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Objective: To evaluate a contribution of selected laboratory parameters for a prediction of progressive and erosive development in patients with early rheumatoid arthritis (RA).Methods: In a prospective study baseline levels of antibodies to cyclic citrullinated peptide (anti-CCP), IgM, IgA, and IgG rheumatoid factors (RFs) were measured by enzyme linked immunosorbent assay (ELISA) in 104 patients with RA with disease duration <2 years. Antikeratin antibodies (AKA) and antiperinuclear factor (APF) were detected by indirect immunofluorescence. Patients were divided into two groups based either on the presence or absence of erosions or according to progression of Larsen score at the end of the 24 months' follow up.Results: Sixty seven (64%) patients developed radiographic erosions, 49 (47%) had progression in Larsen score, and 36 (35%) progressed by more than 10 Larsen units. Significant differences in erosions and progression between the two groups were detected for anti-CCP, AKA, APF, IgM RF, IgA RF, and IgG RF. Baseline Larsen score correlated significantly with anti-CCP, IgM RF, and IgA RF levels, and all measured antibodies correlated with the progression >10 units. The combination of anti-CCP and IgM RF increased the ability to predict erosive and progressive disease.Conclusion: The data confirmed that measurement of anti-CCP, AKA, APF, and individual isotypes of RFs was useful for prediction of structural damage early in the disease course. Combined analysis of anti-CCP and IgM RF provides the most accurate prediction. [ABSTRACT FROM AUTHOR]

Background: Levels of pentosidine (representative of advanced glycation end-products) in sera of patients with rheumatoid arthritis are increased when compared with sera of other diagnoses or healthy controls. These levels have been reported to correlate with clinical indices of rheumatoid arthritis activity and with laboratory markers of inflammation. The purpose of this study was to find out if these findings pertain to other advanced glycation end-products.Methods: We have developed two immunoassays based on new monoclonal antibodies to advanced glycation end-products. Antibody 103-E3 reacts with an unidentified antigen, formed in the reaction of proteins with ribose, while antibody 8-C1 responds to Nepsilon-(carboxyethyl)lysine. We have used these monoclonal antibodies to measure levels of advanced glycation end-products in sera of patients with rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, and healthy controls. We calculated the correlations between advanced glycation end-product levels in rheumatoid arthritis sera and the Disease Activity Score 28 (DAS28), age, disease duration, CRP, anti-CCP, rheumatoid factor and treatment with corticosteroids, respectively.Results: Levels of both glycation products were significantly higher in sera of patients with rheumatoid arthritis when compared with sera of patients with systemic lupus erythematosus, osteoarthritis, or the healthy controls. Neither the level of Nepsilon-(carboxyethyl)lysine nor the level of the 103-E3 antigen in rheumatoid arthritis sera correlated with the DAS28-scored rheumatoid arthritis activity. The levels of both antigens in rheumatoid arthritis sera did not correlate with age, gender, corticosteroid treatment, or levels of CRP, anti-CCP antibodies, and rheumatoid factor in sera.Conclusions: We report highly specific increases in the levels of two advanced glycation end-products in sera of patients with rheumatoid arthritis. This increase could be explained neither by rheumatoid arthritis activity nor by inflammation. We propose a working hypothesis that presumes the existence of a link between advanced glycation end-product formation and induction of autoimmunity. [ABSTRACT FROM AUTHOR]