Changes of glycosylation of IgG in rheumatoid arthritis patients treated with methotrexate.

Abstract Purpose In patients with active rheumatoid arthritis (RA) decrease of galactosylation is correlated with disease activity. The aim of our study was to evaluate an effect of methotrexate therapy on glycosylation disturbances of IgG in RA patients. Materials/methods IgG glycosylation in 40 patients with active RA treated with methotrexate for 12 months prior to and after treatment were compared. The control group consisted of 20 healthy volunteers. IgG glycosylation was assessed using biotinylated lectins and immunosorbent ELISA assay. For galactose specificity Datura stramonium lectin (DSA), for sialic acid Sambucus nigra (SNA) and Maackia amurensis (MAA) and for fucose residue Areulia auranta (AAA) lectins were used. Results In RA-cases N-glycan galactosylation and sialylation of IgG before treatment were significantly lower than in healthy subjects (for DSA, MAA lectins p p p p Conclusions Defect of galactosylation of IgG in RA patients is a useful marker of disease activity that may be used for the assessment of therapy effectiveness. The role of IgG fucosylation and sialylation in RA pathogenesis has still to be determined.