Alpha1-antitrypsin phenotypes and anti-neutrophil cytoplasmic auto-antibodies in inflammatory bowel disease

OBJECTIVES: Alpha1-antitrypsin (alpha1-AT) is encoded by a highly polymorphic gene with over 75 codominantly expressed alleles at the protease inhibitor (Pi) locus classified as normal, deficient, dysfunctional or null. The aim of this study was to determine in patients with inflammatory bowel disease: (i) the prevalence of anti-neutrophil cytoplasmic auto-antibodies (ANCA) and their antigen specificities; (ii) alpha1-AT Pi phenotypes; and (iii) possible associations between ANCA, disease activity and deficient alpha1-AT alleles. DESIGN: Study of 95 consecutive patients with ulcerative colitis (UC) and 63 patients with Crohn's disease (CD). METHODS: Diagnosis and disease activity were determined by clinical, endoscopic and histological criteria. ANCA by indirect immunofluorescence (IIF) and Pi phenotyping by isoelectric focusing were performed for all patients. Positive IIF sera were tested in antigen-specific enzyme-linked immunosorbent assay: proteinase 3 (PR3), myeloperoxidase (MPO), lactoferrin (LF), lysozyme, human leucocyte elastase (HLE), cathepsin G and bactericidal/permeability increasing protein (BPI). RESULTS: Sixty-one patients with UC (64.2%) and only 11 with CD (17.5%) had ANCA (P < 0.001). Antigen specificities were PR3 (7/61), MPO (3/61), LF (6/61), HLE (1/63) and BPI (10/61) in UC, and PR3 (2/11) and BPI (2/11) in CD. Three PiZ alleles were found, matching the prevalence in the normal French control population. No relationship was found between the presence of ANCA, antibody specificity, disease activity and deficient alpha1-AT alleles. CONCLUSION: ANCA are more frequent in UC than CD and do not correlate with disease activity. ANCA and protease/antiprotease imbalance do not appear to modulate the clinical course of inflammatory bowel disease.     

Effect of intrajejunal elemental diet perfusion on jejunal secretion of immunoglobulins, albumin, and hyaluronan in man.

The aim of this work was to study the jejunal secretion of immunoglobulins (Ig), albumin, and hyaluronan in response to jejunal perfusion of an elemental diet. A four lumen tube with a proximal occluding balloon at the angle of Treitz was used for jejunal perfusion in seven healthy volunteers (mean age 23 years). The length of the test segment was 40 cm. The jejunum was successively perfused with a control electrolyte solution for 80 minutes and with an elemental diet (containing 20.5 milligrams of free amino acids and 104.2 milligrams of oligosaccharides) for 100 minutes. The jejunal fluid concentrations of albumin, IgG, monomeric IgA (m-IgA), polymeric IgA (p-IgA), IgM, secretory component, and hyaluronan were measured and their jejunal outputs calculated. Within 20 minutes of starting perfusion with the elemental diet there was a significant increase in the secretion rates of albumin (x3.3), IgG (x5), M-IgA (x3.7), p-IgA (x2), IgM (x2), and secretory component (x1.6), but the hyaluronan secretion rate was not changed. The increase in m-IgA, p-IgA, IgM, and secretory component output suggests that intestinal perfusion of an elemental diet results in stimulation of secretory immunity. The increase in albumin and IgG output probably reflects a nutrient induced leakage from the plasma compartment.     

High prevalence of adherent-invasive Escherichia coli associated with ileal mucosa in Crohn's disease

