Appendiceal inflammation in ulcerative colitis

Common Mistakes in Managing Patients with Inflammatory Bowel Disease

Introduction: Errors are very common in medical practice and in particular, in the healthcare of patients with inflammatory bowel disease (IBD); however, most of these can be prevented. Aim: To address common errors in the management of IBD. Methods: Our approach to this problem consists in identifying mistakes frequently observed in clinical practice (according to our experience) in the management of patients with IBD, then reviewing the scientific evidence available on the subject, and finally proposing the most appropriate recommendation for each case. Results: The most common mistakes in the management of IBD include those related to diagnosis and differential diagnosis, prevention, nutrition and diet, treatment with different drugs (mainly 5-aminosalicylates, corticosteroids, thiopurines, and anti-TNF agents), extraintestinal manifestations, anemia, elderly patients, pregnancy, and surgery. Conclusions: Despite the availability of guidelines for both disease management and preventive aspects of IBD care, a considerable variation in clinical practice still remains. In this review, we have identified common mistakes in the management of patients with IBD in clinical practice. There is a clear need for a greater dissemination of clinical practice guidelines among gastroenterologists and for the implementation of ongoing training activities supported by scientific societies. Finally, it is desirable to follow IBD patients in specialized units, which would undoubtedly be associated with higher-quality healthcare and a lower likelihood of errors in managing these patients.

A case of ulcerative colitis complicated by a simple appendiceal opening

This case report describes the clinical course of a 64-year-old male with intermittent abdominal pain attributed to recurrent ulcers at the appendiceal orifice. Initial investigations in November 2019 revealed chronic gastritis and ulcers at the appendiceal orifice, prompting consideration of ulcerative colitis (UC). The patient responded well to mesalazine therapy, experiencing relief from symptoms and improved colonoscopy findings in May 2020. Despite discontinuing medication, a recurrence of symptoms in August 2021 led to a repeat colonoscopy showing renewed ulcers. Mesalazine was reinstated, resulting in symptom resolution and improved colonoscopy findings by December 2021. However, in May 2023, a subsequent recurrence of abdominal pain and colonoscopy-confirmed mucosal changes at the appendiceal orifice prompted reintroduction of mesalazine. The patient remains under regular monitoring on mesalazine therapy. This case highlights the challenges in managing recurrent appendiceal ulcers and the importance of long-term therapeutic vigilance in suspected UC cases.

Characteristics and Outcomes of Left-sided Ulcerative Colitis With a Cecal/Periappendiceal Patch of Inflammation

Ulcerative colitis (UC) is characterized by continuous mucosal inflammation of the rectum, extending uninterrupted to a variable portion of the colon proximally. However, in some patients with distal colitis, a distinct pattern of skip inflammation (so-called patch) involves the cecum and/or appendiceal orifice, but data on this entity are contradictory, and its significance and prognosis are still debated. We identified 102 adult cases of left-sided UC with a cecal/periappendiceal patch and compared them to 102 controls (left-sided UC only) along clinicopathologic characteristics and disease outcomes. In multivariate analysis, patients with a patch were younger (median age: 31 vs. 41 y; P =0.004) and more likely to have rectosigmoid involvement only (58.8% vs. 28.4%; P <0.001), compared with patients without a patch. During follow-up, patients with a patch were more likely to be eventually diagnosed with Crohn disease (CD) (9.8% vs. 1.0%; P =0.022) and to show proximal extension of inflammation (35.6% vs. 10.0%; P =0.021), but showed no differences in rates of neoplasia, colectomy, or pharmacotherapy escalation. Kaplan-Meier analysis confirmed that patients with a biopsy diagnosis of cecal/periappendiceal patch were more likely to show proximal disease extension ( P <0.001) and to be diagnosed with CD ( P =0.008). In conclusion, cecal/periappendiceal skip inflammation in left-sided UC occurs more often in younger patients and in those with rectosigmoid involvement and is associated with proximal disease extension and, in a small fraction of cases, change of diagnosis to CD. However, it does not portend increased risk of neoplasia, pharmacotherapy escalation, or subsequent colectomy, compared with patients with left-sided UC only.

Childhood appendicitis and future risk of inflammatory bowel disease - A nationwide cohort study in Sweden 1973-2017

AIM

The aim of this study was to investigate the association between juvenile appendicitis, treated conservatively or with appendectomy, and adult risk of inflammatory bowel disease (IBD), either ulcerative colitis (UC) or Crohn's disease (CD). We used nationwide population data from more than 100,000 individuals followed for over four decades.

METHOD

All Swedish patients discharged with a diagnosis of appendicitis before the age of 16 years between 1973 to 1996 were identified. Everyone diagnosed with appendicitis was matched to an individual in the general population without a history of juvenile appendicitis (unexposed) of similar age, sex and region of residence. The study population was retrospectively followed until 2017 for any development of UC or CD. Cox proportional-hazards models compared disease-free survival time between exposed and unexposed individuals, also analysing the impact of treatment (conservative treatment versus appendectomy).

RESULTS

The final cohort consisted of 52,391 individuals exposed to appendicitis (1,674,629 person years) and 51,415 unexposed individuals (1,638,888 person years). Childhood appendicitis with appendectomy was associated with a significantly lower risk of adult IBD [adjusted hazard ratio (aHR) 0.48 (0.42-0.55)], UC [aHR 0.30 (0.25-0.36)] and CD [aHR 0.82 (0.68-0.97)]. Those treated conservatively had a lower risk of adult UC [aHR 0.29 (0.12-0.69)] but not CD [aHR 1.12 (0.61-2.06)] compared with unexposed individuals.

CONCLUSION

Juvenile appendicitis treated with appendectomy was associated with a decreased risk of adult IBD, both UC and CD. Those treated conservatively instead of with surgery had a lower risk of UC only. Our findings warrant more research on the role of the appendix and gut microbiota in the pathogenesis of IBD.

Clinical relevance of endoscopic peri-appendiceal red patch in ulcerative colitis patients

BACKGROUND

Increasing evidence is suggesting appendectomy as an alternative treatment for ulcerative colitis (UC), especially in case of histological appendiceal inflammation. Therefore, preoperative identification of appendiceal inflammation could be beneficial. This study aimed to assess the prevalence of peri-appendiceal red patch (PARP) on colonoscopy. In addition, prognostic relevance of PARP for disease course and its predictive value for histological appendiceal inflammation in patients undergoing appendectomy was assessed.

METHODS

UC patients undergoing colonoscopy in 2014/2015 were included to determine PARP-prevalence in a cross-sectional study. Findings were correlated to patient and disease characteristics, upscaling of treatment and colectomy rates after cross-sectional colonoscopy. In patients undergoing appendiceal resection, histopathological inflammation was assessed using the Robarts Histopathology Index (RHI).

RESULTS

In total, 249 patients were included of which 17.7% (44/249) had a PARP. Patients with PARP were significantly younger with a shorter disease course. The majority of patients with PARP (61.4%) was in endoscopic remission. Patients with PARP required more upscaling of medical therapy (81.8% vs. 58.0%, p < 0.01), and more PARP patients underwent colectomy (13.6% vs. 4.9%, p = 0.04). Patients with PARP had a higher median RHI in resection specimens (14 vs. 7, p < 0.01).

