Christian Genin

Evidence of Toll-like receptor molecules on human platelets

Platelets are primarily involved in thrombosis and haemostasis, and they have recently been shown to have a role in innate immunity and in inflammation. We have determined the markers of innate immunity that are expressed by platelets, specifically the Toll‐like receptors (TLR), originating from mixes of platelet concentrates (MPC, n = 5) between day zero and day five after blood collection. The surface membrane and intracellular expression of TLR were measured, both after and without permeabilization, using flow cytometry. We observed weak expression of TLR2, TLR4 and TLR9 on the surface of CD41+ platelets. The expression levels of TLR4 were high (59 ± 2.2%). Moreover, there was a significant expression of TLR2 (47.5 ± 4.8%), TLR4 (78.8 ± 1.3%) and TLR9 (34.2 ± 7.5%) in the cytoplasm of CD41+ platelets. The expression of the three receptors did not change significantly during the course of the 5 day observation period. The percentage of TLR expression is significantly modulated between activated versus non‐activated platelets, both after and without permeabilization (P < 0.01). Study of the expression of TLR could increase our knowledge of the level of platelet participation during an immune reaction and inflammation. In the same way as the platelet ligand/receptor pair CD40L/CD40 is, the TLR are expressed by platelets, and could serve as a link between innate and adaptive immunity.

Association Between Pharmacokinetics of Adalimumab and Mucosal Healing in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS Little is known about the association between pharmacokinetic features of adalimumab and mucosal healing in patients with inflammatory bowel disease (IBD). METHODS We conducted a cross-sectional study of 40 patients with Crohns disease (CD) or ulcerative colitis (UC) who received adalimumab maintenance therapy and underwent endoscopic evaluation of disease activity and pharmacokinetic analysis (measurements of trough levels and antibodies against adalimumab). Patients in clinical remission were identified based on CD activity index scores less than 150 or Mayo scores less than 3 (for those with UC). Patients with mucosal healing were identified based on Mayo endoscopic scores less than 2 (for UC) or the disappearance of all ulcerations (for CD). RESULTS The median trough level of adalimumab was higher in patients in clinical remission (6.02 μg/mL) than in patients with active disease (3.2 μg/mL; P = .012). Trough levels of adalimumab were also higher in patients with mucosal healing (6.5 μg/mL) than in patients without (4.2 μg/mL;  P  <  .005). These results did not vary with type of IBD. On multivariate analysis, trough levels of adalimumab (relative risk, 0.62; 95% confidence interval, 0.40-0.94; P = .026) and duration of adalimumab treatment (relative risk, 0.82; 95% confidence interval, 0.68-0.97; P = .026) were associated independently with healing mucosa. An absence of mucosal healing was associated with trough levels of adalimumab less than 4.9 μg/mL (likelihood ratio, 4.3; sensitivity, 66%; specificity, 85%). CONCLUSIONS Trough levels of adalimumab are significantly higher in IBD patients who are in clinical remission and in those with mucosal healing. Detection of antibodies against adalimumab predicts a lack of mucosal healing.

New insights in mucosal vaccine development.

Mucosal surfaces are the major entrance for infectious pathogens and therefore mucosal immune responses serve as a first line of defence. Most current immunization procedures are obtained by parenteral injection and only few vaccines are administered by mucosal route, because of its low efficiency. However, targeting of mucosal compartments to induce protective immunity at both mucosal sites and systemic level represents a great challenge. Major efforts are made to develop new mucosal candidate vaccines by selecting appropriate antigens with high immunogenicity, designing new mucosal routes of administration and selecting immune-stimulatory adjuvant molecules. The aim of mucosal vaccines is to induce broad potent protective immunity by specific neutralizing antibodies at mucosal surfaces and by induction of cellular immunity. Moreover, an efficient mucosal vaccine would make immunization procedures easier and be better suited for mass administration. This review focuses on contemporary developments of mucosal vaccination approaches using different routes of administration.

Therapeutic drug monitoring of infliximab and mucosal healing in inflammatory bowel disease: a prospective study.

