Clinical utility of calprotectin and lactoferrin in patients with inflammatory bowel disease: is there something new from the literature?

Differential Diagnosis and Management of Diarrhea in Patients with Neuroendocrine Tumors

Diarrhea is a recurrent symptom in patients with neuroendocrine tumors (NETs) and can represent different etiologies; thus, differential diagnosis is challenging. This paper distinguishes the different causes of chronic diarrhea in patients with gastroenteropancreatic NETs, with the aim to identify the most appropriate therapeutic approach. Underlying causes of diarrhea can be multifactorial, including not only diarrhea that is related to specific hormonal hypersecretory syndromes, but also diarrhea that is secondary to the following: extensive surgery which can cause pancreatic exocrine insufficiency or short bowel syndrome, treatment with somatostatin analogs or other antineoplastic agents, and bile acid malabsorption. After initial management of diarrhea with general treatments (dietary modification, use of antidiarrheals), a proper differential diagnosis is necessary to treat patients with specific etiology-driven therapeutic approaches, such as somatostatin analogs, pancreatic enzyme replacement therapy, and tryptophan hydroxylase inhibitors. In conclusion, NETs should be considered in the differential diagnosis of patients suffering from chronic diarrhea, after the exclusion of more common etiologies. Furthermore, physicians should keep in mind that several different etiologies might be responsible for diarrhea occurrence in NET patients. A prompt diagnosis of the actual cause of diarrhea is necessary to guide the treatment and a multidisciplinary approach is mandatory.

A Robust and Universal Metaproteomics Workflow for Research Studies and Routine Diagnostics Within 24 h Using Phenol Extraction, FASP Digest, and the MetaProteomeAnalyzer

The investigation of microbial proteins by mass spectrometry (metaproteomics) is a key technology for simultaneously assessing the taxonomic composition and the functionality of microbial communities in medical, environmental, and biotechnological applications. We present an improved metaproteomics workflow using an updated sample preparation and a new version of the MetaProteomeAnalyzer software for data analysis. High resolution by multidimensional separation (GeLC, MudPIT) was sacrificed to aim at fast analysis of a broad range of different samples in less than 24 h. The improved workflow generated at least two times as many protein identifications than our previous workflow, and a drastic increase of taxonomic and functional annotations. Improvements of all aspects of the workflow, particularly the speed, are first steps toward potential routine clinical diagnostics (i.e., fecal samples) and analysis of technical and environmental samples. The MetaProteomeAnalyzer is provided to the scientific community as a central remote server solution at www.mpa.ovgu.de.

Metaproteomics of fecal samples of Crohn's disease and Ulcerative Colitis

Crohn's Disease (CD) and Ulcerative Colitis (UC) are chronic inflammatory bowel diseases (IBD) of the gastrointestinal tract. This study used non-invasive LC-MS/MS to find disease specific microbial and human proteins which might be used later for an easier diagnosis. Therefore, 17 healthy controls, 11 CD patients and 14 UC patients but also 13 Irritable Bowel Disease (IBS) patients, 8 Colon Adenoma (CA) patients, and 8 Gastric Carcinoma (GCA) patients were investigated. The proteins were extracted from the fecal samples with liquid phenol in a ball mill. Subsequently, the proteins were digested tryptically to peptides and analyzed by an Orbitrap LC-MS/MS. For protein identification and interpretation of taxonomic and functional results, the MetaProteomeAnalyzer software was used. Cluster analysis and non-parametric test (analysis of similarities) separated healthy controls from patients with CD and UC as well as from patients with GCA. Among others, CD and UC correlated with an increase of neutrophil extracellular traps and immune globulins G (IgG). In addition, a decrease of human IgA and the transcriptional regulatory protein RprY from Bacillus fragilis was found for CD and UC. A specific marker in feces for CD was an increased amount of the human enzyme sucrose-isomaltase. SIGNIFICANCE: Crohn's Disease and Ulcerative Colitis are chronic inflammatory diseases of the gastrointestinal tract, whose diagnosis required comprehensive medical examinations including colonoscopy. The impact of the microbial communities in the gut on the pathogenesis of these diseases is poorly understood. Therefore, this study investigated the impact of gut microbiome on these diseases by a metaproteome approach, revealing several disease specific marker proteins. Overall, this indicated that fecal metaproteomics has the potential to be useful as non-invasive tool for a better and easier diagnosis of both diseases.

