Acute-phase response in early refractory rheumatoid arthritis: long-term follow-up study

In order to investigate the role of the acute-phase response in early rheumatoid arthritis (RA), we followed the changes of alpha 1-acid glycoprotein (AGP), alpha 1-antitrypsin (AT) and alpha 1-antichymotrypsin (ACT) in the sera of 25 patients with refractory rheumatoid arthritis (RA) during the first 3 years of the disease. Serum levels of AGP, ACT and AT were measured using rocket immunoelectrophoresis, and AGP, ACT and AT microheterogeneities were performed using two-dimensional immunoelectrophoresis with concanavalin A (Con A) as ligand. On average, serum levels of AGP, ACT and AT proteins were higher at the onset of the disease as compared with healthy controls. After 3 years, a significant decrease in serum levels of all three acute-phase proteins (APPs) was observed, but only in patients without anatomical progression was this decrease statistically significant. At the beginning of the study, only the AT reactivity coefficient (RC) was decreased in comparison with healthy subjects. However, after 3 years of disease, AGP, ACT and AT RCs all decreased. This investigation provided two new observations. The first is that only AT RC is significantly lower in comparison with normal values at the beginning of RA, whereas AGP RC and ACT RC remain within the normal range of values; a decrease in AGP RC and ACT RC appeared later. The second observation is that the highly elevated levels of APPs at the onset of RA decrease during the course of the disease. Moreover, this decrease does not depend on the disease activity, but a relationship with radiological progression was shown.