Expression of interleukin-32 in the inflamed arteries of patients with giant cell arteritis.

OBJECTIVE: Giant cell (temporal) arteritis (GCA) is a vasculitis that mainly affects the large and medium arteries, especially the branches of the proximal aorta. Interleukin-32 (IL-32) is a recently described Th1 proinflammatory cytokine, and is mainly induced by interferon-γ (IFNγ), IL-1ß, and tumor necrosis factor α (TNFα). This study was undertaken to investigate the expression and tissue distribution of IL-32 in artery biopsy specimens from patients with GCA. METHODS: Quantitative gene expression analysis of IL-32, IL-1ß, TNFα, IFNγ, IL-6, and IL-27 was performed in artery biopsy specimens obtained from 18 patients with GCA and 15 controls. Immunohistochemistry analysis was performed to evaluate IL-32 tissue distribution and identify IL-32-producing cells. Circulating Th1 lymphocytes were evaluated by flow cytometry. RESULTS: We demonstrated a strong and significant up-regulation of IL-32 at both the messenger RNA and protein levels in the artery biopsy samples from patients with GCA. IL-32 was abundantly expressed by vascular smooth muscle cells of inflamed arteries and neovessels within inflammatory infiltrates. IL-32 expression strongly correlated with the intensity of the systemic inflammatory response. IL-32 overexpression was accompanied by strong overexpression of Th1 cytokines, such as IFNγ and IL-27p28, in inflamed arteries from GCA patients. The Th1 lymphocyte population was also expanded among peripheral blood mononuclear cells from GCA patients and produced higher amounts of IL-32 compared to controls. CONCLUSION: Our findings indicate that overexpression of IL-32 together with a clear Th1 response immunologically characterizes the inflammatory response in GCA. In particular, IL-32 seems to be an important mediator of artery inflammation in GCA.

Expansion of intestinal CD4+CD25(high) Treg cells in patients with ankylosing spondylitis: a putative role for interleukin-10 in preventing intestinal Th17 response.

OBJECTIVE: Subclinical gut inflammation has been demonstrated in patients with ankylosing spondylitis (AS). This study was undertaken to determine the frequency of regulatory CD4+CD25(high) T cells (Treg cells) and to evaluate Treg cell-related cytokines (interleukin-2 [IL-2], transforming growth factor ß [TGFß], and IL-10) and transcription factors (FoxP3 and STAT-5) in the ileum of patients with AS. METHODS: Quantitative gene expression analysis, by reverse transcriptase-polymerase chain reaction, of Treg-related cytokines (IL-2, TGFß, and IL-10) and transcription factors (STAT-5 and FoxP3) was performed on ileal biopsy specimens from 18 patients with AS, 15 patients with active Crohn's disease (CD), and 15 healthy subjects. Tissue and circulating Treg cells were also analyzed by flow cytometry. RESULTS: A significant up-regulation of IL-2, TGFß, FoxP3, STAT-5, and IL-10 transcripts in the terminal ileum of AS patients displaying chronic ileal inflammation was observed. Flow cytometric analysis of Treg cells showed significant peripheral expansion in both patients with AS and chronic inflammation and patients with CD (mean ± SD 1.08 ± 0.4% and 1.05 ± 0.3%, respectively) as compared with healthy subjects (0.25 ± 0.12%) (P < 0.05). Interestingly, a 5-fold increase in the proportion of Treg cells was observed in the gut of patients with AS (5 ± 3%) as compared with healthy subjects (1.2 ± 0.4%) (P < 0.001), with 70-80% of these cells also producing IL-10. In vitro studies showed that blocking IL-10 was sufficient to induce Th17 polarization on lamina propria mononuclear cells isolated from AS patients. CONCLUSION: Our findings provide the first evidence that an active Treg cell response, mainly dominated by IL-10 production, occurs in the gut of AS patients and is probably responsible for the absence of a clear Th17 polarization in the ileum of AS patients.

Over-expression of paneth cell-derived anti-microbial peptides in the gut of patients with ankylosing spondylitis and subclinical intestinal inflammation.

OBJECTIVES: Subclinical gut inflammation has been demonstrated in patients with AS. Altered expression of paneth cell (PC) anti-microbial peptides have been reported in the inflamed ileum of patients with Crohn's disease (CD). Here, we investigated the expression of PC-derived peptides in subclinical gut inflammation in AS. METHODS: Multiple adjacent mucosal biopsies from terminal ileum were obtained from 25 patients with AS, 30 CD and 15 healthy controls (HCs). Expression of human α-defensin 5 (HD-5), phospholipase A2 (PLA2), lysozyme and SOX-9 molecules was assessed by quantitative Taqman RT-PCR on mucosal samples. Immunohistochemistry with anti-human HD-5 antibody and genotyping of relevant NOD2 mutations was also performed. RESULTS: HD-5, PLA2 and lysozyme transcript levels were strongly increased in AS and CD with similar degrees of intestinal inflammation when compared with normal controls. Immunohistochemical evaluation showed a normal number of PCs in both AS patients with chronic gut inflammation and CD patients with less-inflamed ileal samples. Conversely, CD patients with higher degree of gut inflammation had a reduced number of PCs and low expression levels of HD-5. CONCLUSION: In this study, we provide evidence that over-expression of PC-derived anti-microbial peptides occurs in the ileum of AS patients with subclinical gut inflammation, likely representing an important early alteration of the mucosal innate immune component and intestinal host defence in AS.

