A patient with improvement of ulcerative colitis after appendectomy

The Role of Appendicectomy in Ulcerative Colitis: Systematic Review and Meta-Analysis

BACKGROUND

This updated systematic review and meta-analysis investigates the putative role of the appendix in ulcerative colitis as a therapeutic target.

METHODS

Ovid Medline, Embase, PubMed and CENTRAL were searched with MeSH terms ("appendectomy" OR "appendicitis" OR "appendix") AND ("colitis, ulcerative") through October 2020, producing 1469 references. Thirty studies, including 118 733 patients, were included for qualitative synthesis and 11 for quantitative synthesis. Subgroup analysis was performed on timing of appendicectomy. Results are expressed as odds ratio (OR) with 95% confidence intervals (CIs).

RESULTS

Appendicectomy before UC diagnosis reduces the risk of future colectomy (OR, 0.76; 95% CI, 0.65-0.89; I2 = 5%; P = .0009). Corresponding increased risk of colorectal cancer and high-grade dysplasia are identified (OR, 2.27; 95% CI, 1.11-4.66; P = .02). Significance is lost when appendicectomy is performed after disease onset. Appendicectomy does not affect hospital admission rates (OR, 0.87; 95% CI, 0.68-1.12; I2 = 93%; P = .27), steroid use (OR, 1.08; 95% CI, 0.78-1.49; I2 = 36%; P = .64), immunomodulator use (OR, 1.04; 95% CI, 0.76-1.42; I2 = 19%; P = .79), or biological therapy use (OR, 0.76; 95% CI, 0.44-1.30; I2 = 0%; P = .32). Disease extent and risk of proximal progression are unaffected by appendicectomy. The majority (71% to 100%) of patients with refractory UC avoid colectomy following therapeutic appendicectomy at 3-year follow-up.

CONCLUSIONS

Prior appendicectomy reduces risk of future colectomy. A reciprocal increased risk of CRC/HGD may be due to prolonged exposure to subclinical colonic inflammation. The results warrant further research, as consideration may be put toward incorporating a history of appendicectomy into IBD surveillance guidelines. A potential role for therapeutic appendicectomy in refractory left-sided UC is also identified.

Appendectomy does not decrease the risk of future colectomy in UC: results from a large cohort and meta-analysis

OBJECTIVES

Early appendectomy is inversely associated with the development of UC. However, the impact of appendectomy on the clinical course of UC is controversial, generally favouring a milder disease course. We aim to describe the effect appendectomy has on the disease course of UC with focus on the timing of appendectomy in relation to UC diagnosis.

DESIGN

Using the National Institute of Diabetes and Digestive and Kidney Diseases Inflammatory Bowel Disease Genetics Consortium database of patients with UC, the risk of colectomy was compared between patients who did and did not undergo appendectomy. In addition, we performed a meta-analysis of studies that examined the association between appendectomy and colectomy.

RESULTS

2980 patients with UC were initially included. 111 (4.4%) patients with UC had an appendectomy; of which 63 were performed prior to UC diagnosis and 48 after diagnosis. In multivariable analysis, appendectomy performed at any time was an independent risk factor for colectomy (OR 1.9, 95% CI 1.1 to 3.1), with appendectomy performed after UC diagnosis most strongly associated with colectomy (OR 2.2, 95% CI 1.1 to 4.5). An updated meta-analysis showed appendectomy performed either prior to or after UC diagnosis had no effect on colectomy rates.

CONCLUSIONS

Appendectomy performed at any time in relation to UC diagnosis was not associated with a decrease in severity of disease. In fact, appendectomy after UC diagnosis may be associated with a higher risk of colectomy. These findings question the proposed use of appendectomy as treatment for UC.

