Table 1.

Effects of nocturnal sleep compared with 24-h wakefulness on immune parameters

Immune parameter	Effect of sleep	Reference
Cell counts
WBC, total monocytes, CD14dimCD16+ monocytes, total lymphocytesa, total NK cellsa, CD16+CD56dim NK cells, total B cells, total T cells, Th cellsa, CTLa, activated T cellsa, pDC	↓	[13, 33]
Pre-mDC, total monocytes, CD14+CD16− monocytes, CD16−CD56bright NK cells, nTreg	=	[8, 33]
Cytokine activity
IL-2 (stimulated whole blood), IFN-γ/IL-4 ratio (stimulated Th cells)a, IL-7 (unstimulated whole blood), TNF-α (stimulated monocytes), IL-12 (stimulated monocytes), IL-12 (stimulated pre-mDC)	↑	[1, 13, 31, 33, 73, 74]
IL-10 (stimulated monocytes), IL-4 (stimulated Th cells)a, IFN-γ (stimulated CTL), TNF-α (stimulated CTL), TNF-α (stimulated whole blood)b, IL-1β (stimulated whole blood)b	↓	[31, 73]
IL-15 (membrane-bound on monocytes, stimulated monocytes), IL-2 (stimulated Th cells), IL-6 (stimulated monocytes), IL-6 (unstimulated whole blood), IFN-α (stimulated whole blood), IFN-α (stimulated whole blood, divided by numbers of pDC)	=	[1, 8, 13, 31–33]
Cytokine receptors
Soluble IL-6 receptor	↑	[32]
Soluble IL-2 receptor, soluble TNF-α receptors, membrane-bound IL-6 receptor, soluble gp130	=	[31, 32, 54]
Other parameters
Th cell proliferation	↑	[8]
nTreg activity	↑	[8]
NK cell activity	↓	[81]
Complement system	↑	[95]
Response to vaccination	↑	[72, 75]

For cytokine activity, the leukocyte subset analysed and whether cytokine activity was measured after stimulation of cells or not (unstimulated) is indicated in brackets

WBC white blood cells, NK cells natural killer cells, Th cells T helper cells, CTL cytotoxic T lymphocytes, pDC plasmacytoid dendritic cells, pre-mDC pre-myeloid dendritic cells, nT _reg natural regulatory T cells, IL interleukin, TNF tumour necrosis factor, IFN interferon

^aEffect reversed during late sleep or subsequent daytime

^bNo change if related to the numbers of circulating monocytes