Serum biomarkers confirming stable remission in inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) have a chronic-remittent course. Optimal management of inflammatory bowel diseases (IBD) relies on early intervention, treat-to-target strategies and a tight disease control. However, it is challenging to assess the risk of relapses in individual patients. We investigated blood-based biomarkers for the confirmation of disease remission in patients with IBD. We retrospectively analyzed samples of 40 IBD patients (30 UC, 10 CD) enrolled in a tight-control follow-up study. Half of the patients had a flare during follow up. Serum was analyzed for S100A12 as well as S100A8/A9 and for 50 further biomarkers in a bead-based multiplex assay. The concentrations of 9 cytokines/chemokines and S100A8/A9 significantly differed in IBD patients with unstable remission (before flares) when compared to IBD patients with stable remission. Although the number of patients was small, ROC curve analyses revealed a number of biomarkers (IL-1β, IL-1RA, IL-8, IL13, IL-15, IL-21, IL-25, IFN-β, CXCL9, CXCL10, CXCL11, Galectin-1, G-CSF and S100A8/A9) that were elevated in patients with later occurring relapses. While earlier studies on peripheral biomarkers in IBD are limited to only few analytes, our study using a broad screening approach identified serum biomarkers with the potential to indicate unstable disease control in IBD, which may help to steer individual therapies to maintain remission

Peripheral monocyte functions and activation in patients with quiescent Crohn's disease.

Recent developments suggest a causal link between inflammation and impaired bacterial clearance in Crohn's disease (CD) due to alterations of intestinal macrophages. Studies suggest that excessive inflammation is the consequence of an underlying immunodeficiency rather than the primary cause of CD pathogenesis. We characterized phenotypic and functional features of peripheral blood monocytes of patients with quiescent CD (n = 18) and healthy controls (n = 19) by analyses of cell surface molecule expression, cell adherence, migration, chemotaxis, phagocytosis, oxidative burst, and cytokine expression and secretion with or without lipopolysaccharide (LPS) priming. Peripheral blood monocytes of patients with inactive CD showed normal expression of cell surface molecules (CD14, CD16, CD116), adherence to plastic surfaces, spontaneous migration, chemotaxis towards LTB4, phagocytosis of E. coli, and production of reactive oxygen species. Interestingly, peripheral blood monocytes of CD patients secreted higher levels of IL1β (p<.05). Upon LPS priming we found a decreased release of IL10 (p<.05) and higher levels of CCL2 (p<.001) and CCL5 (p<.05). The expression and release of TNFα, IFNγ, IL4, IL6, IL8, IL13, IL17, CXCL9, and CXCL10 were not altered compared to healthy controls. Based on our phenotypic and functional studies, peripheral blood monocytes from CD patients in clinical remission were not impaired compared to healthy controls. Our results highlight that defective innate immune mechanisms in CD seems to play a role in the (inflamed) intestinal mucosa rather than in peripheral blood

Cytokine expression and secretion.

<p>(A) Cytokine and chemokine secretion by resting monocytes of healthy controls (n = 19) and patients with CD in remission (n = 17). (B) Cytokine and chemokine secretion by monocytes of healthy controls (n = 13) and patients with CD (n = 13) stimulated with LPS for 2 hours. (C) mRNA expression levels of resting monocytes of healthy controls (n = 13) and patients with CD (n = 14). Error bars indicate SEM. *, P<0.05; ***, P<0.001.</p

Synergistic Signaling of TLR and IFN alpha/beta Facilitates Escape of IL-18 Expression from Endotoxin Tolerance

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Cell surface molecule expression.

