Th1/17 cells, a subset of Th17 cells, are expanded in patients with active systemic lupus erythematosus.

Skewed cytokine production characterizes T cells in Systemic Lupus Erythematosus (SLE). Among Th17 cells that are expanded in lupus, a subset (Th1/17) retains the ability to produce IFNγ. We aimed to analyze Th17 and Th1/17 cells in patients with SLE. Patients with active disease displayed increased percentages of circulating Τh17 and Th1/17 cells. Stimulated T cells from patients with lupus secreted significantly more IL-17 compared to healthy donors. Also, T cells from patients with active SLE released significantly lower levels of IFN-γ compared to controls. However, following stimulation, levels of IFN-γ also rose significantly. Our data suggest that lupus Th1/17 cells are not only expanded but also functional. In summary, in this study it was shown that patients with active SLE display increased Th17 and functional Th1/17 cells. This impaired T-cell axis might represent a possible future therapeutic target.

Evidence that Dkk-1 is dysfunctional in ankylosing spondylitis.

OBJECTIVE: Dkk-1 is an inhibitory molecule that regulates the Wnt pathway, which controls osteoblastogenesis. This study was undertaken to explore the potential role of Dkk-1 in ankylosing spondylitis (AS), a prototypical bone-forming disease. METHODS: Serum Dkk-1 levels were measured in 45 patients with AS, 45 patients with rheumatoid arthritis (RA), 15 patients with psoriatic arthritis (PsA), and 50 healthy subjects by sandwich enzyme-linked immunosorbent assay (ELISA). A functional ELISA was used to assess the binding of Dkk-1 to its receptor (low-density lipoprotein receptor-related protein 6). Furthermore, we studied the effect of sera from patients with AS and healthy subjects on the activity of the Wnt pathway in the Jurkat T cell model, with and without a neutralizing anti-Dkk-1 monoclonal antibody, by Western immunoblotting. RESULTS: Serum Dkk-1 levels were significantly increased in patients with AS (mean +/- SEM 2,730 +/- 135.1 pg/ml) as compared with normal subjects (P = 0.040), patients with RA (P = 0.020), and patients with PsA (P = 0.049). Patients with AS receiving anti-tumor necrosis factor alpha (anti-TNFalpha) treatment had significantly higher serum Dkk-1 levels than patients with AS not receiving such treatment (P = 0.007). Patients with AS studied serially prior to and following anti-TNFalpha administration exhibited a significant increase in serum Dkk-1 levels (P = 0.020), in contrast to patients with RA, who exhibited a dramatic decrease (P < 0.001). Jurkat cells treated with serum from AS patients exhibited increased Wnt signaling compared with cells treated with control serum. In that system, Dkk-1 blockade significantly enhanced Wnt signaling in control serum-treated, but not AS serum-treated, Jurkat T cells. CONCLUSION: Our findings indicate that in patients with AS, circulating bone formation-promoting factors functionally prevail. This can be at least partially attributed to decreased Dkk-1-mediated inhibition.