Profound degradation of FN and low collagen, fibrin and C-terminal domain expressions in FN were only associated with early destructive changes observed in radiographs of the RA patients' hands.

The expressions of terminal sugars in synovial and plasma fibronectins were studied in relation to rheumatoid arthritis (RA) progression defined according to the early, established and late radiological changes in the patients' hands. The relative amounts of sialic acid and fucose were analyzed by lectin-ELISA using appropriate sialic acid-linked alpha2-3 (Maackia amurensis) and alpha2-6 (Sambucus nigra) lectins as well as fucose-linked alpha1-6 (Aleuria aurantia), alpha1-2 (Ulex europaeus), and alpha1-3 (Tetragonolobus purpureus). In the early RA group, the synovial fibronectin reactivities were the lowest with the all lectins used. In the established and late groups, relative sialylation and fucosylation significantly increased. However, sialylation negligibly decreased, whereas fucosylation remained at nearly the same level in the late group. Moreover, the expression of alpha1-6-linked fucose was found to be related to disease activity. In contrast, plasma fibronectin reactivity with lectins showed different dynamic alterations. In the early RA group, the reactivity of fibronectin with the lectins used was similar to that of healthy individuals, whereas it increased significantly in the established RA group compared with the early and normal plasma groups. In the late RA group it decreased to a level similar to that of the normal group. The lower expressions of terminal sugars in synovial fibronectin were mainly associated with the early degenerative processes of RA. In conclusion, such alterations may be applicable as a stage-specific marker for diagnosis and therapy of RA patients. The higher expression of terminal sugars in fibronectin could be associated with repair and adaptation processes in longstanding disease.

The expressions of some terminal glycotopes of synovial immunoglobulins G, A, and M were analysed in relation to rheumatoid arthritis (RA) progression deWned according to early and advanced radiological changes in patients' hands. The relative amounts of terminal monosaccharides were determined by lectin-immunoblotting of immunoglobulin preparations using appropriate lectins able to recognize 2,6-linked (Sambucus nigra agglutinin) and 2,3-linked (Maackia amurensis agglutinin) sialic acid, galactose (Ricinus communis agglutinin I), N-acetylglucosamine (GriVonia simplicifolia agglutinin II) as well as 1,6-linked (Aleuria aurantia lectin), 1,3-linked (Lotus tetragonolobus agglutinin), and 1,2-linked (Ulex europaeus agglutinin) fucose. The results indicate diVerences between early and advanced RA stages in the terminal sugar exposition of synovial IgG and IgA, but not IgM. The galactose-deWcient glycotope with exposed N-acetylglucosamine of the synovial 33.1-kDa IgG fragment appeared exclusively in the early stage of RA. In contrast, this glycotope of intact synovial IgG and IgA was present in both groups, although with higher proportions in advanced RA.The proportions of the sialyl and fucosyl determinants of intact synovial A and G immunoglobulins were clearly lower in the early RA group than in the advanced. The analysis of terminal oligosaccharide exposition in IgG, IgG fragments, and IgA present in the synovial Xuid of RA patients might be applicable as a stage-speciWc marker in the diagnosis and therapy of RA patients.

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