Xiu-Li Zuo

Diagnostic value of confocal laser endomicroscopy for gastric superficial cancerous lesions

Background The identification of gastric superficial cancerous lesions based on conventional white-light endoscopy (WLE) is challenging, and histological analysis remains the ‘gold standard’ for the final diagnosis. Confocal laser endomicroscopy (CLE) can provide in vivo histological observation without the need for biopsy. Objective To develop and evaluate CLE imaging criteria for gastric superficial cancerous lesions and to compare the diagnostic value of real-time integrated CLE (iCLE) and WLE alone in distinguishing gastric superficial cancerous lesions. Design Prospective study. Setting Qilu Hospital, Shandong University, Jinan, China. Patients A total of 182 patients were enrolled into phase I and 1786 patients were enrolled into phase II. Interventions CLE images were blindly evaluated after endoscopy in phase I, and real-time iCLE diagnosis during endoscopy was compared with WLE diagnosis by using histopathology as a gold standard in phase II. Main outcome measurements The validity and reliability of the CLE diagnosis for identifying gastric superficial cancerous lesions. Results Off-line CLE diagnosis for early gastric cancers had a high sensitivity (88.1%) and specificity (98.6%). When the two-tiered CLE classification of non-cancerous lesions and cancer/high-grade intraepithelial neoplasia (HGIN) lesions was introduced, CLE diagnosis led to a higher sensitivity (90.2%) and specificity (98.5%) (phase I). Real-time iCLE diagnosis had a higher sensitivity (88.9%), specificity (99.3%) and accuracy (98.8%) for gastric superficial cancer/HGIN lesions than WLE diagnosis (sensitivity, 72.2%; specificity, 95.1%; and accuracy, 94.1%) (p<0.05) (phase II). Limitations This was a single-centre study. Conclusions CLE can be used to identify gastric superficial cancer/HGIN lesions with high validity and reliability.

Alterations of food antigen‐specific serum immunoglobulins G and E antibodies in patients with irritable bowel syndrome and functional dyspepsia

Background Post‐prandial worsening of symptoms as well as adverse reactions to one or more foods are common in the patients with functional gastrointestinal diseases, such as irritable bowel syndrome (IBS) and functional dyspepsia (FD). However, the role played by true food allergy in the pathogenesis of these diseases is still controversial and there are no well‐established tests to identify food allergy in this condition.

Brain-derived neurotrophic factor contributes to abdominal pain in irritable bowel syndrome

Objective Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, may play a critical role in many chronic pain conditions. The possible involvement of BDNF in the altered gut sensation in patients with irritable bowel syndrome (IBS) was investigated in the present study. Methods Rectosigmoid biopsies were collected from 40 patients with IBS fulfilling the Rome II criteria and 21 healthy controls. Abdominal pain was quantified by a validated questionnaire. The presence of BDNF and nerve fibres in the mucosa was assessed by immunohistochemistry. The structure of mucosal nerve fibres was assessed by transmission electron microscopy. Mucosal BDNF release was measured by ELISA and correlated with abdominal pain scores. Animal studies using BDNF+/− mice were carried out to evaluate visceral sensitivity, mucosal nerve fibre density and ultrastructural changes. Alterations of visceral sensitivity and TrkB expression in dorsal root ganglia were examined in BDNF+/+ mice following different doses of BDNF administration. Results Biopsies from patients with IBS revealed a significant upregulation of BDNF (p=0.003), as compared with controls. Total nerve fibres were also substantially increased in patients with IBS. Electron microscopy showed ultrastructural damage on the mucosal nerve fibres (eg, swollen mitochondria and nerve axons). Elevated BDNF release was significantly correlated with the abdominal pain scores. Meanwhile, abdominal withdrawal reflex scores to colorectal distension and mucosal protein gene product 9.5 immunoreactivity were significantly lowered in BDNF+/− than in BDNF+/+ mice. Electron microscopy showed degenerative changes on the mucosal nerve fibres in BDNF+/− mice. Exogenous BDNF induced an obvious dose-dependent increase in TrkB expression in dorsal root ganglia and dose-dependent decrease in threshold pressure in BDNF+/+ mice. Conclusions The increased expression of BDNF in colonic mucosa, together with the structural alterations of mucosal innervation, may contribute to the visceral hyperalgesia in IBS.

