Blood collection
STERILE
At baseline and after 6 months, samples of blood were taken in sterile 3.5 mL tubes containing clotting activator. After 30 min when blood clotted, samples were centrifuged at 2000 × g for 15 min. at 4 °C degrees. Subsequently, serum was collected at 1.5 mL Eppendorf tubes and frozen at -80 °C.