Down-regulation and Clinical Implication of Galectin-9 Levels in Patients with Acute Coronary Syndrome and Chronic Kidney Disease.

In various autoimmune diseases, Galecin-9 (Gal-9) has been shown to regulate the T-cell balance by decreasing Th1 and Th17, while increasing the number of regulatory T cells (Tregs). However, the role of Gal-9 in the patients with acute coronary syndrome (ACS) and chronic kidney disease (CKD) remains unclear. This study aims to measure the Gal-9 levels in serum and peripheral blood mononuclear cells (PBMCs) in patients with ACS plus CKD and examine their clinical implication. The serum levels of Gal-9 were determined by enzyme-linked immunosorbent assay (ELISA), the expression levels of Gal-9, Tim-3, and Foxp3 mRNA in PBMCs were detected by real-time reverse transcription-polymerase chain reaction (RT-PCR), and the expression of Gal-9 on the surface of PBMCs and in PBMCs was analyzed by flow cytometry. Furthermore, the correlation of serum Gal-9 levels with anthropometric and biochemical variables in patients with ACS plus CKD was analyzed. The lowest levels of Gal-9 in serum and PBMCs were found in the only ACS group, followed by the ACS+CKD group, and the normal coronary artery (NCA) group, respectively. Serum Gal-9 levels were increased along with the progression of glomerular filtration rate (GFR) categories of G1 to G4. Additionally, serum Gal-9 levels were negatively correlated with high-sensitivity C-reactive protein (hs-CRP), estimated GFR (eGFR), and lipoprotein(a), but positively with creatinine, age, osmotic pressure, and blood urea nitrogen (BUN). Notably, serum Gal-9 was independently associated with hs-CRP, osmotic pressure, and lipoprotein(a). Furthermore, serum Gal-9 levels were elevated in patients with type 2 diabetes (T2DM) and impaired glucose tolerance (IGT) in ACS group. It was suggested that the levels of Gal-9 in serum and PBMCs were decreased in patients with simple ACS and those with ACS plus CKD, and hs-CRP, eGFR, osmotic pressure and T2DM may have an influence on serum Gal-9 levels.