Studies on microheterogeneity of acute-phase proteins in rheumatoid arthritis by using crossed affinoimmuno-electrophoresis with free concanavalin A.

Microheterogeneity of two acute-phase proteins: orosomucoid (alpha1-acid glycoprotein, AGP) and alpha 1-antichymotrypsin (ACHT) were studied in the sera of 48 patients with rheumatoid arthritis and 12 healthy individuals. Each rheumatoid patient was assigned to one of four activity grades. Cross affinoimmunoelectrophoresis (aff-EP) with free Concanavalin A (Con A) revealed three microheterogeneity variants of AGP and four microheterogeneity forms of ACHT. The relative amounts of AGP-variants and ACHT-variants observed in the healthy donors were similar to those observed in the patients with activity grade I, but they changed with the increase in the grade of rheumatoid activity. The differences were most significant for AGP. The comparison of serum C-reactive protein (CRP) levels with AGP-variant-O-non reactive with Con A showed significant correlation in respective rheumatoid activity grades.