Background:Data on the value of therapeutic drug monitoring of infliximab (IFX) to predict mucosal healing (MH) in inflammatory bowel diseases (IBD) are scarce. Methods:All consecutive patients with IBD receiving ongoing IFX (5 mg/kg) treatment and developing secondary failure to IFX were enrolled in a prospective study between June 2010 and May 2011. IFX trough levels, antibodies to IFX concentrations, C-reactive protein levels, and fecal calprotectin were measured before IFX optimization and at week 8. A proctosigmoidoscopy was performed on the day of first IFX optimization and at week 8 in all patients with ulcerative colitis (UC). MH was defined by fecal calprotectin <250 &mgr;g/g stools in Crohns disease (CD) and by an endoscopic Mayo score of 0 or 1 in UC. Results:This study included 52 patients with IBD: 34 patients with CD (mean Crohns Disease Activity Index, 300; mean C-reactive protein, 28 ± 10 mg/L; mean fecal calprotectin, 705 ± 300 &mgr;g/g) and 18 patients with UC (mean Simple Clinical Colitis Activity Index, 7; mean Mayo endoscopic score, 3). After IFX dose intensification, half of CD and UC patients achieved MH. Increase in IFX trough levels (called “delta IFX” in micrograms per milliliter) was associated with MH in both CD and UC (P = 0.001). A delta IFX >0.5 &mgr;g/mL was associated with MH (sensitivity [se], 0.88; specificity [sp], 0.77; P = 0.0001, area under the receiver operating characteristic curve, 0.89). On multivariate analysis, the only factor associated with MH after IFX optimization was a delta IFX >0.5 µg/mL (likelihood ratio = 2.02; 95% confidence interval, 1.01–4.08; P = 0.048) in patients with IBD. Conclusions:Therapeutic drug monitoring of IFX strongly predicts the likelihood of achieving MH following IFX dose intensification in both CD and UC.

Serum miR-210 as a novel biomarker for molecular diagnosis of clear cell renal cell carcinoma

OBJECTIVE Our objective was to evaluate the levels of miR-210 in tumor and serum samples of conventional renal cell cancer (cRCC) patients to explore whether circulating miR-210 in serum can be used as a biomarker for the detection of cRCC. METHODS The paired samples from primary cRCC tumors and adjacent non-tumoral renal parenchyma were collected from 32 patients with cRCC. Serum samples were obtained from 68 patients with a cRCC before surgery, 10 samples after one week of surgery, and 42 healthy individuals were included in this study. Real-time PCR was used to measure the microRNA level. The expression of miRNAs was normalized using the dCT method. Expression levels of miR-210 were compared using the Mann-Whitney U test or Wilcoxon test. Diagnostic performance of serum miR-210 level was calculated by using the receiver operating characteristic (ROC) curve. RESULTS The average miR-210 level was higher in primary cRCC tissues than in normal tissue (p=0.004). For serum samples, the average level of miR-210 was significantly higher in cRCC patients than in controls (p<0.001). The serum miR-210 level yielded an AUC (the areas under the ROC curve) of 0.874 with a sensitivity of 81.0% and a specificity of 79.4%. Furthermore, the average serum level of miR-210 was significantly decreased in the patients one week after the operation (p=0.001). CONCLUSION Serum mi-210 may have a potential as a novel noninvasive biomarker for the detection of cRCC.

Recruitment of STAT3 for Production of IL-10 by Colon Carcinoma Cells Induced by Macrophage-Derived IL-6

The immunosuppressive cytokine IL-10 is associated with poor prognosis in colon cancer. Although macrophages are involved in antitumor defenses, production of IL-10 by tumor cells may permit malignant cells escape to cell-mediated immune defenses. To investigate interactions between macrophages and tumor cells in humans, we cultured macrophages isolated from patients and tested the effect of these macrophages on the production of IL-10 by several tumor cell lines. Macrophages were isolated from pleural effusions of patients with malignancy and from noncancer control patients. We demonstrated that culture supernatants of macrophages from both sources strongly stimulated IL-10 production by the three different human colon adenocarcinoma cell lines, Colo 205, Colo 320, and HT29. Recombinant IL-6, but not IL-10, TNF-α, and IFN-α, stimulated the secretion of IL-10 by colon tumor cells. mAbs against IL-6 and IL-6R prevented the effect of macrophage culture supernatants and of rIL-6, respectively, on the production of IL-10 by the three cell lines. Cocultures of macrophages and colon cancer cells showed that these tumor cells first stimulated macrophages to produce IL-6, which was then followed by IL-6-induced IL-10 production by colon cancer cells. Finally, we showed that IL-10 gene regulation was mediated by STAT3, which was phosphorylated after the binding of IL-6 to IL-6R. This is the first demonstration that IL-6, secreted by macrophages, can induce a STAT3-mediated IL-10 production by colon tumor cells.

