A frameshift mutation in NOD2 associated with susceptibility to Crohn's disease

Crohn's disease is a chronic inflammatory disorder of the gastrointestinal tract, which is thought to result from the effect of environmental factors in a genetically predisposed host. A gene location in the pericentromeric region of chromosome 16, IBD1, that contributes to susceptibility to Crohn's disease has been established through multiple linkage studies, but the specific gene(s) has not been identified. NOD2, a gene that encodes a protein with homology to plant disease resistance gene products is located in the peak region of linkage on chromosome 16 (ref. 7). Here we show, by using the transmission disequilibium test and case-control analysis, that a frameshift mutation caused by a cytosine insertion, 3020insC, which is expected to encode a truncated NOD2 protein, is associated with Crohn's disease. Wild-type NOD2 activates nuclear factor NF-kappaB, making it responsive to bacterial lipopolysaccharides; however, this induction was deficient in mutant NOD2. These results implicate NOD2 in susceptibility to Crohn's disease, and suggest a link between an innate immune response to bacterial components and development of disease.

A randomized clinical trial of ciprofloxacin and metronidazole to treat acute pouchitis

Metronidazole is effective for the treatment of acute pouchitis after ileal pouch-anal anastomosis, but it has not been directly compared with other antibiotics. This randomized clinical trial was designed to compare the effectiveness and side effects of ciprofloxacin and metronidazole for treating acute pouchitis. Acute pouchitis was defined as a score of 7 or higher on the 18-point Pouchitis Disease Activity Index (PDAI) and symptom duration of 4 weeks or less. Sixteen patients were randomized to a 2-week course of ciprofloxacin 1,000 mg/d (n = 7) or metronidazole 20 mg/kg/d (n = 9). Clinical symptoms, endoscopic findings, and histologic features were assessed before and after therapy. Both ciprofloxacin and metronidazole produced a significant reduction in the total PDAI score as well as in the symptom, endoscopy, and histology subscores. Ciprofloxacin lowered the PDAI score from 10.1+/-2.3 to 3.3+/-1.7 (p = 0.0001), whereas metronidazole reduced the PDAI score from 9.7+/-2.3 to 5.8+/-1.7 (p = 0.0002). There was a significantly greater reduction in the ciprofloxacin group than in the metronidazole group in terms of the total PDAI (6.9+/-1.2 versus 3.8+/-1.7; p = 0.002), symptom score (2.4+/-0.9 versus 1.3+/-0.9; p = 0.03), and endoscopic score (3.6+/-1.3 versus 1.9+/-1.5; p = 0.03). None of patients in the ciprofloxacin group experienced adverse effects, whereas three patients in the metronidazole group (33%) developed vomiting, dysgeusia, or transient peripheral neuropathy. Both ciprofloxacin and metronidazole are effective in treating acute pouchitis with significant reduction of the PDAI scores. Ciprofloxacin produces a greater reduction in the PDAI and a greater improvement in symptom and endoscopy scores, and is better tolerated than metronidazole. Ciprofloxacin should be considered as one of the first-line therapies for acute pouchitis.

Endoscopic and histologic evaluation together with symptom assessment are required to diagnose pouchitis

BACKGROUND & AIMS

Pouchitis often is diagnosed based on symptoms alone. In this study, we evaluate whether symptoms correlate with endoscopic and histologic findings in patients with ulcerative colitis and an ileal pouch-anal anastomosis.

METHODS

Symptoms, endoscopy, and histology were assessed in 46 patients using Pouchitis Disease Activity Index (PDAI). Patients were classified as either having pouchitis (PDAI score > or =7; N = 22) or as not having pouchitis (PDAI score <7; N = 24).

