Medical therapy for Crohn's disease: the state of the art

Nephrolithiasis as a common urinary system manifestation of inflammatory bowel diseases; a clinical review and meta-analysis

CONTEXT

The extra-intestinal manifestations of inflammatory bowel disease (IBD) are common and involve other organs or systems for example; urinary system.

EVIDENCE ACQUISITIONS

For this review, we used a variety of sources by searching through Web of Science, PubMed, EMBASE, Scopus and directory of open access journals (DOAJ).

RESULTS

Urinary complications may occur in up to 22% of patients and nephrolithiasis or renal/kidney stones have been suggested to be a common manifestation of disease in forms of uric acid, calcium phosphate or calcium oxalate. We performed a meta-analysis on five clinical trials and reported that correlation between IBD and formation of stone in renal system is positive and significant (Fix-effect model; CI: 95%, P <0.001, and randomeffect model; CI: 95%, P = 0.03).

CONCLUSIONS

Based on the reports of the clinical trials, calcium oxalate is more prevalent in Crohn's disease (CD) than in ulcerative colitis (UC).

Melatonin's role as a co-adjuvant treatment in colonic diseases: A review

Melatonin is produced in the pineal gland as well as many other organs, including the enterochromaffin cells of the digestive mucosa. Melatonin is a powerful antioxidant that resists oxidative stress due to its capacity to directly scavenge reactive species, to modulate the antioxidant defense system by increasing the activities of antioxidant enzymes, and to stimulate the innate immune response through its direct and indirect actions. In addition, the dysregulation of the circadian system is observed to be related with alterations in colonic motility and cell disruptions due to the modifications of clock genes expression. In the gastrointestinal tract, the activities of melatonin are mediated by melatonin receptors (MT2), serotonin (5-HT), and cholecystokinin B (CCK2) receptors and via receptor-independent processes. The levels of melatonin in the gastrointestinal tract exceed by 10-100 times the blood concentrations. Also, there is an estimated 400 times more melatonin in the gut than in the pineal gland. Gut melatonin secretion is suggested to be influenced by the food intake. Low dose melatonin treatment accelerates intestinal transit time whereas high doses may decrease gut motility. Melatonin has been studied as a co-adjuvant treatment in several gastrointestinal diseases including irritable bowel syndrome (IBS), constipation-predominant IBS (IBS-C), diarrhea-predominant IBS (IBS-D), Crohn's disease, ulcerative colitis, and necrotizing enterocolitis. The purpose of this review is to provide information regarding the potential benefits of melatonin as a co-adjuvant treatment in gastrointestinal diseases, especially IBS, Crohn's disease, ulcerative colitis, and necrotizing enterocolitis.

Clinical factors contributing to rapid reoperation for Crohn's disease patients undergoing resection and/or strictureplasty

Although surgically induced remission of Crohn's disease following segmental resection/strictureplasty is effective and durable, a subpopulation of patients will require rapid reoperation. We reviewed our inflammatory bowel disease center's database to identify patients who underwent multiple laparotomies. A retrospective analysis of consecutive Crohn's disease patients (1998-2004) was performed, and patients requiring repeat laparotomy were identified. Rapid reoperation was defined as repeat intestinal surgery within 2 years. Demographic data and medical treatment were recorded. Clinical factors contributing to rapid reoperation were defined as (1) symptomatic adhesion, (2) residual strictures/technical error, (3) lack of effective medical therapy, and (4) severe disease despite medical treatment. Of 432 patients, 65 required two or more abdominal explorations, with 32 patients requiring rapid reoperation (50 surgeries). Residual strictures and technical error accounted for 20% of procedures; ineffective medical therapy was identified in 64%, whereas severe disease despite medical therapy was a contributing factor in 14%. Adhesions were found in a single patient. Kaplan-Meier analysis confirmed that rapid reoperation patients had significant and consistently shorter intervals between surgical procedures (i.e., interval between procedures 1 and 2 and 2 and 3). Residual strictures manifest during postop year 1, whereas recurrence of severe disease was the dominant contributing factor during year 2. Our data suggest that operative strategies emphasizing occult stricture detection and adequate medical therapy in Crohn's disease patients may improve outcome and decrease the need for rapid re-exploration.

