Glycosylation of alpha 1-acid glycoprotein in systemic onset juvenile rheumatoid arthritis and acute bacterial infection: value in differential diagnosis.

Agarose based affinity immunoelectrophoresis with free concanavalin A (Con-A) as ligand was used to examine the microheterogeneity of alpha 1-acid glycoprotein in sera of patients with systemic onset juvenile rheumatoid arthritis (JRA) and acute bacterial infections. In JRA, a decreased proportion of Con-A reactive alpha 1-acid glycoprotein variants was found when compared to healthy control. In contrast, acute bacterial infection showed an increased reactivity. Investigation of glycosylation may be useful in the differential diagnosis of systemic onset JRA and acute bacterial infection.