Detection and characterization of murine colitis and carcinogenesis by molecularly targeted contrast-enhanced ultrasound

AIM

To study mucosal addressin cellular adhesion molecule-1 (MAdCAM-1) and vascular endothelial growth factor (VEGF)-targeted contrast enhanced ultrasound (CEUS) for the assessment of murine colitis and carcinogenesis.

METHODS

C57BL/6 mice were challenged with 3% dextran sodium-sulfate (DSS) for three, six or nine days to study the development of acute colitis. Ultrasound was performed with and without the addition of unspecific contrast agents. MAdCAM-1-targeted contrast agent was used to detect and quantify MAdCAM-1 expression. Inflammatory driven colorectal azoxymethane (AOM)/DSS-induced carcinogenesis was examined on day 42 and 84 using VEGF-targeted contrast agent. Highly specific tissue echogenicity was quantified using specialized software. Sonographic findings were correlated to tissue staining, western blot analysis and immunohistochemistry to quantify the degree of inflammation and stage of carcinogenesis.

RESULTS

Native ultrasound detected increased general bowel wall thickening that correlated with more progressed and more severe DSS-colitis (healthy mice: 0.3 mm ± 0.03 vs six days DSS: 0.5 mm ± 0.2 vs nine days DSS: 0.6 mm ± 0.2, P < 0.05). Moreover, these sonographic findings correlated well with clinical parameters such as weight loss (r² = 0.74) and histological damage (r² = 0.86) (P < 0.01). In acute DSS-induced murine colitis, CEUS targeted against MAdCAM-1 detected and differentiated stages of mild, moderate and severe colitis via calculation of mean pixel contrast intensity in decibel (9.6 dB ± 1.6 vs 12.9 dB ± 1.4 vs 18 dB ± 3.33, P < 0.05). Employing the AOM/DSS-induced carcinogenesis model, tumor development was monitored by CEUS targeted against VEGF and detected a significantly increased echogenicity in tumors as compared to adjacent healthy mucosa (healthy mucosa, 1.6 dB ± 1.4 vs 42 d, 18.2 dB ± 3.3 vs 84 d, 18.6 dB ± 4.9, P < 0.01). Tissue echogenicity strongly correlated with histological analysis and immunohistochemistry findings (VEGF-positive cells in 10 high power fields of healthy mucosa: 1 ± 1.2 vs 42 d after DSS start: 2.4 ± 1.6 vs 84 d after DSS start: 3.5 ± 1.3, P < 0.01).

CONCLUSION

Molecularly targeted CEUS is a highly specific and non-invasive imaging modality, which characterizes murine intestinal inflammation and carcinogenesis in vivo.

Chronic Diarrhea: Diagnosis and Management

Chronic diarrhea is a common problem affecting up to 5% of the population at a given time. Patients vary in their definition of diarrhea, citing loose stool consistency, increased frequency, urgency of bowel movements, or incontinence as key symptoms. Physicians have used increased frequency of defecation or increased stool weight as major criteria and distinguish acute diarrhea, often due to self-limited, acute infections, from chronic diarrhea, which has a broader differential diagnosis, by duration of symptoms; 4 weeks is a frequently used cutoff. Symptom clusters and settings can be used to assess the likelihood of particular causes of diarrhea. Irritable bowel syndrome can be distinguished from some other causes of chronic diarrhea by the presence of pain that peaks before defecation, is relieved by defecation, and is associated with changes in stool form or frequency (Rome criteria). Patients with chronic diarrhea usually need some evaluation, but history and physical examination may be sufficient to direct therapy in some. For example, diet, medications, and surgery or radiation therapy can be important causes of chronic diarrhea that can be suspected on the basis of history alone. Testing is indicated when alarm features are present, when there is no obvious cause evident, or the differential diagnosis needs further delineation. Testing of blood and stool, endoscopy, imaging studies, histology, and physiological testing all have roles to play but are not all needed in every patient. Categorizing patients after limited testing may allow more directed testing and more rapid diagnosis. Empiric antidiarrheal therapy can be used to mitigate symptoms in most patients for whom a specific treatment is not available.