Epidemiology and risk factors for IBD

IBD, comprising Crohn's disease and ulcerative colitis, is a chronic immunologically mediated disease at the intersection of complex interactions between genetics, environment and gut microbiota. Established high-prevalence populations of IBD in North America and Europe experienced the steepest increase in incidence towards the second half of the twentieth century. Furthermore, populations previously considered 'low risk' (such as in Japan and India) are witnessing an increase in incidence. Potentially relevant environmental influences span the spectrum of life from mode of childbirth and early-life exposures (including breastfeeding and antibiotic exposure in infancy) to exposures later on in adulthood (including smoking, major life stressors, diet and lifestyle). Data support an association between smoking and Crohn's disease whereas smoking cessation, but not current smoking, is associated with an increased risk of ulcerative colitis. Dietary fibre (particularly fruits and vegetables), saturated fats, depression and impaired sleep, and low vitamin D levels have all been associated with incident IBD. Interventional studies assessing the effects of modifying these risk factors on natural history and patient outcomes are an important unmet need. In this Review, the changing epidemiology of IBD, mechanisms behind various environmental associations and interventional studies to modify risk factors and disease course are discussed.

Appendectomy and the clinical course of ulcerative colitis: a retrospective cohort study and a nested case-control study from Korea

BACKGROUND AND AIM

Appendectomy protects against the development of ulcerative colitis (UC). However, the relationship between appendectomy and the clinical course of UC is complex, and could be impacted by a number of variables. The aim of this study was to compare the clinical course of UC between appendectomized patients and nonappendectomized patients in Korea.

METHODS

Data on 2648 UC patients were retrieved from the Inflammatory Bowel Disease registry at Asan Medical Center. This retrospective cohort study compared the clinical course of UC in 68 patients who received an appendectomy before their UC diagnosis and 2544 patients who did not receive this procedure. A nested case-control study was also conducted to compare the disease course before and after appendectomy in 36 patients who received this surgery after UC diagnosis. To control for potential confounders, 144 matched controls were retrieved from among 2544 nonappendectomized patients

RESULTS

In the retrospective cohort study, an appendectomy before UC diagnosis demonstrated no influence on disease extent at diagnosis, rates of medication use, proximal disease extension, or colectomy. The 10- and 20-year probabilities of receiving a colectomy were 12.7% and 20.6%, respectively, in appendectomized patients, in comparison with 8.9% and 16.4%, respectively, in nonappendectomized patients (P = 0.81). According to the nested case-control study, an appendectomy after UC diagnosis did not change the subsequent disease course in terms of medication use, proximal disease extension, or hospital admission rate. The adjusted ratio of hospital admissions after appendectomy versus before appendectomy was 1.01 (95% confidence interval = 0.46-2.23; P = 0.97).

CONCLUSIONS

Appendectomies performed before or after UC diagnosis do not affect its clinical course in the Korean population.

Environmental risk factors for inflammatory bowel diseases: a review

Inflammatory bowel diseases comprising Crohn's disease (CD) and ulcerative colitis (UC) are chronic immunologically mediated diseases. The key mechanism underlying the pathogenesis of these diseases is a dysregulated immune response to commensal flora in a genetically susceptible host. Thus intestinal microbial dysbiosis, host genetics, and the external environment all play an important role in the development of incident disease and in determining subsequent disease behavior and outcomes. There are several well-defined or putative environmental risk factors including cigarette smoking, appendectomy, diet, stress and depression, vitamin D as well as hormonal influence. The effect of some of the risk factors appears to differ between CD and UC suggesting that despite shared genetic and immunologic mechanisms, distinct pathways of pathogenesis exist. There is a growing body of literature identifying risk factors for incident disease. There is less rigorous literature defining triggers of relapse, and few controlled clinical trials examining if modification of such risk factors results in an improvement in patient outcomes. This is an area of considerable patient, physician, and scientific interest, and there is an important unmet need for rigorous studies of the external environment in disease pathogenesis and subsequent course.

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.

The effect of appendectomy on the course of ulcerative colitis: a systematic review

AIM

Previous studies have shown significantly lower appendectomy rates in ulcerative colitis (UC) patients compared with healthy controls. Evidence indicating that the appendix has an immunomodulatory role in UC has been accumulating. To examine the latest evidence on the effect of appendectomy on the disease course of UC.

