Table 1.

Effect of TNFα and anti-TNFα on bone cells, bone biomarkers, X-rays, and bone mineral density

		TNFα	Anti-TNFα
In vitro	Osteoblasts	Inhibition of differentiation (Gilbert et al 2000; Gilbert et al 2002)	?
		Inhibition of mineralization (Taichman and Hauschka; 1992; Kuroki et al 1994; Nakase et al 1997)
		Skeletal bone matrix synthesis:inhibition (Taichman and Hauschka 1992; Kuroki et al 1994; Nakase et al 1997; Yudoh et al 2000)
		Induction of apoptosis (Hill et al 1997; Jilka et al 1998)
		Stimulation of RANKL expression (Nakashima et al 2000; Hofbauer et al 1998)
	Osteoclasts	Activation via RANK/RANKL	?
		Increasing of OPG production (Collin-Osdoby et al 2001; Hofbauer et al 1998; Marotte et al 2005) Decreasing of OPG production (Nakashima et al 2000)	Decrease of OPG production (Marotte et al 2005)
In vivo	Biomarkers of bone remodeling	Decreasing of biomarkers of bone formation (Bonnet et al 1993) Increasing of biomarkers of bone resorption (Saidenberg-Kermanac’H et al 2004; Joosten et al 1999)	Early restoration of the balance between biomarkers of bone formation and resorption (Lange et al 2005; Vis et al 2005; Vis et al 2006; Chopin et al 2007)
	X-rays	Erosion progression	No erosion progression (Smolen et al 2005; Genovese et al 2002; Keystone et al 2004; Lipsky et al 2000)
	Bone mineral density	Bone loss	Prevention of bone loss (Marotte et al 2007)

Abbreviations: TNFα, tumor necrosis factor alpha; RANKL, receptor activator of nuclear factor κB ligand; RANK, receptor activator of nuclear factor κB; OPG, osteoprotegerin.