Assay for absolute count of T cells, B cells and NK cells
BD multitest 6 colour TBNK reagent and BD TrucountTMtubes were used to enumerate absolute count of T cells, CD4 T cells, CD8 T cells, B cells, and Natural killer (NK) cells using 50 μl of fresh EDTA stabilised blood following stain/lyse/no-wash protocol. Data acquisition was performed on BD FACS Aria Fusion (SORP) Flow cytometer (BD Biosciences) where 5000 events gated on beads count were acquired. Data analysis was carried out using FlowJo software (BD biosciences)