RESULTS

Patients with pouchitis had significantly higher mean total PDAI scores, symptom scores, endoscopy scores, and histology scores. There was a similar magnitude of contribution of each component score to the total PDAI for the pouchitis group. Of note, 25% of patients with symptoms suggestive of pouchitis did not meet the PDAI diagnostic criteria for pouchitis. In both groups, the correlation coefficients between symptom, endoscopy, and histology scores were near zero (range, -0.26 to 0.20; P > 0.05).

CONCLUSIONS

The symptom, endoscopy, and histology scores each contribute to the PDAI and appear to be independent of each other. Symptoms alone do not reliably diagnose pouchitis.

Undetected hepatocellular carcinoma: clinical features and outcome after liver transplantation

The aim of the study was to define the clinical characteristics and outcome of patients found to have an undetected hepatocellular carcinoma (HCC) at liver transplantation. Patients who underwent liver transplantation and were found to have a hepatoma with a prior workup showing normal alpha-fetoprotein levels and no corresponding lesion on radiological evaluation were defined as having an undetected HCC. Detailed information was collected, and the last abdominal computed tomographic (CT) scan before transplantation was performed was retrospectively reviewed. Thirty-nine patients had a tumor that met the criteria for an undetected hepatoma. The most common causes for pretransplantation liver disease were hepatitis C virus (HCV) (49%) and alcohol use (28%). Tumor size was 2 cm or less in 85% of the patients, vascular invasion was detected in 31% of the patients, and tumor, node, metastasis (TNM) classification was stage I or II in 77% of the patients. Review of the last CT scan before transplantation showed that the lesion was evident in retrospect in only 15% of the patients. Thirty-two patients (82%) remained alive at the time of the study with a mean follow-up of 30 months. Metastatic HCC was detected in 1 patient 7 months after transplantation. There were no other tumor recurrences. Survival analysis showed no significant differences when tumor size, stage, presence of vascular invasion, or causes of pretransplantation liver disease were compared. Undetected HCCs represent a significant percentage of total hepatomas in patients undergoing liver transplantation. Most patients have small, early-stage tumors, but tumors greater than 2 cm or of advanced stage are also frequently found in this population. Overall and tumor-free survival appear to be favorable.

Medical therapy to reduce postoperative Crohn's disease recurrence

Clinical recurrence of Crohn's disease after surgical resection is a significant problem, with reported rates as high as 55% at 5 yr and 76% at 15 yr. Specific factors that predispose to postoperative recurrence of Crohn's disease have not been well defined. In addition, the underlying pathophysiology of recurrent disease and the reason for its localization to the neoterminal ileum are not well understood. Various operative techniques have been evaluated but none, aside from formation of an ostomy, has been shown to reduce the risk of recurrence. In contrast, there is increasing evidence that postoperative medical therapy has the potential to decrease the risk of postoperative recurrence. Historically, sulfasalazine may have a modest effect on reducing postoperative recurrence of ileal or ileocolonic disease. However, 5-ASA preparations that can selectively deliver mesalamine to the small bowel or anastomotic margin should be more effective. Indeed, in several studies and as confirmed by a meta-analysis, mesalamine has been demonstrated to reduce significantly postoperative recurrence of Crohn's disease. Metronidazole and 6-mercaptopurine or azathioprine also seem to be of benefit in postoperative prophylaxis of disease recurrence, but additional controlled studies are required to define better the efficacy and dose-response of these agents. Corticosteroids are ineffective at reducing postoperative recurrence.

Management of peristomal pyoderma gangrenosum

PURPOSE

This study was designed to evaluate the presentation, management, and outcome of peristomal pyoderma gangrenosum at a specialist colorectal unit and develop a strategy for therapy.

METHODS

Patients with peristomal pyoderma gangrenosum were identified from a prospectively accrued Institutional Review Board-approved stoma database. Data were collected regarding demographics, disease status, history of illness, time to healing, and treatments used from the database and by chart review.

