Spondylodiscitis and ankylosing spondylitis: HLA typing and nosological implications

Area of Science:

• Rheumatology
• Orthopedics
• Immunogenetics

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the axial skeleton.
• AS commonly involves sacroiliitis and characteristic spinal changes like syndesmophytosis.
• A subset of AS patients may exhibit atypical spinal manifestations requiring further investigation.

Purpose of the Study:

• To describe a peculiar form of spondylodiscitis observed in a subgroup of ankylosing spondylitis patients.
• To differentiate this specific spondylodiscitis from classical spinal involvement in AS.
• To explore the potential clinical and pathological distinctiveness of this subgroup.

Main Methods:

• Retrospective analysis of nine patients with ankylosing spondylitis (AS) exhibiting unusual spondylodiscitis.
• Clinical data and radiographic findings (sclerosis, erosions, syndesmophytosis) were reviewed.
• HLA-B27 antigen status was assessed in the affected patients.

Main Results:

• Nine out of 64 AS patients presented with diffuse, marked vertebral body sclerosis and minimal adjacent plate erosions.
• Classical syndesmophytosis was notably absent in these cases.
• The HLA-B27 antigen was present in only one of the nine affected patients.

Conclusions:

• A distinct subgroup of ankylosing spondylitis patients with a peculiar spondylodiscitis characterized by vertebral sclerosis has been identified.
• This spondylodiscitis pattern, with low prevalence of HLA-B27, suggests a potentially different pathological pathway compared to typical AS.
• Further research is warranted to elucidate the clinical significance and underlying mechanisms of this specific spinal manifestation in AS.