Serum galectin-3/galectin-9 ratio is a novel marker of the disease activity in the rheumatoid arthritis

Abstract

Objective: To investigate the utility of serum galectin-9 and ratio of galectin-3/galectin-9 in the evaluation of the disease activity of rheumatoid arthritis (RA).Method: The serum concentration of galectin-3 and galectin-9 from RA patients and controls was estimated using enzyme-linked immunosorbent assays (ELISAs). We compared serum concentration of galectin-3 and -9 and ratio of galectin-3/galectin-9 according to disease activity in RA. We followed-up active RA patients and measured serum concentration of galectin-3 and -9 and disease activity after treatment after mean 14 months with disease modifying anti-rheumatic drugs (DMARDs) and tumor necrosis factor (TNF)- inhibitors. The follow-up serum concentration of galectin-3 and -9 and ratio of galectin-3/galectin-9 were compared with those of initial visits. Next, we measured serum level of cytokines including TNF-α, interleukin (IL)-1β, IL-10 and interferon gamma (IFN-γ), and analyzed association with not only RA activity but also serum concentration of galectin-3 and -9 and their ratio. Result: Serum concentration of galectin-9 from RA patients was higher than that from controls as well as galectin-3. After treatment active RA mean serum concentration of galectin-9 was significantly elevated than initial concentration, while follow-up mean serum concentration of galectin-3 and galectin-3/ galectin-9 ratio was significantly lower than initial value. Serum concentration of galectin-3 and ratio of galectin-3/galectin-9 in RA patients were positively correlated with DAS 28. Serum level of IFN-γ showed strong association with disease activity, and significantly correlated with serum ratio of galectin-3/galectin-9 as well as concentration of galectin-3.Conclusion : We firstly showed that serum concentration of galectin-9 had negative correlation with disease activity in RA. And the serum ratio of

galectin-3/galectin-9 was more significantly correlated with RA activity than only serum concentration of galectin-3, so it might be a useful complementary serologic marker for assessing disease activity in RA.