The risk of developing Crohn's disease after an appendectomy: a population-based cohort study in Sweden and Denmark

Time Trends of Environmental and Socioeconomic Risk Factors in Patients with Inflammatory Bowel Disease over 40 Years: A Population-Based Inception Cohort 1977-2020

BACKGROUND

Data from population-based studies investigating trends in environmental factors associated with inflammatory bowel disease (IBD) is lacking. We aimed to assess long-term time trends of environmental and socioeconomic factors in IBD patients from a well-defined population-based cohort from Veszprem, Hungary.

METHODS

Patients were included between 1 January 1977, and 31 December 2020. Trends of environmental and socioeconomic factors were evaluated in three periods based on the decade of diagnosis, representing different therapeutic eras: cohort-A,1977-1995; cohort-B,1996-2008 (immunomodulator era); and cohort-C, 2009-2020 (biological era).

RESULTS

A total of 2240 incident patients with IBD were included (ulcerative colitis (UC) 61.2%, male 51.2%, median age at diagnosis: 35 years (IQR 29-49)). Rates of active smoking significantly decreased over time in Crohn's disease (CD): 60.2%, 49.9%, and 38.6% in cohorts A/B/C (p < 0.001). In UC, the rates were low and stable: 15.4%, 15.4%, and 14.5% in cohorts A/B/C (p = 0.981). Oral contraceptive use was more common in CD compared to UC (25.0% vs. 11.6%, p < 0.001). In UC, prevalence of appendectomy before diagnosis decreased over time: 6.4%, 5.5%, and 2.3% in cohorts A/B/C (p = 0.013). No significant changes were found in the socio-geographic characteristics of the IBD population (urban living: UC, 59.8%/64.8%/ 62.5% (p = 0.309) and CD, 62.5%/ 62.0%/ 59.0% (p = 0.636), in cohorts A/B/C). A greater percentage of patients had completed secondary school as the highest education level in later cohorts in both UC (42.9%/50.2%/51.6%, p < 0.001) and CD (49.2%/51.7%/59.5%, p = 0.002). A higher percentage of skilled workers (34.4%/36.2%/38.9%, p = 0.027) was found in UC, but not in CD (p = 0.454).

CONCLUSION

The association between trends of known environmental factors and IBD is complex. Smoking has become less prevalent in CD, but no other major changes occurred in socioeconomic factors over the last four decades that could explain the sharp increase in IBD incidence.

Association between prior appendectomy and the risk and course of Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIMS

The appendix has an important immune function in both health and disease, and appendectomy may influence microbial ecology and immune function. This meta-analysis aims to assess the association between appendectomy and the risk and course of Crohn's disease (CD).

METHODS

PubMed, EMBASE, and the Cochrane Library were used to identify all studies published until June 2022. Data from studies evaluating the association between appendectomy and CD were reviewed.

RESULTS

A total of 28 studies were included in the final analysis, comprising 22 case-control and 6 cohort studies. A positive relationship between prior appendectomy and the risk of developing CD was observed in both case-control studies (odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.22-2.08) and cohort studies (relative risk [RR]: 2.28, 95% CI: 1.66-3.14). The elevated risk of CD persisted 5 years post-appendectomy (RR = 1.24, 95% CI: 1.12-1.36). The risk of developing CD was similarly elevated regardless of the presence (RR = 1.64, 95% CI: 1.17-2.31) or absence (RR = 2.77, 95% CI: 1.84-4.16) of appendicitis in patients. Moreover, significant differences were found in the proportion of terminal ileum lesions (OR = 1.63; 95% CI: 1.38-1.93) and colon lesions (OR = 0.70; 95% CI: 0.5-0.84) between CD patients with appendectomy and those without appendectomy.

CONCLUSIONS

The risk of developing CD following an appendectomy is significant and persists 5 years postoperatively. Moreover, the elevated risk of CD may mainly occur in the terminal ileum.

Appendectomy and Future Risk of Microscopic Colitis: A Population-Based Case-Control Study in Sweden

BACKGROUND AND AIMS

Microscopic colitis (MC) is an inflammatory bowel disease and a common cause of chronic diarrhea. Appendectomy has been suggested to have immunomodulating effects in the colon, influencing the risk of gastrointestinal disease. The relationship between appendectomy and MC has only been sparsely studied.

METHODS

This was a case-control study based on the nationwide ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) cohort, consisting of histopathological examinations in Sweden, linked to national registers. Patients with MC were matched to population controls by age, sex, calendar year of biopsy, and county of residence. Data on antecedent appendectomy and comorbidities were retrieved from the Patient Register. Unconditional logistic regression models were conducted presenting odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for country of birth and matching factors. Further subanalyses were made based on MC subtypes (lymphocytic colitis and collagenous colitis), follow-up time postappendectomy and severity of appendicitis.

RESULTS

The study included 14,520 cases of MC and 69,491 controls, among these 7.6% (n = 1103) and 5.1% (n = 3510), respectively, had a previous appendectomy ≥1 year prior to MC or matching date. Patients with a previous appendectomy had an increased risk of MC in total (OR, 1.50; 95% CI, 1.40-1.61) and per the collagenous colitis subtype (OR, 1.67; 95% CI, 1.48-1.88) or lymphocytic colitis subtype (OR, 1.42; 95% CI, 1.30-1.55). The risk remained elevated throughout follow-up, and the highest risk was observed in noncomplicated appendicitis.

CONCLUSIONS

This nationwide case-control study found a modestly increased risk of developing MC following appendectomy.

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.

Appendectomy and risk for inflammatory bowel disease: effect of age and time post appendectomy - a cohort study

Background and objective

Appendectomy may modulate the risk of inflammatory bowel disease through an effect on the gut microbiota. This study investigated the associations between appendectomy and incidence of Crohn’s disease (CD) or ulcerative colitis (UC), with an emphasis on the influence of age and time post appendectomy.

Methods

This cohort study included 400 520 subjects born in Québec in 1970–1974 and followed until 2014. Administrative health data were used to ascertain appendectomy and cases of CD and UC. Cox proportional hazards models with time-dependent variables (appendectomy and time elapsed post appendectomy) allowed for the estimation of HRs and 95% CIs.

Results

A total of 2545 (0.6%) CD cases and 1134 (0.3%) UC cases were identified during follow-up. Appendectomy increased the risk of CD (HR=2.02; 95% CI: 1.66 to 2.44), especially when performed at 18–29 years of age. The risk of CD was increased in the first 2 years, and decreased significantly after ≥15 years post appendectomy. Appendectomy appeared to protect against UC (HR=0.39; 95% CI: 0.22 to 0.71). The risk of UC was not associated with age at appendectomy, but decreased with time elapsed post appendectomy (HR=0.21; 95% CI: 0.06 to 0.72, comparing ≥5 with 0–4 years after appendectomy).

Conclusions

The increased risk of CD related to appendectomy in young adults may result from detection bias, but physicians should have a low threshold for suspicion of CD in young symptomatic adults with a history of appendectomy. A strong protective effect of appendectomy against UC was observed after 5 years.

Endoscopic retrograde appendicitis therapy versus laparoscopic appendectomy versus open appendectomy for acute appendicitis: a pilot study

Background

An increasing number of studies have shown the merits of endoscopic retrograde appendicitis therapy (ERAT) in diagnosing and treating acute uncomplicated appendicitis. However, no related prospective controlled studies have been reported yet. Our aim is to assess the feasibility and safety of ERAT in the treatment of acute uncomplicated appendicitis.

