Pentosan Polysulfate-Associated Dysplasia in Patients With Inflammatory Bowel Disease: A Case Series.

INTRODUCTION: This study evaluates the potential association of pentosan polysulfate (PPS) with inflammatory bowel disease (IBD) or dysplasia. METHODS: We searched electronic medical records to identify patients with IBD using PPS. RESULTS: Ten of 30 identified patients (33.3%) had colonic dysplasia. Six of them (60%) underwent colectomy for endoscopically unresectable dysplasia. Three (10%) discontinued PPS, each with an apparent benefit. DISCUSSION: Patients with IBD at 2 institutions who had taken PPS had high rates of colonic dysplasia leading to surgery. Patients who stopped PPS showed improvement in their colitis. PPS may play a causal role in the development of colitis and dysplasia.

Transcriptional and Cytotoxic Responses of Human Intestinal Organoids to IFN Types I, II, and III.

The three types of IFN have roles in antimicrobial immunity and inflammation that must be properly balanced to maintain tissue homeostasis. For example, IFNs are elevated in the context of inflammatory bowel disease and may synergize with inflammatory cytokines such as TNF-α to promote tissue damage. Prior studies suggest that in mouse intestinal epithelial cells (IECs), type III IFNs are preferentially produced during viral infections and are less cytotoxic than type I IFN. In this study, we generated human IEC organoid lines from biopsies of ileum, ascending colon, and sigmoid colon of three healthy subjects to establish the baseline responses of normal human IECs to types I, II, and III IFN. We found that all IFN types elicited responses that were qualitatively consistent across intestinal biopsy sites. However, IFN types differed in magnitude of STAT1 phosphorylation and identity of genes in their downstream transcriptional programs. Specifically, there was a core transcriptional module shared by IFN types, but types I and II IFN stimulated unique transcriptional modules beyond this core gene signature. The transcriptional modules of type I and II IFN included proapoptotic genes, and expression of these genes correlated with potentiation of TNF-α cytotoxicity. These data define the response profiles of healthy human IEC organoids across IFN types, and they suggest that cytotoxic effects mediated by TNF-α in inflamed tissues may be amplified by a simultaneous high-magnitude IFN response.

Lupus-associated protein losing enteropathy (LUPLE) complicated by a hypercoagulable state and successfully treated with belimumab.

Protein-losing enteropathy (PLE) is a condition characterized by gut mucosal injury that typically manifests with edema and hypoalbuminemia due to protein loss in the GI tract. We present a rare case of lupus-associated PLE (LUPLE) manifested by profound edema, diarrhea, and thrombotic complications. Through our case report, we discuss the typical clinical presentation, diagnostic studies available, and treatment options for these patients. Our patient's clinical picture and laboratory markers improved with the initiation of corticosteroids and belimumab, which is a novel treatment regimen for LUPLE. Moreover, our patient was found to have a clinically significant hypercoagulable state that was ultimately attributed to PLE in the setting of systemic lupus erythematosus (SLE). We highlight the increased thrombotic risk in these patients and the subsequent management implications with regard to anticoagulation. Gastroenterologists are likely to be involved in the care of these patients, and may be the first to recognize the constellation of findings in PLE, leading to potentially very effective treatment.

Genetic variants synthesize to produce paneth cell phenotypes that define subtypes of Crohn's disease.

BACKGROUND & AIMS: Genetic susceptibility loci for Crohn's disease (CD) are numerous, complex, and likely interact with undefined components of the environment. It has been a challenge to link the effects of particular loci to phenotypes of cells associated with pathogenesis of CD, such as Paneth cells. We investigated whether specific phenotypes of Paneth cells associated with particular genetic susceptibility loci can be used to define specific subtypes of CD. METHODS: We performed a retrospective analysis of 119 resection specimens collected from patients with CD at 2 separate medical centers. Paneth cell phenotypes were classified as normal or abnormal (with disordered, diminished, diffuse, or excluded granule phenotypes) based on lysozyme-positive secretory granule morphology. To uncover the molecular basis of the Paneth cell phenotypes, we developed methods to determine transcriptional profiles from whole-thickness and laser-capture microdissected, formalin-fixed, paraffin-embedded tissue sections. RESULTS: The proportion of abnormal Paneth cells was associated with the number of CD-associated NOD2 risk alleles. The cumulative number of NOD2 and ATG16L1 risk alleles had an additive effect on the proportion of abnormal Paneth cells. Unsupervised clustering analysis of demographic and Paneth cell data divided patients into 2 principal subgroups, defined by high and low proportions of abnormal Paneth cells. The disordered and diffuse abnormal Paneth cell phenotypes were associated with an altered transcriptional signature of immune system activation. We observed an inverse correlation between abnormal Paneth cells and presence of granuloma. In addition, high proportions of abnormal Paneth cells were associated with shorter time to disease recurrence after surgery. CONCLUSIONS: Histologic analysis of Paneth cell phenotypes can be used to divide patients with CD into subgroups with distinct pathognomonic and clinical features.

Role of individual domains and identification of internal gap in human guanylate binding protein-1.

