Histopathological characterization of cholecystectomy specimens in patients with inflammatory bowel disease

Background and aimsInflammatory bowel disease is associated with increased risk of cholelithiasis. However, the histologic patterns in gallbladders have not been extensively studied. This study is designed to characterize the histopathologic features of cholecystectomy specimens in inflammatory bowel disease patients, compared to a control group.MethodsCholecystectomy specimens in 78 Crohn's disease patients and 50 ulcerative colitis patients were reviewed. These were compared with 93 cholecystomies from noninflammatory bowel disease patients of approximate age and sex. The pattern and extent of inflammation was noted.ResultsMarked chronic cholecystitis was present in 12% of ulcerative colitis patients (P < 0.05) and 10.3% of Crohn's disease patients (P > 0.05), compared to 4.3% of the noninflammatory bowel disease control group. Eight percent of ulcerative colitis patients (P < 0.05) and 2.6% of Crohn's disease patients (P > 0.05) had acute serositis, compared to 0% of the noninflammatory bowel disease control. The third inflammatory pattern, nodular lymphoid aggregates, was significantly increased in Crohn's disease patients after adjusting for the effect of cholelithiasis. Nodular lymphoid aggregates were found in 21.2% of Crohn's disease patients and 9.7% of ulcerative colitis patients without cholelithiasis, compared to 5% of noninflammatory bowel disease controls without cholelithiasis, a statistically significant difference between the Crohn's disease and control groups (P < 0.05).ConclusionsInflammatory bowel disease patients show similar inflammatory patterns in cholecystectomy specimens compared to the general population. However, two inflammatory patterns that occur more often in ulcerative colitis patients are marked chronic cholecystitis and acute serositis, while nodular lymphoid aggregates are more common in Crohn's disease patients.     

Histopathological evaluation of liver biopsy specimens in children with chronic hepatitis B.

INTRODUCTION: Histopathological evaluation of the liver remains important diagnostic tool. OBJECTIVE: The aim of this study was to assess inflammatory activity, fibrosis and their correlation to the expression of viral antigens in the liver of children with chronic hepatitis B (CHB) before antiviral treatment. MATERIAL AND METHODS: The study included 190 liver biopsies of children aged 1.5-18 (mean 7.46+/-4.05 years) with CHB. The histopathological examination was based on the modified Knodell system. Additionally, immunomorphological analysis was performed in 125 specimens to detect HBsAg and HBcAg. RESULTS: Necroinflammatory activity was scored for mild in 109 children and moderate in 49. Fibrosis was scored for S1 in 90, S2 in 58 and S3-S4 in seven cases. Positive correlation between grading and staging was observed (chi(2)=77.65, p=0.000002). HBsAg was detected in 62 specimens, while HBcAg was found in the nuclei of 108 samples with cytoplasmic expression in 35-28% cases. No correlation of HBsAg expression to histopathological lesions was established whereas partial correlation of HBcAg expression with inflammatory infiltrate was confirmed. CONCLUSIONS: Progression of liver injury in children with CHB varies in severity. Necroinflammatory activity correlates with fibrosis. Expression of viral antigens is independent of histological changes, however confirms the etiology of liver disease.     

The importance of diagnostic accuracy in colonic inflammatory bowel disease

OBJECTIVE: Crohn's disease (CD) and ulcerative colitis (UC) may both affect the colon. However, in approximately 10-20% of these cases, it is impossible to distinguish between these two entities either clinically or histologically, and a diagnosis of indeterminate colitis (IC) is made. Correct diagnosis is important because surgical treatment and long-term prognosis differ for UC and CD. The purpose of this study was to determine the extent of interobserver agreement among board-certified pathologists and a specialist gastrointestinal (GI) pathologist regarding the histological diagnosis of colonic inflammatory bowel disease (IBD). METHODS: A total of 24 university medical center pathologists from eight institutions evaluated 84 colectomy specimens and 35 sets of biopsy specimens from 119 consecutive patients with colonic IBD. A specialist GI pathologist subsequently reviewed all cases without knowledge of clinical data and prior diagnosis. RESULTS: The GI pathologist's diagnoses differed from the initial diagnoses in 45% of surgical specimens and 54% of biopsy specimens. Of 70 cases initially diagnosed as UC, 30 (43%) were changed to CD or IC, whereas 4 of 23 cases (17%) initially diagnosed as CD were changed to UC or IC. The kappa coefficient for the overall agreement of initial diagnoses with the specialist GI pathologist's diagnoses was -0.01 (p = 0.98). CONCLUSIONS: There is significant interobserver variation in the histological diagnosis of colonic IBD. This may have a profound effect on clinical patient care and, especially, on the choice of operation. More accurate diagnostic criteria are needed to facilitate patient care and to optimize treatment outcome.     

