Long term follow-up of appendiceal and distal right-sided colonic inflammation

The appendix and ulcerative colitis - an unsolved connection

The appendix is thought to have a role in the pathogenesis of ulcerative colitis, but the nature and basis of this association remains unclear. In this Perspective, we consider the biology of the appendix with respect to its immunological function and the microbiome, and how this relates to evidence that supports the involvement of the appendix in ulcerative colitis. In experimental models, removal of the inflamed appendix prevents colitis, and in human observational studies, appendectomy is associated with protection against ulcerative colitis. Further, among people who develop ulcerative colitis, appendectomy before diagnosis might influence the course and outcomes of the disease - some evidence suggests that it protects against colectomy but could increase the risk of colorectal cancer. Appendectomy after onset of ulcerative colitis seems to have disparate consequences. Clinical trials to understand whether appendectomy has a role in the treatment of ulcerative colitis are ongoing. Major questions about the role of the appendix in the pathogenesis of ulcerative colitis remain unanswered, and further research is needed to establish whether the connection is clinically relevant.

Significance of diagnosis and prognosis for appendiceal orifice inflammation in ulcerative colitis: a real-world study

OBJECTIVE

Ulcerative colitis (UC) is a chronic inflammatory disease of the large intestine. At present, the significance of appendiceal orifice inflammation (AOI) in UC prognosis is still controversial. This prospective observational study investigated the importance of AOI in UC diagnosis and prognosis. Additionally, it compared the therapeutic efficacy of treatments in UC patients with or without AOI.

DESIGN

This study was a prospective, observational, single-centre, real-world study. Patients with AOI were included in the observation group, and patients without AOI were assigned to the control group. All patients were followed up for 1 year; the disease remission and treatment efficacy were re-examined by colonoscopy. In addition, the clinical, endoscopic and pathological features were collected before and after the treatment.

RESULTS

Patients with endoscopic diffuse inflammatory changes in the distal colorectum accompanied by AOI had a higher positive UC diagnosis rate than those without (96.5% vs 78.0%). Also, AOI had a specificity of 95.2% and a sensitivity of 28.3% for UC diagnosis. However, no difference in the modified Mayo score (p=0.881) or Baron grading was observed between the control and observation groups, indicating that AOI does not affect the treatment outcome of UC patients.

CONCLUSION

In this study, the observation of AOI improved the UC diagnostic accuracy in patients with diffuse lesions in the distal colorectum. Furthermore, the presence of AOI does not affect the treatment efficacies of UC.

TRIAL REGISTRATION NUMBER

ChiCTR1800017753.

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.

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.

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.

Human gut-associated lymphoid tissues (GALT); diversity, structure, and function

Gut-associated lymphoid tissues (GALT) are the key antigen sampling and adaptive immune inductive sites within the intestinal wall. Human GALT includes the multi-follicular Peyer's patches of the ileum, the vermiform appendix, and the numerous isolated lymphoid follicles (ILF) which are distributed along the length of the intestine. Our current understanding of GALT diversity and function derives primarily from studies in mice, and the relevance of many of these findings to human GALT remains unclear. Here we review our current understanding of human GALT diversity, structure, and composition as well as their potential for regulating intestinal immune responses during homeostasis and inflammatory bowel disease (IBD). Finally, we outline some key remaining questions regarding human GALT, the answers to which will advance our understanding of intestinal immune responses and provide potential opportunities to improve the treatment of intestinal diseases.

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.

Postcolonoscopy Appendicitis: A Review of 57 Cases

The purpose of this study is to review the cases of postcolonoscopy appendicitis (PCA) reported in the literature. A comprehensive search using PubMed, EMBASE, Scopus, and Google Scholar identified 57 cases. The median age at presentations of PCA was 55 years. PCAs typically occurred during the first 24 hours after colonoscopy, and the majority developed after diagnostic colonoscopy. Clinical presentations were similar to those with common acute appendicitis, though with a high perforation rate. Most patients were correctly diagnosed using ultrasound or computed tomography scan. Treatment included open appendicectomy, laparoscopic appendicectomy or cecotomy, radiologic drainage of the abscess, nonoperative treatment with antibiotics. In addition to barotrauma, fecalith impaction into the appendiceal lumen, direct trauma to the appendiceal orifice, and underlying ulcerative colitis, a pre-existing subclinical disease of the appendix seems to play an important role in the pathogenesis. For PCA, timely diagnosis and management are crucial to attain a satisfactory outcome.

