Quantitative Phase Imaging Using Digital Holographic Microscopy to Assess the Degree of Intestinal Inflammation in Patients with Ulcerative Colitis

Ulcerative colitis (UC) is characterized by chronic inflammation of the colorectum. Histological remission has emerged as a potential future treatment goal; however, the histopathological assessment of intestinal inflammation in UC remains challenging with a multitude of available scoring systems and the need for a pathologist with expertise in inflammatory bowel disease (IBD). In previous studies, quantitative phase imaging (QPI) including digital holographic microscopy (DHM) was successfully applied as an objective method for stain-free quantification of the degree of inflammation in tissue sections. Here, we evaluated the application of DHM for the quantitative assessment of histopathological inflammation in patients with UC. In our study, endoscopically obtained colonic and rectal mucosal biopsy samples from 21 patients with UC were analyzed by capturing DHM-based QPI images that were subsequently evaluated using the subepithelial refractive index (RI). The retrieved RI data were correlated with established histological scoring systems including the Nancy index (NI) as well as with endoscopic and clinical findings. As a primary endpoint, we found a significant correlation between the DHM-based retrieved RI and the NI (R² = 0.251, p < 0.001). Furthermore, RI values correlated with the Mayo endoscopic subscore (MES; R² = 0.176, p < 0.001). An area under the receiver operating characteristics (ROC) curve of 0.820 confirms the subepithelial RI as a reliable parameter to distinguish biopsies with histologically active UC from biopsies without evidence of active disease as determined by conventional histopathological examination. An RI higher than 1.3488 was found to be the most sensitive and specific cut-off value to identify histologically active UC (sensitivity of 84% and specificity of 72%). In conclusion, our data demonstrate DHM to be a reliable tool for the quantitative assessment of mucosal inflammation in patients with UC.

Balloon enteroscopy-assisted endoscopic retrograde cholangiography and rendezvous procedures in patients with altered gastrointestinal anatomy

BACKGROUND

Standard endoscopic retrograde cholangiography (ERC) frequently fails to treat biliary obstruction in patients with altered gastrointestinal anatomy. Balloon enteroscopy-assisted ERC (BE-ERC) and combined percutaneous transhepatic endoscopic rendezvous procedures (PTE-RVs) may offer effective rescue approaches.

OBJECTIVE

This study aimed to evaluate the efficacy and safety of BE-ERC and PTE-RV for the treatment of biliary obstruction in patients with altered gastrointestinal anatomy.

METHODS

In this observational study, all patients with altered gastrointestinal anatomy underwent BE-ERC between 2003 and 2016 at a tertiary referral center. In case of procedural failure, a combined PTE-RV was performed in selected cases. Endpoints included the success and safety of the procedures.

RESULTS

A total of 180 BE-ERC performed in 106 patients with altered gastrointestinal anatomy were included. Of the procedures, 76.7% were performed due to benign and 23.3% due to malignant biliary obstruction. BE-ERC was successful in 53% (96/180) of cases. In case of failure, in 23/32 cases a combined PTE-RV was successfully performed, improving the overall success rate of BE-ERC, including PTE-RV, to 66% (119/180). Benign biliary obstruction and repeated procedures were positive predictors of successful BE-ERC (odds ratio 6.8 (95% CI 2.7-17.0), p < .001 and odds ratio 4.1 (2.1-8.2), p < .001). Complications were significantly more frequent in combined PTE-RVs than in BE-ERC procedures alone (34.4% vs. 7.4%; p < .001).

CONCLUSIONS

BE-ERC is effective and safe for the endoscopic management of patients with altered gastrointestinal anatomy and percutaneous transhepatic rendezvous procedures can substantially increase success rates in selected cases.

Digital single-operator video cholangioscopy improves endoscopic management in patients with primary sclerosing cholangitis-a retrospective observational study

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) are at a high risk of developing cholestatic liver disease and biliary cancer, and endoscopy is crucial for the complex management of these patients.

