[Fifteen years of use of anti-TNF antibodies in moderate to severe Crohn's disease: how to make the best of this experience]. / Quinze ans d'anti-TNF dans la maladie de Crohn: comment tirer le meilleur de cette révolution thérapeutique?

After fifteen years of use, the anti-TNF antibodies have become the corner stone of the treatment of moderate and severe Crohn's disease. The skill acquired over the years through experimental trials and clinical experience leads to increased therapeutic efficacy and minimized risks. These antibodies are introduced increasingly earlier in Crohn's disease as well as in a broader range of patients, aiming at changing the natural history of the diseases by avoiding the development of intestinal tissue damage and complications.

[Proteomics studies on arthritis by SELDI-TOF-MS: identification of the S100 proteins family as proteins of interest]. / Protéomique par SELDI-TOF-MS des maladies inflammatoires articulaires: identification des protéines S100 comme protéines d'intérêt.

Clinical proteomics is a technical approach studying the entire proteome expressed by cells, tissues or organs. It describes the dynamics of cell regulation by detecting molecular events related to diseases development. Proteomic techniques focus mainly on identification of new biomarkers or new therapeutic targets. It is a multidisciplinary approach using medical, biological, bioanalytical and bioinformatics knowledges. A strong collaboration between these fields allowed SELDI-TOF-MS proteomics studies to be performed at the CHU and the University of Liège, in GIGA-Research facilities. The aim of these studies was driven along three main axes of research related to the identification of biomarkers specific to a studied pathology, to a common biological pathway and, finally, to a treatment response. This work was presented in the setting of the "Synthèse CHU 2009" meeting.

Cold-adapted enzymes: from fundamentals to biotechnology.

Psychrophilic enzymes produced by cold-adapted microorganisms display a high catalytic efficiency and are most often, if not always, associated with high thermosensitivity. Using X-ray crystallography, these properties are beginning to become understood, and the rules governing their adaptation to cold appear to be relatively diverse. The application of these enzymes offers considerable potential to the biotechnology industry, for example, in the detergent and food industries, for the production of fine chemicals and in bioremediation processes.

Serum calprotectin as a biomarker for Crohn's disease.

BACKGROUND AND AIMS: In Crohn's disease, correlation between clinical assessment and disease activity at tissue level is weak. Our aim was to evaluate the value of serum calprotectin as a biomarker for Crohn's disease. METHODS: The STORI trial patients (n=115) were studied at baseline, in clinical remission before infliximab withdrawal, or at the time of relapse after infliximab withdrawal. Forty healthy controls were also studied. Serum calprotectin level was measured by ELISA. Data were analyzed through correlation analyses, Kaplan Meier curves and Cox model, using available Crohn's Disease Activity Index (CDAI), Crohn's Disease Endoscopic Index of Severity (CDEIS), fecal calprotectin and C-reactive protein levels (hsCRP). RESULTS: Median serum calprotectin was 8892 ng/mL (range: 410-125,000 ng/mL) in Crohn disease patients as compared with 1318 ng/mL (range: 215.8-3770 ng/mL) in controls (P<0.0001). Serum calprotectin was significantly higher for active disease (median=19,584 ng/mL) than for inactive disease (median=8353 ng/mL) (P<0.0001). Serum calprotectin correlated with hsCRP (r=0.4092, P<0.0001) and CDAI (r=0.4442, P<0.0001), but not with CDEIS, on the contrary to fecal calprotectin (r=0.6458, 0.5515, 0.2577 with P<0.0001, P<0.0001, P=0.019 respectively). In multivariate analysis, serum calprotectin used as a discrete variable (threshold: 5675 ng/ml), appeared complementary to hsCRP (>5 mg/l) and fecal calprotectin (>250 µg/g) to predict relapse after infliximab withdrawal (P=0.0173, 0.0024 and 0.0002; HR: 3.191, 3.561 and 4.120). CONCLUSIONS: As a CD biomarker, serum calprotectin has a similar profile as hsCRP. It is also complementary to fecal calprotectin and hsCRP for prediction of relapse after infliximab withdrawal.

Did psychrophilic enzymes really win the challenge?

Organisms living in permanently cold environments, which actually represent the greatest proportion of our planet, display at low temperatures metabolic fluxes comparable to those exhibited by mesophilic organisms at moderate temperatures. They produce cold-evolved enzymes partially able to cope with the reduction in chemical reaction rates and the increased viscosity of the medium induced by low temperatures. In most cases, the adaptation is achieved through a reduction in the activation energy, leading to a high catalytic efficiency, which possibly originates from an increased flexibility of either a selected area of or the overall protein structure. This enhanced plasticity seems in return to be responsible for the weak thermal stability of cold enzymes. These particular properties render cold enzymes particularly useful in investigating the possible relationships existing between stability, flexibility, and specific activity and make them potentially unrivaled for numerous biotechnological tasks. In most cases, however, the adaptation appears to be far from being fully achieved.