The Appendix in Parkinson's Disease: From Vestigial Remnant to Vital Organ?

Parkinson's disease (PD) has long been considered a brain disease, but studies now point to the gastrointestinal (GI) tract as a potential starting point for PD. In particular, the human vermiform appendix has been implicated in PD. The appendix is a tissue rich in immune cells, serving as part of the gut-associated lymphoid tissue and as a storehouse for the gut microbiome. The functions of the appendix converge with recent evidence demonstrating that gut inflammation and shifts in the microbiome are linked to PD. Some epidemiological studies have linked removal of the appendix to lowered PD risk, though there is controversy among these associations. What is apparent is that there is an abundance of aggregated forms of α-synuclein in the appendix relevant to PD pathology. α-Synuclein pathology is thought to propagate from gut to brain via the vagus nerve, which innervates GI tract locations, including the appendix. Remarkably, α-synuclein aggregates in the appendix occur not only in PD patients, but are also present in healthy individuals. This has led to the proposal that in the appendix α-synuclein aggregates are not unique to PD. Moreover, the molecular events leading to PD and the mechanisms by which α-synuclein aggregates transfers from gut to brain may be identifiable in the human appendix. The influence of the appendix on GI inflammation, autoimmunity, microbiome storage, and the lymphatic system may be yet unexplored mechanisms by which the appendix contributes to PD. Overall, the appendix represents a promising tissue site to advance our understanding of PD pathobiology.

Effects of Appendectomy on the Onset and Course of Ulcerative Colitis in Chinese Patients

Background

Previous epidemiological studies have suggested that appendectomy may be a protective factor against the development of ulcerative colitis (UC). However, the results of these studies were inconsistent, with rare studies in Chinese populations.

Aim

This study examined the associations between appendectomy performed before UC diagnosis and the occurrence and clinical course of UC in Chinese patients.

Methods

A case control study was conducted to compare the rate of appendectomy between UC patients and controls matched for age and sex at two Chinese hospitals. Clinical course of UC was compared between UC patients who underwent appendectomies before UC diagnosis and who did not.

Results

402 UC patients and 402 controls were included. The percentage of appendectomy performed before UC diagnosis in UC patients did not differ significantly from controls (2.74% vs 3.98%, P = 0.442). Subgroup analysis on the basis of localization of UC patients did not find significant difference from controls. The extent of disease involvement in UC patients who underwent appendectomy was smaller than patients who did not (P = 0.009). Appendectomy was found to be significantly related to the location of the disease independent of smoking status in multivariate analysis (P < 0.001). Appendectomy did not influence severity of disease and need for immunosuppressive treatment or colectomy.

Conclusion

We did not find a significant negative association between appendectomy and the UC occurrence in Chinese patients. Appendectomy performed before UC diagnosis may reduce the extent of UC involvement.

Appendiceal orifice inflammation is associated with proximal extension of disease in patients with ulcerative colitis

AIM

Ulcerative colitis (UC) is considered to be a disease of continuous mucosal inflammation extending proximally from the rectum. However, appendiceal orifice inflammation (AOI) is a skip lesion with segments of continuous involvement from the rectum. The aim of this study was to examine the clinical characteristics and clinical course, particularly focused on proximal extension, of UC in patients with AOI.

METHOD

A retrospective evaluation of patients with UC who underwent total colonoscopy at the Department of Surgical Oncology, The University of Tokyo, from 2004 to 2014. The degree of AOI was graded endoscopically as follows: 0 (no inflammation); 1 (slight oedema); 2 (moderate inflammation); and 3 (marked inflammation). A total of 189 patient records were reviewed retrospectively. The presence of AOI was analysed with regard to the clinical information of each patient, and its association with proximal extension of proctitis or left-sided colitis was evaluated.

RESULTS

Of 189 patients with UC who underwent total colonoscopy at our institution, 92 were diagnosed with pancolitis, 50 with left-sided colitis and 47 with proctitis. Endoscopic findings of AOI were observed in 26 patients, including 11 (12.0%) with pancolitis, six (12.0%) with left-sided colitis and nine (19.1%) with proctitis. During follow up, proximal extension of the disease occurred in all nine patients with proctitis AOI.