CONCLUSION

PARP was present during colonoscopy regardless disease activity and was predominantly found in UC patients with younger age and shorter disease duration. PARP patients had a more severe course of UC, and in case of appendectomy, more severe histopathological appendiceal inflammation. Appendectomy as an experimental therapy for UC has been suggested to be predominantly effective in UC patients with appendiceal inflammation. This study demonstrates that presence of a PARP on colonoscopy predicts appendiceal inflammation. After consensus has been reached on the therapeutic effect of appendectomy, assessing PARP presence during colonoscopy could therefore contribute to identifying patients most likely to respond.

Appendix and Ulcerative Colitis: a Key to Explaining the Pathogenesis and Directing Novel Therapies?

The vermiform appendix is generally considered a redundant organ, but recent evidence suggests that the appendix could contribute to the pathogenesis of inflammatory bowel diseases, in particular ulcerative colitis (UC), and may even have a therapeutic role; however, mechanisms of the appendix involvement remain unclear. Here, we highlight current evidence on the link between the appendix and UC and consider plausible therapeutic implications. A literature search was conducted using PubMed and PubMed Central from inception to Nov 2021 using the terms "Appendix", "UC", "Appendix & UC," "Appendectomy", and "Peri-appendicular patch," including only articles published in English. Reference lists from the selected studies were manually searched and reviewed to gather additional related reports. Inflammation around the appendix ("peri-appendicular patch") has been frequently observed in UC patients without other cecal involvement, and this inflammation can even precede the onset of UC. Epidemiologic studies propose that appendectomy reduces the risk of developing UC or even the risk of flare after UC is diagnosed, although this remains controversial. We reviewed studies showing altered host-microbe interactions in the appendix in UC, which suggest that the appendix could act as a priming site for disease via alterations in the immune response and changes in microbiota carried distally to the colon. In summary, recent literature suggests a possible role for microbes and immune cells within the appendix; however, the role of the appendix in the pathogenesis of UC remains unclear. Further research could clarify the therapeutic potential related to this organ.

High prevalence of ulcerative appendicitis in patients with ulcerative colitis

BACKGROUND

Previous studies have indicated that the appendix may be a priming site of ulcerative colitis (UC). Appendectomy is inversely associated with the development of UC, and is suggested to have a beneficial effect on the disease course in patients with refractory disease.

OBJECTIVE

The aim of the current study was to assess histological features of appendices from patients with UC and their clinical relevance.

METHODS

Patients with UC in remission and active UC (therapy refractory) that underwent appendectomy between 2012 and 2019 were included. Histological features of UC appendices were compared to those of patients with acute appendicitis and colon carcinoma. The Robarts Histopathology Index (RHI) was used to assess appendiceal inflammation. In patients with active UC, histological and clinical characteristics were compared between patients with and without endoscopic response following appendectomy.

RESULTS

In total, 140 appendix specimens were assessed (n = 35 UC remission, n = 35 active UC, n = 35 acute appendicitis, n = 35 colon carcinoma). Histological features of appendices from UC patients looked like UC rather than acute appendicitis. The presence of active appendiceal inflammation was comparable between patients in remission versus active disease (53.7% vs. 46.3%, p = 0.45) and limited versus extensive disease (58.5% vs. 41.5%, p = 0.50). Endoscopic response (Mayo 0-1) following appendectomy, assessed in 28 therapy refractory patients, was more frequently seen in patients with higher RHI scores (RHI > 6: 81.8% vs. RHI ≤ 6: 9.1%, p = 0.03) and limited disease (proctitis/left sided 63.6% vs. pancolitis 36.4%, p = 0.02).

CONCLUSION

The presence of active appendiceal inflammation is common in UC and does not correlate with colonic disease activity. More than 50% of UC patients in remission showed active histological disease in the appendix. Favorable response to appendectomy for refractory UC was seen in cases with ulcerative appendicitis. These findings might support the role of the appendix as a pivotal organ in UC.

CT imaging findings of anti-PD-1 inhibitor-related enterocolitis

PURPOSE

Immune checkpoint inhibitors promote the antitumor activity of T cells; however, there is a risk of side effects. The aim of this study was to characterize the computed tomography (CT) findings of one such side effect, anti-programmed cell death-1 antibody-related enterocolitis (αPD-1-EC).

METHODS

This single-institution retrospective study included 21 patients with αPD-1-EC who underwent CT between January 2015 and April 2020. Two board-certified radiologists independently evaluated the CT findings, including the pattern of intestinal wall enhancement, maximum bowel wall thickness, maximum appendiceal diameter, and involvement of enterocolitis in each intestinal segment. Symptoms and their severity were also investigated.

RESULTS

Pancolitis and skip lesions involving both the rectosigmoid colon and the cecum were found in 9 patients each (42.9%). The rectum was the most frequently involved lesion (18/21, 85.7%), and appendiceal involvement was found in 11 patients (52.4%). The most frequent wall enhancement pattern was the gray pattern (i.e., mild homogeneous enhancement of the thickened bowel wall). The mean maximum diameter of the involved appendix was 9.6 ± 4.5 mm (range 4.5-18 mm). Frequent symptoms included diarrhea (21/21), fever (8/21), and abdominal pain (7/21). Other concomitant immune-related adverse events were found in 6 patients.

CONCLUSIONS

Pancolitis, skip lesions, and appendiceal involvement were frequent in patients with αPD-1-EC. When combining these characteristic findings with other clinical findings, such as low-grade diarrhea, other concomitant immune-related adverse events, and anti-PD-1 therapy administration, CT may be a useful diagnostic tool for αPD-1-EC.

Clinical significance of pathologic abnormalities in biopsy samples from the appendiceal orifice

AIMS

Appendiceal orifice mucosa often appears inflamed endoscopically, even when other colonic segments appear normal. Histological findings in biopsy samples taken from endoscopically abnormal mucosa may simulate a variety of inflammatory colitides. We performed this study to evaluate the clinical implications of inflammatory changes isolated to the appendiceal orifice.

METHODS AND RESULTS

In this double cohort study, biopsy samples from 26 histologically abnormal appendiceal orifices were reviewed. Twenty-five control cases were culled from endoscopically normal (n = 11) and abnormal (n = 14) appendiceal orifices that were histologically normal. Histological findings were correlated with presentation, medication history, findings at other colonic sites and clinical outcomes. Study cases displayed active inflammation (n = 12), chronic active inflammation (n = 13) or features simulating collagenous colitis (n = 1). Eighteen patients had biopsies taken from other colonic sites; these revealed benign polyps (n = 10) or displayed active (n = 4) or chronic active (n = 4) inflammation. All patients with findings isolated to the appendiceal orifice were asymptomatic at most recent clinical follow-up. Four of eight (50%) of the patients with inflammation in other biopsy samples were ultimately diagnosed with ulcerative colitis, in keeping with the well-established role of the appendix as a 'skip lesion' in that disorder. Control patients presented for screening colonoscopy (n = 19), iron deficiency anaemia (n = 3) or change in bowel habits (n = 3) and none reported gastrointestinal symptoms upon follow-up, regardless of the endoscopic appearance of the appendiceal orifice.