AIM

To clarify the utility of recently introduced digital single-operator video cholangioscopy (SOVC) for the endoscopic management of PSC patients.

METHODS

In this observational study, all patients with a history of PSC and in whom digital SOVC (using the SpyGlass DS System) was performed between 2015 and 2019 were included and retrospectively analysed. Examinations were performed at a tertiary referral centre in Germany. In total, 46 SOVCs performed in 38 patients with a history of PSC were identified. The primary endpoint was the evaluation of dominant biliary strictures using digital SOVC, and the secondary endpoints were the performance of selective guidewire passage across biliary strictures and the diagnosis and treatment of biliary stone disease in PSC patients.

RESULTS

The 22 of 38 patients had a dominant biliary stricture (57.9%). In 4 of these 22 patients, a cholangiocellular carcinoma was diagnosed within the stricture (18.2%). Diagnostic evaluation of dominant biliary strictures using optical signs showed a sensitivity of 75% and a specificity of 94.4% to detect malignant strictures, whereas SOVC-guided biopsies to gain tissue for histopathological analysis showed a sensitivity of 50% and a specificity of 100%. In 13% of examinations, SOVC was helpful for guidewire passage across biliary strictures that could not be passed by conventional methods (technical success rate 100%). Biliary stone disease was observed in 17.4% of examinations; of these, in 37.5% of examinations, biliary stones could only be visualized by SOVC and not by standard fluoroscopy. Biliary stone treatment was successful in all cases (100%); 25% required SOVC-assisted electrohydraulic lithotripsy. Complications, such as postinterventional cholangitis and pancreatitis, occurred in 13% of examinations; however, no procedure-associated mortality occurred.

CONCLUSION

Digital SOVC is effective and safe for the endoscopic management of PSC patients and may be regularly considered an additive tool for the complex endoscopic management of these patients.

International consensus to standardise histopathological scoring for small bowel strictures in Crohn's disease

OBJECTIVE

Effective medical therapy and validated trial outcomes are lacking for small bowel Crohn's disease (CD) strictures. Histopathology of surgically resected specimens is the gold standard for correlation with imaging techniques. However, no validated histopathological scoring systems are currently available for small bowel stricturing disease. We convened an expert panel to evaluate the appropriateness of histopathology scoring systems and items generated based on panel opinion.

DESIGN

Modified RAND/University of California Los Angeles methodology was used to determine the appropriateness of 313 candidate items related to assessment of CD small bowel strictures.

RESULTS

In this exercise, diagnosis of naïve and anastomotic strictures required increased bowel wall thickness, decreased luminal diameter or internal circumference, and fibrosis of the submucosa. Specific definitions for stricture features and technical sampling parameters were also identified. Histopathologically, a stricture was defined as increased thickness of all layers of the bowel wall, fibrosis of the submucosa and bowel wall, and muscularisation of the submucosa. Active mucosal inflammatory disease was defined as neutrophilic inflammation in the lamina propria and any crypt or intact surface epithelium, erosion, ulcer and fistula. Chronic mucosal inflammatory disease was defined as crypt architectural distortion and loss, pyloric gland metaplasia, Paneth cell hyperplasia, basal lymphoplasmacytosis, plasmacytosis and fibrosis, or prominent lymphoid aggregates at the mucosa/submucosa interface. None of the scoring systems used to assess CD strictures were considered appropriate for clinical trials.

CONCLUSION

Standardised assessment of gross pathology and histopathology of CD small bowel strictures will improve clinical trial efficiency and aid drug development.