Aberrant expression of monoclonal antibody-defined colonic mucosal antigens in inflammatory bowel disease

Human proximal colon from patients with inflammatory bowel disease and from controls was studied by two techniques to detect tumor-associated antigen expression. A panel of four murine monoclonal antibodies that recognize tumor-associated antigens was used to test purified colonic mucins for epitope expression by radioimmunoassay and to test formalin-fixed, deparaffinized sections of colon by the immunoperoxidase technique. The panel included monoclonal antibodies 19-9, B72.3, DU-PAN-2, and CSLEX1. Colonic mucins were purified from uninvolved surgical specimens by gel filtration with Sepharose 4B and cesium chloride-guanidine hydrochloride density gradient ultracentrifugation. Purified mucins from uninvolved colonic mucosal specimens from 4 of 7 patients with ulcerative colitis expressed one or more of these epitopes by radioimmunoassay, whereas mucins from 6 disease controls did not. Reactivity patterns were heterogeneous. Immunoperoxidase testing demonstrated staining with two or more antibodies in 14 of 18 involved inflammatory bowel disease segments, whereas control sections rarely stained with these antibodies, with the exception of 19-9. Sections of uninvolved mucosa from 4 of 9 patients with ulcerative colitis stained with two or more antibodies. Staining patterns were heterogeneous. The results demonstrate that colonic expression of tumor-associated epitopes occurs frequently in involved segments from both patients with ulcerative colitis and with Crohn's disease, whereas only patients with ulcerative colitis frequently expressed these epitopes in uninvolved segments.     

Enhanced mucosal cytokine production in inflammatory bowel disease.

Proliferation, maturation, chemotaxis, and activation of neutrophils and monocytes are mediated largely by cytokines, including colony-stimulating factors and lymphokines. Cytokines produced in the intestinal mucosa contribute to the increased migration of neutrophils and monocytes into the lesion of inflammatory bowel disease and to the activation of these inflammatory cells. Lamina propria mononuclear cells isolated from colon tissue from 14 patients with inflammatory bowel disease (IBD) and from histologically normal controls were studied. Cells from IBD-affected tissue produced significantly more colony-stimulating factor activity (1402 +/- 252 U) per 2 x 10(6) cells than those from normal mucosa (362 +/- 85 U), mainly because of the increased production of granulocyte colony-stimulating factor and interleukin 1. This was accompanied by increases in the amount of specific messenger RNA for these two cytokines in lamina propria mononuclear cells from mucosa of patients with Crohn's disease (CD) compared with normal controls. By contrast, there was a substantial reduction in interleukin 3 production in CD and in ulcerative colitis lamina propria mononuclear cells, and this was reflected in significantly reduced expression of interleukin 3 messenger RNA in CD cells. Of the agents used in the therapy of IBD, hydrocortisone and 5-aminosalicylic acid, but not cyclosporin A, markedly suppressed in vitro production of cytokines by lamina propria mononuclear cells, suggesting that their therapeutic efficacy in vivo may be due in part to down-regulation of cytokine production in the inflamed mucosa.     

Colonic mucosal interleukin-6 in inflammatory bowel disease.

Interleukin-6, a cytokine produced by various cell types, has a major role in inflammatory and immunological reactions. To define its potential role in inflammatory bowel disease, its concentrations in endoscopic biopsy samples from patients with ulcerative colitis and Crohn's disease were measured. The involved colonic mucosa from active disease was found to contain significantly larger amounts of interleukin-6 than that from inactive disease or normal controls. Colonic mucosal interleukin-6 levels correlated well with the grade of macroscopic inflammation, especially in patients with ulcerative colitis. The levels of interleukin-6 decreased in parallel with clinical improvement following the start of therapy in patients with both forms of inflammatory bowel disease. Mucosal interleukin-6 is thus concluded to accurately reflect the degree of colonic inflammation and may be importantly associated with inflammatory and immunological phenomena seen in inflammatory bowel disease.     

Rectal mucosal plasma cells in inflammatory bowel disease.

