KLEBSIELLA PNEUMONIAE-REACTIVE T-CELLS IN BLOOD AND SYNOVIAL-FLUID OFPATIENTS WITH ANKYLOSING-SPONDYLITIS - COMPARISON WITH HLA-B27-FLUID T-CELL CLONES( HEALTHY CONTROL SUBJECTS IN A LIMITING DILUTION STUDY AND DETERMINATION OF THE SPECIFICITY OF SYNOVIAL)

Objective, To study the frequency of Klebsiella pneumoniae-responsive T cells in the peripheral blood (PB) of ankylosing spondylitis (AS) pa tients compared with that in healthy HLA-B27 + donors, and to examine T lymphocyte clones (TLC) derived from AS patient synovial fluid (SF) for the presence of Klebsiella reactivity. Methods, Limiting dilution analysis of PB T cells in 8 patients with active AS and in 8 HLA-B27 healthy subjects was used to determine the frequency of PB T cells re sponsive to K pneumoniae and Escherichia coli GroEL, SF T cells from a patient with active AS were cloned, and 125 TLC were characterized in proliferation assays. Results, There were fewer T cells in the PB of AS patients that reacted with K pneumoniae than in the PB of healthy H LA-B27+ subjects, The frequencies of E coli GroEL-responsive T cells w ere similar to 5-10 times lower in all subjects tested (healthy donors and AS patients), but without significant differences between the 2 g roups, Two CD4+ TLC that recognized K pneumonine (1 cross-reactive wit h E coli) as well as 3 TLC that recognized GroEL (2 CD4+, 1 T cell rec eptor gamma/delta+) were isolated from the SF of a patient with active AS. Conclusion, Our results indicate that there is a quantitative red uction of K pneumoniae-responsive T cells in the PB of AS patients as compared with healthy controls. This may reflect a defective periphera l T cell defense in the immune response to Klebsiella and may allow ba cterial antigens to reach the synovium, where they initiate specific T cell responses.