CONCLUSION

Isolated inflammation of the appendiceal orifice mucosa should not be regarded as a feature of evolving inflammatory bowel disease or other types of chronic colitis.

Ultrasound features of secondary appendicitis in pediatric patients

Purpose

The purpose of this study was to evaluate the ultrasonographic findings of secondary appendicitis (SA) and to discuss the differential findings compared with primary appendicitis.

Methods

In this study, we analyzed the ultrasonographic findings of 94 patients under 15 years old of age treated at our institution from May 2005 to May 2014 who had bowel inflammation and an inflamed appendix with a maximal outer diameter >6 mm that improved with nonsurgical treatment (the SA group). Ninety-nine patients with pathologically proven acute appendicitis (the primary appendicitis [PA] group) from June 2013 to May 2014 and 44 patients with pathologically negative appendectomy results from May 2005 to May 2014 were also included to compare the ultrasonographic features of these conditions. A retrospective review of the ultrasonographic findings was performed by two radiologists. The clinical and laboratory findings were also reviewed. The results were statically analyzed using analysis of variance, the Pearson chi-square test, and the two-tailed Fisher exact test.

Results

Compared with PA, cases of SA had a smaller diameter (9.8 mm vs. 6.6 mm, P<0.001), and were less likely to show periappendiceal fat inflammation (98% vs. 6%, P<0.001) or an appendicolith (34% vs. 11%, P<0.001). SA showed mural hyperemia on color Doppler ultrasonography as frequently as PA (P=0.887).

Conclusion

The ultrasonographic features of SA included an increased diameter compared to a healthy appendix and the same level of hyperemia as in PA. However, the diameter was commonly in the equivocal range (mean diameter, 6.6 mm), and periappendiceal fat inflammation was rarely present in SA.

The immunology of the vermiform appendix: a review of the literature

This literature review assesses the current knowledge about the immunological aspects of the vermiform appendix in health and disease. An essential part of its immunological function is the interaction with the intestinal bacteria, a trait shown to be preserved during its evolution. The existence of the appendiceal biofilm in particular has proved to have a beneficial effect for the entire gut. In assessing the influence of acute appendicitis and the importance of a normally functioning gut flora, however, multiple immunological aspects point towards the appendix as a priming site for ulcerative colitis. Describing the immunological and microbiotical changes in the appendix during acute and chronic inflammation of the appendix, this review suggests that this association becomes increasingly plausible. Sustained by the distinct composition of cells, molecules and microbiota, as well as by the ever more likely negative correlation between the appendix and ulcerative colitis, the idea of the appendix being a vestigial organ should therefore be discarded.

The Link between the Appendix and Ulcerative Colitis: Clinical Relevance and Potential Immunological Mechanisms

The human appendix has long been considered as a vestigial organ, an organ that has lost its function during evolution. In recent years, however, reports have emerged that link the appendix to numerous immunological functions in humans. Evidence has been presented for an important role of the appendix in maintaining intestinal health. This theory suggests that the appendix may be a reservoir or 'safe house' from which the commensal gut flora can rapidly be reestablished if it is eradicated from the colon. However, the appendix may also have a role in the development of inflammatory bowel disease (IBD). Several large epidemiological cohort studies have demonstrated the preventive effect of appendectomy on the development of ulcerative colitis, a finding that has been confirmed in murine colitis models. In addition, current studies are examining the possible therapeutic effect of an appendectomy to modulate disease course in patients with ulcerative colitis. This literature review assesses the current knowledge about the clinical and immunological aspects of the vermiform appendix in IBD and suggests that the idea of the appendix as a vestigial remnant should be discarded.

Identification of pathologic features associated with “ulcerative colitis-like” Crohn’s disease

AIM: To identify pathologic features associated with this “ulcerative colitis (UC)-like” subgroup of Crohn’s disease (CD).

METHODS: Seventeen subjects diagnosed as having UC who underwent proctocolectomy (RPC) from 2003-2007 and subsequently developed CD of the ileal pouch were identified. UC was diagnosed based on pre-operative clinical, endoscopic, and pathologic studies. Eighteen patients who underwent RPC for UC within the same time period without subsequently developing CD were randomly selected and used as controls. Pathology reports and histological slides were reviewed for a wide range of gross and microscopic pathological features, as well as extent of disease. The demographics, gross description and histopathology of the resection specimens were reviewed and compared between the two groups.

RESULTS: Patients with “UC-like” CD were on average 13 years younger than those with “true” UC (P < 0.01). More severe disease in the proximal involved region and active ileitis with/without architectural distortion were observed in 6 of 17 (35%) and 7 of 17 (41%) “UC-like” CD cases, respectively, but in none of the “true” UC cases (P < 0.05). Active appendicitis occurred in 8 of 16 (50%) “UC-like” CD cases but in only two (11%) “true” UC cases (P < 0.05). Conspicuous lamina propria neutrophils were more specific for “UC-like” CD (76% vs 22%, P < 0.05). In addition, prominent lymphoid aggregates tended to be more common in “UC-like” CD (P = 0.07). The “true” UC group contained a greater number of cases with severe activity (78% vs 47%). Therefore, the features more commonly seen in “UC-like” CD were not due to a more severe disease process. Crohn’s granulomas and transmural inflammation in non-ulcerated areas were absent in both groups.

CONCLUSION: More severe disease in the proximal involved region, terminal ileum involvement, active appendicitis, and prominent lamina propria neutrophils may be morphological factors associated with “UC-like” CD.

Appendiceal skip inflammation and ulcerative colitis

In recent decades, the appearance of inflammation near the appendix in patients with distal ulcerative colitis (UC) has been highlighted. Many epidemiological studies have confirmed the link between appendectomy and decreased incidence of UC. However, the clinical significance of appendiceal orifice inflammation (AOI) or peri-appendiceal red patch (PARP) as a "skip lesion" in UC has not been well elucidated. In this review, we summarized the literature regarding AOI/PARP and the role of this lesion in relation to UC. Since the appendiceal "skip area" in UC was first described in 1958, several reports using histologic examination of colectomy specimens and colonoscopy have been published. AOI/PARP has been more frequently associated with distal, mild UC than extensive, severe disease. Although it is still controversial, AOI/PARP seems to have little prognostic implication in the disease course of UC, including remission, relapse and proximal disease extension. However, some case reports have raised the possibility of a relationship between AOI/PARP and appendiceal neoplasms such as appendiceal cystadenoma and appendiceal adenocarcinoma. In addition, some investigators have treated UC patients who were resistant to conventional medical therapy with appendectomy and have reported inconsistent therapeutic effect. Further research may lead to the discovery of etiologic and pathogenic roles of appendiceal inflammation in UC.