Methods

In this open-label, randomized trial, participants were randomly allocated to the ERAT group, laparoscopic appendectomy (LA) group and open appendectomy (OA) group. The primary outcome was the clinical success rate of the treatment. Intention-to-treat analysis was used in the study.

Results

The study comprised of 99 patients, with 33 participants in each group. The clinical success rate was 87.88% (29/33), 96.97% (32/33) and 100% (33/33) in the ERAT, LA and OA group, respectively. In the ERAT group, 4 patients failed ERAT due to difficult cannulation. In LA group, 1 patient failed because of abdominal adhesion. There were no significant differences among the three treatment groups regarding the clinical success rate (P = 0.123). The median duration of follow-up was 22 months. There were no significant differences (P = 0.693) among the three groups in terms of adverse events and the final crossover rate of ERAT to surgery was 21.21% (7/33).

Conclusion

ERAT can serve as an alternative and efficient method to treat acute uncomplicated appendicitis.

Trial registration The study is registered with the WHO Primary Registry-Chinese Clinical Trial Registry (ChiCTR1900025812).

Long-term impacts of appendectomy associated with increased incidence of inflammatory bowel disease, infection, and colorectal cancer

PURPOSE

Although the appendix has been suggested to play a role in maintaining the gut microbiome and immune system, the ramifications of appendectomy on the development inflammatory bowel disease, sepsis, and colorectal cancer are yet to be determined. The purpose of this study was to evaluate the potential long-term impacts of appendectomy, with a focus on inflammatory bowel disease, infection, and colorectal cancer, using the National Healthcare Insurance Service (NHIS) database of Korea.

METHODS

The National Healthcare Insurance Service database in Korea was used for analysis. Adult patients who received appendectomy between 2005 and 2013 were identified. The control group consisted of patients who did not receive appendectomy were matched by baseline characteristics including comorbidities and frequency of healthcare resource utilization. The primary outcome was the incidence-rate ratio (IRR) of Crohn's disease, ulcerative colitis, Clostridium difficile infection, sepsis, and colorectal cancer after appendectomy or the index date.

RESULTS

We identified 914,208 patients who underwent appendectomy, and after matching with control patients, a total of 486,844 patients were included for analysis. Patients who underwent appendectomy showed a significantly higher incidence of Crohn's disease (IRR 4.40, 95% confidence interval (CI) 3.78-5.13) and ulcerative colitis (IRR 1.78, 95% CI 1.63-1.93) compared to the control group during the 5-year follow-up period. The associations between appendectomy and Clostridium difficile infection, sepsis, and colorectal cancer were all found to be significant.

CONCLUSION

Patients who underwent appendectomy may be at increased risk for developing Crohn's disease, ulcerative colitis, Clostridium difficile infection, sepsis, and colorectal cancer.

Effect of Endoscopic Appendix Intubation and Irrigation on Acute Uncomplicated Appendicitis

OBJECTIVE

To investigate the efficacy and safety of endoscopic appendix intubation and irrigation (EAI) on acute uncomplicated appendicitis.

METHODS

This prospective non-randomized study examined 169 patients with suspected acute uncomplicated appendicitis at The First Affiliated Hospital of Fujian Medical University from October 2015 to 2017. Patients were divided into three groups: endoscopic appendix intubation and irrigation (EAI, n = 18), laparoscopic appendectomy (LA, n = 87), and antibiotic alone (A, n = 64). The treatment success rate, duration of hospitalization, medical costs, operation time, duration of abdominal pain, fasting time, complications, and recurrence were analyzed.

RESULTS

The three groups had no significant differences in baseline characteristics (age, gender, Alvarado score, white blood cell count, and neutrophil count; all P > 0.05). Compared to the LA group, the EAI group had shorter durations of the operation, fasting, and abdominal pain; less use of oral and intravenous antibiotics; and lower medical costs (all P < 0.05). Compared to the A group, the EAI group had shorter durations of abdominal pain and hospitalization, and less use of intravenous antibiotics (all P < 0.05). The EAI group had no complications, but 3 patients (3.4%) in the LA group had surgery-related complications.

CONCLUSION

EAI is a safe and effective treatment for acute uncomplicated appendicitis. Patients who received EAI had shorter durations of abdominal pain and hospitalization than those who received LA or conservative antibiotic treatment.

TRIAL REGISTRATION NUMBER AND AGENCY

ChiCTR-IPN-15006565, Chinese Clinical Trial Registry.

Associations of hair cortisol concentrations with paediatric appendicitis

The pathogenesis of paediatric appendicitis is still an enigma. In recent years, it has become more evident that our inherent immunological responses affect the trajectory of the disease course. Long-term stress has an impact on our immune system; however, it is practically and ethically challenging to prospectively track blood measurements of cortisol-levels in asymptomatic children should an acute appendicitis episode develop. The aim of this case–control study was therefore to evaluate the effect of increased stress measured as historical imprints in hair (hair cortisol concentrations [HCC]), on the risk of developing appendicitis and complicated appendicitis. 51 children (aged < 15 years) with appendicitis (34 with complicated appendicitis), were compared to 86 healthy controls. HCC reflecting the activity of the HPA-axis 0–3 and 4–6 months prior to sampling was evaluated and compared between groups as well as between the two measurements of each study subject. In the univariate analysis with both cases and controls, an increase in HCC between the measurement timepoints was associated with a substantial increase in risk of appendicitis (OR 7.52 [95% CI 2.49–22.67], p = 0.001). This increased risk remained in the multivariate analysis after adjustment for age, sex and season (aOR OR 10.76 [95%CI 2.50–46.28], p  = 0.001). When comparing the cases of uncomplicated and complicated appendicitis through a multivariate analysis, adjusted for age and sex, the children with an increased HCC prior to appendicitis had a substantial and statistically significant increase in risk of complicated appendicitis (aOR 7.86 [95% CI 1.20–51.63], p = 0.03). Biological stress, measured as an increase in HCC, seems to be associated with an increased risk of paediatric appendicitis and a more complicated disease course.

Long-term effects of appendectomy in humans: is it the optimal management of appendicitis?

INTRODUCTION

Appendectomy remains the gold standard for treating uncomplicated and complicated appendicitis. However, the vermiform appendix may play a significant role in the immune system (secondary immune function) and maintain a reservoir of the normal microbiome for the human body. The aim of this study was to summarize the long-term effects after appendectomy and discuss whether appendectomy is suitable for all appendicitis patients.

AREAS COVERED

A comprehensive and unbiased literature search was performed in PubMed. The terms 'appendix,' 'appendicitis,' 'appendectomy,' and 'endoscopic retrograde appendicitis therapy' were searched in the title and/or abstract. This review summarizes the long-term effects of appendectomy on some diseases in humans and describes three methods including appendectomy, medical treatment, and an 'organ-sparing' technique, named endoscopic retrograde appendicitis therapy (ERAT) to treat appendicitis.

EXPERT OPINION

Appendectomy remains the first-line therapy for appendicitis. The patient's problem is appendix, not appendicitis. If we treat appendicitis, the problem should be resolved. During COVID-19, an initial antibiotic treatment of mild appendicitis represents a promising strategy. For patients who are worried about the long-term adverse effect after appendectomy and have a strong desire to preserve the appendix and are aware of the risk of appendicitis recurrence, medical treatment, or ERAT could be proposed.