Risk for Osteoporosis and Antiresorptive Therapies in Patients with Crohn's Disease

Background:

The risk of osteoporosis is greater in patients with inflammatory bowel disease (IBD) because of several related risk factors such as the prolonged use of corticosteroids, the malabsorption of calcium and vitamin D following small-bowel disease or small-bowel resections, and the inflammatory process resulting from the illness. A reduction in bone mineral density (BMD) has been reported in 30–75% of patients with IBD (Crohn's disease or ulcerative colitis). An evaluation of the risk factors of osteoporosis should be performed to identify those in need of antiresorptive drug therapies (ART) and/or calcium and vitamin D supplements.

Objective:

To determine whether patients with Crohn's disease at risk for osteoporosis or already having decreased BMD were identified as such and treated with appropriate therapy.

Methods:

A cross-sectional study was performed among 54 white patients with Crohn's disease who attended a gastroenterology specialized clinic between January and March 2002. All patients with Crohn's disease having an outpatient medical visit were asked to participate in the study. Patients who agreed to the study were questioned for Crohn's disease activity index (CDAI) and osteoporosis risk factors such as nutrition, lifestyle, and corticosteroid therapy. Serum bone-specific markers and nutritional status were assessed. BMD test of the lumbar vertebrae (L2–L4) and the nondominant hip were assessed with dual-energy X-ray absorptiometry if the participants did not have a BMD test in the year prior to the study. ART and calcium/vitamin D use were assessed through a questionnaire and on community pharmaceutical drug services in the 2 year period prior to the evaluation.

Results:

Mean age and CDAI severity score were 41.5 years and 145, respectively. None of the patients was evaluated for BMD in the year prior to the study. Osteopenia at the nondominant hip and/or lumbar vertebrae was seen in 29 patients. Eighty-two percent of patients with a T score under −2 SD had not been exposed to ART; 84% of patients with more than 4 risk factors for osteoporosis and a T score less than −1.5 SD had not received ART. Moreover, 88% of patients with a T score less than −1.5 SD and receiving corticosteroid therapy had not been treated with ART.

Conclusions:

The presence of osteoporosis risk factors and osteopenia had not been recognized and treated in our population. Adequate osteoporosis management should be implemented in patients with Crohn's disease to reduce the occurrence of osteoporotic fractures.

Canine inflammatory bowel disease: retrospective analysis of diagnosis and outcome in 80 cases (1995-2002)

The case records of 80 dogs in which idiopathic inflammatory bowel disease (IBD) had been diagnosed were reviewed, and owners were contacted for follow-up information using a telephone questionnaire. The types of IBD encountered were lymphocytic (n=6), lymphocytic-plasmacytic (n=38), eosinophilic (n=6) and mixed inflammation (n=30). Prednisolone, sulphasalazine, metronidazole and tylosin were the most frequently prescribed medications. At follow-up, 21 dogs (26 per cent) were classified as being in remission (for a median of 14 months), 40 dogs (50 per cent) had intermittent clinical signs (for a median of 17 months) and three dogs (4 per cent) had uncontrolled disease (for a median of 19 months). Ten dogs (13 per cent) had been euthanased due to refractory IBD and four of these had entered remission for a median of 21 months prior to developing severe relapse and refractoriness to further treatment. Six dogs (8 per cent) had been euthanased or had died for reasons unrelated to IBD. Hypoalbuminaemia at the time of diagnosis was significantly associated with a negative outcome (P=0.0007). No association was found between the site (P=0.75), type (P=0.44) and severity (P=0.75) of disease. Dietary change to single protein and carbohydrate commercial diets had no association with outcome (P=0.12). Owner assessment of quality of life at follow-up was significantly associated with outcome (P=0.006).