Ulcerative colitis or Crohn's disease? Pitfalls and problems

The interpretation of colorectal biopsies taken for the initial diagnosis of chronic idiopathic inflammatory bowel disease (IBD) is challenging. Subclassification of IBD as ulcerative colitis (UC) or Crohn's disease, which may be particularly difficult, is the subject of this review. Biopsies taken at first presentation are emphasised, partly because their features have not been modified by time or treatment. Aspects of longstanding disease and of resections are also mentioned. The first part of the review comprises background considerations and a summary of histological features that are discriminant, according to published evidence, between UC and Crohn's disease in initial biopsies. Pitfalls and problems associated with making the distinction between UC and Crohn's disease are then discussed. These include: mimics of IBD; inadequate clinical details; unreliable microscopic features; absence of histological changes in early IBD; discontinuity in UC; cryptolytic granulomas; differences between paediatric and adult UC; reliance on ileal and oesophagogastroduodenal histology; and atypical features in IBD resections. Avoidance by pathologists of known pitfalls should increase the likelihood of accurate and confident subclassification of IBD, which is important for optimum medical and surgical management.

Inflammatory bowel disease biopsies: updated British Society of Gastroenterology reporting guidelines

Accurate histopathological assessment of biopsies is important for the diagnosis, subclassification, and management of chronic idiopathic inflammatory bowel disease (IBD). British Society of Gastroenterology (BSG) guidelines for the initial histopathological diagnosis of IBD were published in 1997. Changes since then include: more widespread use of full colonoscopy; greater recognition of the effects of time and treatment; improved documentation of variations in anatomical distribution; better understanding of the mimics of IBD; significant progress in clinical management; and modifications of terminology. Accordingly, an update is required. These revised guidelines aim to optimise the quality and consistency of reporting of biopsies taken for the initial diagnosis of IBD by summarising the literature and making recommendations based on the available evidence. Advice from existing clinical guidelines is also taken into account. Among the subjects discussed are: distinguishing IBD from other colitides, particularly infective colitis; subclassification of IBD (as ulcerative colitis, Crohn's disease, or IBD unclassified); the discriminant value of granulomas; aspects of disease distribution, including discontinuity in ulcerative colitis; time-related changes; differences between paediatric and adult IBD; the role of ileal and upper gastrointestinal biopsies; differential diagnoses such as diverticular colitis and diversion proctocolitis; and dysplasia. The need to correlate the histological features with clinical and endoscopic findings is emphasised. An approach to the conclusion of an IBD biopsy report based on the acronym Pattern, Activity, Interpretation, Dysplasia (PAID) is suggested. The key recommendations are listed at the end of the document.

Appendiceal Orifice Inflammation in an 8-Year-Old Girl with Ulcerative Colitis Complicating Wilson's Disease

Appendiceal orifice inflammation (AOI) may occur as a skipped lesion in ulcerative colitis (UC). Cases of ulcerative colitis complicated by Wilson's disease have also been reported. We report herein a case of AOI that occurred as a missed lesion in an 8-year-old girl with UC complicating Wilson's disease, which is rare in children.

Appendiceal mucinous cystadenoma is a neoplastic complication of IBD: case-control study of primary appendiceal neoplasms

BACKGROUND

IBD is a risk factor for development of colorectal neoplasia. Although IBD frequently involves the appendix microscopically, it is uncertain whether it also predisposes to appendiceal neoplasia.

METHODS

We performed a retrospective case-control study of incidental appendiceal neoplasms in colectomy specimens of adults with and without IBD (cases and controls, respectively) based on surgical pathology records spanning 54 months. To minimize referral bias, patients were excluded if they had preoperative clinical evidence or a principal pathologic diagnosis of appendiceal disease. The pathologic diagnoses were confirmed retrospectively.

RESULTS

Eleven appendiceal cystadenomas and 6 appendiceal carcinoid tumors were identified among 705 IBD cases (377 ulcerative colitis, 317 Crohn's disease, 11 indeterminate colitis) and 498 non-IBD controls meeting our inclusion criteria. There was no significant difference in prevalence of cyst adenomas between the cases and controls (9/705 [1.3%] versus 2/498 [0.4%], respectively, OR 3.2 [95% CI 0.7-14.9]). However, cyst adenomas were 15-fold more prevalent among cases with synchronous colorectal neoplasia compared with controls (4/69 [5.8%] versus 2/498 [0.4%], OR 15.3 [95% CI 2.7-85]) and 8-fold higher compared with cases without synchronous neoplasia (4/69 [5.8%] versus 5/636 [0.8%], OR 7.8 [95% CI 2.0-29.6]). Appendiceal carcinoids were equally prevalent in cases and controls (4/705 [0.6%] versus 2/498 [0.4%], OR 1.4 [95% CI 0.3-7.8]), cases with synchronous neoplasia and controls (1/69 [1.4%] versus 2/498 [0.4%], OR 3.6 [95% CI 0.3-40.8]), and cases with and without synchronous colorectal neoplasia (1/69 [1.4%] versus 3/636 [0.5%], OR 3.1 [95% CI 0.3-30.2]).

CONCLUSIONS

IBD with synchronous colorectal dysplasia or cancer is a risk factor for development of appendiceal cystadenomas, implicating this tumor as a neoplastic complication of IBD. IBD does not predispose to the development of appendiceal carcinoids.

Acute appendicitis is characterized by a uniform and highly selective pattern of inflammatory gene expression

Acute appendicitis (AA) is the most common life-threatening surgical emergency in pediatrics. To characterize the nature of the inflammatory response in AA, gene expression profiles were generated. We found remarkable uniformity in the genes that were differentially expressed between patients with appendicitis and control groups. Sixty-four probe sets were differentially expressed in samples from patients with both severe and mild appendicitis compared to control samples, and within this group we were able to identify four dominant clusters. Interestingly, expression levels of interleukin (IL)-8 significantly correlated with histologic score, and expression of IL-8 protein was observed within both neutrophils and mononuclear cells by immunohistochemistry, suggesting a possible role in the etiology of appendicitis. Although there was some overlap between genes reported to be differentially expressed in Crohn's disease (CD) and those observed in AA, differential expression of genes involved in interferon responses that characterize CD was not observed.

Differentiating ulcerative colitis from Crohn disease in children and young adults: report of a working group of the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition and the Crohn's and Colitis Foundation of America

BACKGROUND

Studies of pediatric inflammatory bowel disease (IBD) have varied in the criteria used to classify patients as having Crohn disease (CD), ulcerative colitis (UC), or indeterminate colitis (IC). Patients undergoing an initial evaluation for IBD will often undergo a series of diagnostic tests, including barium upper gastrointestinal series with small bowel follow-through, abdominal CT, upper endoscopy, and colonoscopy with biopsies. Other tests performed less frequently include magnetic resonance imaging scans, serological testing, and capsule endoscopy. The large amount of clinical information obtained may make a physician uncertain as to whether to label a patient as having CD or UC. Nevertheless, to facilitate the conduct of epidemiological studies in children, to allow the entry of children into clinical trials, and to allow physicians to more clearly discuss diagnosis with their patients, it is important that clinicians be able to differentiate between CD and UC.

METHODS

A consensus conference regarding the diagnosis and classification of pediatric IBD was organized by the Crohn's and Colitis Foundation of America. The meeting included 10 pediatric gastroenterologists and 4 pediatric pathologists. The primary aim was to determine the utility of endoscopy and histology in establishing the diagnosis of CD and UC. Each member of the group was assigned a topic for review. Topics evaluated included differentiating inflammatory bowel disease from acute self-limited colitis, endoscopic and histological features that allow differentiation between CD and UC, upper endoscopic features seen in both CD and UC, ileal inflammation and "backwash ileitis" in UC, patchiness and rectal sparing in pediatric IBD, periappendiceal inflammation in CD and UC, and definitions of IC.