Unlike other GTPases, interferon-gamma-induced human guanylate binding protein-1 has the ability to hydrolyze GTP to both GDP and GMP, with GMP being the major product of the reaction. This protein has two domains, an N-terminal globular domain and a C-terminal helical domain. These two domains are connected by a short intermediate region consisting of a two-stranded beta-sheet and a helix. As human guanylate binding protein-1 has been shown to undergo stimulated GTPase activity without external GTPase-activating protein, we sought to understand the roles of each of the two individual domains, the intermediate region, a conserved motif ((103)DXEKGD(108)), and the mechanism of the stimulation of GTPase activity. The steady-state assays using radiolabeled [alpha-(32)P]GTP on the wild-type protein suggest that the stimulation of activity primarily occurs during the cleavage of the second phosphate of GTP rather than the first, through allosteric interaction. Using several truncated and mutant proteins, we demonstrate for the first time that both the alpha-helix of the intermediate region and the (103)DXEKGD(108) motif play critical roles for the hydrolysis to GMP, but they appear to act in different ways: alpha-helix acts through structural stabilization by allosteric interaction and, thus, acts as an internal GTPase-activating protein, whereas the motif might act by providing necessary catalytic residues. Our data also show that the N-terminal globular domain is able to perform only the first catalysis (GTP to GDP, an activity associated with basal level), but the helical domain in the full-length protein stimulates the hydrolysis of GTP to GMP with higher GMP formation by preventing the dissociation of GDP-bound enzyme dimer.

Risk factors for the detection of Barrett's esophagus in patients with erosive esophagitis.

BACKGROUND: Barrett's esophagus (BE) results from metaplastic healing of injured esophageal mucosa after erosive esophagitis (EE). OBJECTIVE: Our purpose was to determine whether severity of esophagitis, indication for endoscopy, or proton pump inhibitor treatment affects the subsequent incidence of BE diagnosis in patients found to have EE on EGD performed for any indication. DESIGN: We identified patients with primary or secondary International Classification of Diseases, 9th revision diagnosis codes of EE from 1996 to 2006 who had at least 2 EGDs on record. Patients with prevalent BE on the first EGD were excluded. SETTING: Inpatients and outpatients at Stanford University and Palo Alto Veterans Affairs Health Care System. INTERVENTIONS: Retrospective review of EGD and pathology reports to confirm BE. MAIN OUTCOME MEASUREMENTS: Detection of BE after diagnosis of EE. RESULTS: A total of 1095 patients were identified between 1996 and 2000, and 102 (9%) were included. Sixty-two (61%) patients were veterans, 87 (85%) were male, and 83 (81%) were white. The mean (+/-SD) age was 58 +/- 14 years (range 24-83 years). BE was detected in 9 (9%) patients (95% CI, 4.5%-17.6%) over a mean of 13.3 +/- 5.7 months (range 1-53.5 months), and all had prior grade 4 esophagitis. The mean BE length was 4 +/- 1.8 cm (range 1-18 cm). Six patients had upper GI bleeding as the indication for EGD, whereas the other 3 complained of dysphagia. The association of grade 4 esophagitis (P = .01) and GI hemorrhage (P = .01) to the subsequent detection of BE was highly statistically significant. LIMITATIONS: Retrospective study, small number of patients with BE after EE. All patients were receiving care at tertiary medical centers. CONCLUSIONS: BE was detected in 9% of patients with prior EE and was detected exclusively on follow-up of patients with severe esophagitis. The majority of the patients found to have BE had upper GI bleeding as the presentation for EGD.

Barrett's esophagus: Incidence, etiology, pathophysiology, prevention and treatment.

Barrett's esophagus is a metaplastic alteration of the normal esophageal epithelium that is detected on endoscopic examination and pathologically confirmed by the presence of intestinal metaplasia on biopsy. Its major significance is as a predisposing factor for esophageal adenocarcinoma, which carries a high mortality rate and a rapidly growing incidence in the United States. Detection of Barrett's esophagus allows for endoscopic surveillance in order to detect the potential development of dysplasia and early cancer before symptoms develop, and thereby significantly increases treatment options and may lower mortality from esophageal adenocarcinoma. Much current work in the field is aimed at reducing the risk of progression from Barrett's esophagus to cancer, and in the identification of biomarkers that may predict progression towards cancer. Barrett's esophagus is present in 10%-20% of patients with gastroesophageal reflux disease (GERD) and has also been detected in patients who deny classic GERD symptoms and are undergoing endoscopy for other indications. We used an evidence-based approach to describe treatment options for patients with Barrett's esophagus.

Golgi targeting of human guanylate-binding protein-1 requires nucleotide binding, isoprenylation, and an IFN-gamma-inducible cofactor.

Human guanylate-binding protein-1 (hGBP-1) is a large GTPase, similar in structure to the dynamins. Like many smaller GTPases of the Ras/Rab family, it is farnesylated, suggesting it may dock into membranes and perhaps play a role in intracellular trafficking. To date, however, hGBP-1 has never been associated with a specific intracellular compartment. Here we present evidence that hGBP-1 can associate with the Golgi apparatus. Redistribution from the cytosol to the Golgi was observed by immunofluorescence and subcellular fractionation after aluminum fluoride treatment, suggesting that it occurs when hGBP-1 is in its GTP-bound state. Relocalization was blocked by a farnesyl transferase inhibitor. The C589S mutant of hGBP-1, which cannot be farnesylated, and the previously uncharacterized R48P mutant, which cannot bind GTP, both failed to localize to the Golgi. These two mutants had a dominant-negative effect, preventing endogenous wild-type hGBP-1 from efficiently redistributing after aluminum fluoride treatment. Furthermore, hGBP-1 requires another IFN-gamma-induced factor to be targeted to the Golgi, because constitutively expressed hGBP-1 remained cytosolic in cells treated with aluminum fluoride unless the cells were preincubated with IFN-gamma. Finally, two nonhydrolyzing mutants of hGBP-1, corresponding to active mutants of Ras family proteins, failed to constitutively associate with the Golgi; we propose three possible explanations for this surprising result.