CONCLUSION

AOI is more frequently observed in patients with proctitis. Our results showed correlations between AOI and subsequent proximal extension of mucosal inflammation in patients with proctitis.

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.

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.

Clinical features and course of ulcerative colitis diagnosed in asymptomatic subjects

BACKGROUND AND AIMS

Although some ulcerative colitis (UC) patients are diagnosed when they do not have any UC-related symptoms, clinical features and prognosis of UC diagnosed in asymptomatic patients remain unclear.

METHODS

Data for UC patients who were asymptomatic at diagnosis were retrospectively reviewed from the IBD database of the Asan Medical Center. The clinical characteristics and prognosis of those patients were analyzed and compared with matched (1:4) symptomatic UC patients.

RESULTS

Only nineteen asymptomatic UC patients (1.1%) were identified from 1665 UC patients. The proportion of males was 78.9% (n=15), and their median age at diagnosis was 48 years (range, 34-71 years). At diagnosis, proctitis was noted in 11 patients (57.9%), left-sided colitis in 4 (21.1%), extensive colitis in 0 (0%), and atypical distribution in 4 (21.1%). The 5-year cumulative probability of symptom development was 68.5% (95% confidence interval [CI], 62.8%-74.2%). After UC diagnosis, oral 5-aminisalicylic acid (ASA) and topical 5-ASA were used in 14 (73.7%) and 16 (84.2%) patients, respectively. During follow-up (3.7-year median for asymptomatic patients versus 3.7-year median for symptomatic patients; P=0.961), the 5-year cumulative probability of corticosteroids (23.7% versus 57.1%; P=0.022) and azathioprine (0% versus 24.7%; P=0.003) use was higher in symptomatic patients than in asymptomatic patients.

CONCLUSIONS

The frequency of asymptomatic UC patients was 1.1% in our UC patient cohort. A majority of these patients became symptomatic during follow-up. Asymptomatic UC patients at diagnosis appear to have a better prognosis than symptomatic UC patients.

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.

Diverticular colitis of the ascending colon preceding the onset of ulcerative colitis

We present a case of diverticular colitis of the ascending colon preceding the onset of ulcerative colitis. A 58-year-old man presented with positive faecal occult blood test. Colonoscopy disclosed diverticular colitis of the ascending colon. After a year's follow-up, typical ulcerative colitis developed and diverticular colitis improved. Diverticular colitis is a newly established disorder of chronic segmental mucosal inflammation affected by diverticular disease. There is increasing recognition of such cases with diverticular colitis preceding ulcerative colitis. There may be a possible pathogenic relationship between the two diseases.

Atypical distribution of inflammation in newly diagnosed ulcerative colitis is not rare

BACKGROUND

Appendiceal orifice inflammation (AOI) is a common 'skip lesion' in patients with ulcerative colitis (UC). However, other skip lesions are less well known.

OBJECTIVE

To evaluate the atypical distribution of UC lesions, other than AOI, in terms of their frequency, pattern, risk factors and prognostic implications.

METHODS

A retrospective analysis of colonoscopic findings and clinical course of 240 adult UC patients who were initially diagnosed at Asan Medical Center (Seoul, South Korea) was performed. #

RESULTS

Of 240 patients, 46 (19.2%) showed an atypical distribution of lesions at initial colonoscopy: eight (3.3%) had rectal sparing (segmental-type UC); and 38 (15.8%) had patchy⁄segmental skip lesions other than AOI. Skip lesions were detected more frequently in proximal segments of the colon than in distal segments (P=0.001). An atypical distribution was more common in patients with AOI (31.3%) than in those without AOI (10.6%; P<0.001). The clinical course of patients with an atypical distribution was not different from that of patients with a typical distribution in terms of remission, relapse, disease extension, colectomy and mortality. In addition, of the 36 patients with an atypical distribution of lesions at diagnosis who underwent follow-up colonoscopy, 24 (66.7%) demonstrated a typical distribution of lesions.

CONCLUSIONS

Patchy⁄segmental skip lesions and rectal sparing occur not infrequently in adult patients with newly diagnosed, untreated UC. As such, these features alone should not be considered to be definitive evidence against a diagnosis of UC. There does not appear to be a prognostic implication of an atypical distribution of lesions.