RESULTS

Patients with UC may have histological features such as microscopic inflammation of the ileum, histological gastritis, periappendiceal inflammation, patchiness, and relative rectal sparing at the time of diagnosis. These findings should not prompt the clinician to change the diagnosis from UC to CD. Other endoscopic findings, such as macroscopic cobblestoning, segmental colitis, ileal stenosis and ulceration, perianal disease, and multiple granulomas in the small bowel or colon more strongly suggest a diagnosis of CD. An algorithm is provided to enable the clinician to differentiate more reliably between these 2 entities.

CONCLUSIONS

The recommendations and algorithm presented here aim to assist the clinician in differentiating childhood UC from CD. We hope the recommendations in this report will reduce variability among practitioners in how they use the terms "ulcerative colitis," "Crohn disease," and "indeterminate colitis." The authors hope that progress being made in genetic, serological, and imaging studies leads to more reliable phenotyping.

[Acute appendicitis in inactive extensive ulcerative colitis]

Appendectomy is associated with a reduced risk of developing ulcerative colitis (UC). In addition, there may be appendicular involvement in UC in patients with extensive or even left-sided disease. However, no data are available on the incidence, clinical presentation and outcome of acute appendicitis in patients previously diagnosed with UC. The impact of appendectomy in this subset of patients also remains to be determined. We describe 2 cases of acute appendicitis in the setting of inactive extensive ulcerative colitis and compare their histologic features with those of the surgical specimens of 2 further UC patients colectomized for refractory and extensive disease.

Pouchitis in Ulcerative Colitis: Correlation between Predictors from Colectomy Specimens and Clinico-Histological Features

Pouchitis after restorative proctocolectomy for ulcerative colitis is usually of ill-defined etiology and is encountered with sclerosing cholangitis, bacterial overgrowth, and ischemia. Recently, appendiceal involvement, ileitis, and fissures in the colectomy specimen have been associated with short- and long-term development of pouchitis. To corroborate these recent findings, the histology of 40 colectomies (70% males; mean age 46.3 years, age range 20-70 years; mean follow-up period 3.7 years, range 1-13 years) with yearly follow-up biopsies was correlated with pouchitis and clinical symptoms. Appendicitis, fissures, and ileitis were present in 47, 45 and 5% of the patients, respectively. Pouchitis in patients with appendicitis or with fissures was noted in 44 and 50% at first biopsy and in 70 and 58% during follow-up (p = NS). Of the patients without appendicitis or without fissures, 33 and 33% demonstrated pouchitis at the first biopsy and 30 and 55% during follow-up (p = NS). Clinico-histological correlation revealed normal/near-normal biopsies with the lowest clinical severity score in 77% and with the highest clinical score in 43% (p < 0.025). The histological findings of appendiceal involvement, fissuring ulcers, and ileitis in colectomies for ulcerative colitis do not correlate with the finding of pouchitis in early or late pouch biopsies. A high clinical suspicion score is frequently not correlated with significant inflammation of the pouch.

Skip inflammation of the appendiceal orifice: a prospective endoscopic study

OBJECTIVE

The purpose of the study was to evaluate the incidence of discontinuous inflammation of the appendiceal orifice in patients undergoing colonoscopy for diagnosis or surveillance of colonic disease.

MATERIAL AND METHODS

Consecutive and unselected patients subjected to colonoscopy over a 3-year period were included in a prospective study. Biopsies were taken within 2 cm of the orifice of the appendix, from the caecum and from predefined colonic segments. Discontinuous inflammation of the appendiceal orifice was defined as an area of macroscopic inflammatory changes distinct from a normal caecum of ascending colon. The biopsies were graded histologically for the presence and severity of inflammation by a pathologist without knowledge of the endoscopic findings.

RESULTS

A total of 271 patients were included. The final diagnoses were: ulcerative colitis (UC) (83 patients), Crohn's disease (CD) (54), indeterminate colitis (12), irritable bowel syndrome (IBS) (54), microscopic colitis (15) and other disease (53). Endoscopic discontinuous inflammation of the appendiceal orifice was found in 27% (95% CI: 17-38%) of patients with UC, 24% (95% CI: 13-39%) with CD, 40% (95% CI: 12-74%) with indeterminate colitis, 8% (95% CI: 0-36%) with microscopic colitis, 10% (95% CI: 3-24%) of patients with IBS and in 9% (95% CI: 2-021%) of other diseases (p<0.05). A correlation was found for endoscopic and histological discrimination between normal and inflamed mucosa (p<0.001). However, in 24% of patients, endoscopic inflammation was without histological signs of inflammation, primarily in an otherwise normal colon.

CONCLUSIONS

Discontinuous inflammation of the appendiceal orifice is common in patients with IBD irrespective of clinical activity. However, patients with otherwise normal colon may also show congestion of this area without or with minimal microscopic inflammation.

Appendix is a priming site in the development of ulcerative colitis

AIM: The role of the appendix has been highlighted in the pathogenesis of ulcerative colitis (UC). The aims of this study were to elucidate the immuno-imbalances in the appendix of UC patients, and to clarify the role of the appendix in the development of UC.

METHODS: Colonoscopic biopsy specimens of the appendix, transverse colon, and rectum were obtained from 86 patients with UC: active pancolitis (A-Pan; n = 15), active left-sided colitis (A-Lt; n = 25), A-Lt with appendiceal involvement (A-Lt/Ap; n = 10), inactive pancolitis (I-Pan; n = 14), and inactive left-sided colitis (I-Lt; n = 22), and from controls. In the isolated mucosal T cells, the CD4/CD8 ratio and proportion of activated CD4+ T cells were investigated, and compared with controls.

RESULTS: In the appendix, the CD4/CD8 ratio significantly increased in A-Lt and A-Lt/Ap. The ratio in the appendix also tended to increase in A-Pan. In the rectum, the ratio significantly increased in all UC groups. In the appendix, the proportion of CD4+CD69+ (early activation antigen) T cells significantly increased in all UC groups. In the rectum, the proportion of CD4+CD69+ T cells significantly increased only in A-Pan. The proportion of CD4+HLA-DR+ (mature activation antigen) T cells significantly increased only in the rectum of A-Pan, but not in the other areas of any groups.

CONCLUSION: The increased CD4/CD8 ratio and predominant infiltration of CD4+CD69+ T cells in the appendix suggest that the appendix is a priming site in the development of UC.

