2.3. Biological Sample Collection

Whole blood samples were obtained by venepuncture and collected into vacutainer tubes containing potassium heparin for plasma, no anticoagulant for serum and BD Vacutainer^® CPT™ tubes with sodium citrate for peripheral blood mononuclear cells, early in the morning to avoid circadian variations. Samples were transported in a cooler (4 °C, transport within 30 min maximum), and immediately processed for the different biological endpoints. After centrifugation at 769× g for 10 min the serum (following 1–2 h rest at room temperature) and plasma were aliquoted and stored at −80 °C until analysis of immune and inflammatory biomarkers. Peripheral blood mononuclear cells were isolated from BD Vacutainer^® CPT™ tubes with sodium citrate (Becton, Dickinson and Company) for oxidative DNA damage evaluation. All samples were coded and analysed under blinded conditions.