Long-Term Follow-Up, Association between CARD15/NOD2 Polymorphisms, and Clinical Disease Behavior in Crohn's Disease Surgical Patients

Background

CARD15/NOD2 is the most significant genetic susceptibility in Crohn's disease (CD) even though a relationship between the different polymorphisms and clinical phenotype has not been described yet. The study is aimed at analyzing, in a group of CD patients undergoing surgery, the relationship between CARD15/NOD2 polymorphisms and the clinical CD behavior after a long-term follow-up, in order to identify potential clinical biomarkers of prognosis.

Methods

191 surgical CD patients were prospectively characterized both for the main single nucleotide polymorphisms of CARD15/NOD2 and for many other environmental risk factors connected with the severe disease form. After a mean follow-up of 7.3 years, the correlations between clinical features and CD natural history were analyzed.

Results

CARD15/NOD2 polymorphisms were significantly associated with younger age at diagnosis compared to wild type cases (p < 0.05). Moreover, patients carrying a 3020insC polymorphism presented a larger Δ between diagnosis and surgery (p = 0.0344). Patients carrying an hz881 and a 3020insC exhibited, respectively, a lower rate of responsiveness to azathioprine (p = 0.012), but no difference was found in biologic therapy. Finally, the risk of surgical recurrence was significantly associated, respectively, to age at diagnosis, to familial CD history, to diagnostic delay, to arthritis, and to the presence of perioperative complications.

Conclusions

3020insC CARD15 polymorphism is associated with an earlier CD onset, and age at CD diagnosis < 27 years was confirmed to have a detrimental effect on its clinical course. In addition, the familiarity seems to be connected with a more aggressive postoperative course. Finally, for the first time, we have observed a lower rate of responsiveness to azathioprine in patients carrying an hz881 and a 3020insC.

Appendectomy Does Not Increase the Risk of Future Emergence of Parkinson's Disease: A Meta-analysis

OBJECTIVE

To explore the impact of appendectomy history on emergence of Parkinson's disease (PD).

BACKGROUND

Although there are several studies to investigate the relationship between appendectomy history and emergence of PD, the results are still controversial.

METHODS

We performed a comprehensive electronic search of the literature (the Cochrane Library, PubMed, and the Web of Science) up to April 2020 to identify studies that had employed databases allowing comparison of emergence of PD between patients with and those without appendectomy history. To integrate the impact of appendectomy history on emergence of PD, a meta-analysis was performed using random-effects models to calculate the risk ratio (RR) and 95% confidence interval (CI) for the selected studies, and heterogeneity was analyzed using I² statistics.

RESULTS

Four studies involving a total of 6 080 710 patients were included in this meta-analysis. Among 1 470 613 patients with appendectomy history, 1845 (.13%) had emergences of PD during the observation period, whereas among 4 610 097 patients without appendectomy history, 6743 (.15%) had emergences of PD during the observation period. These results revealed that patients with appendectomy history and without appendectomy had almost the same emergence of PD (RR, 1.02; 95% CI, .87-1.20; P = .83; I² = 87%).

CONCLUSION

This meta-analysis has demonstrated that there was no significant difference in emergence of PD between patients with and those without appendectomy history.

A link between appendectomy and gastrointestinal cancers: a large-scale population-based cohort study in Korea

An association between appendectomy and subsequent gastrointestinal (GI) cancer development has been postulated, although the evidence is limited and inconsistent. To provide clarification, we investigated the link between appendectomy and GI cancers in a large nationwide appendectomy cohort. This cohort was derived from the claims database of the National Health Insurance Service in South Korea and comprised 158,101 patients who had undergone appendectomy between 2007 and 2014. A comparison cohort of 474,303 subjects without appendectomy was selected after 1:3 matching by age and sex. The incidence of GI cancers after appendectomy was observed, and risk factors for GI cancers were determined by using a multivariable-adjusted proportional hazards model. Appendectomy did not significantly increase the incidence of GI cancers in the overall population (1.529 and 1557 per 1000 person-years in the non-appendectomy and appendectomy cohorts, respectively). However, appendectomy significantly increased the incidence of GI cancers in subgroups consisting of elderly (≥ 60 years) patients (adjusted HR, 1.102; 95% confidence interval, 1.011-1.201; p = 0.028) or women (adjusted HR, 1.180; 95% confidence interval, 1.066-1.306; p = 0.001).

Initiation and Transmission of α-Synuclein Pathology in Parkinson's Disease

The pathogenesis of Parkinson's disease (PD) involves the accumulation of aggregated forms of α-synuclein in the body. The location for the initiation of misfolded forms of α-synuclein is now a contentious issue, what was once thought to be a disease of the central nervous system (CNS) now appears to involve multiple organs in the body. In particular, the two regions in the body where the nervous system is exposed to the environment, the olfactory bulb and the enteric nervous system, are now thought to play an important role in the initial phase of the disease. Epidemiological studies point to the gastrointestinal tract, including the appendix, as a potential site for the misfolding and transmission of α-synuclein, with the vagus nerve providing a conduit between the gut and brain. A growing body of animal studies also support this pathway, implicating the transmission of pathological α-synuclein from outside the CNS in the development of PD.

Prior Appendectomy and the Onset and Course of Crohn's Disease in Chinese Patients

Background and Aim

The relationship between prior appendectomy and Crohn's disease (CD) has previously revealed conflicting findings. The present study investigates the relationship between prior appendectomy and CD development in Chinese patients.

Methods

A retrospective case-control study was performed to compare prior appendectomy rate between CD patients and age- and gender-matched controls at two Chinese hospitals. The clinical course of CD was determined in patients who underwent and did not undergo appendectomies before CD diagnosis.

Results

A total of 617 CD patients and 617 controls were included. The appendectomy rate before CD diagnosis in patients was higher, when compared to controls (6.65% versus 3.73%, P = 0.033). Appendectomy was a risk factor for the onset of CD independent of smoking in the multivariate analysis (OR: 1.878; 95% CI: 1.111–3.174; P = 0.019). Appendectomies were performed closer to the date of CD diagnosis in the trend test (P = 0.039). The rate of appendectomy within one year or 1-5 years before CD diagnosis was higher in patients when compared to that in controls (0.97% versus 0%, P = 0.031; 1.13% versus 0.32%, P = 0.180). However, the rate of appendectomy over five years before CD diagnosis was close to controls (4.54% versus 3.40%, P = 0.392). No significant differences in disease location, behavior, medication, and intestinal resection between appendectomy and nonappendectomy CD patients were found, even in the subgroup analysis by age of appendectomy.

Conclusion

Prior appendectomy is a risk factor for the onset of CD. However, the appendectomy rate only increased for a short duration before CD diagnosis, likely reflecting a diagnostic bias. Prior appendectomy did not influence the features or course of CD.

Impact of Genes and the Environment on the Pathogenesis and Disease Course of Inflammatory Bowel Disease

Crohn's disease and ulcerative colitis constitute two major subgroups of inflammatory bowel diseases (IBD), a group of complex polygenic diseases characterized by chronic and progressive inflammation in the gastrointestinal tract. In recent years, methodological advances in genetic analysis have greatly expanded our understanding of the genetic background of IBD. So far, more than 240 genetic risk loci have been identified for IBD. However, these risk alleles explain less than 30% of the susceptibility to disease development, suggesting that environmental factors contribute considerably. The increasing occurrence of IBD in Eastern countries following their 'westernization', as well as the increased risk of disease among those who migrate to high-incidence regions, also suggest that the environment is key in the pathogenesis of IBD. In this review, we summarize the current evidence on the role of genetic and environmental factors in the susceptibility to, and disease course of, IBD, and we suggest how these findings might be applied to clinical practice.

