Cytokines in chronic rheumatic diseases: is everything lack of homeostatic balance?

Table 1 Balance in cytokine activities according to biological processes

Process	Cytokines
Inflammation	IL-1/IL-1 receptor antagonist, IL-1 receptor II, soluble IL-1 receptor I, soluble IL-1 receptor II
	TNF/soluble TNF receptor I, soluble TNF receptor II
	IL-6/soluble gp130
	IL-18/IL-18 binding protein
	IL-22/IL-22 binding protein
	IL-13/IL-13 receptor alpha
	CXCL^ELR+ /CXCL^ELR-
	Several proinflammatory chemokines (CXC and CC)/Duffy antigen receptor for chemokines
	Several proinflammatory chemokines (CC not CXC)/D6
	CCL19, CCL21, CCL25, CXCL13/CCX-CKR
	Chemerin 9/chemerin 15
Immune cell responses	Th1 cells/Th2 cells
	Th17 cells/Th2 cells
	Th17 cells/T cells with regulatory function
	T cells with regulatory function/Th1, Th2, Th17 cells
Tissue repair and remodeling	Transforming growth factor beta/TNF
	IL-1/IFNγ
	IL-4/IFNγ
CD4 T-cell differentiation	IL-12/IL-4
	Transforming growth factor beta/IL-6 + T-cell growth factor beta
Tissue destruction	Osteoprotegerin/RANKL
	WNT/Dickkopf-1
Metabolism	Adiponectin/leptin, vistatin, resistin

In view of the pleiotropic actions of cytokines, the table presents a far from complete view of possible opposing activities of cytokines and their ligands. The back slash (/) separates the opposing molecules in respect of a given biological activity. RANKL, receptor activator of NKκB ligand; WNT, wingless integration site.