Bone microarchitecture in patients with autoimmune hepatitis.

Area of Science:

• Bone Biology
• Hepatology
• Radiology

Background:

• Osteoporosis is a common complication in autoimmune hepatitis (AIH).
• Bone quality and fracture risk depend on bone microarchitecture, not just bone mineral density.
• Skeletal microarchitecture changes in AIH patients are not well understood.

Purpose of the Study:

• To assess geometric, volumetric, and microarchitectural changes in the bone of female AIH patients.
• To compare AIH patients with healthy controls and patients with AIH/primary biliary cholangitis (PBC) overlap syndrome or PBC alone.
• To investigate associations between bone microarchitecture and clinical factors like age, liver stiffness, and prednisolone use.

Main Methods:

• High-resolution peripheral quantitative computed tomography (HR-pQCT) of the distal radius and tibia.
• Dual-energy x-ray absorptiometry (DXA) of the lumbar spine and hip.
• Inclusion of clinical characteristics, transient elastography (FibroScan), and laboratory analyses.

Main Results:

• AIH patients showed significantly reduced cortical thickness (Ct.Th) at the distal radius and tibia compared to controls.
• Trabecular bone parameters like bone volume fraction (BV/TV) did not differ significantly between groups.
• Age was negatively associated with Ct.Th; duration of high-dose prednisolone was negatively associated with trabecular thickness (Tb.Th) at the distal radius.

Conclusions:

• AIH patients exhibit age-dependent deterioration of cortical bone microarchitecture.
• This cortical bone loss is likely a major contributor to increased fracture risk in AIH.
• No significant differences in bone microarchitecture were found between AIH, AIH/PBC, and PBC groups.