Confocal laser endomicroscopy for superficial esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIMS Confocal laser endomicroscopy (CLE) allows subsurface imaging of gastrointestinal mucosa in vivo. The goal of the present study was to compare the endomicroscopic characteristics of cells and intrapapillary capillary loops (IPCLs) in normal and superficial esophageal squamous cell carcinoma (SESC). PATIENTS AND METHODS We recruited consecutive patients with SESC diagnosed by conventional endoscopy and confirmed by histopathology between July 2006 and May 2008. The confocal endoscopic images of these patients were collected and compared with the corresponding histology. The characteristic patterns of cells and IPCLs was then analyzed from these images of malignant and normal mucosa. The quality of images and interobserver variations of two endoscopists were also evaluated. RESULTS Overall, 64 samples from 57 subjects (27 SESCs, 30 controls) were examined by CLE. The confocal images corresponded to the hematoxylin and eosin staining from the same sites. The confocal images showed that there was a significantly higher proportion of squamous epithelial cells with irregular arrangement (79.4 % vs. 10.0 %, P < 0.001), increased diameter of IPCLs (26.0 microm vs. 19.2 microm, P < 0.001), and irregular shape IPCLs (82.4 % vs. 36.7 %, P = 0.0002) in the SESC group compared with the controls. Massive IPCLs with tortuous vessels (44.1 % vs. 0 %, P < 0.0001), and long branching IPCLs (23.5 % vs. 3.3 %, P = 0.0204) were frequently observed in the SESC group. In this study, about 35.5 % of images were graded as good quality, and the interobserver agreement for the prediction of cancerous mucosa was graded as substantial. CONCLUSIONS CLE can be used to distinguish cancerous from normal epithelium, which gives it potential value for early detection of esophageal carcinoma. The difficulty in obtaining good images in the esophagus by CLE is a latent problem.

Differentiation of colonic polyps by confocal laser endomicroscopy.

BACKGROUND AND STUDY AIM The real-time identification and removal of adenomas is a cost-effective strategy to improve the prognosis of colorectal cancer. Confocal laser endomicroscopy (CLE) could provide real-time histological-level observation. We aimed to evaluate the efficacy of CLE diagnosis using a simple classification system that differentiates adenomas from non-neoplastic polyps with intravenous fluorescein staining alone. PATIENTS AND METHODS An endoscope integrated confocal laser microscopy system was used in this study. CLE images of 35 colonic polyps, including 15 hyperplastic polyps and 20 adenomas confirmed by histology, were first evaluated to develop criteria for diagnosis of neoplastic and non-neoplastic polyps. The diagnostic criteria included goblet cell depletion, villous architecture, and microvascular alterations. We then performed a prospective study of colonic polyps found during CLE and classified them according to the established criteria. A total of 115 patients with 115 colonic polyps were included. The real-time CLE diagnosis was compared with that from histology. The stored CLE images were evaluated later by a blinded observer. RESULTS The sensitivity, specificity, positive predictive value, and negative predictive value of real-time CLE in identifying colonic adenomas were 93.9 % (95 % confidence interval [CI] 85.4 - 97.6), 95.9 % (95 % CI 86.2 - 98.9), 96.9 % (95 % CI 89 - 99), and 92.2 % (95 % CI 81 - 97), respectively, compared with histological results. Interobserver agreement between real-time and post-CLE still-image evaluation was excellent (kappa = 0.929). Goblet cell depletion alone had a sensitivity of 84.9 % (95 % CI 73 - 92) and a specificity of 87.8 % (95 % CI 75 - 95), as well as excellent interobserver agreement (kappa = 0.824). CONCLUSIONS Endoscope integrated CLE with fluorescein staining may reliably assist in the real-time identification of colonic adenomas. Among three diagnostic categories, goblet cell depletion can be used to distinguish adenomas and hyperplastic polyps.

In vivo molecular imaging of epidermal growth factor receptor in patients with colorectal neoplasia using confocal laser endomicroscopy

Epidermal growth factor receptor (EGFR) plays an important role in tumorigenesis of colorectal cancer (CRC), and its in vivo molecular imaging in rodent models has become the subject of an increased number of studies using novel imaging techniques for gastrointestinal endoscopy. Current study aimed to evaluate the use of confocal endomicroscopy (CLE) for in vivo molecular imaging of EGFR in patients with colorectal neoplasia. Molecular imaging of colorectal neoplasia in patients was performed by CLE after topical application of a fluorescent-labeled molecular probe against EGFR. Representative images of CLE were chosen to calculate EGFR-specific fluorescence intensity. Targeted biopsy specimens were taken from each examined site during in vivo imaging for histology and immunohistochemistry (IHC). During in vivo molecular imaging in 37 patients, an EGFR-specific fluorescence signal was present in 18/19 CRC, and 12/18 colorectal adenomas. No or only weak fluorescence signal was observed in vivo in 10 cases of normal mucosa. CLE is a novel tool that could be used in molecular imaging with specific targeting of EGFR in patients with colorectal neoplasia. This technique demonstrates a promising imaging approach for targeted therapies of colorectal neoplasia.

