Stimulation of whole blood cultures in patients with ankylosing spondylitis by a mitogen derived from Mycoplasma arthritidis (MAS) and other mitogens

Rheumatol Int. 1997;16(5):207-11. doi: 10.1007/BF01330297.


In this study we compared cytokine production and cell proliferation of immunocompetent cells derived from patients with ankylosing spondylitis (AS) to those from healthy blood donors using a whole blood assay. To this end, blood cell cultures were stimulated with the superantigens MAS (Mycoplasma arthritidis supernatant) and staphylococcal enterotoxin B (SEB) and the plant lectins phytohaemagglutinin (PHA) and concanavalin A (Con A). The number of white blood cells (WBC) and lymphocyte subsets were also determined. Cell proliferation and levels of interferon-gamma (IFN-gamma), interleukin-1 beta (IL-1 beta) and interleukin-6 (IL-6) were measured after stimulation with the different mitogens. An ELISA test was used to analyse supernatant cytokine levels. Individuals with AS showed significantly lower IFN-gamma concentrations and markedly lower cell proliferation rates with all tested mitogens than healthy controls, while there was no significant difference in IL-6 synthesis. IL-1 beta levels were slightly impaired in the patient group, but only blood cell cultures stimulates with MAS showed a statistical significance. Furthermore, there was a significant elevation of leucocytes and lymphocytes in patients with AS resulting in higher numbers of CD4-positive cells, which implies a higher CD4:CD8 cell ratio. CD19- and CD8-positive cells were not significantly distinct compared to healthy controls. This deviation in cytokine levels and cell proliferation points to a suppression of T lymphocytes. A disturbed T-lymphocyte function may play a part in the pathogenesis of AS.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Antigens
  • Antigens, Bacterial
  • Cells, Cultured / drug effects
  • Cytokines / biosynthesis*
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Flow Cytometry
  • Humans
  • Lymphocyte Activation* / drug effects
  • Male
  • Middle Aged
  • Mitogens / pharmacology*
  • Proteins
  • Spondylitis, Ankylosing / blood*
  • Spondylitis, Ankylosing / immunology
  • Spondylitis, Ankylosing / pathology
  • Superantigens / pharmacology*
  • T-Lymphocytes / drug effects
  • T-Lymphocytes / metabolism*


  • Antigens
  • Antigens, Bacterial
  • Cytokines
  • Mitogens
  • Mycoplasma arthritidis mitogen
  • Proteins
  • Superantigens