CD19 and myalgic encephalomeyelitis/chronic fatigue syndrome: The absolute numbers and percentages of B cells (CD19+), NK cells (CD3-CD56+CD16+), T cells (CD3+), CD4 T cells (CD3+CD4+) and CD8 T cells (CD3+CD8+) in the CD45+ lymphocyte gate were similar between CFS individuals and healthy donors (data not shown and Figure 1).