Granulomatous appendicitis and the appendix in idiopathic inflammatory bowel disease

Granulomatous appendicitis is a rare condition, accounting for less than 2% of all cases of appendicitis. The initial belief that it represented a manifestation of Crohn's disease is incorrect in the great majority of cases, as only 5-10% of patients with granulomatous appendicitis develop Crohn's disease elsewhere in their gastrointestinal tract. The remaining etiologies are diverse. Unusual causes include sarcoidosis, foreign body reaction, and infection by mycobacteria, fungi, or parasites. These conditions combined explain less than 10% of cases. More recently, two etiologies have been recognized that potentially account for most of the previous "idiopathic" cases of granulomatous appendicitis. The first is infection by pathogenic Yersinia species, now demonstrated in approximately 25% of cases. The second cause may be the most common of all, namely subacute/recurrent appendicitis with interval appendectomy. This condition likely produces a granulomatous reaction in relation to a protracted secondary inflammatory response to appendicitis and temporizing measures to delay appendectomy, such as antibiotic therapy. Thus, granulomatous appendicitis only rarely represents a manifestation of Crohn's disease. Rather, the overwhelming majority of patients with this condition are cured by appendectomy alone. The appendix, however, can be involved by idiopathic inflammatory bowel disease, both Crohn's disease and ulcerative colitis. It can be involved by ulcerative colitis in patients with distal colonic involvement and sparing of the intervening colonic segment, a phenomenon known as the appendiceal "skip lesion" or "cecal patch" and this pattern of involvement does not necessarily indicate Crohn's disease. Interestingly, appendectomy has been shown to provide some protection against developing inflammatory bowel disease and in reducing its severity if performed before the onset of disease.

[Cecal cytomegalovirus infection following appendicectomy in a patient with ulcerative colitis]

We report a patient who, 3 months after being diagnosed with ulcerative colitis, was admitted to hospital because of malaise and right lower abdominal pain. An open appendectomy was performed. Histological study showed ulcerative colitis affecting the appendix. After surgery, the patient presented a refractory outbreak of ulcerative colitis requiring treatment with steroids and cyclosporin A. Despite this treatment, the patient continued to pass abundant fresh blood associated with severe anemia. Colonoscopy showed only granular and congestive cecal mucosa. Biopsies showed intracytoplasmic inclusion bodies with immunohistochemical stains positive for cytomegalovirus (CMV) infection. Rectorrhagia and anemia quickly disappeared after beginning treatment with ganciclovir. Appendicular ulcerative colitis is not uncommonly associated with distal colitis. In addition, diffuse CMV infection complicating ulcerative colitis treatment is not unusual. By contrast, isolated, segmentary infection by CMV in the proximal colon is extremely rare. Until now, only three patients with localized CMV infection have been described, and all three cases occurred in the context of ileoanal anastomosis.

Skip lesion of the cecum associated with proctitis: an atypical case of ulcerative colitis

The authors report the clinical case of a patient who underwent total colectomy for acute ulcerative colitis. The unusual element in this case was the presence of a lesion ('skip lesion'), typical of ulcerative colitis, in the periappendiceal area of the cecum, which was discontinuous to the main site of disease located in the rectum and left colon. The presence of skip lesions, whose clinicopathological relevance is still unknown, would seem to disprove the widely held view that ulcerative colitis involves only the mucous membrane of the large intestine, with inflammatory processes of varying intensity, but without intervening normal areas. The alteration in mucosal immune response by sharing of some factors as bacterial flora, stasis and secretory products is a suggestive pathogenetic supposition.

The clinical significance of right-sided colonic inflammation in patients with left-sided chronic ulcerative colitis

BACKGROUND

Rarely, patchy right colonic inflammation has been observed in patients with left sided chronic ulcerative colitis (CUC), but the clinical significance of this finding is unknown. Therefore, the aim of this study was to evaluate the clinical and pathologic features and natural history of CUC patients with left-sided colitis combined with patchy right colonic inflammation and to compare the clinical course to a control group of patients with isolated left-sided CUC.

METHODS

Twelve patients with clinically and pathologically confirmed left-sided CUC, but also with patchy right colonic inflammation, were identified from a cohort of 352 consecutive patients with CUC who underwent colonoscopy at the Brigham and Women's Hospital between 1996 and 2000. In this cohort, 127 patients had left-sided colitis. As the first study to use controls in this setting, 35 consecutive patients with left-sided CUC, but without patchy right colonic inflammation, were selected and evaluated during the same time period. In all patients, the medical records were reviewed for a wide variety of clinical, endoscopic, and pathologic features. The mean follow-up time for the study and control groups was 105 +/- 128 and 112 +/- 80 months, respectively.

RESULTS

Patients in the study group were significantly older than the control group at the time of diagnosis (47 +/- 17 years vs 35 +/- 14 years, p = 0.048), but the two groups had a similar gender distribution (25% male vs 40% male), prevalence of extraintestinal manifestations (25% vs 11%), frequency of nonsteroidal anti-inflammatory drug use (75% vs 50%), family history of colitis (27% vs 15%), current tobacco use (8% vs 3%), history of appendectomy (8% vs 0%), and overall severity of disease (33% vs 46%). None of the patients in the study group, and only one control patient, had disease progression to pancolitis. One study patient developed high-grade dysplasia in the rectum that required a colectomy. None of the study or control patients developed clinical or pathologic features of Crohn's disease.

CONCLUSIONS

Rarely patients with left-sided CUC may have patchy right colonic inflammation. The clinical features and natural history of patients with left-sided CUC and patchy right colonic inflammation is similar to patients with isolated left-sided CUC.

Increased expression of minichromosome maintenance protein 2 in active inflammatory bowel disease

OBJECTIVE

Minichromosome maintenance protein 2 (Mcm2) is an accurate indicator of cell cycle entry in tissue samples, but its expression in inflammatory bowel disease (IBD) has not previously been investigated. We have used immunohistochemistry to assess the expression of Mcm2, in comparison to the existing proliferation marker Ki-67, in active IBD and IBD without inflammatory activity.

MATERIALS AND METHODS

For this experimental study, sections from colonic biopsy and resection specimens of 48 patients with IBD (5 inactive/quiescent Crohn's disease (CD), 13 active CD, 19 inactive/quiescent ulcerative colitis (UC) and 11 active UC) and 15 normal controls were immunostained with antibodies to Mcm2 and Ki-67. The percentage of immunopositive epithelial nuclei was determined by calculating a labelling index (LI) for entire glands and for gland thirds (superficial, middle and basal).

RESULTS

The Mcm2 LI was significantly increased in the superficial third of glands in active vs. inactive/quiescent UC (P < 0.0001) and active vs. inactive/quiescent CD (P = 0.001). The Mcm2 LI was significantly greater than the Ki-67 LI in active IBD, both in entire glands (P < 0.0001) and in the superficial third of glands (UC, P = 0.001; CD, P = 0.0002). Mcm2 LIs for entire glands were significantly higher in UC (all cases) compared to CD (all cases) (P = 0.032).

CONCLUSIONS

There is increased cell cycle entry, as indicated by expression of Mcm2 and to a lesser extent Ki-67, in the superficial third of colonic glands in active IBD compared to inactive/quiescent IBD. Detection of Mcm2 may contribute to improved histological assessment of small tissue biopsies and may enable the development of a direct stool-based test for detection of active IBD and potentially for assessment of disease activity.

Does Appendectomy Reduce the Risk of Ulcerative Colitis?

BACKGROUND

Persons who have had an appendectomy are less prone to develop ulcerative colitis than those who have not. The underlying mechanism and the clinical use of this finding are unknown.

