Establishment of GDF15 time-resolved fluorescence immunoassay and its clinical application in colorectal cancer

This study aimed to develop a highly sensitive time-resolved fluoroimmunoassay for growth differentiation factor 15 (GDF15-TRFIA) and investigate its clinical applicability in colorectal cancer (CRC).

Using the principle of double-antibody sandwich immunity, the GDF15-TRFIA was established by solid-phase capture antibody and labeled detection antibody with europium as a tracer, the levels of serum GDF15 were quantified in healthy controls (HCs) and patients, and the value of GDF15 in the diagnosis of CRC was analyzed.

The established method has a wide measurement range and good linearity. The HOOK effect was not observed when GDF15 was less than 2000 ng/mL. The intra-analytical coefficients of variation (CVs) were 3.27 %-4.54 %, and the inter-analytical CVs were 5.84 %-10.41 %, and recoveries were 88.15 %-112.36 %. The correlation between GDF15-TRFIA and ELISA was good (ρ = 0.9284). Serum GDF15 levels were significantly higher in CRC patients than in benign colorectal tumor (BCT) patients and HCs (P < 0.0001). ROC analysis showed that simultaneous detection of CEA, CA19-9, and GDF15 significantly improved the diagnostic efficiency of CEA and CA19-9.

A highly sensitive GDF15-TRFIA method for serum GDF15 was successfully established. It can be used for preliminary diagnosis of CRC, and expected to be a good auxiliary tool for the future clinical diagnosis of CRC.