To achieve optimum staining and reproducible counts of plasma cells in paraffin embedded tissue with the immunoperoxidase technique we have found it essential to obtain a plateau count by titration of antisera for each specimen. This modification was used to study IgA, IgM, IgE, and IgG plasma cells in rectal biopsies from 20 controls, 20 patients with ulcerative proctocolitis, 20 with Crohn's colitis, 20 with non-specific proctitis, 15 with bacterial colitis, and seven with Crohn's disease but no apparent large bowel involvement. Counts were correlated with the characteristic histological features of inflammatory bowel disease. In controls the ratio of the mean counts for IgA, IgM, IgE, and IgG plasma cells was 8:3:3:1. All types of plasma cells were very significantly increased in the patients with ulcerative proctocolitis, Crohn's colitis, and non-specific proctitis and counts correlated with the severity of inflammation. There was no significant difference between the counts in these three groups. All counts tended to be higher in bacterial colitis than in controls, the difference being significant for IgA and IgE. When matched for severity of inflammation there was no significant difference between the counts in bacterial colitis and inflammatory bowel disease. The counts in patients with Crohn's disease but no large bowel involvement were not significantly different from controls. These results suggest that changes in plasma cell counts in inflammatory bowel disease are a non-specific response to mucosal damage, possible by a luminal irritant, and do not differentiate the type of inflammatory bowel disease.     

Alterations in mucosal content of colonic glycoconjugates in inflammatory bowel disease defined by monoclonal antibodies

The presence of several glycoconjugates in colonic mucosa of patients with inflammatory bowel disease was assessed through indirect immunofluorescent staining using a collection of 23 monoclonal antibodies directed against human colonic mucin glycoproteins (anti-HCM MAbs). Intensity and distribution of staining by three anti-HCM MAbs were significantly altered in mucosa from patients with ulcerative colitis (UC) (n = 14) when compared with normal tissue (n = 15) and with tissue from patients with Crohn's disease as well as other inflammatory disorders (n = 15). Staining by anti-HCM MAb 17, which binds to colonic mucin glycoprotein species IV and V, was absent or diminished in 86% of samples from patients with active UC in contrast to 14% of normal and disease control specimens. Reduction in anti-HCM MAb 17 staining was less marked in mucosal biopsy specimens from patients with UC lacking acute inflammatory activity (n = 8). In contrast to the apparent loss of the MAb 17-defined epitopes, staining with anti-HCM MAbs 10 and 22 was enhanced in UC tissue compared with normal and disease controls. Increased staining with MAb 10 was present in 93% of samples from UC patients demonstrating active inflammation. Increased MAb 10 staining was not apparent in noninvolved mucosa from UC patients, indicating that increased expression of the specified epitope is related to the acute inflammatory process. In contrast, indirect immunofluorescent staining with MAb 22 was apparent in both involved (78%) and uninvolved (67%) UC mucosa in contrast to normal and disease controls (less than 12%). In addition, staining with several other anti-HCM MAbs (MAbs 3, 11, 15) was modestly and variably diminished (14%-28%) in UC, Crohn's disease, and other inflammatory disorders. These findings demonstrate the presence of alterations in mucosal content of specific glycoconjugate structures in association with UC. Inflammatory processes may also result in broad changes in glycoconjugate determinants generally.     

Changes in the expression and distribution of the inducible and endothelial nitric oxide synthase in mucosal biopsy specimens of inflammatory bowel disease

OBJECTIVE: The role of nitric oxide (NO) in the pathophysiology of inflammatory bowel disease (IBD) is controversial. The aim of this study was to investigate the expression and localization of nitric oxide synthase isoforms (iNOS, eNOS) in IBD colonic mucosa. MATERIAL AND METHODS: Forty-four patients with IBD (24 ulcerative colitis (UC), 20 Crohn's disease (CD) and 16 controls) were investigated by colonoscopy. iNOS and eNOS in tissue sections was demonstrated by histochemistry (NADPH-diaphorase reaction) and immunohistochemistry. Cell type analysis and quantitative assessment of the iNOS immunoreactive (IR) cells and densitometry of iNOS in immunoblots were also performed. RESULTS: iNOS-IR cells were significantly numerous in inflamed mucosa of UC (64+/-4 cells/mm2) than in CD (4+/-2 cells/mm2). iNOS-IR/CD15-IR cells showed significant elevation in inflamed (i) versus uninflamed (u) UC mucosa (UCu 8+/-3%, UCi 85+/-10%) In CD, the percentage of iNOS-IR/CD68-IR cells was lower in inflamed sites (CDu 23+/-8%, CDi 4+/-3%). Immunoblot of biopsies revealed significant elevation of iNOS in active UC compared with uninflamed sites, whereas in CD no significant changes were detected. Differences were observed in eNOS and endothelial marker CD31 immunoreactivity. In patients with UC and in controls the ratios of eNOS/CD31-IR vessels were 82.3% and 92.0% respectively, whereas in CD the ratio was 8.3% with a concomitantly significant increase of CD31-IR vessels. The distribution and morphological characteristics of the NOS-IR inflammatory cells and endothelia were similar to those showing NADPH-diaphorase reactivity. CONCLUSIONS: Differences observed in the expression and distribution of NOS isoforms in immune and endothelial cells may contribute to better understanding of the structural and physiological changes in UC and CD.     

