Serum galectin-9 could be a potential biomarker in assessing the disease activity of antineutrophil cytoplasmic antibody-associated vasculitis

Objective Serum galectin levels have been reported to be associated with the activity in autoimmune diseases. This study investigated whether serum levels of galectin (Gal)-1, Gal-3, and Gal-9 could be used as biomarkers in assessing the disease activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods Eighty AAV patients were selected for inclusion in our AAV cohort. AAV-specific indices and clinical and laboratory data were assessed on the same day when blood samples were obtained from the patient and serum levels of Gal-1, Gal-3, and Gal-9 were measured by ELISA from obtained sera. High disease activity was defined as Birmingham vasculitis activity score (BVAS) ≥ 12. The optimal cut-off value of galectins was extrapolated by receiver operator characteristic analysis and linear and logistic regression analyses were performed to evaluate the association between Gal-3, Gal-9, and BVAS. Results The median values of BVAS, Gal-1, Gal-3, and Gal-9 were 8.0, 38.1 ng/mL, 12.4 ng/mL, and 1017.7 ng/mL, respectively. Serum Gal-3 and Gal-9 levels were correlated with BVAS (r=0.375 and r=0.462), while only serum Gal-9 levels were independently associated with BVAS (β=0.250) in linear regression analyses. Serum Gal-9 ≥10.28 ng/mL was also associated with high activity of AAV (odds ratio 5.303) in multivariable logistic regression analysis. In addition, serum Gal-1, Gal-3, and Gal-9 levels were found to differ according to ANCA positivity status and the presence of renal manifestations. Conclusion These results suggest the potential possibility of serum Gal-9 levels in assessing AAV disease activity.