The association between environmental factors and the development of Crohn's disease with focusing on passive smoking: A multicenter case-control study in Japan

BACKGROUND

The number of patients with Crohn's disease (CD) in Japan has recently been increasing. We examined the association between environmental factors and the development of CD in Japanese focusing on passive smoking.

METHODS

We conducted a multicenter case-control study and compared the environmental factors of 93 cases who were newly diagnosed with CD to the environmental factors of 132 controls (hospital-, age-, and sex-matched patients with other diseases). The odds ratio (OR) of each factor for the development of CD and the 95% confidence interval (CI) were calculated using a logistic regression model. The association between the details of passive smoking history and the development of CD was examined for those who had an active smoking history "no". Odds ratios of number of passively smoked cigarettes (per day), time of passive smoking (per day) and period of passive smoking (year) were calculated using "passive smoking 'No'" as a reference.

RESULTS

History of appendicitis, family history of inflammatory bowel disease, and active smoking history were not significantly associated with the development of CD. Drinking history showed a decreased OR for the development of CD (0.39, 0.19-0.77). "Passive smoking Yes" showed significantly increased OR (2.49, 1.09-5.73). Regarding the association between passive smoking and the development of CD, the OR increased as the number of cigarettes per day, smoking time per day, and smoking duration increased, and there was a dose-response relationship (trend P = 0.024, 0.032, 0.038).

CONCLUSIONS

The association between environmental factors and the development of CD among Japanese was examined by case-control study. It was suggested that the passive smoking history may be associated to the development of CD.

Women who had appendectomy have increased risk of systemic lupus erythematosus: a nationwide cohort study

The appendix is involved in immune function, and an appendectomy may alter the immune system. Studies evaluating the relationship between previous appendectomy and the risk of systemic lupus erythematosus (SLE) are lacking. This nationwide cohort study investigated the incidence and risk of SLE in patients who underwent appendectomy. Patients aged > 20 years who received appendectomy from 2000 to 2011 were identified from the National Health Insurance Research Database and assigned to the appendectomy cohort. Patients without appendectomy were randomly selected from the NHIRD and assigned to the control cohort; they were frequency matched to each study patient at a 4:1 ratio by sex, age, and index year. All patients were followed until SLE diagnosis, withdrawal from the National Health Insurance program, or the end of 2011. We used Cox models to estimate the hazard ratio (HR) and 95% confidence interval (CI) to compare the risk of SLE between the appendectomy and control cohorts. From 23.74 million people in the cohort, 80,582 patients undergoing appendectomy and 323,850 patients without appendectomy were followed for 723,438 and 2,931,737 person-years, respectively. The appendectomy cohort had a 2.04-fold higher risk of SLE than the control cohort (adjusted HR = 2.04, 95% CI = 1.52-2.76). Women aged ≤ 49 years who underwent appendectomy had a 2.27-fold higher risk of SLE than the corresponding controls (adjusted HR = 2.27, 95% CI = 1.62-3.19). Women aged ≤ 49 years who underwent appendectomy have a significantly higher risk of SLE.

Long-Term Complications of Appendectomy: A Systematic Review

BACKGROUND AND AIMS

Appendectomy is a common surgical procedure, but no overview of the long-term consequences exists. Our aim was to systematically review the long-term complications of appendectomy for acute appendicitis.

MATERIALS AND METHODS

This systematic review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A protocol was registered on PROSPERO (CRD42017064662). The databases PubMed and EMBASE were searched for original reports on appendectomy with n ≥ 500 and follow-up >30 days. The surgical outcomes were ileus and incisional hernia; other outcomes were inflammatory bowel disease, cancer, fertility, and mortality.

RESULTS

We included 37 studies. The pooled estimate of the ileus prevalence was 1.0% over a follow-up period of 4.6 (range, 0.5-15) years. Regarding incisional hernia, we found a pooled estimate of 0.7% prevalence within a follow-up period of 6.5 (range, 1.9-10) years. Ulcerative colitis had a pooled estimate of 0.15% prevalence in the appendectomy group and 0.19% in controls. The opposite pattern was found regarding Crohn's disease with a pooled estimate of 0.20% prevalence in the appendectomy group and 0.12% in controls. No clear pattern was found regarding most of the examined cancers in appendectomy groups compared with background populations. Pregnancy rates increased after appendicitis compared with controls in most studies. Mortality was low after appendectomy.

CONCLUSION

Appendectomy had a low prevalence of long-term surgical complications. We did not find any significant other long-term complications, though the prevalence of Crohn's disease was higher and the prevalence of ulcerative colitis was lower after appendectomy than in controls. Appendectomy did not impair fertility.

Inflammatory Bowel Diseases: Review of Known Environmental Protective and Risk Factors Involved

Inflammatory bowel diseases consisting of Crohn's disease and ulcerative colitis are chronic inflammatory diseases of the gastrointestinal tract. In addition to genetic susceptibility and disturbances of the microbiome, environmental exposures forming the exposome play an important role. Starting at birth, the cumulative effect of different environmental exposures combined with a predetermined genetic susceptibility is thought to cause inflammatory bowel disease. All these environmental factors are part of a Western lifestyle, suiting the high incidence rates in Europe and the United States. Whereas receiving breastfeeding, evidence of a Helicobacter pylori infection and vitamin D are important protective factors in Crohn's disease as well as ulcerative colitis, increased hygiene, experiencing a bacterial gastroenteritis in the past, urban living surroundings, air pollution, the use of antibiotics, nonsteroidal anti-inflammatory drugs, and oral contraceptives are likely to be the most important risk factors for both diseases. Current cigarette smoking yields a divergent effect by protecting against ulcerative colitis but increasing risk of Crohn's disease, whereas former smoking increases chances of both diseases. This review gives a clear overview of the current state of knowledge concerning the exposome. Future studies should focus on measuring this exposome yielding the possibility of combining all involved factors to one exposome risk score and our knowledge on genetic susceptibility.

Family history, comorbidity, smoking and other risk factors in microscopic colitis: a case-control study

OBJECTIVES

Data on heredity, risk factors and comorbidity in microscopic colitis, encompassing collagenous colitis (CC) and lymphocytic colitis (LC), are limited.

AIM

The aim was to carry out a case-control study of family history, childhood circumstances, educational level, marital status, smoking and comorbidity in microscopic colitis.

METHODS

A postal questionnaire was sent in 2008-2009 to microscopic colitis patients resident in Sweden and three population-based controls per patient, matched for age, sex and municipality.

