Immune function in ankylosing spondylitis: apparent relationship between streptococcal responses and HLA B27

Area of Science:

• Immunology
• Rheumatology
• Genetics

Background:

• Ankylosing spondylitis (AS) is a chronic inflammatory disease primarily affecting the spine.
• Immune system dysregulation is implicated in the pathogenesis of AS.
• The association between AS and the human leukocyte antigen HLA-B27 is well-established.

Purpose of the Study:

• To evaluate cell-mediated and humoral immune function in patients with ankylosing spondylitis.
• To investigate potential correlations between immune responses and the presence of HLA-B27.

Main Methods:

• Assessed cell-mediated immunity via skin testing with ubiquitous antigens.
• Measured humoral immunity through antibody responses to vaccinations (tetanus toxoid, Salmonella typhi) and antibody titers (anti-Streptolysin O, anti-E Coli, isohemagglutinins).
• Compared immune parameters between 54 AS patients and 26 healthy controls.

Main Results:

• AS patients exhibited reduced delayed hypersensitivity to Candida but augmented responses to Streptococcal antigen.
• Antibody responses to tetanus toxoid and Salmonella O antigen were normal, with a hyper-response to Salmonella H antigen.
• Resting titers for anti-Streptolysin O were relatively low, while anti-E Coli and isohemagglutinin titers were normal, indicating no generalized humoral immune depression.

Conclusions:

• Patients with ankylosing spondylitis display a complex immunological profile characterized by both impaired and exaggerated immune responses to specific antigens.
• These immune findings may be associated with the genetic influence of HLA-B27, suggesting a role for immune response genes in AS pathogenesis.