Multivariate analysis suggests improved perioperative outcome in Crohn's disease patients receiving immunomodulator therapy after segmental resection and/or strictureplasty

BACKGROUND

Medical management of moderate to severe Crohn's disease (CD) using immunomodulator agents has not eliminated surgical treatment of disease complications. The effect of improved medical treatment on perioperative CD surgical outcome is not known. We analyzed the impact of immunomodulator therapy on the rate of intraabdominal septic complications (IASC) in CD patients undergoing bowel reanastomosis or strictureplasty.

METHODS

Surgical outcome was reviewed in 100 consecutive CD patients who underwent segmental resection with primary anastomosis or strictureplasty between 1998 and 2002. Multivariate analysis was performed to determine the effect of immunomodulator therapy on rate of IASC (intraabdominal abscess, anastomotic leak, or enterocutaneous fistulae). Immunomodulator agents included azathioprine, 6-MP, methotrexate, and infliximab.

RESULTS

IASC developed in 11 of 100 (11%) operations. Immunomodulator use was associated with fewer IASC (4/72 procedures; 5.6%), compared with 7/28 (25%) cases with patients not on therapy (P<.01). IASC were not influenced by steroid use, smoking status, preoperative abscess, or fistula or albumin levels. Immunomodulator use did not affect the length of resection or the rate and number of strictureplasties.

CONCLUSION

Medical management with immunomodulator therapy is safe and significantly decreases postoperative IASC in CD patients undergoing surgical procedures requiring bowel anastomosis or strictureplasty.

Bacterial colonization leads to the colonic secretion of RELMbeta/FIZZ2, a novel goblet cell-specific protein

BACKGROUND & AIMS

Goblet cells are highly polarized exocrine cells found throughout the small and large intestine that have a characteristic morphology due to the accumulation of apical secretory granules. These granules contain proteins that play important physiologic roles in cellular protection, barrier function, and proliferation. A limited number of intestinal goblet cell-specific proteins have been identified. In this study, we investigate the expression and regulation of RELMbeta, a novel colon-specific gene.

METHODS

The regulation of RELMbeta messenger RNA expression was determined in LS174T, Caco-2, and HT-29 cell lines in response to stimulation with interleukin 13 and lipopolysaccharide. Quantitative reverse-transcription polymerase chain reaction, immunoblots, and immunohistochemistry were used to examine the expression of RELMbeta in BALB/c and C.B17.SCID mice housed in conventional, germ-free, and gnotobiotic environments.

RESULTS

Messenger RNA for RELMbeta is restricted to the undifferentiated, proliferating colonic epithelium. Immunohistochemistry shows that this protein is expressed in goblet cells located primarily in the distal half of the colon and cecum with lower levels detectable in the proximal colon. High levels of RELMbeta can be detected in the stool of mice and humans, where it exists as a homodimer under nonreducing conditions. Interestingly, the secretion of RELMbeta is dramatically reduced in germ-free mice. Furthermore, introduction of germ-free mice into a conventional environment results in enhanced expression and robust secretion of RELMbeta within 48 hours.

CONCLUSIONS

These studies define a new goblet cell-specific protein and provide the first evidence that colon-specific gene expression can be regulated by colonization with normal enteric bacteria.

Utility of measuring 6-methylmercaptopurine and 6-thioguanine nucleotide levels in managing inflammatory bowel disease patients treated with 6-mercaptopurine in a clinical practice setting

BACKGROUND

Measuring levels of 6-mercaptopurine (6-MP) metabolites (6-thioguanine nucleotides [6-TGNs] and 6-methylmercaptopurine [6-MMP]) has been proposed as a method to adjust 6-MP dose to optimize therapeutic response while minimizing toxicity in patients with inflammatory bowel disease. A 6-TGN level of >230 pmol/8 x 108 red blood cells (RBCs) has been reported to be associated with a higher efficacy rate, and a level of >450 pmol/8 x 108 RBCs has been reported to be associated with myelotoxicity. A 6-MMP level of >5,700 pmol/8 x 108 RBCs has been reported to be associated with an increased frequency of abnormal results of liver function tests (LFTs).

