Bone health and chronic viral infections: A narrative literature review

Figure 1 Contemporary literature about skeletal alterations in patients with chronic viral infections (human immunodeficiency virus, hepatitis C virus, and hepatitis B virus): Importance of multiscale assessment of bone hierarchical organization. The number of plus signs indicates the number of studies present in the literature. The emphasis is put on the relatively low number of studies in patients with hepatitis B virus, and the complete absence of small-scale bone studies in patients with chronic viral infections. HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus; BMC: Bone mineral content; BMD: Bone mineral density; NPCs: Non-collagenous proteins.

Figure 2 Etiopathogenesis and mechanisms of bone alterations in patients with chronic viral infections. A: Etiopathogenesis; B: Mechanisms. HBV: Hepatitis B virus; HCV: Hepatitis C virus; HIV: Human immunodeficiency virus; Oc: Osteoclasts; Ob: Osteoblasts; Ot: Osteocytes; Nef: Negative factor; Vpr: Viral protein R; Tat: Trans-activator of transcription; gp120: Glycoprotein 120; RANKL: Receptor activator of nuclear factor-κB; IL: Interleukins; TNF: Tumor necrosis factor; Vit D: Vitamin D; ROS: Reactive oxygen species; ART: Antiretroviral therapy; PIs: Protease inhibitors; TDF: Tenofovir disoproxil fumarate.