Humoral Immune Response in IBD Patients Three and Six Months after Vaccination with the SARS-CoV-2 mRNA Vaccines mRNA-1273 and BNT162b2

Severe acute respiratory syndrome coronovirus-2 (SARS-CoV-2) is the cause of the coronavirus disease 2019 (COVID-19) pandemic. Vaccination is considered the core approach to containing the pandemic. There is currently insufficient evidence on the efficacy of these vaccines in immunosuppressed inflammatory bowel disease (IBD) patients. The aim of this study was to investigate the humoral response in immunosuppressed IBD patients after COVID-19 mRNA vaccination. In this prospective study, IgG antibody levels (AB) against the SARS-CoV-2 receptor-binding domain (spike-protein) were quantitatively determined. For assessing the potential neutralizing capacity, a SARS-CoV-2 surrogate neutralization test (sVNT) was employed in IBD patients (n = 95) and healthy controls (n = 38). Sera were examined prior to the first/second vaccination and 3/6 months after second vaccination. Patients showed lower sVNT (%) and IgG-S (AU/mL) AB both before the second vaccination (sVNT p < 0.001; AB p < 0.001) and 3 (sVNT p = 0.002; AB p = 0.001) and 6 months (sVNT p = 0.062; AB p = 0.061) after the second vaccination. Although seroconversion rates (sVNT, IgG-S) did not differ between the two groups 3 months after second vaccination, a significant difference was seen 6 months after second vaccination (sVNT p = 0.045). Before and three months after the second vaccination, patients treated with anti-tumor necrosis factor (TNF) agents showed significantly lower AB than healthy subjects. In conclusion, an early booster shot vaccination should be discussed for IBD patients on anti-TNF therapy.

Loss of Mucosal p32/gC1qR/HABP1 Triggers Energy Deficiency and Impairs Goblet Cell Differentiation in Ulcerative Colitis

BACKGROUND & AIMS

Cell differentiation in the colonic crypt is driven by a metabolic switch from glycolysis to mitochondrial oxidation. Mitochondrial and goblet cell dysfunction have been attributed to the pathology of ulcerative colitis (UC). We hypothesized that p32/gC1qR/HABP1, which critically maintains oxidative phosphorylation, is involved in goblet cell differentiation and hence in the pathogenesis of UC.

METHODS

Ex vivo, goblet cell differentiation in relation to p32 expression and mitochondrial function was studied in tissue biopsies from UC patients versus controls. Functional studies were performed in goblet cell-like HT29-MTX cells in vitro. Mitochondrial respiratory chain complex V-deficient, ATP8 mutant mice were utilized as a confirmatory model. Nutritional intervention studies were performed in C57BL/6 mice.

RESULTS

In UC patients in remission, colonic goblet cell differentiation was significantly decreased compared to controls in a p32-dependent manner. Plasma/serum L-lactate and colonic pAMPK level were increased, pointing at high glycolytic activity and energy deficiency. Consistently, p32 silencing in mucus-secreting HT29-MTX cells abolished butyrate-induced differentiation and induced a shift towards glycolysis. In ATP8 mutant mice, colonic p32 expression correlated with loss of differentiated goblet cells, resulting in a thinner mucus layer. Conversely, feeding mice an isocaloric glucose-free, high-protein diet increased mucosal energy supply that promoted colonic p32 level, goblet cell differentiation and mucus production.

CONCLUSION

We here describe a new molecular mechanism linking mucosal energy deficiency in UC to impaired, p32-dependent goblet cell differentiation that may be therapeutically prevented by nutritional intervention.

Inflammatory Bowel Disease-associated GP2 Autoantibodies Inhibit Mucosal Immune Response to Adherent-invasive Bacteria

Adherent-invasive Escherichia coli have been suggested to play a pivotal role within the pathophysiology of inflammatory bowel disease (IBD). Autoantibodies against distinct splicing variants of glycoprotein 2 (GP2), an intestinal receptor of the bacterial adhesin FimH, frequently occur in IBD patients. Hence, we aimed to functionally characterize GP2-directed autoantibodies as a putative part of IBD's pathophysiology. Ex vivo, GP2-splicing variant 4 (GP2#4) but not variant 2 was expressed on intestinal M or L cells with elevated expression patterns in IBD patients. The GP2#4 expression was induced in vitro by tumor necrosis factor (TNF)-α. The IBD-associated GP2 autoantibodies inhibited FimH binding to GP2#4 and were decreased in anti-TNFα-treated Crohn's disease patients with ileocolonic disease manifestation. In vivo, mice immunized against GP2 before infection with adherent-invasive bacteria displayed exacerbated intestinal inflammation. In summary, autoimmunity against intestinal expressed GP2#4 results in enhanced attachment of flagellated bacteria to the intestinal epithelium and thereby may drive IBD's pathophysiology.