RESULTS

Some 212 patients and 627 controls participated in the study. There was an association with a family history of microscopic colitis in both CC [odds ratio (OR): 10.3; 95% confidence interval (CI): 2.1-50.4, P=0.004] and LC (OR not estimated, P=0.008). Current smoking was associated with CC [OR: 4.7; 95% CI: 2.4-9.2, P<0.001) and LC (OR: 3.2; 95% CI: 1.6-6.7, P=0.002). The median age at diagnosis was around 10 years earlier in ever-smokers compared with never-smokers.CC was associated with a history of ulcerative colitis (UC) (OR: 8.7, 95% CI: 2.2-33.7, P=0.002), thyroid disease (OR: 2.3; 95% CI: 1.1-4.5, P=0.02), coeliac disease (OR: 13.1; 95% CI: 2.7-62.7, P=0.001), rheumatic disease (OR 1.9; 95% CI: 1.0-3.5, P=0.042) and previous appendicectomy (OR: 2.2; 95% CI: 1.3-3.8, P=0.003), and LC with UC (OR: 6.8; 95% CI: 1.7-28.0, P=0.008), thyroid disease (OR: 2.4; 95% CI: 1.1-5.4, P=0.037) and coeliac disease (OR: 8.7; 95% CI: 2.8-26.7, P<0.001).

CONCLUSION

Association with a family history of microscopic colitis indicates that familial factors may be important. The association with a history of UC should be studied further as it may present new insights into the pathogenesis of microscopic colitis and UC.

The mesentery: structure, function, and role in disease

Systematic study of the mesentery is now possible because of clarification of its structure. Although this area of science is in an early phase, important advances have already been made and opportunities uncovered. For example, distinctive anatomical and functional features have been revealed that justify designation of the mesentery as an organ. Accordingly, the mesentery should be subjected to the same investigatory focus that is applied to other organs and systems. In this Review, we summarise the findings of scientific investigations of the mesentery so far and explore its role in human disease. We aim to provide a platform from which to direct future scientific investigation of the human mesentery in health and disease.

Diabetes increases the risk of an appendectomy in patients with antibiotic treatment of noncomplicated appendicitis

BACKGROUND

This retrospective cohort study examined whether diabetic patients have a higher risk for recurrent appendicitis during a 1-year follow-up period after successful antibiotic treatment for patients with acute uncomplicated appendicitis than nondiabetic patients using a population-based database.

METHODS

We included 541 appendicitis patients who received antibiotic treatment for acute appendicitis. We individually tracked each patient for a 1-year period to identify those who subsequently underwent an appendectomy during the follow-up period.

RESULTS

Cox proportional hazard regressions suggested that the adjusted hazard ratio of an appendectomy during the 1-year follow-up period was 1.75 for appendicitis patients with diabetes than appendicitis patients without diabetes. We found that among females, the adjusted hazard ratio of an appendectomy was 2.18 for acute appendicitis patients with diabetes than their counterparts without diabetes. However, we failed to observe this relationship in males.

CONCLUSIONS

We demonstrated a relationship between diabetes and a subsequent appendectomy in females who underwent antibiotic treatment for noncomplicated appendicitis.

The intestinal microbiome, barrier function, and immune system in inflammatory bowel disease: a tripartite pathophysiological circuit with implications for new therapeutic directions

We discuss the tripartite pathophysiological circuit of inflammatory bowel disease (IBD), involving the intestinal microbiota, barrier function, and immune system. Dysfunction in each of these physiological components (dysbiosis, leaky gut, and inflammation) contributes in a mutually interdependent manner to IBD onset and exacerbation. Genetic and environmental risk factors lead to disruption of gut homeostasis: genetic risks predominantly affect the immune system, environmental risks predominantly affect the microbiota, and both affect barrier function. Multiple genetic and environmental 'hits' are likely necessary to establish and exacerbate disease. Most conventional IBD therapies currently target only one component of the pathophysiological circuit, inflammation; however, many patients with IBD do not respond to immune-modulating therapies. Hope lies in new classes of therapies that target the microbiota and barrier function.

How to Diagnose and Treat IBD Mimics in the Refractory IBD Patient Who Does Not Have IBD

Inflammatory bowel disease (IBD) is a chronic inflammatory disease of the gastrointestinal tract and includes both Crohn's disease and ulcerative colitis. Patients with IBD often present with abdominal pain, diarrhea, and rectal bleeding but may also have a wide variety of other symptoms such as weight loss, fever, nausea, vomiting, and possibly obstruction. Given that the presentation of IBD is not specific, the differential diagnosis is broad and encompasses a wide spectrum of diseases, many of which can mimic and/or even coexist with IBD. It is important for physicians to differentiate symptoms due to refractory IBD from symptoms due to IBD mimics when a patient is not responding to standard IBD treatment. Many of the various IBD mimics include infectious etiologies (viral, bacterial, mycobacterial, fungal, protozoal, and helminthic infections), vascular causes, other immune causes including autoimmune etiologies, drug-induced processes, radiation-induced, and other etiologies such as small intestinal bacterial overgrowth, diverticulitis, and bile acid malabsorption. Thoughtful consideration and evaluation of these potential etiologies through patient history and physical examination, as well as appropriate tests, endoscopic evaluation, and cross-sectional imaging is required to evaluate any patient presenting with symptoms consistent with IBD.

Influence of environmental factors in the development of inflammatory bowel diseases

Idiopathic inflammatory bowel diseases (IBD), Crohn’s disease (CD) and ulcerative colitis (UC), are multifactorial diseases that are manifested after disruption of a genetic predisposed individual and its intestinal microflora through an environmental stimulus. Urbanization and industrialization are associated with IBD. Epidemiological data, clinical observations and family/immigrants studies indicate the significance of environmental influence in the development of IBD. Some environmental factors have a different effect on the subtypes of IBD. Smoking and appendectomy is negatively associated with UC, but they are aggravating factors for CD. A westernized high fat diet, full of refined carbohydrates is strongly associated with the development of IBD, contrary to a high in fruit, vegetables and polyunsaturated fatty acid-3 diet that is protective against these diseases. High intake of nonsteroidal antiinflammatory drug and oral contraceptive pills as well as the inadequacy of vitamin D leads to an increased risk for IBD and a more malignant course of disease. Moreover, other factors such as air pollution, psychological factors, sleep disturbances and exercise influence the development and the course of IBD. Epigenetic mechanism like DNA methylation, histone modification and altered expression of miRNAS could explain the connection between genes and environmental factors in triggering the development of IBD.

Influence of environmental factors on the onset and course of inflammatory bowel disease

Numerous environmental factors have been linked with inflammatory bowel disease. These include smoking, diet, hygiene, drugs, geographical and psychosocial factors. These factors may either increase the risk of or protect against developing this condition and can also affect the course of illness in a positive or negative manner. A number of studies have examined the influence of environmental factors on inflammatory bowel diseases as a whole as well as on ulcerative colitis and Crohn’s disease separately. As there are differences in the pathogenesis of ulcerative colitis and Crohn’s disease, the effect of environmental factors on their onset and course is not always similar. Some factors have shown a consistent association, while reports on others have been conflicting. In this article we discuss the current evidence on the roles of these factors on inflammatory bowel disease, both as causative/protective agents and as modifiers of disease course.

Acute appendicitis: modern understanding of pathogenesis, diagnosis, and management

Acute appendicitis is one of the most common abdominal emergencies worldwide. The cause remains poorly understood, with few advances in the past few decades. To obtain a confident preoperative diagnosis is still a challenge, since the possibility of appendicitis must be entertained in any patient presenting with an acute abdomen. Although biomarkers and imaging are valuable adjuncts to history and examination, their limitations mean that clinical assessment is still the mainstay of diagnosis. A clinical classification is used to stratify management based on simple (non-perforated) and complex (gangrenous or perforated) inflammation, although many patients remain with an equivocal diagnosis, which is one of the most challenging dilemmas. An observed divide in disease course suggests that some cases of simple appendicitis might be self-limiting or respond to antibiotics alone, whereas another type often seems to perforate before the patient reaches hospital. Although the mortality rate is low, postoperative complications are common in complex disease. We discuss existing knowledge in pathogenesis, modern diagnosis, and evolving strategies in management that are leading to stratified care for patients.