A Th1 but not a Th17 response is present in the gastrointestinal involvement of Behçet's disease.

OBJECTIVES: Behçet's disease has been historically classified as a Th1 disease. The recently described IL-17/IL-23 pathway seems to play an important role in many inflammatory diseases and in the intestinal abnormalities of AS and CD. The aim of the present study was to evaluate the IL-17/IL-23 axis in parallel with Th1 and IL-27 response in the intestine of patients with BD and gastrointestinal abnormalities. METHODS: Quantitative TaqMan reverse transcriptase-polymerase chain reaction (RT-PCR) was utilised for all determinations on ileal biopsy specimens obtained from BD, AS and CD patients. The serum levels of Th1 and Th17 cytokines were evaluated by enzyme-linked immunosorbent assay. RESULTS: A Th1 but not a Th17 response is present in the gastrointestinal involvement of Behçet's disease. CONCLUSIONS: Although BD shares clinical manifestations with both CD and AS, the immunologic abnormalities seen in the intestine are quite different, indicating that other immune mechanisms should be taken into account.

A 2-year comparative open label randomized study of efficacy and safety of etanercept and infliximab in patients with ankylosing spondylitis.

The signs and symptoms of ankylosing spondylitis (AS) respond inadequately to nonsteroidal antiinflammatory drugs, corticosteroids, and disease modifying antirheumatic drugs in quite a number of patients. Tumor necrosis factor inhibitors have demonstrated to be of value in reducing AS disease activity in clinical trials. The efficacy and safety of both etanercept and infliximab in patients with ankylosing spondylitis were compared in a 2-year open label randomised study. Our results are consistent with a significant more rapid clinical improvement in the infliximab treated group. Treatment with both etanercept and infliximab at the end of the study was effective, safe, and well tolerated.

Phenotype and functional changes of Vgamma9/Vdelta2 T lymphocytes in Behçet's disease and the effect of infliximab on Vgamma9/Vdelta2 T cell expansion, activation and cytotoxicity.

INTRODUCTION: Infliximab is a chimeric monoclonal antibody against tumor necrosis factor alpha (TNF-alpha) that has been introduced recently for Behçet's disease (BD) patients who were resistant to standard treatment. The aim of this study was to analyse the functional changes of Vgamma9/Vdelta2 T lymphocytes in both active and inactive disease and the effect of infliximab on Vgamma9/Vdelta2 T cell expansion, activation and cytotoxicity. METHODS: We investigated 1) cell expansion, 2) expression of TNFRII receptor, 3) perforin and gamma interferon (IFN) content, 4) release of granzyme A (GrA) and 5) phenotype changes, in vitro and in vivo, in Vgamma9/Vdelta2 T lymphocytes by means of fluorescence-activated cell sorter analysis of lymphocyte cultures from patients with active and inactive BD and healthy subjects. RESULTS: Cell expansion, expression of TNFRII, perforin and gamma IFN content and release of granzyme A were significantly higher in active patients. In vitro and ex vivo treatment with infliximab resulted in a significant reduction of all parameters together with changes in the phenotype of Vgamma9/Vdelta2 T cells. CONCLUSIONS: All together these data indicate that infliximab is capable of interfering with Vgamma9/Vdelta2 T cell function in BD and although cell culture models cannot reliably predict all potential effects of the drug in vivo, our results present the possibility that this drug may find use in a range of immunological disorders, characterized by dysregulated cell-mediated immunity.

Overexpression of interleukin-23, but not interleukin-17, as an immunologic signature of subclinical intestinal inflammation in ankylosing spondylitis.

OBJECTIVE: Subclinical gut inflammation is common in spondylarthritis, but the immunologic abnormalities underlying this process are undefined. Perturbation of the interleukin-23 (IL-23)/Th17 axis has emerged as a fundamental trigger of chronic inflammation. This study was undertaken to investigate the expression and tissue distribution of IL-23/Th17-related molecules in Crohn's disease (CD) and in subclinical gut inflammation in ankylosing spondylitis (AS). METHODS: Quantitative gene expression analysis of Th1/Th2 and IL-23/Th17 responses was performed in intestinal biopsy samples obtained from 12 patients with CD, 15 patients with AS, and 13 controls. IL-23 tissue distribution and identification of IL-23-producing cells were evaluated by immunohistochemistry. RESULTS: We demonstrated a strong and significant up-regulation of IL-23p19 transcripts in the terminal ileum in patients with AS and patients with CD. IL-23 was abundantly produced by infiltrating monocyte-like cells in inflamed mucosa from AS and CD patients. Notably, we also identified Paneth cells as a major source of IL-23 in patients with AS, patients with CD, and normal controls. Unlike CD, in AS patients, IL-23 was not associated with up-regulation of IL-17 and the IL-17-inducing cytokines IL-6 and IL-1beta. Finally, while the Th1-related cytokines interferon-gamma, IL-12p35, and IL-27p28 were overexpressed only in CD patients, IL-4, IL-5, and STAT-6 were also significantly increased in AS patients. CONCLUSION: Our findings indicate that overexpression of IL-23, but not IL-17, is a pivotal feature of subclinical gut inflammation in AS. Identification of resident Paneth cells as a pivotal source of IL-23 in physiologic and pathologic conditions strongly suggests that IL-23 is a master regulator of gut mucosal immunity, providing a pathophysiologic significance to the reported association between IL-23 receptor polymorphisms and intestinal inflammation.