Serum galectin-3 can help distinguish lupus nephritis from systemic lupus erythematosus and is also correlated with the degree of renal damage in lupus nephritis.

Lupus nephritis (LN) constitutes a substantial contributor to morbidity and mortality in systemic lupus erythematosus (SLE). The monitoring of renal function in patients with LN is associated with improved prognostication. The objective of this study was to evaluate the clinical utility of serum galectin-3 (Gal-3) levels in differentiating LN from SLE. Moreover, we sought to ascertain whether serum galectin-3 levels can serve as a marker for the degree of renal impairment in patients with LN. In this cross-sectional study, 42 patients with LN and 12 patients with SLE without nephritis were enrolled. Furthermore, 110 healthy subjects were recruited as controls. Serum Gal-3 levels were quantified using a time-resolved fluoroimmunoassay. Furthermore, Gal-3 levels were analyzed in conjunction with other clinical variables. The results demonstrated that patients with LN exhibited a significantly elevated serum Gal-3 concentration (35.98 ± 20.68 ng/mL) in comparison to healthy controls (10.11 ± 2.75 ng/mL, P < .001) and patients with SLE (14.38 ± 2.26, P < .001). The area under the curve of Gal-3 in distinguishing patients with SLE from patients with LN was 0.9157. When the cutoff value was set to 18.91 ng/mL, the sensitivity was 83.33%, and the specificity was 100%. There was a tendency for serum Gal-3 levels to increase with worsening renal impairment in patients with LN. In conclusion, Gal-3 could be a valuable biomarker for distinguishing LN from SLE, providing a useful clinical reference. Elevated serum Gal-3 levels may be associated with the severity of renal impairment in patients with LN.