Biomarkers were selected based on a previous study7 (link) and have been used in Western population studies.26 (link)
human IL-6, IL-8, TNF-α, and matrix metalloproteinase (MMP)-9 levels were measured by commercial enzyme-linked immunosorbent assay kits. The minimum detection limits of human IL-6 (R&D Systems), IL-8 (R&D Systems), TNF-α (R&D Systems), and MMP-9 (GE Healthcare, Amersham, Buckinghamshire, UK) were 2.0, 31.3, 15.6, and 1,000 pg/mL, respectively. A half value limit of detection for each biomarker was used for statistical analysis when levels were not detected.
human IL-6, IL-8, TNF-α, and matrix metalloproteinase (MMP)-9 levels were measured by commercial enzyme-linked immunosorbent assay kits. The minimum detection limits of human IL-6 (R&D Systems), IL-8 (R&D Systems), TNF-α (R&D Systems), and MMP-9 (GE Healthcare, Amersham, Buckinghamshire, UK) were 2.0, 31.3, 15.6, and 1,000 pg/mL, respectively. A half value limit of detection for each biomarker was used for statistical analysis when levels were not detected.