[Acute Abdomen: Diagnostic Management]

Acute abdomen is a common and sometimes dramatic clinical condition, which can be fatal if diagnosis is not made in time. A large number of diseases can cause an acute abdomen which makes a targeted and rapid diagnostic approach utterly important. The initial diagnostic approach is based on the clinical assessment (including medical history and physical examination) which allows doctors to quickly establish a suspected diagnosis with a relatively high sensitivity but a rather low specificity. Further diagnostics, including laboratory markers, imaging and - if necessary - interventional diagnostics should be initiated quickly after the first clinical assessment in order to confirm the suspected diagnosis or to further classify unclear cases. The clinical assessment is the leading diagnostic tool that determines further diagnostic approaches for patients with an acute abdomen and thus enables adequate and timely therapy.

Systematic review with meta-analysis: efficacy of balloon-assisted enteroscopy for dilation of small bowel Crohn's disease strictures

BACKGROUND

Evidence for endoscopic balloon dilation of small intestinal strictures in Crohn's disease (CD) using balloon-assisted enteroscopy is scarce.

AIM

To evaluate endoscopic balloon dilation for the treatment of small intestinal CD strictures using balloon-assisted enteroscopy.

METHODS

Citations in Embase, MEDLINE, and Cochrane were systematically reviewed. In a meta-analysis of 18 studies with 463 patients and 1189 endoscopic balloon dilations, technical success was defined as the ability to dilate a stricture. Individual data were also obtained on 218 patients to identify outcome-relevant risk factors.

RESULTS

In the pooled per-study analysis, technical success rate of endoscopic balloon dilation was 94.9%, resulting in short-term clinical efficacy in 82.3% of patients. Major complications occurred in 5.3% of patients. During follow-up, 48.3% of patients reported symptom recurrence, 38.8% were re-dilated and 27.4% proceeded to surgery. On the per-patient-based multivariable analysis, that patients with disease activity in the small intestine had lower short-term clinical efficacy (odds ratio 0.32; 95% confidence interval 0.14-0.73, P = 0.007). Patients with concomitant active disease in the small and/or large intestine had an increased risk to proceed toward surgery (hazard ratio 1.85; 95% confidence interval 1.09-3.13, P = 0.02 and hazard ratio 1.77; 95% confidence interval 1.34-2.34, P < 0.001).

CONCLUSIONS

Balloon-assisted enteroscopy for dilatation of CD-associated small intestinal strictures has high short-term technical and clinical efficacy and low complication rates. However, up to two-thirds of patients need re-dilation or surgery.

Conversion from Standard-Release Tacrolimus to MeltDose® Tacrolimus (LCPT) Improves Renal Function after Liver Transplantation

Renal impairment is a typical side effect of tacrolimus (Tac) treatment in liver transplant (LT) recipients. One strategy to avoid renal dysfunction is to increase the concentration/dose (C/D) ratio by improving drug bioavailability. LT recipients converted from standard-release Tac to MeltDose^® Tac (LCPT), a novel technological formulation, were able to reduce the required Tac dose due to higher bioavailability. Hence, we hypothesize that such a conversion increases the C/D ratio, resulting in a preservation of renal function. In the intervention group, patients were switched from standard-release Tac to LCPT. Clinical data were collected for 12 months after conversion. Patients maintained on standard-release Tac were enrolled as a control group. Twelve months after conversion to LCPT, median C/D ratio had increased significantly by 50% (p < 0.001), with the first significant increase seen 3 months after conversion (p = 0.008). In contrast, C/D ratio in the control group was unchanged after 12 months (1.75 vs. 1.76; p = 0.847). Estimated glomerular filtration rate (eGFR) had already significantly deteriorated in the control group at 9 months (65.6 vs. 70.6 mL/min/1.73 m² at study onset; p = 0.006). Notably, patients converted to LCPT already had significant recovery of mean eGFR 6 months after conversion (67.5 vs. 65.3 mL/min/1.73 m² at study onset; p = 0.029). In summary, conversion of LT recipients to LCPT increased C/D ratio associated with renal function improvement.