Serum Carbonic Anhydrase 9 Level is Associated With Postoperative Recurrence of Conventional Renal Cell Cancer

PURPOSE We explored the clinical usefulness of serum carbonic anhydrase 9 as a potential biomarker for conventional renal cell cancer. MATERIALS AND METHODS This study included 91 patients with conventional renal cell cancer and 32 healthy individuals. Enzyme linked immunosorbent assay was used to measure the carbonic anhydrase 9 level. A followup (median 38 months) was performed to track early recurrence after surgery for patients with localized disease. Recurrence-free survival curves were calculated by the Kaplan-Meier method and compared using the log rank test. RESULTS The mean serum carbonic anhydrase 9 level in patients with metastatic conventional renal cell cancer (216.68 +/- 67.02 pg/ml) or localized conventional renal cell cancer (91.65 +/- 13.29 pg/ml) was significantly higher than in healthy individuals (14.59 +/- 6.22 pg/ml, p <0.001 and p = 0.001, respectively). The mean serum carbonic anhydrase 9 level in patients with metastatic conventional renal cell cancer was significantly higher than in those with localized disease (p = 0.004). Of patients with localized disease those with recurrence had a significantly higher serum carbonic anhydrase 9 than those without recurrence (p = 0.001). On univariate analysis serum carbonic anhydrase 9, tumor stage, tumor grade and tumor size were associated with recurrence. The recurrence-free survival curve indicates that patients with a high serum carbonic anhydrase 9 level had a significantly higher recurrence rate than those with a low serum carbonic anhydrase 9 (p = 0.001). CONCLUSIONS Our data suggest that serum carbonic anhydrase 9 is increased as the tumor progression occurs. A high carbonic anhydrase 9 level is associated with postoperative recurrence.

S100A1: a powerful marker to differentiate chromophobe renal cell carcinoma from renal oncocytoma

Aims:  The common subtypes of renal tumours are conventional, papillary, chromophobe carcinoma and oncocytoma. The morphological differentiation between chromophobe carcinoma and oncocytoma may be difficult. The aim was to evaluate S100A1 as a new marker for the differentiation of the two subtypes.

Pharmacokinetics of adalimumab in inflammatory bowel diseases: a systematic review and meta-analysis.

Background:The aim of this meta-analysis was to explore the magnitude of the association between pharmacokinetics of adalimumab and clinical response in patients with inflammatory bowel disease. Methods:A literature search was performed up to December 2013. MEDLINE, EMBASE, Cochrane, and meeting abstracts were reviewed. Studies were included if they analyzed the association of trough levels of adalimumab (TRA) or antibodies against adalimumab (AAA) with clinical response in adult or pediatric inflammatory bowel disease. A Mantel–Haenszel pooled risk estimate provided a measure of the association. Results:Fourteen studies enrolling 1941 patients with inflammatory bowel disease were included in the systematic review. Thirteen studies analyzed clinical outcomes according to TRA. In only 1 study, there was no correlation between high TRA and clinical response. Six of the 7 studies reported a negative correlation between AAA and clinical outcomes. Six studies enrolling 536 patients (Crohns disease [CD] only) met the meta-analysis inclusion criteria. The pooled odds ratio (OR) for loss of clinical response to adalimumab in patients with CD (N = 4) with positive AAAs was 10.15 (95% confidence interval [CI]: 3.90–26.40, P < 0.0001). Patients with CD with TRA over a predefined cutoff were more likely to be in clinical remission with an OR of 2.6 (95% CI: 1.79–3.77, P < 0.0001). The association was stronger if the analysis was limited to the adult population (N = 3, OR: 7.05, 95% CI: 3.58–13.9, P < 0.0001). Conclusions:The presence of AAA is associated with a higher risk of loss of clinical response to adalimumab, whereas high TRA is associated with greater clinical response rates in CD. More data are needed in ulcerative colitis.

Characterization of CCL20 secretion by human epithelial vaginal cells: involvement in Langerhans cell precursor attraction

Mucosa represents the main site of pathogen/cell interactions. The two main types of cells forming the epithelial structure [epithelial cells and Langerhans cells (LC)] coordinate the first defense responses to avoid infection. To evaluate the involvement of epithelial cells in the early steps leading to a specific adaptive immune response, we have studied the interactions between vaginal epithelial and LC through the establishment of a human vaginal epithelial mucosa. We demonstrate that normal human vaginal epithelial cells constitutively secrete the chemokine macrophage inflammatory protein 3α/CC chemokine ligand 20 (CCL20), known to recruit LC precursors (LCps) selectively via its cognate CC chemokine receptor 6 (CCR6). This secretion is up‐regulated by the proinflammatory cytokine interleukin‐1β through the nuclear factor‐κB pathway. Similar results were obtained with the human vaginal epithelial cell line SiHa, which displays numerous homologies with normal vaginal cells. The chemotactic activity of the secreted CCL20 was demonstrated by its ability to attract LCp CCR6+. Moreover, the use of neutralizing polyclonal antibodies directed against the CCL20 molecule abolished this migration completely, suggesting that CCL20 is the main attracting factor for LCps, which is produced by the vaginal cells. These data indicate that vaginal epithelial cells play an important role in the immunological defense by attracting immune cells to the site of epithelial/pathogen contact.