The Possible Role of the Novel Cytokines IL-35 and IL-37 in Inflammatory Bowel Disease

Interleukin- (IL-) 35 and IL-37 are newly discovered immune-suppressing cytokines. They have been described in inflammatory diseases such as collagen-induced arthritis and asthma. However, their expressions in inflammatory bowel disease (IBD) patients have not been yet explored. Our aim was to evaluate serum and inflamed mucosal levels in IBD patients. In 20 ulcerative colitis (UC) patients, 7 Crohns disease (CD) patients, and 15 healthy subjects, cytokine levels in serum were determined using ELISA and mucosal expression studies were performed by immunohistochemistry, quantitative real-time PCR, and Western blot. The results showed that serums IL-35 and IL-37 levels were significantly decreased in UC and CD patients compared with healthy subjects. The cytokines levels correlated inversely with UC activity. IL-35 was expressed in infiltrating immune cells while IL-37 in intestinal epithelial cells as well as inflammatory cells. IBD patients had significantly higher Ebi3, p35 (two subunits of IL-35), and IL-37b gene expressions; IL-35 and IL-37 protein expressions were higher in IBD patients compared with controls. The study showed that serums IL-35 and IL-37 might be potentially novel biomarkers for IBD. Intestinal IL-35 and IL-37 proteins are upregulated, suggesting that regulating the expression of the two cytokines may provide a new possible target for the treatment of IBD.

Confocal laser endomicroscopy for in vivo diagnosis of gastric intraepithelial neoplasia: a feasibility study

BACKGROUND Confocal laser endomicroscopy (CLE) is a novel endoscopic modality that allows subsurface analysis of the gastric mucosa during ongoing endoscopy. Several studies have reported that this technique is of value in the diagnosis of premalignant lesions in the GI tract, but as yet no investigations have reported its application in the analysis of gastric intraepithelial neoplasia (GIN). OBJECTIVE To assess the feasibility of CLE for the identification and grading of GIN. DESIGN Prospective double-blind feasibility study. SETTING Qilu Hospital, Shandong University, Jinan, China. PATIENTS CLE images of 33 patients were first evaluated to establish the diagnostic criteria for gastric lesions. Eligible patients were then prospectively investigated by CLE using the newly established criteria. INTERVENTIONS All endoscopically suspicious lesions were examined by CLE, and CLE diagnoses were compared with corresponding histopathologic results. MAIN OUTCOME MEASUREMENTS Sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of biopsy-proven intraepithelial neoplasia by per-lesion analysis. RESULTS The sensitivity, specificity, and positive and negative likelihood ratios of CLE diagnosis of GIN were 77.8%, 81.8%, 4.28, and 0.27, respectively. The mean κ value for interobserver agreement for the diagnosis of GIN was 0.70 among endoscopists and 0.71 between endoscopist and GI pathologist. Intraepithelial neoplasia score ≥5 differentiated high-grade from low-grade intraepithelial neoplasia with a sensitivity of 66.7% and a specificity of 88.0%. LIMITATIONS Nonrandomized single-center study, limited number of patients. CONCLUSIONS CLE is an acceptable and potentially useful technology for the identification and grading of GIN in vivo. The diagnostic accuracy needs to be improved.

Confocal endomicroscopy for in vivo prediction of completeness after endoscopic mucosal resection

BackgroundEndoscopic mucosal resection (EMR) is an alternative to surgery for removal of superficial gastric neoplastic lesions. Residual neoplastic tissue of the resection interface is difficult to detect by conventional endoscopy. The aim of this study is to assess the efficacy of confocal laser endomicroscopy (CLE) in predicting complete resection margins after EMR.MethodsEMR was performed by using cap-assisted or “inject and cut” resection technique. Two weeks after EMR, the circumferential margins of the defect were inspected by using CLE, and completeness of excision was predicted from the CLE image. Additional EMR was performed if necessary. In vivo CLE diagnosis was validated against final histopathology.ResultsTwenty-seven lesions were removed by EMR in 27 patients. After excluding 3 patients for gastrectomy, a total of 24 patients underwent CLE assessment, of whom 9 with indefinite lateral margins underwent at least two consecutive CLE follow-ups. A total of 19 lesions were regarded as complete remission, and 5 lesions (21.7%) were incompletely excised according to final pathologic diagnosis. Accuracy of CLE in predicting incomplete resection for original lesions was 91.7%, with sensitivity and specificity of 100.0 and 89.5%, respectively. The residual lesions were treated by additional EMR guided by CLE. There was no recurrence on endoscopic biopsies at mean (range) follow-up of 8.3 (4–15) months.ConclusionsConfocal laser endomicroscopy has high accuracy for prediction of remnant tissue after EMR, and may lead to significant improvements in clinical surveillance after endoscopic resection.

Confocal laser endomicroscopy for diagnosis of Helicobacter pylori infection: A prospective study

Background and Aim:  Confocal laser endomicroscopy (CLE) is a new endoscopy technique for subsurface analysis of the gastric mucosa and in vivo histology examination during endoscopy. We aimed to compare the clinical applicability and predictive power of CLE with the diagnosis of Helicobacter pylori infection in patients with gastrointestinal symptoms.