RESULTS

Sixteen patients presented between 1997 and 2002 with peristomal ulceration consistent with a diagnosis of peristomal pyoderma gangrenosum. Diagnosis was predominantly clinically based on a classic presentation of painful, undermined peristomal ulceration. The underlying diagnosis was Crohn's disease in 11 patients, ulcerative colitis in 3, indeterminate colitis in 1, and posterior urethral valves in 1. At the time of development of peristomal pyoderma gangrenosum, the underlying disease was active in 69 percent of patients. Stoma care, ulcer debridement with unroofing of undermined edges, and intralesional corticosteroid injection was associated with a 40 percent complete response rate and further 40 percent partial response rate. Of five patients who received infliximab, four (80 percent) responded to therapy. Complete response after all forms of therapy, including stoma relocation in seven patients, was 87 percent.

CONCLUSIONS

Local wound management and enterostomal therapy are extremely important for patients with peristomal pyoderma gangrenosum. Infliximab may provide a useful option for those failing other forms of medical therapy. Relocation of the stoma is reserved for persistent ulceration failing other therapies, because peristomal pyoderma gangrenosum may recur at the new stoma site.

Molecular pathways underlying IBD-associated colorectal neoplasia: therapeutic implications

Chronic inflammatory diseases, depending upon the duration and severity, are frequently associated with an increased risk of developing cancer. A classic paradigm is the enhanced risk of colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD). Carcinogenesis is a multifactorial process that involves accumulation of genetic defects, protein modification, and cell-matrix interaction. In this review, we discuss aspects of chronic inflammation in IBD that influence the development of CRC and highlight the key molecular mediators involved in this process. Also, we identify potential targets that could facilitate earlier detection of dysplasia. The targeted manipulation of specific molecules or pathways could provide opportunities for the development of therapeutic and chemopreventive interventions, which may prove effective in arresting the progression of colitis-associated cancer (CAC), with clinical implications.

Colonic motor function in humans is not affected by gender

Functional abdominal pain, including the irritable bowel syndrome, is more common in females. Our aim was to determine if differences in motility or biomechanical properties of the colon could account for this gender difference. In 18 healthy subjects (nine males), a catheter assembly incorporating a balloon and perfused side holes, connected to a barostat, was positioned in the left colon. The system was used to determine compliance, sensation in response to phasic balloon distension, and changes in motor activity and tone in response to a meal. There was no significant difference in any of these variables between males and females. We conclude that there is no gender difference in colonic motor function or sensation to balloon distension. The increased prevalence of irritable bowel syndrome in females may be related to psychosocial factors rather than differences in colonic motor function.

Mild neoterminal ileal post-operative recurrence of Crohn's disease conveys higher risk for severe endoscopic disease progression than isolated anastomotic lesions

There are conflicting data assessing the impact of isolated post-operative anastomotic inflammation on future disease progression. The aim of this study was to determine the relative risk of severe disease progression in post-operative Crohn's disease (CD) patients with isolated anastomotic disease.

METHODS

Retrospective cohort study of adult CD patients undergoing ileocolonic resection between 2009 and 2020. Patients with a post-operative ileocolonoscopy ≤18 months from surgery and ≥1 subsequent ileocolonoscopy were included. Disease activity was assessed using the modified Rutgeerts' score (RS). Primary outcome was severe endoscopic progression, defined as i3 or i4 disease, on immediate subsequent ileocolonoscopy and during entire post-operative follow-up. Secondary outcome was surgical recurrence.

RESULTS

One hundred and ninety-nine CD patients had an ileocolonoscopy ≤18 months from surgery, index RS of i0-i2b and ≥1 subsequent ileocolonoscopy. At index ileocolonoscopy, 34.7% had i0 disease, 16.1% i1, 24.6% i2a and 24.6% i2b. On multivariable logistic regression, i2b disease was associated with severe endoscopic progression compared to i0 or i1 (aOR 5.53; P < 0.001) and i2a disease patients (aOR 2.63; P = 0.03). However, i2a disease did not confer increased risk compared to i0 or i1 disease (P = 0.09). Furthermore, i2b patients experienced severe endoscopic progression significantly earlier than i0 or i1 disease (aHR 4.68; P < 0.001), whereas i2a disease did not differ from i0 or i1 disease (P = 0.25). Surgical recurrence was not associated with index RS i0-i2b (P = 0.86).