BACKGROUND & AIMS: Adherent-invasive Escherichia coli (AIEC) pathovar has been identified in the intestinal mucosa of patients with Crohn's disease (CD). AIEC reference strain LF82 is able to adhere to intestinal epithelial cells, to invade epithelial cells via a mechanism involving actin polymerization and microtubules, and to survive and replicate within macrophages. This study was performed to assess the prevalence of AIEC associated with intestinal mucosa of patients with CD, ulcerative colitis (UC), and of controls. METHODS: A search for E. coli strains was performed with ileal specimens of 63 patients with CD and 16 controls without inflammatory bowel disease (IBD), and with colonic specimens of 27 patients with CD, 8 patients with UC, and 102 controls. The abilities of E. coli strains to invade epithelial cells and to survive and replicate within macrophages were assessed using the gentamicin protection assay. Bacterial uptake by epithelial cells was analyzed using cytoskeletal inhibitors. Bacterial adhesion was quantified with Caco-2 and Intestine-407 cells. The presence of known E. coli virulence genes was assessed by polymerase chain reaction and DNA hybridization. RESULTS: In ileal specimens, AIEC strains were found in 21.7% of CD chronic lesions vs. in 6.2% of controls. In neoterminal ileal specimens, AIEC strains were found in 36.4% of CD early lesions (P = 0.034 vs. controls) and 22.2% of healthy mucosa of CD patients. In colonic specimens, AIEC strains were found in 3.7% of CD patients, 0% of UC patients, and 1.9% of controls. CONCLUSIONS: AIEC strains are associated specifically with ileal mucosa in CD.     

Highly sensitive and specific novel biomarkers for the diagnosis of transitional bladder carcinoma

Transitional bladder carcinoma (BCa) is prevalent in developed countries, particularly among men. Given that these tumors frequently recur or progress, the early detection and subsequent monitoring of BCa at different stages is critical. Current BCa diagnostic biomarkers are not sufficiently sensitive for substituting or complementing invasive cystoscopy. Here, we sought to identify a robust set of urine biomarkers for BCa detection. Using a high-resolution, mass spectrometry-based, quantitative proteomics approach, we measured, compared and validated protein variations in 451 voided urine samples from healthy subjects, non-bladder cancer patients and patients with non-invasive and invasive BCa. We identified five robust biomarkers: Coronin-1A, Apolipoprotein A4, Semenogelin-2, Gamma synuclein and DJ-1/PARK7. In diagnosing Ta/T1 BCa, these biomarkers achieved an AUC of 0.92 and 0.98, respectively, using ELISA and western blot data (sensitivity, 79.2% and 93.9%; specificity, 100% and 96.7%, respectively). In diagnosing T2/T3 BCa, an AUC of 0.94 and 1.0 was attained (sensitivity, 86.4% and 100%; specificity, 100%) using the same methods. Thus, our multiplex biomarker panel offers unprecedented accuracy for the diagnosis of BCa patients and provides the prospect for a non-invasive way to detect bladder cancer.     

A putative biomarker signature for clinically effective AKT inhibition: correlation of in vitro,in vivo and clinical data identifies the importance of modulation of the mTORC1 pathway

Our identification of dysregulation of the AKT pathway in ovarian cancer as a platinum resistance specific event led to a comprehensive analysis of in vitro, in vivo and clinical behaviour of the AKT inhibitor GSK2141795. Proteomic biomarker signatures correlating with effects of GSK2141795 were developed using in vitro and in vivo models, well characterised for related molecular, phenotypic and imaging endpoints. Signatures were validated in temporally paired biopsies from patients treated with GSK2141795 in a clinical study. GSK2141795 caused growth-arrest as single agent in vitro, enhanced cisplatin-induced apoptosis in vitro and reduced tumour volume in combination with platinum in vivo. GSK2141795 treatment in vitro and in vivo resulted in ~50-90% decrease in phospho-PRAS40 and 20-80% decrease in fluoro-deoxyglucose (FDG) uptake. Proteomic analysis of GSK2141795 in vitro and in vivo identified a signature of pathway inhibition including changes in AKT and p38 phosphorylation and total Bim, IGF1R, AR and YB1 levels. In patient biopsies, prior to treatment with GSK2141795 in a phase 1 clinical trial, this signature was predictive of post-treatment changes in the response marker CA125. Development of this signature represents an opportunity to demonstrate the clinical importance of AKT inhibition for re-sensitisation of platinum resistant ovarian cancer to platinum.     

