Blood was drawn into EDTA-containing collection tubes (BD Vacutainer) and processed within 30 min of collection. The whole blood samples were centrifuged at 4°C at 1,500g for 15 min to obtain plasma.

In order to minimize the platelets count, the blood was allowed to clot (BD Vacutainer Plus SST), and serum was separated immediately (by centrifugation at 3,500 rpm for 15 min after sampling), then ...