Histopathology Scoring Systems of Stenosis Associated With Small Bowel Crohn's Disease: A Systematic Review

BACKGROUND & AIMS

Stenosis is a common complication of Crohn's disease (CD) that has no effective medical therapy. Development of antifibrotic agents will require testing in randomized controlled trials. Computed tomography enterography- and magnetic resonance enterography-based technologies might be used to measure outcomes in these trials. These approaches have been validated in studies of patients with symptomatic strictures who underwent imaging evaluations followed by resection with histopathologic grading of the intestinal tissue for inflammation and/or fibrosis (the reference standard). Imaging findings have correlated with findings from quantitative or semiquantitative histologic evaluation of the degree of fibromuscular stenosis and/or inflammation on the resection specimen. However, it is not clear whether histologic findings are an accurate reference standard. We performed a systematic review of all published histologic scoring systems used to assess stenosing CD.

METHODS

We performed a comprehensive search of Embase and MEDLINE of studies through March 13, 2019, that used a histologic scoring system to characterize small bowel CD and assessed inflammatory and fibrotic alterations within the same adult individual. All scores fitting the criteria were included in our analysis, independent of the presence of stricturing disease, as long as inflammation and fibrosis were evaluated separately but in the same scoring system.

RESULTS

We observed substantial heterogeneity among the scoring systems, which were not derived from modern principles for evaluative index development. None had undergone formal validity or reliability testing. None of the existing indices had been constructed according to accepted methods for the development of evaluative indices. Basic knowledge regarding their operating properties were lacking. Specific indices for evaluating the important pathologic component of myofibroblast hypertrophy or hyperplasia have not been proposed.

CONCLUSIONS

In a systematic review of publications, we found a lack of validated histopathologic scoring systems for assessment of fibromuscular stenosis. Data that describe the operating properties of existing cross-sectional imaging techniques for stenosing CD should be questioned. Development and validation of a histopathology index is an important research priority.

Serum levels of ferritin and transferrin serve as prognostic factors for mortality and survival in patients with end-stage liver disease: A propensity score-matched cohort study

BACKGROUND

Patients with end-stage liver disease are known to suffer from a significantly high risk of mortality, but accurate prediction of the course of disease is challenging.

OBJECTIVE

The study aim was to evaluate the independent prognostic and clinical importance of serum levels of ferritin and transferrin for 90-day survival of patients with liver disease.

METHODS

Patients with end-stage liver disease treated during a 2-year period were enrolled retrospectively in a single-centre study. Unmatched and propensity score matching (PSM) analyses were applied.

RESULTS

The study cohort comprised 286 patients with end-stage liver disease, of which 22.9% died during the observational period. High serum ferritin levels and low serum transferrin levels were associated significantly with increased 90-day mortality in the unmatched (p < 0.001) and PSM study population (p = 0.017). Serum levels of ferritin and transferrin had high prognostic capability to predict 90-day survival similar to the Model for End-stage Liver Disease. Patients with serum ferritin values >1030.5 µg/l had a 50% risk of dying within 11 days after measurement, which translated up to a 90-day mortality of 83%.

CONCLUSION

Serum levels of ferritin and transferrin have independent and excellent capabilities to determine prognosis in patients with end-stage liver disease. Ferritin measurements can reliably identify those with high mortality in daily practice.