METHODS

Two competing hypotheses were examined: (1) the inverse association between appendectomy and ulcerative colitis is conferred by a mutual determinant such as genes, and (2) the appendix itself has biologic effects that promote the development of ulcerative colitis. We performed a population-based cohort study of all 234,559 persons who had an appendectomy performed in Denmark 1977 through 1999. We used a bidirectional cohort design, calculating the standardized incidence rate of ulcerative colitis both before and after the appendectomy. If the hypothesis of a constant, confounding factor were true, incidence rates of ulcerative colitis would be equal before and after appendectomy. If the incidence of ulcerative colitis were lower after appendectomy than before, it would support the second hypothesis and a true protective effect of the appendectomy. We controlled confounding by age and sex using direct standardization.

RESULTS

Of 234,559 persons who had an appendectomy, 559 developed ulcerative colitis during a mean follow up of 17.5 years. The standardized incidence rate of ulcerative colitis was lower in the postappendectomy period than in the preappendectomy period (incidence rate ratio = 0.74; 95% confidence interval = 0.62-0.88).

CONCLUSIONS

The inverse association between appendectomy and ulcerative colitis is not explained by time-stable factors such as genes. Appendectomy might have a genuine protective effect toward development of ulcerative colitis.

Multiple myenteric networks in the human appendix

The general histological organization of the appendix, including its innervation, is believed to be generally similar to that of the large intestine. However, several authors described an unusual arrangement of the myenteric ganglia within the appendiceal muscle, but conflicting reports do not allow clear conclusions on this matter. The aim of this work was to examine the appendiceal innervation in detail. The myenteric plexus of the human appendix was examined using sections and whole mount preparations. Human small and large intestines were used for comparison. The nerves were stained using immunohistochemistry, enzyme histochemistry for NADPH-diaphorase, and vital staining with 4-(4-diethylaminostyryl)-methylpyridinium iodide. Appendices from rabbits were also studied. In most cases, the innervation of the external muscle of the appendix consisted of three concentric networks of ganglia. These networks were located both between the circular and longitudinal muscle layers and within them. The middle network made connections with the other two. Such arrangement was not observed in the human small and large intestines. The myenteric plexus in the rabbit appendix displayed a much smaller degree of three-dimensional distribution compared with that of the human appendix. It is concluded that the myenteric plexus in the human appendix consists of several distinct networks, and appears to be unique in comparison with the other parts of the intestine.

Multiple microcarcinoids in a patient with long standing ulcerative colitis

A male patient with a 17 year history of intractable ulcerative colitis of the entire type was treated by total proctocolectomy. Colonoscopy before surgery did not identify dysplasia. Histological examination of the resected colorectum revealed that, in addition to chronic inflammatory infiltrates, there were 21 areas of microcarcinoids located in the muscularis propria and in the superficial layer of the submucosa. Carcinoids may be more common than previously thought, and they may be a reactive phenomenon to a variety of factors in ulcerative colitis.

Rare benign and malignant appendiceal lesions: spectrum of computed tomography findings with pathologic correlation

Although acute appendicitis is the most common disease of the appendix, the appendix can be involved by a wide range of diseases. Diseases other than acute appendicitis may produce signs and symptoms indistinguishable from those of acute appendicitis. Computed tomography (CT) can provide important information for diagnosis and evaluation of appendiceal diseases. The various CT and histologic features of appendiceal benign and neoplastic diseases are discussed, illustrated, and correlated in this article. Radiologists need to understand the full spectrum of appendiceal abnormalities, their underlying pathologic changes, and associated CT imaging findings.

[Ulcerative colitis with segmental involvement]

INTRODUCTION

Ulcerative colitis is a chronic inflammatory disease affecting areas of the colon or the full length. From the endoscopic point of view, ulcerative colitis presents lesions that stretch continuously from the rectum to variable colon segments, a characteristic that is of great value when distinguishing it from Crohn's disease. Continuous involvement, without healthy patches, justifies ending endoscopic exploration once the distal end of the lesion has been reached.

OBJECTIVE

To retrospectively study the frequency of segmental lesions in the colonoscopies performed in patients with ulcerative colitis.

METHODS

Diagnosis of ulcerative colitis and proctitis was established by clinical, endoscopic, histologic, analytical, and radiological criteria. The indication and number of endoscopies was made on the basis of the clinical criteria of diagnosis, acute episodes, refractoriness or dysplasia screening. The extent of the examination also depended on clinical criteria: the severity of the episode, tolerance to colonoscopy or the degree of cleansing.

RESULTS

A total of 155 coloscopies were performed. In 113 colonoscopies (73%) the distal end of the lesion was reached and in 70 (45%) the cecum was reached. Of the 80 patients, 27 (33%) presented ulcerative proctitis at diagnosis. Nine of the 80 patients (11.3%) biopsies were performed in healthy colonic patches, which confirmed histological normality. Six of the 9 patients were receiving no treatment. In all patients except two, the cecum was reached in one or more of the colonoscopies. The distribution of the segmental lesions varied but these were mainly found in the periappendicular region and in the cecum in 6 of the 7 patients in whom the cecum was reached. Of the 80 patients, endoscopic evidence of rectal sparing was found in 5 (6.3%); of these, 4 were receiving systemic or topical treatment. Histological analysis confirmed the absence of inflammatory lesions in these patients. The only patient who was not receiving treatment presented microscopic lesions compatible with ulcerative colitis.

CONCLUSIONS

Endoscopic segmental lesions in ulcerative colitis were present in 11.3% of patients. Segmental lesions were most frequently found in the cecum and periappendicular region. Endoscopic and histologic evidence of rectal sparing may be the result of systemic or topical treatment.

Appendectomy protects against the development of ulcerative colitis but does not affect its course

OBJECTIVES

Appendectomy has been shown to protect against the development of ulcerative colitis. The objective of this study was to examine the effect of appendectomy on the clinical features and natural history of colitis.

METHODS

A total of 259 consecutive adults patients with ulcerative colitis were studied. Of the patients, 20 had undergone appendectomy (12 before onset of colitis and eight after diagnosis).

RESULTS

The frequency of appendectomy was significantly less than in a group of 280 controls, which comprised partners of the patients and a group from the community (OR = 0.25; 95% CI = 0.14-0.44). This was even more significant if only the 12 patients who underwent surgery before the onset of colitis were considered (OR = 0.15; 95% CI = 0.07-0.28). Patients with prior appendectomy developed symptoms of ulcerative colitis for the first time at a significantly later age than those without appendectomy (42.5 +/- 6.5 vs 32.1 +/- 0.8 yr; p < 0.01) or those who had appendectomy after the onset of colitis (24.6 +/- 3.4 yr; p < 0.05). Appendectomy did not influence disease extent, need for immunosuppressive treatment with azathioprine or 6-mercaptopurine (as a marker of resistant disease), or the likelihood of colectomy. Five patients in the appendectomy group had clinical evidence of primary sclerosing cholangitis (25%). This was more common than in those without appendectomy (8%; OR = 4.09; 95% CI = 1.04-13.60).

CONCLUSIONS

These results indicate that although appendectomy may delay onset of colitis, it does not influence its course. However, it is associated with the development of primary sclerosing cholangitis. Appendectomy is unlikely to be of benefit in established ulcerative colitis.

