Table 1.

Main lymphocyte types' alterations in sepsis.

Lymphocyte type	Roles	Outcomes in sepsis	References
CD4+ T cells	TH1: positive feedback on antigen presenting cells. TH2: promoting downregulation.	Lack of a shift from TH1 to TH2 increases survival.	[35]
	TH17: producing IL-17, IL-21, TNF-α, and IFN-γ.	TH17 lymphocyte count in survivors was higher.	[52]
	Treg: immunosuppressive activity.	Treg lymphocyte counts higher in surviving patients	[41]
CD8+ T cells	Effector cytotoxic cells.	In survivors, CD8+ T lymphocytes showed a further drop on day 3 of follow-up.	[36]
NK cells	Effector cytotoxic activity and immunoregulatory function.	CD69+, an activation marker, increases in nonsurvivors. CD57+, a marker of long-lived and differentiated NK cells, shows higher percentage in nonsurvivors.	[72]
B cells	Ability to differentiate into immunoglobulin secreting plasma cells.	An inverse correlation between count and survival, but this relation affects heterogeneously the subsets.	[23, 101]

Abbreviations: T_H: T helper; IL: interleukin; TNF: tumor necrosis factor; IFN: interferon.