Endoscopic Radiofrequency Ablation Prolongs Survival of Patients with Unresectable Hilar Cholangiocellular Carcinoma - A Case-Control Study

The life expectancy of unresectable hilar cholangiocellular carcinomas (CCCs) is very limited and endoscopic radiofrequency ablation (ERFA) of the biliary tract may prolong survival. Our single-center-study retrospectively analysed all CCC cases, in whom ERFAs of the biliary tract were performed between 2012 and 2017 and compared these to historical control cases who received the standard treatment of sole stent application. ERFA was performed in 32 patients with malignant biliary strictures that were mainly caused by Bismuth III and IV hilar CCCs (66%). 14 of these patients received repeated ERFAs, for an overall performance of 54 ERFAs. Stents were applied after examination of all patients (100%). Adverse events occurred in 18.5% of examinations. Case-control analysis revealed that the survival time of cases with unresectable Bismuth type III and IV hilar CCCs (n = 20) treated with combined ERFA and stent application significantly increased compared to controls (n = 22) treated with sole stent application (342 +/- 57 vs. 221 +/- 26 days; p = 0.046). In conclusion, ERFA therapy significantly prolonged survival in patients with unresectable Bismuth type III and IV hilar CCC. As an effective and safe method, ERFA should be considered as a palliative treatment for all these patients.

Assessment of Crohn's disease-associated small bowel strictures and fibrosis on cross-sectional imaging: a systematic review

Patients with Crohn's disease commonly develop ileal and less commonly colonic strictures, containing various degrees of inflammation and fibrosis. While predominantly inflammatory strictures may benefit from a medical anti-inflammatory treatment, predominantly fibrotic strictures currently require endoscopic balloon dilation or surgery. Therefore, differentiation of the main components of a stricturing lesion is key for defining the therapeutic management. The role of endoscopy to diagnose the nature of strictures is limited by the superficial inspection of the intestinal mucosa, the lack of depth of mucosal biopsies and by the risk of sampling error due to a heterogeneous distribution of inflammation and fibrosis within a stricturing lesion. These limitations may be in part overcome by cross-sectional imaging techniques such as ultrasound, CT and MRI, allowing for a full thickness evaluation of the bowel wall and associated abnormalities. This systematic literature review provides a comprehensive summary of currently used radiologic definitions of strictures. It discusses, by assessing only manuscripts with histopathology as a gold standard, the accuracy for diagnosis of the respective modalities as well as their capability to characterise strictures in terms of inflammation and fibrosis. Definitions for strictures on cross-sectional imaging are heterogeneous; however, accuracy for stricture diagnosis is very high. Although conventional cross-sectional imaging techniques have been reported to distinguish inflammation from fibrosis and grade their severity, they are not sufficiently accurate for use in routine clinical practice. Finally, we present recent consensus recommendations and highlight experimental techniques that may overcome the limitations of current technologies.

Percutaneous-transhepatic-endoscopic rendezvous procedures are effective and safe in patients with refractory bile duct obstruction

Background

Percutaneous-transhepatic-endoscopic rendezvous procedures (PTE-RVs) are rescue approaches used to facilitate biliary drainage.

Objective

The objective of this article is to evaluate the safety and the technical success of PTE-RVs in comparison with those of percutaneous transhepatic cholangiographies (PTCs).

Methods

Percutaneous procedures performed over a 10-year period were retrospectively analyzed in a single-center cohort. Examinations were performed because of a previous or expected failure of standard endoscopic methods including endoscopic retrograde cholangiography (ERC) or balloon-assisted ERC to achieve biliary access.

Results

In total, 553 percutaneous procedures including 163 PTE-RVs and 390 PTCs were performed. Overall, 71.3% of the patients suffered from malignant disease with pancreas-carcinoma (32.8%) and cholangio-carcinoma (19.0%) as the most frequent, while 28.7% of the patients suffered from benign disease. Many patients had a postoperative change in bowel anatomy (50.8%).PTC had a higher technical success rate (89.7%); however, the technical success rate of PTE-RVs was still high (80.4%; p < 0.003). Overall complications occurred in 23.5% of all procedures. Significantly fewer complications occurred after performing PTE-RVs than after PTCs (16.6% vs 26.4%; p = 0.037).