GOALS

To report our experience with 6-MMP and 6-TGN levels in a clinical practice setting.

STUDY

Using outpatient clinic medical records, we identified 53 measurements. Indications for measurement, 6-MP dose, and subsequent adjustments were documented.

RESULTS

Indications for measurements included the following: persistent symptoms, 31 cases (58.5%); abnormal LFT results, 7 (13.2%); steroid dependency, 6 (11.3%); anemia, 4 (7.5%); and leukopenia, 2 (3.8%). Of the 31 cases with persistent symptoms, 12 had "therapeutic" 6-TGN levels and other interventions were undertaken. 6-TGN levels were "subtherapeutic" in 19. The 6-MP dose was increased, and remission was achieved in 10 cases after a mean period of 3.6 weeks. Among the cases with abnormal LFT results, 6-MMP levels were high in five and low in two. Among the steroid dependency cases, 6-TGN levels were "subtherapeutic" in five. The dose was increased and steroids were weaned in three cases. The 6-TGN level was high in one of the leukopenia cases and the 6-MP dose was decreased. 6-TGN levels were not above the "target range" in any of the anemia cases.

CONCLUSION

Measuring levels of 6-MP metabolites may have a role in customizing 6-MP dosing. This role is not completely clear and needs to be explored in larger well-controlled studies.

Natalizumab for active Crohn's disease

BACKGROUND

In chronic inflammatory conditions such as Crohn's disease, the migration of leukocytes from the circulation into the parenchyma and their activation within inflammatory sites are mediated in part by alpha4 integrins.

METHODS

We conducted a double-blind, placebo-controlled trial of the alpha4 integrin-specific humanized monoclonal antibody natalizumab in 248 patients with moderate-to-severe Crohn's disease. Patients were randomly assigned to receive one of four treatments: two infusions of placebo; one infusion of 3 mg of natalizumab per kilogram of body weight, followed by placebo; two infusions of 3 mg of natalizumab per kilogram; or two infusions of 6 mg of natalizumab per kilogram. Infusions were given four weeks apart. Outcomes included changes in scores for the Crohn's Disease Activity Index (higher scores indicate more severe disease), the health-related quality of life, and C-reactive protein levels.

RESULTS

The group given two infusions of 6 mg of natalizumab per kilogram did not have a significantly higher rate of clinical remission (defined by a score of less than 150 on the Crohn's Disease Activity Index) than the placebo group at week 6 (the prospectively defined primary end point in the efficacy analysis). However, both groups that received two infusions of natalizumab had higher remission rates than the placebo group at multiple time points. Natalizumab also produced a significant improvement in response rates (defined by a reduction of at least 70 points in the score on the Crohn's Disease Activity Index). The highest remission rate was 44 percent and the highest response rate was 71 percent (at week 6 in the group given two infusions of 3 mg per kilogram). Overall, the two infusions of 6 mg of natalizumab per kilogram and of 3 mg per kilogram had similar effects. The quality of life improved in all natalizumab groups; C-reactive protein levels improved in groups receiving two infusions of natalizumab. The rates of adverse events were similar in all four groups.

CONCLUSIONS

Treatment with the selective adhesion-molecule inhibitor natalizumab increased the rates of clinical remission and response, improved the quality of life and C-reactive protein levels, and was well tolerated in patients with active Crohn's disease.

Determination of thiopurine methyltransferase genotype or phenotype optimizes initial dosing of azathioprine for the treatment of Crohn's disease

BACKGROUND

although azathioprine (AZA) is an effective immunomodulator in treating Crohn's disease, some patients develop leukopenia and risk severe infections. Thiopurine methyltransferase (TPMT) is an enzyme responsible for the metabolism of AZA, and its activity is inversely related to the risk of developing acute leukopenia.