CONCLUSION

Post-operative ileal disease recurrence, not isolated anastomotic inflammation, confers increased risk for severe endoscopic disease progression. Location of CD recurrence may impact optimal management strategies.

Medical management of postoperative complications of inflammatory bowel disease: pouchitis and Crohn's disease recurrence

Surgical intervention is often required for patients with inflammatory bowel disease. Total proctocolectomy with ileal pouch-anal anastomosis is the surgical treatment of choice for patients with ulcerative colitis. The main long-term complication of this surgery is pouchitis, with 10-year cumulative incidence rates between 24% and 46%. For patients with Crohn's disease, postoperative recurrence is a significant problem, with clinical recurrence rates as high as 55% at 5 years and 76% at 15 years. Increasing evidence suggests that postoperative medical therapy has the potential to decrease the risk of postoperative Crohn's disease recurrence.

Test Characteristics of Cross-sectional Imaging and Concordance With Endoscopy in Postoperative Crohn's Disease

BACKGROUND & AIMS

Postoperative Crohn's disease (CD) surveillance relies on endoscopic monitoring. The role of cross-sectional imaging is less clear. We evaluated the concordance of cross-sectional enterography with endoscopic recurrence and the predictive ability of radiography for future CD postoperative recurrence.

METHODS

We performed a multi-institution retrospective cohort study of postoperative adult patients with CD who underwent ileocolonoscopy and cross-sectional enterography within 90 days of each other following ileocecal resection. Imaging studies were interpreted by blinded, expert CD radiologists. Patients were categorized by presence of endoscopic postoperative recurrence (E+) (modified Rutgeerts' score ≥i2b) or radiographic disease activity (R+) and grouped by concordance status.

RESULTS

A total of 216 patients with CD with paired ileocolonoscopy and imaging were included. A majority (54.2%) exhibited concordance (34.7% E+/R+; 19.4% E-/R-) between studies. The plurality (41.7%; n = 90) were E-/R+ discordant. Imaging was highly sensitive (89.3%), with low specificity (31.8%), in detecting endoscopic postoperative recurrence. Intestinal wall thickening, luminal narrowing, mural hyper-enhancement, and length of disease on imaging were associated with endoscopic recurrence (all P < .01). Radiographic disease severity was associated with increasing Rutgeerts' score (P < .001). E-/R+ patients experienced more rapid subsequent endoscopic recurrence (hazard ratio, 4.16; P = .033) and increased rates of subsequent endoscopic (43.8% vs 22.7%) and surgical recurrence (20% vs 9.5%) than E-/R- patients (median follow-up, 4.5 years).

CONCLUSIONS

Cross-sectional imaging is highly sensitive, but poorly specific, in detecting endoscopic disease activity and postoperative recurrence. Advanced radiographic disease correlates with endoscopic severity. Patients with radiographic activity in the absence of endoscopic recurrence may be at increased risk for future recurrence, and closer monitoring should be considered.

Intra-abdominal septic complications after ileocolic resection increases risk for endoscopic and surgical postoperative Crohn's disease recurrence

BACKGROUND

Postoperative recurrence [POR] of Crohn's disease following ileocolonic resection is common. The impact of immediate postoperative intra-abdominal septic complications [IASC] on endoscopic and surgical recurrence has not been elucidated.

AIMS

To evaluate if IASC is associated with an increased risk for endoscopic and surgical POR.