Opportunistic infections in patients with inflammatory bowel disease: prevention and diagnosis

Because of the increasing use of immunosuppressive and biological drugs, the occurrence of opportunistic infections has become a key safety issue for patients with inflammatory bowel disease (IBD). Consequently, improvement of healthcare workers' knowledge of this domain is urgent. In this review, the preventive measures that would help to reduce the rate of opportunistic infections in patients with IBD are listed, and the management of situations frequently confronting doctors is considered. In the absence of national and international recommendations, the information given here should help doctors to optimise patient outcomes.     

Celiac disease in adults: new aspects

INTRODUCTION: Celiac disease also known as gluten-sensitive enteropathy is a complex disorder where genetically susceptible individuals develop in typical cases signs of malabsorption after ingestion of cereals. Malabsorption is due to total or subtotal atrophy of the small intestinal mucosa regressing after adherence to a gluten-free diet. The only effective therapy is life-long strict abstinence from wheat, rye and barley. CURRENT KNOWLEDGE AND KEY POINTS: During the last two decades spectrum of clinical features of adult celiac disease has been modified. About 60% of cases are now revealed by extraintestinal manifestations. Moreover, recent studies that used serological methods revealed existence of both latent and silent celiac sprue. The finding of the high frequency of atypical celiac sprue contributed to underestimation of the true prevalence of celiac disease until now, and explained that celiac disease could be unknown for a long time, with increased risk of nutritional deficiencies and malignancy. Concurrently, the finding that celiac disease is primarily associated to a few HLA class II molecules, and recent advent of tissue transglutaminase as the main auto-antigen eliciting anti-endomysial antibodies allowed to propose new pathogenesis hypothesis and efficient screening tests for celiac disease diagnosis. FUTURE PROSPECTS AND PROJECTS: New epidemiological data concerning adult celiac disease must incite to a more systematic screening in patients with atypical but evocative features, or in at-risk subjects. Introduction of enzyme linked immunosorbent assays (ELISA) for the detection for anti-tissue transglutaminase antibodies allows to make use of a new available and efficient diagnosis parameter, which could constitute the main screening test in the near future.     

Detection of antisynthetic mannoside antibodies (ASigmaMA) reveals heterogeneity in the ASCA response of Crohn's disease patients and contributes to differential diagnosis, stratification, and prediction

OBJECTIVES: Anti- S. cerevisiae mannan antibodies (ASCA) are human antibodies associated with Crohn's disease (CD) reacting with Saccharomyces cerevisiae ( S. cerevisiae ) mannan polymer. As mannan is a complex and variable repertoire of oligomannoses acting as epitopes, we chemically synthesized (Σ) two major oligomannose epitopes, Man α-1,3 Man α-1,2 Man (ΣMan3) and Man α-1,3 Man α-1,2 Man α-1,2 Man (ΣMan4), and then explored how antisynthetic mannoside antibodies (AΣMA) compare with ASCA as markers of CD.
METHODS: The study involved different cohorts of CD and ulcerative colitis (UC) patients and healthy controls who had been studied previously in several medical centers in Europe, the United States, and North Africa to determine the clinical value of ASCA in terms of differential diagnosis, evolution of indeterminate colitis (IC), and serotype-phenotype correlations. The comparison of AΣMA and ASCA included a total of 1,365 subjects: 772 CD, 261 UC, 43 IC, and 289 controls.
RESULTS: The specificity of AΣMA was similar to that of ASCA (89% vs 93%), although the sensitivity was lower (38% vs 55%). Unexpectedly, 24% of the CD patients who were negative for ASCA and/or other CD-associated serologic markers were positive for AΣMA. AΣMA were associated with colonic involvement in CD (odds ratio [OR] 1.609, 95% confidence interval [CI] 1.033–2.506, P = 0.03) and were 100% predictive of CD in patients with IC.
CONCLUSIONS: AΣMA reveal the heterogeneity of the antioligomannose antibody response in CD patients and increase the sensitivity of CD diagnosis when combined with ASCA. The subset of ASCA-negative CD patients diagnosed by AΣMA had preferentially a colonic involvement, which confirms the high predictive value of AΣMA for determining IC evolution toward CD.