A serological marker of the N-terminal neoepitope generated during LOXL2 maturation is elevated in patients with cancer or idiopathic pulmonary fibrosis

OBJECTIVES: Lysyl oxidase like 2 (LOXL2) is associated with poor prognosis in idiopathic pulmonary disease (IPF) and cancer. We developed an Enzyme-linked immunosorbent assay (ELISA) targeting the LOXL2 neo-epitope generated through the release of the signal peptide during LOXL2 maturation. DESIGN AND METHODS: An ELISA targeting the N-terminal site of the human LOXL2 was developed including technical optimization and validation steps. Serum LOXL2 was measured in patients with breast, colorectal, lung, ovarian, pancreatic and prostate cancer, melanoma, IPF and in healthy controls (n = 16). RESULTS: A technically robust and specific assay was developed. LOXL2 was detectable in serum from healthy controls and showed reactivity towards recombinant LOXL2. Compared to controls, LOXL2 levels were significantly (p < 0.001–0.05) elevated in serum from patients with breast, colerectal, lung, ovarian and pancreatic cancer (mean range: 49–84 ng/mL), but not in prostate cancer (mean: 36 ng/mL) and malignant melanoma patients (41 ng/mL). Serum LOXL2 was elevated in IPF patients compared to healthy controls (mean: 76.5 vs 46.8 ng/mL; p > 0.001) CONCLUSIONS: A specific ELISA towards the N-terminal neo-epitope site in LOXL2 was developed which detected significantly elevated serum levels from patients with above-mentioned cancer types or IPF compared to healthy controls.