GOALS

the aim of this retrospective study is to determine whether initial AZA dosing based on TPMT genotype or phenotype alters the likelihood of developing acute leukopenia.

STUDY

between January 2000 and February 2001, 71 patients with Crohn's disease considered for AZA therapy and with a recorded TPMT genotype or phenotype were identified using a comprehensive text-oriented database at the University of Pittsburgh Medical Center, Presbyterian Hospital, Pittsburgh, PA. The baseline demographics, TPMT genotype or phenotype, initial dose of oral AZA, subsequent white blood counts, and complications that necessitated discontinuation of therapy were evaluated.

RESULTS

of the 63 patients with normal TPMT activity, 45 were started on 2 to 2.5 mg/kg/d of AZA, seven received doses less than 2 mg/kg/d, and 11 did not start AZA. Of the eight patients with intermediate TPMT activity, seven were started on 1 to 1.5 mg/kg/d of AZA, and one did not receive treatment. None of the patients that received AZA developed acute leukopenia (< 3,000/mm ).

CONCLUSIONS

patients with Crohn's disease and normal TPMT activity who were started on high-dose AZA (2-2.5mg /kg/d) and patients with intermediate enzyme activity who were started on reduced doses of AZA did not develop acute leukopenia.

Extraintestinal manifestations of inflammatory bowel disease

Numerous extraintestinal diseases have been associated with IBD. The role of the gastrointestinal tract in host response to the foreign antigens present in the gut makes the enteric immune system highly susceptible to any external perturbation to the system. Dysregulation of the enteric immune response results in pathology in various organs outside of the gut. The site-specific manifestations of this immune response are not understood fully. Better understanding of the pathogenesis of IBD and the complex interactions between the gut immune system and the extraintestinal systems would provide insights into the development of many of these extraintestinal manifestations. Much is unknown about the presence of cardiac, pulmonary, and hematologic diseases in patients with IBD. True association or coincidental presence of the diseases in these organ systems with IBD requires better delineation. An important consideration in all patients with IBD presenting with extraintestinal manifestations should be a careful search for medication-related complications.

Neurologic manifestations of gastrointestinal disease

Although previously considered rare, neurologic manifestations of gastrointestinal diseases are increasingly recognized. Understanding of Whipple disease and gluten sensitivity is in transition and these conditions are becoming the province of neurologists. Recent improvements in diagnostic testing have improved our understanding and case finding for vitamin B12 deficiency. Many patients with these conditions present with neurologic manifestations alone. Therefore, these conditions are becoming the province of neurologists, and neurologic manifestations of gastrointestinal disease are becoming a more common part of neurologic practice.

Integrating anti-tumor necrosis factor therapy in inflammatory bowel disease: current and future perspectives

Crohn's disease and ulcerative colitis are two idiopathic inflammatory disorders of the GI tract. Manifestations of disease can be severe and lead to long term therapy with a variety of medications and/or surgery. Standard medical therapy consists of agents that either treat suppurative complications or modulate the inflammatory cascade in a nonspecific manner. Many specific chemokine and cytokine effectors that promote intestinal inflammation have been identified. Such work has led to experimental clinical trials with a variety of cytokine antagonists. Compounds directed against one such cytokine, tumor necrosis factor alpha (TNF), have demonstrated the greatest clinical efficacy to date. This is consistent with scientific observations that suggest a central role for TNF in the inflammatory cascade. Infliximab is a chimeric monoclonal antibody against TNF that has been demonstrated to be effective for the treatment of Crohn's disease. Infliximab is Food and Drug Administration approved for the treatment of Crohn's disease. There exist several other TNF antagonists in various phases of investigation, including the monoclonal antibody CDP 571, the fusion peptide etanercept, the phosphodiesterase inhibitor oxpentifylline, and thalidomide. The clinical efficacy of these agents and the role of TNF in the pathogenesis of inflammatory bowel disease is reviewed.