Comparison of Fecal Calprotectin Methods for Predicting Relapse of Pediatric Inflammatory Bowel Disease

Background. Pediatric inflammatory bowel disease (IBD) is on the rise worldwide. Endoscopies are necessary for IBD assessment but are invasive, expensive, and inconvenient. Recently, fecal calprotectin (FCal) was proposed as a noninvasive and specific marker of gut inflammation. We evaluated the analytical performance of three FCal assays and their clinical performance in predicting relapse in pediatric IBD. Methods. This study used 40 pediatric IBD and 40 random non-IBD patients' fecal samples. Two automated ELISAs (Bühlmann and PhiCal® Calprotectin-EIA) and an EliA (Phadia 250 EliA-Calprotectin) were used to evaluate the analytical performance. The clinical performance was assessed by PhiCal Calprotectin-EIA, EliA-Calprotectin, and Bühlmann immunochromatographic point-of-care test (POCT). Results. All assays displayed acceptable analytical performance below and above the medical decision cut-off [imprecision (CV < 10% intra-assay; <15% interassay); linearity (overall mean % deviation < 16.5%)]. The agreement with PhiCal Calprotectin-EIA was 100% and 78.6% for Bühlmann (95% CI, 87.5-100; Kappa: 1) and EliA-Calprotectin (95% CI, 60.5-89.8; Kappa: 0.32), respectively, and 63.6% between Bühlmann and EliA-Calprotectin (95% CI, 46.6-77.8; Kappa: 0.16). All assays evaluated had similar clinical performance [AUC: 0.84 (EliA-Calprotectin); 0.83 (POCT and PhiCal Calprotectin-EIA)]. Conclusion. FCal levels determined using the same method and assay together with clinical history would be a noninvasive and useful tool in monitoring pediatric IBD.

Measuring disease activity in Crohn's disease: what is currently available to the clinician

Crohn’s disease (CD) is a chronic inflammatory bowel disease characterized by a relapsing-remitting clinical behavior and dominated by intestinal inflammation. Being a chronic disorder that with time develops into a disabling disease, it is important to monitor the severity of inflammation to assess the efficacy of medication, rule out complications, and prevent progression. This is particularly true now that the goals of treatment are mucosal healing and deep remission. Endoscopy has always been the gold standard for assessing mucosal activity in CD, but its use is limited by its invasiveness and its inability to examine the small intestine, proximal to the terminal ileum. Enteroscopy and the less invasive small bowel capsule endoscopy enable the small bowel to be thoroughly explored and scores are emerging for classifying small bowel disease activity. Cross-sectional imaging techniques (ultrasound, magnetic resonance, computed tomography) are emerging as valid tools for monitoring CD patients, assessing inflammatory activity in the mucosa and the transmucosal extent of the disease, and for excluding extra-intestinal complications. Neither endoscopy nor imaging are suitable for assessing patients frequently, however. Noninvasive markers such as C-reactive protein, and fecal biomarkers such as calprotectin and lactoferrin, are therefore useful to confirm the inflammatory burden of the disease and to identify patients requiring further investigations.

Advances in the diagnosis and management of inflammatory bowel disease: challenges and uncertainties

Over the past two decades, several advances have been made in the management of patients with inflammatory bowel disease (IBD) from both evaluative and therapeutic perspectives. This review discusses the medical advancements that have recently been made as the standard of care for managing patients with ulcerative colitis (UC) and Crohn's Disease (CD) and to identify the challenges associated with implementing their use in clinical practice. A comprehensive literature search of the major databases (PubMed and Embase) was conducted for all recent scientific papers (1990-2013) giving the recent updates on the management of IBD and the data were extracted. The reported advancements in managing IBD range from diagnostic and evaluative tools, such as genetic tests, biochemical surrogate markers of activity, endoscopic techniques, and radiological modalities, to therapeutic advances, which encompass medical, endoscopic, and surgical interventions. There are limited studies addressing the cost-effectiveness and the impact that these advances have had on medical practice. The majority of the advances developed for managing IBD, while considered instrumental by some IBD experts in improving patient care, have questionable applications due to constraints of cost, lack of availability, and most importantly, insufficient evidence that supports their role in improving important long-term health-related outcomes.