<p>(A) Example of CD14 and CD16 expression on naïve PBMCs after Ficoll isolation gated for viable monocytes. Upper left quadrant shows CD14++/CD16– monocytes, upper right quadrant shows CD14++/CD16++ monocytes, and CD14+/CD16++ monocytes are represented in the lower right quadrant. (B) Shown is the CD116 expression on naïve monocytes of healthy controls (n = 11) and patients with CD in remission (n = 12) as mean fluorescence intensity. (C) Cell surface expression of CD14 and CD16 on viable PBMC monocytes of healthy controls (n = 17) and patients with CD (n = 18) analyzed by flow cytometry as shown in (A). All bars represent means ± SEM.</p

Functional cell assays.

<p>(A) Adhesion of monocytes of healthy controls (n = 15) and CD (n = 16) to fibronectin-coated plastic surface. (B) Migration and chemotaxis studies of monocytes of healthy controls (n = 5) and patients with CD (n = 5) using a modified Boyden chamber and LTB4 as a chemoattractant. (C) Phagocytosis of FITC-labeled <i>E. coli</i> by monocytes of healthy controls (n = 12) and patients with CD (n = 11). (D) Production of reactive oxygen species (ROS) by monocytes of healthy controls (n = 11) and patients with CD (n = 12) with and without further LPS stimulation for 2 hours. All bars represent means ± SEM.</p

Characteristics of Crohn’s disease patients and healthy controls.

<p>Characteristics of Crohn’s disease patients and healthy controls.</p

Effect of Adalimumab on Peripheral Blood Mononuclear Cells in Non-Infectious Uveitis

<p><i>Purpose:</i> This study analyzed the effect of adalimumab on peripheral blood mononuclear cells (PBMCs) in uveitis.</p> <p><i>Methods:</i> PBMCs and serum S100A12 levels from 14 uveitis patients and 28 healthy controls were analyzed. Patient samples were taken before (w0), and 6 (w6) and 12 (w12) weeks after initiation of adalimumab therapy.</p> <p><i>Results:</i> Monocytes expressing CD124, CD86, CD39, CD115, and MHCII were decreased in patients. Adalimumab induced CD86+ and CD39+ monocytes, and further decreased the frequency of MHCII- and CD124-positive cells. Patients (w0) had increased percentages of Th1-, Th17-, and Th2 cells and T cell subsets showed a pro-inflammatory polarization (<i>p</i> = 0.02 ratio Th17/Treg patients w0 vs controls), which was reduced upon adalimumab treatment (<i>p</i> = 0.05 w0 vs w6). S100A12 levels were increased in patients (<i>p</i> = 0.02) and reduced under treatment (<i>p</i> = 0.02 for w6/w12).</p> <p><i>Conclusions:</i> The phenotype of PBMCs from uveitis patients is modified upon adalimumab treatment. Serum S100A12 levels reflect the systemic immune response.</p

Primer sequences for RT-PCR.

<p>Primer sequences for RT-PCR.</p

Increased Circulating Proinflammatory T Lymphocytes in Children with Different Forms of Anterior Uveitis: Results from a Pilot Study

<p><i>Purpose</i>: To characterize peripheral blood T cells in juvenile idiopathic arthritis-associated uveitis (JIAU).</p> <p><i>Methods</i>: Blood samples were taken from children with JIAU (n = 18), JIA without ocular involvement (n = 11), idiopathic anterior uveitis (IAU, n = 12), and healthy controls (n = 11). Cells were stained for T cell surface markers, and intracellular cytokine staining was performed after cell stimulation and analyzed by flow cytometry.</p> <p><i>Results</i>: The Th1/Th2 ratio was increased in JIAU patients. Numbers of IL-13-expressing cells an level of IL-13 and IL-10 expression per cell were increased in all patient groups; whereas, percentages of IL-5-expressing T cells were decreased. Numbers of proinflammatory Th17 cells and T cells expressing CTLA-4 were increased in all patient groups; whereas, γ/δ T cell numbers were decreased. Results from JIA and IAU were similar.</p> <p><i>Conclusion</i>: T cell subtypes and potential T cell function are altered in pediatric patients with uveitis and arthritis as compared to healthy children.</p