Conclusion

Beside a high technical efficacy of PTE-RVs, significantly fewer complications occur following PTE-RVs than following PTCs; thus, PTE-RV should be preferred over PTC alone in selected patients.

Successful treatment of oral Crohn's disease by anti-TNF-alpha dose escalation - a case report

BACKGROUND

Crohn's Disease (CD) is typically characterized by abdominal symptoms, however, besides gastrointestinal symptoms, CD patients may suffer from extraintestinal manifestations which are far less common and medical treatment can be challenging.

CASE PRESENTATION

We report about a 34-year-old Crohn's Disease (CD) patient in clinical remission under adalimumab therapy who presented in the clinic for Cranio-Maxillo Surgery due to severe pain in the mandibular area. Ulcerative lesions of the buccal-side mucosa of the right mandible were detected. To rule out malignancy, a biopsy was obtained and revealed ulcerative stomatitis with noncaseating granulomas consistent with oral CD. Shortening the adalimumab administration interval to weekly injections resulted in a complete healing of the oral CD lesions without residual inflammation.

CONCLUSION

The case presented here demonstrates that gastroenterologists should evaluate and consider oral CD lesions as a possible marker of disease activity in patients despite having quiescent intestinal CD.

Safety, diagnostic accuracy and therapeutic efficacy of digital single-operator cholangioscopy

Background

Digital single-operator cholangioscopes (digital SOCs), equipped with an improved image quality, have been recently introduced.

Objective

The aim of this study is to evaluate the safety and diagnostic and therapeutic efficacy of digital SOCs (Spyglass™ DS).

Methods

Sixty-seven digital SOC procedures performed between 2015 and 2017 were retrospectively analyzed.

Results

The most frequent indications for examination were indeterminate biliary strictures (61.2%) and biliary stone disease (23.9%). In 25 patients (37.3), visual findings predicted malignancy with a sensitivity of 88.9%, a specificity of 97.6%, a positive predictive value (PPV) of 96.0% and a negative predictive value (NPV) of 92.9%. For histological analysis, forceps biopsies were performed in 29 patients (43.2%). Compared with visual findings, forceps biopsies yield a lower diagnostic efficacy in diagnosing malignancy (sensitivity 62.5%, specificity 90.0%, PPV 90.9%, NPV 60.0%). Therapeutic interventions were performed in 19 patients with a technical success rate of 89.4%. Adverse events were observed in 17 patients (25.4%). Of these, 11 patients (16.4%) suffered from severe adverse events (pancreatitis, cholangitis or major bleeding), which led to a prolonged hospital stay.

Conclusion

Digital SOCs have excellent diagnostic and therapeutic efficacies, but are accompanied by high rates of adverse events; therefore, physicians should use digital SOCs in carefully selected cases.

Quantitative phase microscopy for evaluation of intestinal inflammation and wound healing utilizing label-free biophysical markers

Inflammatory bowel diseases (IBD) are inflammatory disorders of the gastrointestinal tract characterized by a chronic relapsing disease course. As uncontrolled intestinal inflammation can result in severe disease complications, recent treatment targets of IBD evolved toward seeking the absence of mucosal and histological inflammation. However, this approach requires adequate histological evaluation of IBD disease activity. The diagnostic challenge of histological examination of intestinal inflammation is documented by the multitude of proposed histological scoring systems. In this context, we review quantitative phase imaging (QPI) techniques such as digital holographic microscopy (DHM) for characterizing intestinal inflammation. DHM determines optical path-length delays in a stain-free manner, thereby providing the tissue refractive index as a biophysical marker that directly correlates to tissue density. Recently, DHM has been successfully applied in cell biology, cancer cell research and infectious-induced cellular alterations. We summarized the capabilities of DHM and related QPI techniques to assess the severity of intestinal inflammation in experimental colitis as well as in colonic samples from human IBD patients. Moreover, we illustrate major advantages of DHM facilitated multimodal evaluation of epithelial wound healing processes as assessed by physical parameters like cell volume, density, thickness and dry mass in vitro. Furthermore, potential limitations of DHM and future utilities of QPI are discussed. In conclusion, DHM represents a promising, easy-to-use quantitative tool to provide accurate and objective assessment of intestinal inflammation and may pave the way towards automated label-free digital pathology and related in vitro cell culture analysis in future.

