Interleukin-6 and tumor necrosis factor-α in osteoimmunology: Aging, and anticytokine therapies

Table 3 Anticytokine therapies and skeletal outcomes described in the manuscript

Agent(s)	Target	Skeletal effects reported
Etanercept	TNF-α (decoy receptor-Fc fusion protein)	Lowers osteoclast activity, maintains bone mineral density, slows radiographic erosion progression
Infliximab, adalimumab	TNF-α (monoclonal antibodies)	Neutralize soluble and membrane-bound TNF-α; osteoprotective effects alongside disease control
Tocilizumab, sarilumab	IL-6 receptor	Disrupt IL-6 signaling and JAK/STAT activation, reduce osteoclastogenesis, lower bone turnover markers, and may protect bone comparably to anti-TNF in some settings

Reported fracture-reduction estimates from observational studies should be interpreted cautiously, as noted in the text. BMD: Bone mineral density; IL-6: Interleukin-6; TNF-α: Tumor necrosis factor-α; JAK: Janus kinase; STAT: Signal transducer and activator of transcription; TNF: Tumor necrosis factor.