Terminal monosaccharide screening of synovial immunoglobulins G and A for the early detection of rheumatoid arthritis

Ewa Maria Kratz (1) , Krzysztof Borysewicz (2) , Iwona Kątnik-Prastowska (1)

1 Department of Chemistry and Immunochemistry
2 Department of Rheumatology and Internal Diseases of the University Clinical Hospital

The expressions of some terminal glycotopes of synovial immunoglobulins G, A, and M were analysed in relation to rheumatoid arthritis (RA) progression defined 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 α2,6-linked ( agglutinin) and α2,3-linked ( agglutinin) sialic acid, galactose ( agglutinin I), -acetylglucosamine ( agglutinin II) as well as α1,6-linked ( lectin), α1,3-linked ( agglutinin), and α1,2-linked ( agglutinin) fucose. The results indicate differences between early and advanced RA stages in the terminal sugar exposition of synovial IgG and IgA, but not IgM. The galactose-deficient glycotope with exposed -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 fluid of RA patients might be applicable as a stage-specific marker in the diagnosis and therapy of RA patients.

Mots clés: Immunoglobulins; Rheumatoid arthritis; Sialylation; Galactosylation; Fucosylation; Synovial fluid

Ewa Maria Kratz, Krzysztof Borysewicz, Iwona Kątnik-Prastowska. Terminal monosaccharide screening of synovial immunoglobulins G and A for the early detection of rheumatoid arthritis. Rheumatology International, 2009, 30 (10), pp.1285-1292. ⟨10.1007/s00296-009-1139-5⟩. ⟨hal-00552494⟩