Asialylated IgG in the serum and synovial fluid of patients with rheumatoid arthritis.

Abstract

A novel enzyme linked immunosorbent assay has been developed that detects an asialylation change in the IgG molecules from patients with rheumatoid arthritis (RA) by the binding of biotinylated RCA 1 (ricin) to capture IgG. Elevated levels of asialylated IgG were detected in paired serum and synovial fluids (SF) of patients with RA. When compared with healthy controls, particularly in the SF (p less than 0.05) correlations of the asialylation change were found in paired samples (p less than 0.01) and between asialylated IgG and rheumatoid factors (p less than 0.01), C-reactive protein (p less than 0.02) and the Lee and Ritchie indices p less than 0.02 and 0.05, respectively. We found the proportion of asialylated IgG was higher in DR4 positive patients, indicating a possible association of these individuals to a sialyl transferase abnormality.