Changes in the expression and distribution of the inducible and endothelial nitric oxide synthase in mucosal biopsy specimens of inflammatory bowel disease

Objective The role of nitric oxide (NO) in the pathophysiology of inflammatory bowel disease (IBD) is controversial. The aim of this study was to investigate the expression and localization of nitric oxide synthase isoforms (iNOS, eNOS) in IBD colonic mucosa. Material and methods Forty-four patients with IBD (24 ulcerative colitis (UC), 20 Crohn's disease (CD) and 16 controls) were investigated by colonoscopy. iNOS and eNOS in tissue sections was demonstrated by histochemistry (NADPH-diaphorase reaction) and immunohistochemistry. Cell type analysis and quantitative assessment of the iNOS immunoreactive (IR) cells and densitometry of iNOS in immunoblots were also performed. Results iNOS-IR cells were significantly numerous in inflamed mucosa of UC (64±4 cells/mm²) than in CD (4±2 cells/mm²). iNOS-IR/CD15-IR cells showed significant elevation in inflamed (i) versus uninflamed (u) UC mucosa (UC_u 8±3%, UC_i 85±10%) In CD, the percentage of iNOS-IR/CD68-IR cells was lower in inflamed sites (CD_u 23±8%, CD_i 4±3%). Immunoblot of biopsies revealed significant elevation of iNOS in active UC compared with uninflamed sites, whereas in CD no significant changes were detected. Differences were observed in eNOS and endothelial marker CD31 immunoreactivity. In patients with UC and in controls the ratios of eNOS/CD31-IR vessels were 82.3% and 92.0% respectively, whereas in CD the ratio was 8.3% with a concomitantly significant increase of CD31-IR vessels. The distribution and morphological characteristics of the NOS-IR inflammatory cells and endothelia were similar to those showing NADPH-diaphorase reactivity. Conclusions Differences observed in the expression and distribution of NOS isoforms in immune and endothelial cells may contribute to better understanding of the structural and physiological changes in UC and CD.     

Gut mucosal lymphocytes in inflammatory bowel disease

We have developed an enzymatic technique for isolating human intestinal mucosal lymphoid cells. This method was found to be superior to mechanical methods in regard to cell yield and survival. It is based on treating mucosa with serum-free solutions containing collagenase and deoxyribonuclease, followed by isolating the lymphoid cells through centrifugation steps involving fetal calf serum and ficoll-hypaque. Exposure of peripheral blood lymphocytes to the components of the enzymatic solution did not appreciably alter their uptake of tritiated thymidine in the presence or absence of mitogens. Application of the method to derive lymphoid cells from Crohn's disease, ulcerative colitis, and normal intestinal mucosa has shown that gut mucosal lymphocytes from inflammatory bowel disease (1) exceed the number of those from normal mucosa by a factor of 3 to 5; (2) show different degrees of tritiated thymidine uptake, spontaneously and in response to mitogens, depending upon the time they are harvested during the dissociation process; (3) are better stimulators than responders in the allogeneic mixed lymphocyte reaction; (4) generate suppressor cell activity comparable to that of peripheral blood lymphocytes; (5) cannot, in contrast to peripheral blood lymphocytes, generate antibody-dependent cell mediated cytotoxicity; and (6) produce an average of 5 times more IgM than equal numbers of peripheral blood lymphocytes.     

Apoptosis: implications for inflammatory bowel disease

Cells of the intestinal mucosa live in a harsh environment and therefore rely heavily on the highly regulated process of cell death, apoptosis, to maintain tissue integrity. Imbalance in the intracellular events that modulate apoptosis may contribute to the pathogenesis of inflammatory bowel disease.     

Clinical implications of mucosal healing in the management of patients with inflammatory bowel disease

The natural history of Crohn's Disease and ulcerative colitis is characterized by repeated episodes of inflammation and ulceration of the bowel. This results in complications implying a worse quality of life and significant healthcare costs, due to hospitalization, surgery and an escalation of therapy.     

5-Aminosalicylic acid is a potent inhibitor of interleukin 1 beta production in organ culture of colonic biopsy specimens from patients with inflammatory bowel disease.