An appendectomy increases the risk of rheumatoid arthritis: a five-year follow-up study

Many studies have reported a possible association of an appendectomy with rheumatoid arthritis (RA). However, findings of the relationship between an appendectomy and RA remain inconsistent. Furthermore, all such studies were conducted in Western societies, and relevant studies on the relationship between an appendectomy and RA in Asian countries are still lacking. In this study, we investigated the relationship between an appendectomy and the subsequent risk of RA using a population-based dataset. We retrieved data for this retrospective cohort study from the Taiwan "Longitudinal Health Insurance Database 2005". We included 4,294 subjects who underwent an appendectomy in the study cohort and 12,882 matched subjects in the comparison cohort. We individually tracked each subject for a 5-year period from their index date to identify those who developed RA. A stratified Cox proportional hazard regression was performed to calculate the hazard ratio (HR) and its corresponding 95% confidence interval (CI) for the subsequent development of RA during the 5-year follow-up period between subjects who underwent an appendectomy and comparison subjects. Of the sampled subjects, 93 (0.54%) received a diagnosis of RA during the 5-year follow-up period: 33 from the study cohort (0.77% of subjects who underwent an appendectomy) and 60 from the comparison cohort (0.47% of comparison subjects) (p<0.001). After censoring individuals who died during the follow-up period and adjusting for subjects' monthly income and geographic region, the HR of RA during the 5-year follow-up period was 1.61 (95% CI = 1.05~2.48) for subjects who underwent an appendectomy compared to comparison subjects. We found that among females, the adjusted HR of RA was 1.76 (95% CI = 1.04~2.96) for subjects who underwent an appendectomy compared to comparison subjects. However, there was no increased hazard of RA for males who underwent an appendectomy compared to comparison subjects. We concluded that female subjects who undergo an appendectomy have a higher risk of RA than comparison female subjects.

Environment and the inflammatory bowel diseases

Inflammatory bowel diseases (IBD), which consists of Crohn disease and ulcerative colitis, are chronic inflammatory conditions of the gastrointestinal tract. In genetically susceptible individuals, the interaction between environmental factors and normal intestinal commensal flora is believed to lead to an inappropriate immune response that results in chronic inflammation. The incidence of IBD have increased in the past century in developed and developing countries. The purpose of the present review is to summarize the current knowledge of the association between environmental risk factors and IBD. A number of environmental risk factors were investigated including smoking, hygiene, microorganisms, oral contraceptives, antibiotics, diet, breastfeeding, geographical factors, pollution and stress. Inconsistent findings among the studies highlight the complex pathogenesis of IBD. Additional studies are necessary to identify and elucidate the role of environmental factors in IBD etiology.

Experimental appendicitis and appendectomy modulate the CCL20-CCR6 axis to limit inflammatory colitis pathology

BACKGROUND

Crohn's disease and ulcerative colitis are the two spectral variations of inflammatory bowel diseases (IBD). The complex interplay between genetic predisposition, gastrointestinal bacteria, and gut immunity in IBD is yet to be deciphered. The newly described IL-17-secreting subset of CD4+ T cells, called Th17 cells (and its "Th17 system"), has been increasingly implicated in the pathogenesis of inflammatory changes in inflammatory/autoimmune diseases including IBD. The chemokine ligand CCL20 and its receptor CCR6 are both upregulated in colon biopsy samples during active IBD. Appendicitis and appendectomy (AA) prevents or significantly ameliorates human IBD.

METHODS

We pioneered the first animal model of AA. AA was performed on 5-week-old male BALB/c mice, and distal-colon samples were harvested. Mice with two laparotomies each served as sham and sham (SS) controls. RNA was extracted from individual colonic replicate samples (AA and SS groups) and each sample microarray analyzed and reverse transcription-polymerase chain reaction (RT-PCR) validated. Gene set enrichment analysis (GSEA) software was used to further analyze the microarray data.

RESULTS

Prior AA ameliorates experimental colitis in our murine model. CCL20 expression was significantly suppressed (along with components of the Th17 system) in the most distal colon 3 and 28 days after AA was done at the most proximal colon.

CONCLUSION

Teasing out the pathways involved in the changes induced by AA on the colon in clinical studies and, most importantly, in our unique murine AA model will lead to the development of techniques to manipulate different components of the CCL20-CCR6 axis and Th17 system resulting in significant advances in IBD management.

A novel model of appendicitis and appendectomy to investigate inflammatory bowel disease pathogenesis and remediation

The appendix contains copious lymphoid tissue and is constantly exposed to gut flora. Appendicitis and appendectomy (AA) has been shown to prevent or significantly ameliorate ulcerative colitis. In our novel murine AA model, the only existing experimental model of AA, the appendiceal pathology closely resembles that of human appendicitis; and AA offers an age-, bacteria- and antigen-dependent protection against colitis. Appendicitis and appendectomy performed in the most proximal colon curbs T helper 17 cell activity, curtails autophagy, modulates interferon activity-associated molecules, and suppresses endothelin vasoactivity-mediated immunopathology/vascular remodelling in the most distal colon. These AA-induced changes contribute to the limitation/amelioration of colitis pathology. Investigating strategies to manipulate and modulate different aspects of these pathways (using monoclonal antibodies, combinatorial peptides, and small molecules) would offer novel insight into inflammatory bowel disease pathogenesis, and will augment the development of new therapeutic options to manage recalcitrant colitis.

Autophagy suppression by appendicitis and appendectomy protects against colitis

BACKGROUND

When done at a young age, appendicitis followed by appendectomy (AA) offers protection against ulcerative colitis development in later life. We developed the first ever murine AA model. Using this model, we showed earlier that previous AA ameliorated colitis. We aimed to determine whether autophagy genes contribute to the anti-colitis protection conferred by AA, and if so, to delineate the autophagy-linked genes involved in this.

METHODS

Mice with 2 laparotomies each served as controls (sham-sham). Distal colons were harvested (4 AA-group colons, 4 sham-sham group colons), and RNA extracted from each. The RNA was taken through microarray analysis or reverse transcription-polymerase chain reaction validation. Gene set enrichment analysis software was used to analyze the microarray data.

RESULTS

Out of 28 key autophagy-related genes investigated (VPS15, VPS34, FIP200, ATG03, ATG04A, ATG04B, ATG05, ATG07, ATG10, ATG12, ATG13b, ATG14, ATG16L1, BECN1, GABARAPL1, IRGM1, IRGM2, LAMP2, LC3A, LC3B, RAB7A, UVRAG, NOD2, XBP1, LRRK2, ULK1, ULK2, PTPN2), 7 have genetic associations with inflammatory bowel diseases (ATG16L1, IRGM1, NOD2, XBP1, LRRK2, ULK1, PTPN2). There was slight upregulation of IRGM1, FIP200, and ATG04A (P < 0.05), but no variations with the other 25 genes. In contrast, gene set enrichment analysis revealed that AA downregulated 74 gene sets (associated with 28 autophagy genes) while upregulating only 5 (false discovery rate <5%; P < 0.001) gene sets. Additionally, 22 gene sets associated with the 7 autophagy + inflammatory bowel disease-associated genes were downregulated by AA, whereas only 3 were upregulated. The genes with maximum AA-induced gene set suppression were VPS15, LAMP2, LC3A, XBP1, and ULK1.