Hyponatremia upon presentation to the emergency department - the need for urgent neuroimaging studies

This study aims to evaluate the necessity of urgent neuroimaging for emergency admissions exhibiting symptomatology of profound hyponatremia. We retrospectively analyzed the medical records of all patients admitted to the emergency room of the University Hospital Münster from 2010 to 2014 with a serum sodium value < 125 mmol/L. From 52918 emergency admissions, 261 patients with profound hyponatremia were identified, of whom 140 (54%) had neurological symptoms. Unspecific weakness and confusion were the most prevalent of these symptoms (59%). Focal neurological signs [FNS] were present in 31% of cases and neuroimaging was performed in 68% (95/140) of symptomatic patients. Multiple logistic regression analysis identified FNS, seizures, altered consciousness and age as independent predictors for conducting neuroimaging (all p < 0.05). Significant pathological findings consistent with acute symptomatology were evident in 17 cases, all of whom had FNS. Recursive partitioning analyses confirmed FNS as the best predictor of neuroimaging pathology (p < 0.001). Absence of FNS had a negative predictive value of 100% [95% confidence interval: 93-100%] for excluding neuroimaging pathology. In conclusion, emergency patients with profound hyponatremia frequently show nonspecific-neurological symptoms and may undergo neuroimaging unnecessarily. The lack of FNS may serve as a valuable criterion for withholding neuroimaging until hyponatremia has been corrected.

Skap2 is required for β2 integrin-mediated neutrophil recruitment and functions

Integrin activation is required for neutrophil functions. Impaired integrin activation on neutrophils is the hallmark of leukocyte adhesion deficiency (LAD) syndrome in humans, characterized by impaired leukocyte recruitment and recurrent infections. The Src kinase-associated phosphoprotein 2 (Skap2) is involved in integrin functions in different leukocyte subtypes. However, the role of Skap2 in β2 integrin activation and neutrophil recruitment is unknown. In this study, we demonstrate the crucial role of Skap2 in regulating actin polymerization and binding of talin-1 and kindlin-3 to the β2 integrin cytoplasmic domain, thereby being indispensable for β2 integrin activation and neutrophil recruitment. The direct interaction of Skap2 with the Wiskott-Aldrich syndrome protein via its SH3 domain is critical for integrin activation and neutrophil recruitment in vivo. Furthermore, Skap2 regulates integrin-mediated outside-in signaling events and neutrophil functions. Thus, Skap2 is essential to activate the β2 integrins, and loss of Skap2 function is sufficient to cause a LAD-like phenotype in mice.

Common exonic missense variants in the C2 domain of the human KIBRA protein modify lipid binding and cognitive performance

The human KIBRA gene has been linked to human cognition through a lead intronic single-nucleotide polymorphism (SNP; rs17070145) that is associated with episodic memory performance and the risk to develop Alzheimer's disease. However, it remains unknown how this relates to the function of the KIBRA protein. Here, we identified two common missense SNPs (rs3822660G/T [M734I], rs3822659T/G [S735A]) in exon 15 of the human KIBRA gene to affect cognitive performance, and to be in almost complete linkage disequilibrium with rs17070145. The identified SNPs encode variants of the KIBRA C2 domain with distinct Ca(2+) dependent binding preferences for monophosphorylated phosphatidylinositols likely due to differences in the dynamics and folding of the lipid-binding pocket. Our results further implicate the KIBRA protein in higher brain function and provide direction to the cellular pathways involved.