METHOD

PubMed, The Cochrane Library and EMBASE were searched. Primary end-points were number of relapses, use of steroids, number of hospital admissions and number of colectomies.

RESULTS

The search resulted in six observational studies (five case-control studies and one cohort study) totalling 2532 patients. Owing to clinical heterogeneity, no meta-analysis could be conducted. One study found lower relapse rates in patients appendectomized before the onset of UC [absolute risk reduction (ARR)=21.5%; 95% CI: 1.71-45.92%]. Another two studies found a reduced requirement for immunosuppression in appendectomized patients (ARR=20.2%; 95% CI: 9.67-30.46% in the first study and ARR=21.4%; 95% CI: 10.32-32.97% in the second study). In addition, one study found lower colectomy rates in nonappendectomized patients (ARR=8.7%; 95% CI: 1.29-18.66%) and two studies found lower colectomy rates in appendectomized patients (ARR=21.4%; 95% CI: 13.17-28.79% in the first study and ARR=18.7%; 95% CI: 7.50-29.97% in the second study).

CONCLUSION

There are limited and conflicting data available regarding the effect of appendectomy on the disease course of UC. Most studies suggest a beneficial effect and the minority find no, or a negative, effect.

Effects of appendectomy and oral tolerance on dextran sulfate sodium colitis

AIM: To evaluate the concomitant effects of appendectomy and oral tolerance on colitis.

METHODS: Delayed-type hypersensitivity (DTH) was investigated at a 7-d interval after ovalbumin (OVA) administration and immunization under normal and colitis conditions in appendectomized or sham-operated mice. Pathological scores for the colon were graded after ingestion of colon-extracted protein (CEP) and induction of dextran sulfate sodium (DSS) colitis in appendectomized or sham-operated mice. Thereafter, Th1 and Th2 in Peyer’s patches and spleen lymphocytes were detected in CEP-treated and bovine serum albumin (BSA)-treated control mice.

RESULTS: In appendectomized mice, DTH was not inhibited at day 7 after OVA administration and at the initial phase of DSS colitis, whereas it was inhibited at day 14 and day 21. However, in sham-operated mice, it was inhibited during the whole procedure and the onset of DSS colitis. The protective role of CEP against DSS colitis was present in sham-operated mice, with predominant improvement of colonic pathological changes, while vanished in the appendectomized mice. A shift from Th1 to Th2 in Peyer’s patches resulted from a decrease of Th1 cells with the ingestion of CEP. Compared with BSA in the sham-operated group, no predominant changes were observed in the appendectomized mice.

CONCLUSION: Appendectomy interferes with the protective role of CEP in DSS colitis via a shift from Th2 to Th1 during oral tolerance induction.

[Remission of ulcerative colitis after appendectomy: a case report]

The inverse correlation of appendectomy and ulcerative colitis is well known, but the effect of appendectomy on the clinical course of ulcerative colitis remains unclear. Although the majority of opinions were negative for the therapeutic advantage of appendectomy in patients with ulcerative colitis, advocates for positive effect of appendectomy have been proposed in a few case reports and a prospective study from Western countries. We herein report a case of ulcerative colitis who experienced clinical remission after appendectomy for acute appendicitis. The patient was 35 year old male and had been managed with immunosuppressant before appendectomy. The very acute change in clinical course and a long period of remission after appendectomy highly suggest the therapeutic effect of appendectomy for ulcerative colitis.

The role of appendicectomy in the subsequent development of inflammatory bowel disease: a UK-based study

BACKGROUND

Several studies have shown an inverse relationship between appendicectomy and subsequent development of inflammatory bowel disease (IBD), although these findings remain contentious. This study aims to further elucidate the role appendicitis/appendicectomy has in the development of IBD.

METHOD

All patients undergoing appendicectomy at Hereford County Hospital between 1986 and 2005 were identified from pathology records. Those already diagnosed with IBD were excluded. Age- and sex-matched controls were randomly selected from a database of orthopaedic clinic attendees. Those with prior history of IBD or appendicectomy were excluded. The incidence of IBD was determined by cross-referencing with the histology database, colonoscopy database and IBD register.