CONCLUSIONS

AA induces profound autophagy suppression in the distal colon. The AA-induced upregulation of individual genes (IRGM1, FIP200, ATG04A) could be a reflection of complex compensatory changes or the initial abnormality that led to the pronounced autophagy suppression. Autophagy suppression by AA may induce lesser antigen processing, leading to lesser cross-reactive immunity between microbes and self-antigens, and subsequent amelioration of colitis.

Characteristic changes in microbial community composition and expression of innate immune genes in acute appendicitis

Appendicitis represents a common and severe gastrointestinal illness in younger individuals worldwide. The disease is characterized by an excessive inflammatory response and it is believed that bacterial overgrowth due to blockage of the appendix lumen might be involved. Despite the high incidence, only limited data on the pathophysiological changes exist; in particular, the innate immune responses involved are largely unknown. Real-time PCR analysis of tissue samples from inflamed and normal appendices demonstrated differentially regulated expression patterns of epithelial-derived antimicrobial peptides (AMP). The α-defensins human neutrophil peptides 1–3, HD5 and HD6, as well as the two β-defensins, human β-defensins (hBD)-2 and hBD-3, were up-regulated, whereas hBD-1 was down-regulated in acute appendicitis. Expression of upstream regulators of AMP expression, NOD-2 and TLRs 1, 2, 4, 5, 7, 8 and 10 was significantly increased as detected by real-time PCR. Finally, we confirmed the involvement of the pro-inflammatory cytokines IL-1β and IL-8, and detected characteristic changes in microbial community composition in appendicitis tissue specimens by 16S rDNA based detection techniques. In this study, we demonstrate a differential regulation of the innate immune system along with an altered bacterial diversity in acute appendicitis.

Environmental influences on the onset and clinical course of Crohn's disease-part 1: an overview of external risk factors

The pathogenesis of Crohn's disease (CD) involves host, genetic, and environmental factors. These factors result in disturbances in the innate and adaptive immune systems and composition of the intestinal microbiota. Epidemiologic and migration studies support an environmental component in the development of CD. Environmental risk factors include childhood hygiene, air pollution, breastfeeding, smoking, diet, stress, exercise, seasonal variation, and appendectomy. This review, part 1 of a 2-part series, provides an overview of these external contributors to the development or exacerbation of CD. Part 2, which will be published in a subsequent issue, will discuss the influences of infections, vaccinations, and medications (including antibiotics, nonsteroidal anti-inflammatory agents, and oral contraceptives) on CD.

Inflammatory bowel disease in Asia: a systematic review

The incidence and prevalence of inflammatory bowel diseases (IBD), Crohn's disease (CD) and ulcerative colitis (UC), are lower in Asia than in the West. However, across Asia the incidence and prevalence of IBD has increased rapidly over the last two to four decades. These changes may relate to increased contact with the West, westernization of diet, increasing antibiotics use, improved hygiene, vaccinations, or changes in the gut microbiota. Genetic factors also differ between Asians and the Caucasians. In Asia, UC is more prevalent than CD, although CD incidence is rapidly increasing in certain areas. There is a male predominance of CD in Asia, but a trend towards equal sex distribution for UC. IBD is diagnosed at a slightly older age than in the West, and there is rarely a second incidence peak as in the West. A positive family history is much less common than in the West, as are extra-intestinal disease manifestations. There are clear ethnic differences in incidence within countries in Asia, and an increased incidence in IBD in migrants from Asia to the West. Research in Asia, an area of rapidly changing IBD epidemiology, may lead to the discovery of critical etiologic factors that lead to the development of IBD.

Pre-colectomy appendectomy and risk for Crohn's disease in patients with ileal pouch-anal anastomosis

BACKGROUND

A subset of patients with a pre-operative diagnosis of ulcerative colitis can develop Crohn's disease (CD) of the pouch after restorative proctocolectomy. While appendectomy has been implicated to be associated with an increased risk for CD, its impact on the development of de novo CD of the pouch in patients' ileal pouch-anal anastomosis (IPAA) has not been studied. The aims of the study were to assess the prevalence of CD of the pouch in patients with pre-colectomy appendectomy and to investigate the impact of appendectomy on the development of de novo CD of the pouch.

METHODS

All eligible patients with restorative proctocolectomy and IPAA for IBD who had available information on pre-colectomy appendectomy were studied. Demographic and clinical characteristics were evaluated. Cox regression analysis was performed.

RESULTS

The study included 434 patients (44.9 % male) with a mean age of 45.2 ± 4.4 years and follow-up of 4.6 ± 2.3 years. Forty patients (9.2 %) had had appendectomy prior to colectomy. Appendectomy was not shown to be associated with CD of the pouch or its phenotypes in both univariable and multivariable analyses. In the Cox model, independent risk factors associated with CD of the pouch were active smoking (hazard ratio [HR] =1.58; 95 % confidence interval [CI], 1.03-2.43) and family history of CD (HR=1.82; 95 % CI, 0.99-3.32).

CONCLUSIONS

While this study has shown no association between previous appendectomy and the development of CD of pouch, active smoking was an independent risk factor for development of CD of the pouch.

Epidemiology and clinical course of Crohn's disease: Results from observational studies

The authors review the clinical outcome in patients with Crohn’s disease (CD) based on studies describing the natural course of the disease. Population-based studies have demonstrated that the incidence rates and prevalence rates for CD have increased since the mid-1970s. The authors search for English language articles from 1980 until 2011. Geographical variations, incidence, prevalence, smoking habits, sex, mortality and medications are investigated. An increasing incidence and prevalence of CD have been found over the last three decades. The disease seems to be most common in northern Europe and North America, but is probably increasing also in Asia and Africa. Smoking is associated with an increased risk of developing CD. Age < 40 at diagnosis, penetrating/stricturing complications, need for systemic steroids, and disease location in terminal ileum are factors associated with higher relapse rates. A slight predominance of women diagnosed with CD has been found. Ileocecal resection is the most commonly performed surgical procedure, and within the first five years after the diagnosis about one third of the patients have had intestinal surgery. Smoking is associated with a worse clinical course and with increased risk of flare-ups. In most studies the overall mortality is comparable to the background population. To date, the most effective treatment options in acute flares are glucocorticosteroids and tumor necrosis factor (TNF)-α- blockers. Azathioprine/methotrexate and TNF-α-blockers are effective in maintaining remission.

