Establishment of Galectin-3 time-resolved fluoroimmunoassay and its application in idiopathic membranous nephropathy

Abstract Objectives The aim of this study was to establish a time-resolved fluorescent immunoassay (TRFIA) for the detection of serum galactose agglutinin 3 (Gal-3) and apply this method to evaluate the clinical significance of serum Gal-3 in predicting Idiopathic Membranous Nephropathy (IMN) progression. Methods The Gal-3-TRFIA was established using the double antibody sandwich method, with the capture antibodies coated on a 96-well microplate and the detection antibodies chelated to Europium (III) (Eu3+). Serum Gal-3 was detected in 81 patients with IMN and 123 healthy controls to further evaluate the value of the Gal-3 in staging of IMN. Results The sensitivity of the Gal-3-TRFIA assay was 0.85 ng/mL, and the detection range was 0.85–1000 ng/mL. The Gal-3 intra-batch and inter-batch coefficients of variation were 3.45% and 5.12%, respectively. The correlation coefficient (R) between the Gal-3-TRFIA assay and commercially available enzyme-linked immunosorbent assay kits was 0.83. The serum Gal-3 concentration was higher in patients with IMN (65.57 ± 55.90 ng/mL) compared to healthy controls (16.29 ± 9.91 ng/mL, P < 0.0001). Conclusions In this study, a wide detection range Gal-3-TRFIA assay was developed using lanthanide (Eu3+) chelates for the detection of Gal-3 concentrations in serum. The Gal-3-TRFIA also detected the severity of the IMN course.