Monocyte Chemoattractant Protein-1

Itching assessment. The intensity of pruritus was assessed using a numerical rating scale (NRS; 0 = ”no pruritus,” 1–2 = ”mild pruritus,” 3–6 = ”moderate pruritus,” 7–8 = ”severe pruritus”, 9–10 = ”very severe pruritus”) (11 (link)) and the 12-item Pruritus Severity Score (12–PSS, 3–6 points = ”mild pruritus,” 7–11 points = ”moderate pruritus,” and 12–22 points = ”severe pruritus”) (12 (link)). The NRS score reflects mean pruritus within the past 24 h. The treatment modalities for itching, including systemic and topical drugs, were also documented.
Multiplex immunoassay. The mediator levels in 87 sera samples were analysed by the Inflammation Core Facility, Institute of Biomedical Sciences, Academia Sinica, Taiwan. The core facility is funded by the Academia Sinica Core Facility and Innovative Instrument Project (AS-CFII-108-118; support number: 206f-1083818). Blood samples were collected using an antiblocked reagent and then diluted 4- and 7-fold for the quantification of mediator levels. The levels of 21 mediators were measured in duplicate, and these mediators are outlined as follows: interleukin (IL)-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-9, IL-12, IL-13, IL-15, IL-17A, IL-23, tumour necrosis factor (TNF)-α, interferon-γ (IFN-γ), IL-31, granulocyte colony-stimulating factor (G-CSF), granulocyte–macrophage colony-stimulating factor (GM-CSF), C-X-C motif chemokine ligand 10 (CXCL10), monocyte chemoattractant protein-1 (MCP-1), high-sensitivity C-reactive protein, and transforming growth factor beta (TGF-β). In brief, antibody-coupled magnetic beads were incubated with standard or sera samples for 2 h. After being washed, the beads were incubated with detection antibody for 1 h, washed, and subsequently incubated with 1 μg/mL streptavidin–phycoerythrin (SA–PE) for 30 min. The beads were rewashed, suspended in 100 μL assay buffer, and analysed through a Bio-Plex 200 system (Bio-Rad, Hercules, CA, USA). All assays were protected from light and performed at room temperature. The detection limits of the 21 mediators are listed in Table SI.
Biochemistry. Venous blood samples were collected to measure fasting plasma glucose (fasting period of at least 8 h), postprandial (2 h after a meal) plasma glucose, glycated haemoglobin A1c (HbA1c), creatinine, estimated glomerular filtration rate (eGFR), and alanine aminotransferase (ALT) levels by using central laboratory systems.