RESULTS

Three thousand eight hundred twenty-nine patients were included in each group, with mean follow-up of 12 +/- 5.9 years. Twelve patients in the appendicectomy group developed IBD. Mean age at diagnosis was 30.3 years, and mean interval from appendicectomy of 3.7 years. Age at appendicectomy and appendicectomy for appendicitis conferred no benefit (Mann-Whitney test, p = 0.991). Eleven patients in the control group developed IBD, with no significant differences in any of the measured outcomes.

CONCLUSION

This study has shown no relationship between appendicitis/appendicectomy and development of IBD.

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.

Appendicectomy as a therapy for ulcerative proctitis

OBJECTIVES

Available data regarding whether appendicectomy performed after the onset of ulcerative colitis can modulate its clinical course are currently limited. This study aimed at addressing this issue.

METHODS

In this study, we report a prospective case series of 30 adult patients (median age 35 years, range 17-70 years; male/female: 11/19) with ulcerative proctitis (median duration of symptoms 5 years, range 8 months to 30 years; median Simple Clinical Colitis Activity Index score 9, range 7-12), who underwent appendicectomy in the absence of any history suggestive of previous appendicitis. Patients were subsequently followed up clinically with the assessment of the Simple Clinical Colitis Activity Index for a median of 14 months (range 9-32 months).

RESULTS

After appendicectomy, the clinical activity index improved significantly to a median score of 2 (range 0-12) (P<0.0005). The improvement in the clinical activity index occurred in 27 of 30 (90%) patients, whereas the index remained unchanged in the remaining 3 of 30 (10%) patients. Furthermore, 12 of 30 (40%) patients experienced a complete resolution of symptoms (clinical activity index score of 0) by 12 months, such that all pharmacological treatments could be withdrawn, and have remained in remission off all previous treatments for a median 9 months (range 6-25 months). The time required for a complete resolution of symptoms post appendicectomy ranged from 1 to 12 months (median 3 months) (Kaplan-Meier analysis). None of the clinical or histological factors analyzed were significantly associated with post-appendicectomy outcome.

CONCLUSIONS

This case series, the largest reported so far, provides rationale for controlled trials to properly evaluate the possible role of appendicectomy in the treatment of ulcerative proctitis.

Appendicitis, mesenteric lymphadenitis, and subsequent risk of ulcerative colitis: cohort studies in Sweden and Denmark

OBJECTIVE

To determine whether the repeatedly observed low risk of ulcerative colitis after appendicectomy is related to the appendicectomy itself or the underlying morbidity, notably appendicitis or mesenteric lymphadenitis.

DESIGN

Nationwide cohort studies.

SETTING

Sweden and Denmark.

PARTICIPANTS

709 353 Swedish (1964-2004) and Danish (1977-2004) patients who had undergone appendicectomy were followed up for subsequent ulcerative colitis. The impact of appendicectomy on risk was also studied in 224 483 people whose parents or siblings had inflammatory bowel disease.

MAIN OUTCOME MEASURES

Standardised incidence ratios and rate ratios as measures of relative risk.

RESULTS

During 11.1 million years of follow-up in the appendicectomy cohort, 1192 patients developed ulcerative colitis (10.8 per 100 000 person years). Appendicectomy without underlying inflammation was not associated with reduced risk (standardised incidence ratio 1.04, 95% confidence interval 0.95 to 1.15). Before the age of 20, however, appendicectomy for appendicitis (0.45, 0.39 to 0.53) or mesenteric lymphadenitis (0.65, 0.46 to 0.90) was associated with significant risk reduction. A similar pattern was seen in those with affected relatives, whose overall risk of ulcerative colitis was clearly higher than the background risk (1404 observed v 446 expected; standardised incidence ratio 3.15, 2.99 to 3.32). In this cohort, appendicectomy without underlying appendicitis did not modify risk (rate ratio 1.04, 0.66 to 1.55, v no appendicectomy), while risk after appendicectomy for appendicitis was halved (0.49, 0.31 to 0.74).