METHODS

This was a retrospective study of adult Crohn's disease patients undergoing ileocolonic resection with primary anastomosis between 2009 and 2020. IASC was defined as anastomotic leak or intra-abdominal abscess within 90 days of the date of surgery. Multivariable logistic and Cox proportional hazard modelling were performed to assess the impact of IASC on endoscopic POR [modified Rutgeerts' score ≥ i2b] at index postoperative ileocolonoscopy and long-term surgical recurrence.

RESULTS

In 535 Crohn's disease patients [median age 35 years, 22.1% active smokers, 35.7% one or more prior resection] had an ileocolonic resection with primary anastomosis. A minority of patients [N = 47; 8.8%] developed postoperative IASC. In total, 422 [78.9%] patients had one or more postoperative ileocolonoscopies, of whom 163 [38.6%] developed endoscopic POR. After adjusting for other risk factors for postoperative recurrence, postoperative IASC was associated with significantly greater odds (adjusted odds ratio [aOR]: 2.45 [1.23-4.97]; p = 0.01) and decreased time (adjusted hazards ratio [aHR]: 1.60 [1.04-2.45]; p = 0.03] to endoscopic POR. Furthermore, IASC was associated with increased risk (aOR: 2.3 [1.04-4.87] p = 0.03) and decreased survival-free time [aHR: 2.53 [1.31-4.87]; p = 0.006] for surgical recurrence.

CONCLUSION

IASC is associated with an increased risk for endoscopic and surgical POR of Crohn's disease. Preoperative optimization to prevent IASC, in addition to postoperative biological prophylaxis, may help reduce the risk for endoscopic and surgical POR.

Azathioprine formulation optimizes metabolite profile in inflammatory bowel disease

BACKGROUND

Recent studies have suggested that mercaptopurine metabolism is influenced by drug formulation (mercaptopurine vs. azathioprine) and concomitant use of 5-aminosalicylic acid medications.

AIM

To determine the influence of dose, formulation and 5-aminosalicylic acid use on mercaptopurine metabolism.

METHODS

Metabolites from 131 inflammatory bowel disease patients were analysed. Logistic regression was used to analyse correlations between dose and metabolite levels. Multivariate analysis was used to determine the effects of drug formulation and 5-aminosalicylic acid use.

RESULTS

A positive correlation was detected between dose and 6-tioguanine nucleotides levels for azathioprine/Imuran formulation (P = 0.005) but not for mercaptopurine formulation. Adjusted mean 6-tioguanine nucleotides levels were similar for both formulations. Adjusted mean 6-methylmercaptopurine levels were higher for mercaptopurine formulation than for azathioprine formulation (1950 vs. 1056, P = 0.04). 5-Aminosalicylic acid use: 6-tioguanine nucleotides levels did not differ based on concomitant 5-aminosalicylic acid use. However, 5-aminosalicylic acid use did result in higher adjusted mean 6-methylmercaptopurine levels: 2078 on 5-aminosalicylic acid vs. 991 off 5-aminosalicylic acid (P = 0.004).

CONCLUSIONS

(i) Azathioprine may have metabolic benefits by achieving a correlation of dose with 6-tioguanine nucleotides levels and by leading to lower mean 6-methylmercaptopurine levels. (ii) 5-aminosalicylic acid use does not significantly impact 6-tioguanine levels and may lead to higher 6-methylmercaptopurine levels.

Risk of extraesophageal malignancy in patients with adenocarcinoma arising in Barrett's esophagus

OBJECTIVES

It has been suggested that the presence of Barrett's mucosa is a marker for potential malignancy in other organs. Our objective was to study subjects with adenocarcinoma of the esophagus arising in Barrett's epithelium.

METHODS

We reviewed the medical records of patients with esophageal adenocarcinoma, with esophageal squamous cell carcinoma, and with no esophageal pathology and recorded the occurrence of extraesophageal malignancies and the heavy use of tobacco and alcohol.

