Blood lymphocytes from ankylosing spondylitis patients fail to induce disease-specific cytotoxic T lymphocytes

The intriguing observation made by Geczy et al. (1) showing the possibility of generating specific ankylosing spondylitis--cytotoxic T lymphocytes by presenting HLA-B27+AS+ cells as antigen-specific stimulator cells prompted us (by using Geczy's approach) to identify cytotoxic T lymphocytes specific for this apparent B27+AS+ target structure. Peripheral blood mononuclear cells (PBMC) of 21 healthy B27+ individuals were stimulated in primary and in short-term cultures with PBMC of an HLA-identical sibling suffering from definite AS (n = 12). In addition, PBMC in vitro modified by "Geczy bacterial products" from two healthy B27+ individuals were used to stimulate B27+ AS- lymphocytes (either autologous or from a healthy HLA-identical sibling). Effector cells raised in primary AS- versus AS+ and AS- versus "modified B27" mixed lymphocyte culture combinations showed no proliferative nor cytotoxic activity at all. The scarcely observed cytotoxic reactivity of restimulated mixed lymphocyte culture was not restricted to AS+B27+ cells. These results demonstrate that PBMC from ankylosing spondylitis patients fail to induce disease-specific cytotoxic T lymphocytes and suggest that an ankylosing spondylitis--related "modified B27" structure does not exist, at least in the patient material tested.