CONCLUSIONS

In individuals with or without a familial predisposition to inflammatory bowel disease, appendicitis and mesenteric lymphadenitis during childhood or adolescence are linked to a significantly reduced risk of ulcerative colitis in adulthood. Appendicectomy itself does not protect against ulcerative colitis.

[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.

Overview of role of the immune system in the pathogenesis of inflammatory bowel disease

Crohn's disease (CD) and ulcerative colitis (UC) are caused by the over-activity of the immune system. Current and novel therapies are designed to dampen these over-active responses. Analysis of the types of immune responses ongoing in diseased mucosa of inflammatory bowel disease patients has revealed that CD and UC are fundamentally different diseases. The former has the molecular imprints of a Th1 dominant cell-mediated hypersensitivity response whereas the latter appears to involve antibody-mediated hypersensitivity.

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.

[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.

Clinical course of distal ulcerative colitis in relation to appendiceal orifice inflammation status

BACKGROUND

Although appendiceal orifice inflammation (AOI) is frequently observed as a skip lesion of ulcerative colitis (UC), its clinical significance is not clearly understood. We aimed to evaluate whether AOI is associated with the clinical course of UC.

METHODS

Ninety-four patients with newly diagnosed distal UC were prospectively enrolled at the Asan Medical Center between March 1996 and October 2002. Clinical features and colonoscopic findings during the follow-up period were analyzed in relation to initial AOI status.

RESULTS

Forty-eight patients were found to be initially AOI-positive and 46 to be initially AOI-negative. We found no difference in the baseline demographics and clinical characteristics between these two groups. The median follow-up periods for AOI-positive and AOI-negative groups were 45 and 41 months, respectively. Clinical remission was achieved in all patients of each group. The cumulative risk of relapse at 1, 3, and 5 years after remission was 31.2%, 59.8%, and 69.2%, respectively, in the AOI-positive group and 17.4%, 46.5%, and 67.2%, respectively, in the AOI-negative group (P = 0.124). The cumulative risk of proximal disease extension at 1, 3, and 5 years after diagnosis was 17.9%, 24.9%, and 44.5%, respectively, in the AOI-positive group and 9.8%, 21.5%, and 43.9%, respectively, in the AOI-negative group (P = 0.522). Proctocolectomy was performed in no patients in the AOI-positive group and in 1 patient in the AOI-negative group. No mortalities were observed in either group.

CONCLUSIONS

In patients with distal UC, AOI may have no prognostic implications in terms of remission, relapse, or proximal disease extension.

Current concept of pathophysiological understanding and natural course of ulcerative colitis

INTRODUCTION

According to the current paradigm both ulcerative colitis (UC) and Crohn's disease (CD) result from a complex interplay of genetic susceptibility factors, environmental factors, alterations of the physiological intestinal flora and a defective regulation of the intestinal immune system.

DISCUSSION

The objective of this review is to give an overview of these factors and mechanisms, including genetic, environmental and microbial factors, with special alterations of relevant cellular components of the intestinal immune system such as T cells, macrophages and epithelial cells will then be addressed. In addition, the most relevant animal model systems that have contributed to our current pathogenetic understanding will be introduced. Clinically, the natural course of UC with special reference to the risk of colorectal cancer will be addressed.

CONCLUSION

The elucidation of pathomechanisms at the level of the intestinal immune system provides the potential for novel, effective treatment strategies. Best surgical management of patients with UC, however, still remains a challenge.

Cigarette smoking and appendectomy are risk factors for extraintestinal manifestations in ulcerative colitis

OBJECTIVE

Two common factors, cigarette smoking and appendectomy, have been found to play a role in ulcerative colitis (UC). Data on their role in the development of extraintestinal manifestations (EIM) are scarce.

METHODS

The relationship between cigarette smoking, appendectomy, and EIM was examined in a prospective study involving 535 (M/F = 319/216) consecutive UC patients followed up for 18 yr. We considered the major EIM: seronegative spondyloarthropathy, pyoderma gangrenosum/erythema nodosum, acute anterior uveitis, and primary sclerosing cholangitis. We excluded patients with a history of EIM or those colectomized before study entry, ex-smokers, and those who started to smoke during the course of UC.

