MICROHETEROGENEITY OF ACUTE-PHASE PROTEINS IN PATIENTS WITH CLINICALLY ACTIVE AND CLINICALLY NONACTIVE OSTEOARTHRITIS

Microheterogeneity of two acute phase glycoproteins, alpha-1-acid glyc oprotein (AGP) and a-l-antichymotrypsin (ACT), concentrations of AGP, ACT, and C-reactive protein (CRP), and levels of three cytokines: inte rleukin 1 beta (IL-1-beta), interleukin 6 (IL-6), and tumor necrosis f actor alpha (TNF-alpha) were determined in 61 serum samples and 7 syno vial fluids (SFs) obtained from patients (n=61) with osteoarthritis. U sing affinity immunoelectrophoresis with concanavalin A (conA), a sign ificant decrease in the reactivity of AGP and ACT with this lectin was found in patients with clinically active osteoarthritis when compared to those with clinically nonactive disease (p < 0.001 and p < 0.05, r espectively). There was no increase in the concentration of AGP ACT, a nd C-reactive protein (CRP) in the sera examined. In particular, no in crease in the serum level of these proteins was found in the patients with clinically active disease. Low concentrations of IL-6 and TNF-alp ha were found in most sera and SFs examined. In 6 out of 7 SFs availab le, IL-6 concentrations were higher than in the respective serum sampl es but for TNF-alpha the same could be shown in one case only. Low con centrations of IL-1-beta were found in 4 serum samples obtained from p atients with clinically active osteoarthritis and in no SF specimen st udied. In the entire group, serum level of TNF-cr correlated weakly wi th the AGP and ACT reactivity coefficients with conA (r=0.3634, p < 0. 005 and r=0.3324, p<0.02, respectively). Our findings suggest that the re are changes in the microheterogeneity of acute phase glycoproteins in some patients with osteoarthritis similar to those observed in rheu matoid arthritis and other chronic inflammations. Possible mechanisms of the involvement of cytokines in the regulation of glycosylation of acute phase glycoproteins in osteoarthritis are discussed.