Predictors of aggressive inflammatory bowel disease

Inflammatory bowel disease comprises a group of conditions characterized by idiopathic inflammation of the gastrointestinal tract. The natural course of disease can range from an indolent course with prolonged periods of remission to aggressive, incapacitating disease. Predicting which patients are more susceptible to developing severe disease is important, especially when choosing therapeutic agents and treatment strategies. This paper reviews current evidence on the main demographic, clinical, endoscopic, histologic, serologic, and genetic markers that predict aggressive inflammatory bowel disease. In ulcerative colitis, we considered disease to be aggressive when patients had a high relapse rate, need for admission and/or surgery, development of colon cancer, or extraintestinal manifestations. We defined aggressive Crohn's disease as having a high relapse rate, development of penetrating disease, need for repeat surgery, or multiple admissions for flares. In Crohn's disease, involvement of the upper gastrointestinal tract and ileum, penetrating disease, early age at diagnosis, smoking, extensive ulceration of the mucosa, high titers of serum antibodies, and mutations of the NOD2 gene are markers of aggressive disease. In ulcerative colitis, patients with more extensive involvement of the colon (pancolitis) have more symptomatology and are at higher risk for needing a colectomy and developing colon cancer. Also, plasmocytic infiltration of the colonic mucosa and crypt atrophy predict treatment failure. As with diagnosis, no single method can predict disease aggressiveness. Multiple serologic and genetic tests are being developed to refine the accuracy of prediction. Endoscopic findings can also predict the future course of disease. At present, clinical manifestations are the most useful way to make therapeutic decisions.

Challenges associated with identifying the environmental determinants of the inflammatory bowel diseases

In the last several years there has been an explosion in the discovery of inflammatory bowel disease (IBD) susceptibility genes; however, similar advances in identifying and defining environmental risk factors associated with IBD have lagged behind. Moreover, many studies that have explored the same or similar environmental risk factors of IBD have demonstrated disparate results and come to conflicting conclusions. In order for the field to move forward, it is important to understand and resolve why these differences exist. This significant heterogeneity has blurred the identification of the fundamental environmental determinants of IBD. The purpose of this review article is to explore the factors that have likely contributed to the heterogeneity among observational studies of environmental risk factors in IBD. In doing so, it is hoped that methodological standardization may lead to consistent environmental associations.

Familial aggregation in inflammatory bowel disease: Is it genes or environment?

Inflammatory bowel disease (IBD) develops in genetically susceptible individuals due to the influence of environmental factors, leading to an abnormal recognition of microbiota antigens by the innate immune system which triggers an exaggerated immune response and subsequent bowel tissue damage. IBD has been more frequently found in families, an observation that could be due to either genetic, environmental or both types of factors present in these families. In addition to expanding our knowledge on IBD pathogenesis, defining the specific contribution to familial IBD of each one of these factors might have also clinical usefulness. We review the available evidence on familial IBD pathogenesis.

Cigarette smoking and appendectomy: effect on clinical course of diverticulosis

AIM

To investigate the effect of appendectomy and cigarette smoking on the clinical course of diverticulosis.

MATERIALS AND METHODS

A retrospective case-control study of 207 consecutive patients (45.8% male mean age 64.0 years), 150 with asymptomatic diverticulosis, and 57 with acute diverticulitis. Diagnosis of diverticulosis was defined on the basis of clinical and colonoscopic criteria, diverticulitis was defined by means of clinical, colonoscopic and computerised tomography criteria. Logistic regression function was used to define the relationship between the dependent variable (diverticulitis) and several covariates: sex, age, body mass index, smoking habit, and history of appendectomy.

RESULTS

According to the final model, the risk of diverticulitis was 4.94-fold higher (95% confidence interval: 1.98-12.37) in patients with a history of appendectomy with emergency resection, compared to patients not submitted to appendectomy or with a history of elective resection (P < 0.001); and 2.79-fold higher (95% confidence interval: 1.30-5.96) in smokers than in non-smokers (P = 0.008). The effects of the two determinants were found to be independent, thus the cumulative risk of diverticulitis was 13.78-fold higher for smokers with a history of emergency surgical treatment.

CONCLUSION

Smoking and emergency appendectomy are important predictive factors for the clinical course of diverticulosis.

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.

Disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease

The cause of Crohn's disease (CD) remains poorly understood. Counterintuitively, these patients possess an impaired acute inflammatory response, which could result in delayed clearance of bacteria penetrating the lining of the bowel and predispose to granuloma formation and chronicity. We tested this hypothesis in human subjects by monitoring responses to killed Escherichia coli injected subcutaneously into the forearm. Accumulation of (111)In-labeled neutrophils at these sites and clearance of (32)P-labeled bacteria from them were markedly impaired in CD. Locally increased blood flow and bacterial clearance were dependent on the numbers of bacteria injected. Secretion of proinflammatory cytokines by CD macrophages was grossly impaired in response to E. coli or specific Toll-like receptor agonists. Despite normal levels and stability of cytokine messenger RNA, intracellular levels of tumor necrosis factor (TNF) were abnormally low in CD macrophages. Coupled with reduced secretion, these findings indicate accelerated intracellular breakdown. Differential transcription profiles identified disease-specific genes, notably including those encoding proteins involved in vesicle trafficking. Intracellular destruction of TNF was decreased by inhibitors of lysosomal function. Together, our findings suggest that in CD macrophages, an abnormal proportion of cytokines are routed to lysosomes and degraded rather than being released through the normal secretory pathway.

Role of Klebsiella and collagens in Crohn's disease: a new prospect in the use of low-starch diet

Crohn's disease is suggested to result from a microbially triggered immune-mediated autoimmune process, involving mainly the terminal ileum and ileo-caecal junction. Klebsiella pneumoniae shares certain molecular structures present in pullulanase pulA and pulD secretion enzymes with various self-antigens present in collagens and HLA-B27 molecules, respectively. A link exists between high dietary starch intake and the growth of intestinal microflora, involving especially Klebsiella microbes. Increased exposure to Klebsiella in the gut as the result of high starch intake would lead to high production of antiKlebsiella antibodies as well as autoantibodies to the cross-reactive self-antigens with the resultant inflammation at the pathological sites. Eradication of these microbes from the gut in patients with Crohn's disease with the use of low-starch diet and antibacterial agents as well as immunomodulatory measures could be beneficial in the management of this disease.

Reproductive Factors and Risk of Systemic Lupus Erythematosus: Nationwide Cohort Study in Denmark

Objective.

The female predominance in systemic lupus erythematosus (SLE) suggests the possible involvement of reproductive factors in its etiology. We evaluated the relationship between parity and pregnancy losses and subsequent risk of SLE in a population-based cohort study.

Methods.

We followed 4.4 million Danes aged 15–69 years for first inpatient hospitalizations for SLE between 1977 and 2004. As measures of relative risk, we used Poisson regression-derived hospitalization rate ratios (RR) with 95% confidence intervals (CI) for cohort members with different reproductive histories.

Results.

Overall, 1614 women and 274 men were hospitalized with SLE during 88.9 million person-years of followup. Number of children was unrelated to SLE risk in men, but women with at least one liveborn child were at lower risk than nulliparous women (RR 0.74; 95% CI 0.64–0.86), and women with 2 or more children were at lower risk than 1-child mothers. Recurrent idiopathic pregnancy losses, including spontaneous abortions, missed abortions, and stillbirths, were associated with markedly increased SLE risk (RR 3.50; 95% CI 2.38–4.96, for 2+ vs none; p < 0.001).

Conclusion.

Nulliparous women, 1-child mothers, and women who experience spontaneous abortions, missed abortions, or stillbirths are at increased SLE risk. Theoretically, immunological processes involved in subfertility or idiopathic pregnancy losses might act as initiating or contributing factors in some cases of SLE. However, considering the well established excess of pregnancy complications in women with established SLE, the observed associations more likely reflect the effect of subclinical immunological processes in women destined to develop SLE.