Hsil 6

To investigate the potential mechanisms of sThy-1 regulation in patients with kidney failure, six patients on chronic hemodialysis were recruited from the KfH renal center at St. Georg Hospital Leipzig, Leipzig, Germany. Patients were included if they were under stable conditions on thrice-weekly hemodialysis without signs of infection or acute diseases. Hemodialysis was performed with Nikkiso DBB-05 and DBB-EXA dialysis machines (Nikkiso Europe, Langenhagen, Germany) using a high-flux filter (Nipro Elisio 19H, Nipro, Mechelen, Belgium). All patients fasted for at least 6 h before blood and dialysate collection. Paired blood and dialysate samples were collected within 10 to 20 min after the start of each hemodialysis session. The study was approved by the Ethical Committee of the Saxonian Board of Physicians (EK-BR-14/20-3), and all subjects gave written informed consent before taking part.
Routine serum parameters, including creatinine, fasting glucose, triglycerides, total, HDL, and LDL cholesterol, as well as urinary albumin and creatinine, were measured in a certified laboratory by standard methods. High-sensitivity IL-6 was determined using enzyme-linked immunosorbent assays according to the manufacturer’s instructions (hsIL-6, R&D Systems, Minneapolis, MN, USA).

Cytokine levels were determined using commercially available ELISA kits for high sensitive IL-6 (hs-IL6; R&D Systems, MN, USA) and PAI-1 (Technoclone, Austria) in EDTA plasma samples as suggested by the manufacturers. Concentrations of highly sensitive CRP (hs-CRP) were measured using particle-enhanced immunoturbidimetric assay on cobas® 8000 modular analyzer (Cardiac C-Reactive Protein (Latex) High Sensitive, Roche Diagnostics, Switzerland).

Blood samples for biochemical analyses were taken 6 times from the antecubital vein and centrifuged at 4000 rpm and 4 °C: before, 30 minutes after, and 24-hours after the first exposure; and before the final cryotherapy session and 30 minutes and 24-hours after recovery following the final cryotherapy session. The serum was separated from the sample and stored at −70 °C.
HsCRP and myoglobin levels were measured by immunoenzymatic assay using commercially available kits (DRG International Inc., Springfield Township, NJ, USA; test sensitivity: 0.1 mg/L and 5 ng/mL), as were the levels of hsIL6 (R&D Systems Inc., Minneapolis, MN, USA; test sensitivity: 0.039 pg/mL), irisin (Aviscera Bioscience Inc., Santa Clara, CA, USA; test sensitivity: 100 pg/mL), and Mst (Immundiagostik AG, Bensheim, Germany; test sensitivity: 0.37 ng/mL). The serum concentration of 25(OH)D was measured by chemiluminescent immunoassay (CLIA, DiaSorin Liaison, Stillwater, USA; test sensitivity: 4 ng/mL).