Interleukin 1 beta in biopsy specimens from inflamed colonic mucosa of patients with active inflammatory bowel disease was studied. Compared with normal colonic mucosal biopsy specimens, a significantly greater amount of interleukin 1 beta was present in rectal mucosa before (median (range) 4.3 (2.0-11.8) v 119.2 (30.1-286.8) pg/mg; p less than 0.01) and produced during organ culture (39.1 (9.4-106.8) v 97.6 (28.2-991.6) pg/mg; p less than 0.01). Values of interleukin 1 beta after culture correlated with concentrations of thromboxane B2. Organ culture of inflamed biopsy specimens in the presence of 5 aminosalicylic acid and dexamethasone reduced the amount of interleukin 1 beta detected. At the doses studied, 5 aminosalicylic acid also reduced the amount of leukotriene B4 detected after culture.     

肠黏膜屏障与炎症性肠病

炎症性肠病（Innammatory bowel disease，IBD）是一组病因不明的慢性肠道炎症性疾病，主要包含两个独立的疾病，溃疡性结肠炎（Ulcerative colitis，UC）和克罗恩病（Crohn’s disease，CD）。近年研究发现，肠黏膜屏障功能异常在IBD发病机制中发挥重要作用。更好地了解正常及疾病状态下肠黏膜屏障的结构和功能可以为IBD的治疗提供新的思路。     

Noninvasive evaluation of mucosal healing in inflammatory bowel diseases

Current opinions increasingly cite the need to achieve not only clinical response but also endoscopic mucosal healing in the treatment of both types of inflammatory bowel disease: ulcerative colitis (UC) and Crohn’s disease (CD). Although endoscopic procedures are necessary for confirmation of mucosal healing, undergoing colonoscopy is invasive and burdensome to patients. Therefore, alternative noninvasive methods of evaluating or predicting mucosal status have been eagerly desired. For this purpose, blood, fecal, and radiologic modalities have been suggested and examined. C-reactive protein and fecal markers such as fecal calprotectin can evaluate active inflammation to some extent in both UC and CD. However, their predictive values for mucosal healing have not yet been fully evaluated and current knowledge indicates that the values were rather insufficient. Radiologic modalities such as computed tomography, magnetic resonance, and ultrasound can also evaluate mucosal inflammation but are currently not suitable for detection of healing. Capsule endoscopy may be optimal for evaluating mucosal status of the small bowel in CD patients, but sufficient data are not yet available, particularly for mucosal healing. Thus, these candidates for the surrogate modality are currently imperfect for evaluation of mucosal healing, but the changes in values/findings of these modalities after initiation of therapy appear to be rather promising as a marker of efficacy of the therapy. Finally, our recent data showed that a fecal immunochemical test for evaluation of mucosal healing in UC was very promising and this method should be further evaluated in CD also.     

Evolving diagnostic modalities in inflammatory bowel disease

Over the past several years, significant advances have been made in the diagnostic techniques used in the management of ulcerative colitis and Crohn’s disease. These advances have occurred mainly in the area of gastrointestinal endoscopy and radiology. Capsule endoscopy and double-balloon endoscopy have permitted better visualization of the small bowel mucosa. Advanced imaging techniques, including chromoendoscopy, magnification endoscopy, confocal endomicroscopy, and spectroscopy, may aid in the diagnosis of colorectal neoplasia in patients with long-standing disease. Improved radiographic imaging techniques based on computed tomography and magnetic resonance imaging allow noninvasive means of evaluating the small bowel in patients with known or suspected Crohn’s disease. Finally, positron emission tomography is an investigative tool for inflammatory bowel disease that may also aid in the detection of inflammation in these diseases.     

炎症性肠病患者肠黏膜组织细胞凋亡

炎症性肠病(inflammatory bowel disease,IBD)是发生在胃肠道慢性非特异性炎症性疾病,其病因及发病机制尚未十分明确,可能与环境因素、遗传因素和免疫因素等有关.研究表明细胞凋亡在IBD的发病中起着重要的作用,表现为炎症肠黏膜组织内存在细胞凋亡紊乱,肠上皮细胞凋亡过度、黏膜固有层组织内淋巴细胞凋亡抵抗,以及PMN凋亡迟滞.这是造成IBD肠道炎症发生和持续的重要原因.研究发现发生细胞凋亡的主要机制在于激活了Fas/FasL信号传导途径、Bcl-2和Bax调节途径而实施的.研究细胞凋亡机制对揭示IBD的发病机制.靶向性阻断细胞凋亡通路治疗IBD发生有重要意义.