. Using a re
cently developed ELISA, sLe(x) expression was determined in IgG isolated fr
om 8 healthy individuals, 20 RA sufferers (10 early and 10 with more long-s
tanding disease) and 20 patients with other rheumatic conditions (osteoarth
ritis, ankylosing spondylitis, systemic lupus erythematosus). S Le(x) expre
ssion on IgG was elevated above the reference range in all but one of the R
A patients and this change was highly significant (P < 0.0006). Expression
of this antigen on IgG was also significantly different from normal in the
other arthritic groups (P < 0.02), but the changes were much less than that
observed for RA. In early RA, sLe(x) was inversely correlated with paramet
ers used to measure disease activity. This was not observed with the establ
ished RA, where there was weak positive association. These preliminary resu
lts indicate that a change in sLe(x) expression on IgG is an early finding
in the development of RA, which may be important in the development of the
disease or for predicting its outcome.