RESULTS

The prevalence of extraesophageal malignancies was not higher in patients with esophageal adenocarcinoma (15%) than in patients in either control group (14% each). Patients with either type of cancer of the esophagus had higher rates of tobacco and alcohol use than normal controls (tobacco: p = 0.02 and p < 0.01 for adenocarcinoma and squamous cell carcinoma, respectively, vs. normal controls; alcohol: p < 0.01 for each esophageal malignancy vs. normal controls). The rate of tobacco and alcohol use was higher in patients with esophageal squamous cell carcinoma than in those with adenocarcinoma, but only the difference in alcohol consumption was statistically significant (p < 0.01).

CONCLUSION

Patients with adenocarcinoma of the esophagus are not at higher risk for development of extraesophageal malignancy. This observation applies to both those with and without underlying Barrett's epithelium. Alcohol and tobacco use appear to be related to the malignant transformation of esophageal epithelium.

Association of cancer with comorbid inflammatory conditions and treatment in patients with Lynch syndrome

BACKGROUND

Individuals with Lynch syndrome (LS) and hereditary non-polyposis colorectal cancer (HNPCC) are at increased risk of both colorectal cancer and other cancers. The interplay between immunosuppression, a comorbid inflammatory condition (CID), and HNPCC on cancer risk is unclear.

AIM

To evaluate the impact of CIDs, and exposure to monoclonal antibodies and immunomodulators, on cancer risk in individuals with HNPCC.

METHODS

Individuals prospectively followed in a hereditary cancer registry with LS/HNPCC with the diagnosis of inflammatory bowel disease or rheumatic disease were identified. We compared the proportion of patients with cancer in LS/HNPCC group with and without a CID. We also compared the proportion of patients who developed cancer following a CID diagnosis based upon exposure to immunosuppressive medications.

RESULTS

A total of 21 patients with LS/HNPCC and a CID were compared to 43 patients with LS/HNPCC but no CID. Cancer occurred in 84.2% with a CID compared to 76.7% without a CID (P = 0.74) with no difference in age at first cancer diagnosis 45.5 ± 14.6 vs 43.8 ± 7.1 years (P = 0.67). LS specific cancers were diagnosed in 52.4% with a CID vs 44.2% without a CID (P = 0.54). Nine of 21 (42.9%) patients were exposed to biologics or immunomodulators for the treatment of their CID. Cancer after diagnosis of CID was seen in 7 (77.8%) of exposed individuals vs 5 (41.7%) individuals unexposed to biologics/immunomodulators (P = 0.18). All 7 exposed compared to 3/5 unexposed developed a LS specific cancer. The exposed and unexposed groups were followed for a median 10 years and 8.5 years, respectively. The hazard ratio for cancer with medication exposure was 1.59 (P = 0.43, 95%CI: 0.5-5.1).

CONCLUSION

In patients with LS/HNPCC, the presence of a concurrent inflammatory condition, or use of immunosuppressive medication to treat the inflammatory condition, might not increase the rate of cancer occurrence in this limited study.

Real-world effectiveness and safety of ustekinumab and vedolizumab in elderly patients with Crohn's disease

Studies report favorable efficacy and safety profiles of ustekinumab (UST) and vedolizumab (VDZ) in Crohn's disease (CD), but effectiveness and safety data in elderly patients with CD is lacking. We retrospectively analyzed 78 elderly patients (39 each UST and VDZ) and found that patients on UST and VDZ experienced similar rates of clinical response, remission and mucosal healing despite high proportion of prior biologic exposure. Both UST and VDZ appear to be effective and safe in this at-risk CD population. Further large studies are needed to validate our findings.

Nonobstructing Crohn's Disease

Although our existing medical management improves the quality of life of the majority of patients with Crohn's disease (CD), a substantial proportion of individuals still experience unpleasant symptoms from either the disease or therapy. Many patients ultimately require surgery. In the near future it is highly likely that new drugs will be available that are able to favorably modify the natural history of the disease.