RESULTS

In UC patients, seronegative spondyloarthropathy and dermatologic complications were found increased in smokers (p < 0.0001; p = 0.001) or in subjects with appendectomy (p = 0.0003; p = 0.02), while acute anterior uveitis and primary sclerosing cholangitis did not differ. The Kaplan-Meier analysis showed 18-yr rates for EIM of 71% in smokers and 45% in nonsmokers (log-rank test, p = 0.0001), and of 85% in patients with appendectomy and 48% in those without (p = 0.0001). Cox proportional-hazard model showed that cigarette smoking and appendectomy are independent factors promoting EIM. In smokers with appendectomy the adjusted hazard ratio (3.197, 95% CI 1.529-6.684) was higher than in patients with appendectomy alone (2.617, 95% CI 1.542-4.442) or smoking alone (1.947, 95% CI 1.317-2.879).

CONCLUSIONS

In UC patients, appendectomy and cigarette smoking are prognostic factors for the development of EIM. The unfavorable effect of cigarette smoking on EIM is additive to that of appendectomy.

Immune networks in animal models of inflammatory bowel disease

The animal models of inflammatory bowel disease provide a framework to define the immunopathogenesis of intestinal inflammation. Studies in these models support the hypothesis that exaggerated immune responses to normal enteric microflora are involved in the initiation and perpetuation of chronic intestinal inflammation. A major pathway involves development of acquired immune responses by the interactions of CD4+ T-cell receptor alphabeta T cells with antigen-presenting cells (dendritic cells). Immunoregulatory cells, including Tr1 cells, Th3 cells, and CD4+ CD25+ T cells and B cells, directly or indirectly affect the T-cell receptor alphabeta T cell-induced immune responses and bridge innate and acquired immunity. The study of these complicated immune networks provides the rationale for the development of new therapeutic interventions in inflammatory bowel disease.

[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.

Ulcerative colitis

Ulcerative colitis is a chronic inflammatory disease of the rectum and colon. Results from many studies in people and animals of intestinal inflammation suggest that ulcerative colitis results from environmental factors triggering a loss of tolerance for normal intestinal flora in genetically susceptible individuals. Although progress has been made in the overall management of the disease, no innovative treatment has been developed. By contrast with Crohn's disease, there are few clinical data on biological agents. Probiotics seem the most promising of several experimental and traditional agents that have been investigated in controlled clinical trials.

Medical therapies for ulcerative colitis and Crohn's disease

This review focuses on data reported in the last year on medical treatment of Crohn's disease and ulcerative colitis. In Crohn's disease, a broad range of cytokine-based therapies are currently being tested. Although all are very exciting, the anti-tumor-necrosis-factor (TNF) approach remains the most effective, with infliximab (a chimeric monoclonal antibody directed against TNF) being the most active agent. With repeated infusions every 8 weeks, remission is induced and can be maintained even in refractory patients with no major apparent side effects. Thalidomide, an oral agent with anti-TNF effects, shows promise in non-controlled experience. Important new data on azathioprine/6-mercaptopurine (6-MP) and its metabolites are also helpful. Methotrexate can induce remissions in 6-MP-allergic or refractory Crohn's patients and has now shown efficacy as a maintenance agent. Beneficial effects are also reported for a variety of new agents: mycophenolate mofetil, tacrolimus (FK506), growth hormone, and granulocyte colony-stimulating factor (G-CSF). Important observations in ulcerative colitis (UC) over the past year include evidence of a protective effect of 5-aminosalicylic acid (5-ASA) with respect to colorectal cancer, negative results from a study for heparin monotherapy, and results from a comparison of mycophenolate mofetil versus azathioprine as maintenance therapy. Epidemiologically, the negative association between appendectomy and UC was corroborated in a meta-analysis, suggesting an immunologic role for this organ. Finally, in chronic pouchitis, probiotic therapy was found to maintain remissions very significantly.