Role of appendicitis and appendectomy in the pathogenesis of ulcerative colitis: a critical review

Besides a genetic predisposition, a causal role of various environmental factors has been considered in the etiology of ulcerative colitis (UC). The association between appendectomy and UC has recently been the subject of intense scrutiny in the hope that it may lead to the identification of important pathogenetic mechanisms. Published data from animal models of colitis demonstrated reduction in experimental colitis after appendectomy, especially if performed at an early age. Several epidemiological case control and cohort studies have shown a strong and consistent relationship. The metaanalysis of 17 case-controlled studies showed an overall odds ratio 0.312 (95% confidence intervals = 0.261-0.373) in favor of appendectomy (p < 0.0001). One of the two recent large cohort studies is in agreement with these results, but the other failed to confirm them. All these studies have suggested that alterations in mucosal immune responses leading to appendicitis or resulting from appendectomy may negatively affect the pathogenetic mechanisms of UC. Further investigation of the role of appendectomy in UC is expected to open new fields for basic scientific research and may lead to the improvement of our understanding for the disease pathogenesis.

Significance of appendiceal involvement in patients with ulcerative colitis

BACKGROUND

The appendix is occasionally involved in patients with distal ulcerative colitis. This study investigated the clinical significance of patchy involvement at the appendiceal orifice in ulcerative colitis.

METHODS

Colonoscopy was performed in 40 patients with active distal ulcerative colitis of mild to moderate severity. Patients were divided into 2 groups based on the presence or absence (positive or negative) of involvement at the appendiceal orifice at colonoscopy. Clinical activity, histologic grade of inflammation, and subsequent clinical course were compared between patients who were positive (appe(+)) and negative (appe(-)).

RESULTS

Twenty-three patients had involvement at the appendiceal orifice (reddish mucosa with mucinous exudate). The proximal-most extent of involvement by ulcerative colitis, the endoscopic grade, and clinical activity were not different between appe(+) and appe(-) groups. However, histologic grade of inflammation in the ascending colon was higher in the appe(+) group than in the appe(-) group. The endoscopic remission rate at 12 months was higher in the appe(+) group than in the appe(-) group (84% vs. 40%, p < 0.05).

CONCLUSIONS

In patients with distal ulcerative colitis, involvement at the appendiceal orifice may be indicative of histologically active disease, which responds reasonably well to pharmacotherapy.

Role of appendix and spleen in experimental colitis

There is growing clinical evidence suggesting that certain secondary lymphoid tissues (e.g., appendix and spleen) contribute to the initiation and/or perpetuation of ulcerative colitis. In this study, the importance of secondary lymphoid tissues in inducing colitis was assessed experimentally by removing the spleen and/or appendix (or sham operation) prior to inducing colitis in mice. Feeding 2.5% dextran sulphate sodium (DSS) in drinking water over 7 days induced colitis. Clinical disease activity was assessed based on weight loss, stool consistency, and presence of blood in stools. Additional measurements included white blood cell count and hematocrit, and myeloperoxidase activity (MPO) in colon samples. Colonic injury was assessed by histology and computerized image analysis. DSS treatment in sham-operated mice produced colitis associated with weight loss, bloody diarrhea, and mucosal ulceration. Clinical assessment of DSS-treated mice subjected to appendectomy or combined appendectomy/splenectomy exhibited a delayed onset and course of disease activity. Histomorphologic examination revealed significantly lower damage scores and a reduction in ulcerated mucosal surface area. Colonic MPO activity, which correlated with tissue injury and disease activity, was lowest in appendectomized mice. No beneficial effects of splenectomy were observed after 7 days of colitis. These findings support the hypothesis that appendicular lymphoid tissue, but not the spleen, contributes to the development of colitis.

Diverticular colitis: diagnosis and management

Diverticular colitis is a recently recognized nosological entity in which a chronic focal mucosal sigmoid colitis occurs in association with diverticulosis. It usually presents with rectal bleeding and may be difficult to distinguish clinically, endoscopically and pathologically from other segmental colitides including ulcerative, Crohn's, ischaemic, infective and NSAID-induced colitis as well as diverticulitis. Uncontrolled data suggests that most patients respond satisfactorily to treatment with a high fibre diet, antibiotics and/or aminosalicylates, but a minority with persistent or recurrent symptoms require sigmoid resection. This paper reviews the literature on diverticular colitis and concludes with an algorithm suggesting the optimal management of patients who present with rectal bleeding in association with segmental sigmoid colitis and diverticulosis.

A patient with improvement of ulcerative colitis after appendectomy

Recently, several retrospective studies have shown an inverse association between appendectomy and development of ulcerative colitis. We describe a 21-year-old man with distal ulcerative colitis and appendiceal involvement. The patient passed bloody stools continually during the 3 years before admission. Macroscopic and microscopic findings showed chronic moderate inflammation of the appendix and rectum. The ratio of CD4 to CD8 lymphocytes isolated from rectal and appendiceal mucosa was increased (4.3 and 3.8, respectively) compared with controls (n = 11; 1.0 in the rectum and 1.4 in the appendix). Clinical symptoms and colonoscopic and microscopic findings improved significantly after appendectomy. In addition, the amount of interferon gamma secreted from rectal lymphocytes was reduced to 89 pg/mL after surgery (before appendectomy, 254 pg/mL). However, interleukin 4 production was below detectable levels both before and after appendectomy. These findings suggest that appendectomy resulted in altered T-helper (Th)1/Th2 balance in this patient. In the 3 years since surgery, the patient has been in good condition without recurrence of symptoms. This is the first report demonstrating therapeutic benefit of appendectomy in a patient with ulcerative colitis and potential mechanistic relationship.

Appendectomy and the development of ulcerative colitis: results of a metaanalysis of published case-control studies

OBJECTIVE

Numerous epidemiological studies have been performed to determine risk factors that might contribute to the development of ulcerative colitis (UC). Recent studies have focused on the role of appendectomy in the disease's pathogenesis. This report aims to review and analyze the degree of evidence from recent published studies.

METHODS

Medline and Embase databases were scrutinized for studies published between 1987 and January 1999. Reference lists from published articles, reviews, and abstracts from major gastrointestinal (GI) meetings were also reviewed. All studies specifically designed to evaluate the association between appendectomy and UC were selected. Thirteen studies that satisfied our selection criteria were evaluated by metaanalysis.

RESULTS

The 13 case-control studies collectively gathered evidence from 2770 patients with UC and 3352 controls. Combining the results of the individual studies gave an overall odds ratio of 0.307 (95% confidence interval [CI] = 0.249-0.377) in favor of appendectomy (p<0.0001). This suggests that appendectomy gives a 69% reduction in the risk of developing UC (95% CI = 62%-75%). The test for heterogeneity (of all 13 studies) was not significant (chi2 = 16.213, d.f. = 12, p>0.10). The influence of potential confounding factors (mainly smoking) on these results could be excluded.

CONCLUSIONS

The review of the literature and the metaanalysis of the selected studies suggest that the inverse association between appendectomy and UC is strong and consistent. Further studies are needed to establish whether a causal relationship exists.