Review article: maintenance of remission in ulcerative colitis

Prediction of treatment failure during infliximab induction therapy in inflammatory bowel disease patients based on pharmacokinetic and pharmacodynamic modeling

BACKGROUND

In infliximab (IFX) treatment for Crohn's disease (CD) and ulcerative colitis (UC), it is difficult to predict treatment failure during the induction phase. In the present study for optimal IFX treatment, we attempted to estimate serum IFX concentration and clinical response in individual patients during the induction phase to predict the indication of therapeutic effect and the possibility of treatment failure in the maintenance phase.

METHODS

We estimated pharmacokinetic and pharmacodynamic (PK/PD) parameters and predicted the serum IFX concentration and clinical response using a PK/PD model and Markov chain Monte Carlo Bayesian analysis method during the induction phase. Then, we determined whether the indication of therapeutic effect between predicted and observed clinical response were matched during the maintenance phase.

RESULTS

Data obtained from 15 patients were analyzed. The correlation between predicted and observed values of serum IFX concentration (Pearson product-moment correlation coefficient, 0.700; P < 0.0001, n = 68) and clinical response of CD patients (0.790; P < 0.0001, n = 25) and UC patients (0.702; P = 0.0004, n = 21) were significantly high. The indication of therapeutic effect at the final time point of each patient (from day 115 to day 203) were successfully predicted in 14 of 15 patients (93.3%).

CONCLUSIONS

This study presents prediction of serum IFX concentration and clinical response in individual patients during induction therapy, with presumption of the indication of therapeutic effect and the treatment failure in the maintenance phase. Our results show the possibility of optimizing IFX therapy during the induction phase.

Sanhuang Shu'ai decoction alleviates DSS-induced ulcerative colitis via regulation of gut microbiota, inflammatory mediators and cytokines

BACKGROUND

Sanhuangshu'ai decoction (SH), a traditional Chinese medicine (TCM) prescription, has been safely used to treat diarrhea, dysentery and other inflammatory diseases with little side effect and low cost for thousands of years. However, its mechanism remains elusive. This study was designed to investigate the anti-ulcerative colitis (UC) activity of SH and mechanism by detecting its anti-inflammatory, anti-oxidative, and intervention effects of intestinal flora with the dextran sodium sulfate (DSS)-induced colitis mice.

METHODS

The DSS-induced colitis mice was orally administered SH for 1 week with 0.8 or 1.6 g kg^-1 d^-1 dosage. A clinical disease activity score was evaluated daily. The colonic tissues of the mice were collected and prepared to detect its anti-inflammatory, anti-oxidative, intervention effects of intestinal flora and hydrogen peroxide(H₂O₂) in vivo, cytotoxicity and ROS influencing effects in vitro. Histological colitis severity and expression of cytokines were also determined.

RESULTS

Oral administration of SH significantly prevented the development of colitis. It reduced the expression of interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-α in the colon. Moreover, SH administration alleviated the oxidative stress in the colon of DSS-induced colitis mice, evidenced by the decrease of myeloperoxidase (MPO) activity and malondialdehyde (MDA) level, and increase of ROS level. Furthermore, SH can prevent the decrease ofLactobacillus sp. and population abundance of intestinal flora caused by DSS.

CONCLUSION

SH significantly ameliorates the symptoms of DSS-induced colitis mice and the potential mechanism of SH may involve in multiple kinds of metabolic pathway including the regulation of gut microbiota, inflammatory mediators and cytokines.

Microbial dysbiosis in inflammatory bowel diseases: results of a metagenomic study in Saudi Arabia

BACKGROUND

The intestinal microbiota plays an essential role in the pathogenesis of ulcerative colitis (UC)and Crohn disease (CD).

METHODS

Metagenomic studies were used to study microbiota in the diagnosed cases of UC and CD at King Fahad Medical City, Riyadh, Saudi Arabia. Each segment of the colon was flushed with distilled water during colonoscopy, and the material was aspirated, immediately frozen for the study. The patients attending for screening colonoscopies were taken as age-matched healthy controls. The UC patients were followed clinically for any signs of exacerbation relapse, and CD patients were followed for any complications.

RESULTS

The metagenomic data on 46 (24 females) patients with CD were analyzed along with a group of age and gender-matched controls. Their age ranged from 14 to 65 years, mean age 25.19±10.67 years. There were 50 UC patient (28 females) mean age of 34.42±12.58, and their age ranged from 13-58 years. This study identified enrichment of 19 genera in the control group (Abiotrophia, Anaerofustis, Butyrivibrio, Campylobacter, Catenibacterium, Coprococcus, Dorea, Eubacterium, Facklamia, Klebsiella, Lactococcus, Oscillibacter, Paenibacillus, Parabacteroides, Parasutterella, Porphyromonas, Prevotella, Ruminococcus, Treponema). There was a significant enrichment of 14 genera in our CD cohort (Beggiatoa, Burkholderia, Cyanothece, Enterococcus, Escherichia, Fusobacterium, Jonquetella, Mitsuokella, Parvimonas, Peptostreptococcus, Shigella, Succinatimonas, ThermoanaerobacterVerrucomicrobiales, Vibrio). There was a significant enrichment of 7 genera in UC cohort (Beggiatoa, Burkholderia, Parascardovia, Parvimonas, Pseudoflavonifractor, Thermoanaerobacter, Verrucomicrobiales).

CONCLUSIONS

A significant dysbiosis was found in UC and CD patients compared to controls.

Ectopic expression of OX1R in ulcerative colitis mediates anti-inflammatory effect of orexin-A

Orexins (orexin-A and orexin-B) are hypothalamic peptides that are produced by the same precursor and are involved in sleep/wake control, which is mediated by two G protein-coupled receptor subtypes, OX1R and OX2R. Ulcerative colitis (UC) is an inflammatory bowel disease, (IBD) which is characterized by long-lasting inflammation and ulcers that affect the colon and rectum mucosa and is known to be a significant risk factor for colon cancer development. Based on our recent studies showing that OX1R is aberrantly expressed in colon cancer, we wondered whether orexin-A could play a role in UC. Immunohistochemistry studies revealed that OX1R is highly expressed in the affected colonic epithelium of most UC patients, but not in the non-affected colonic mucosa. Injection of exogenous orexin-A specifically improved the inflammatory symptoms in the two colitis murine models. Conversely, injection of inactive orexin-A analog, OxB7-28 or OX1R specific antagonist SB-408124 did not have anti-inflammatory effect. Moreover, treatment with orexin-A in DSS-colitis induced OX1R^-/- knockout mice did not have any protective effect. The orexin-A anti-inflammatory effect was due to the decreased expression of pro-inflammatory cytokines in immune cells and specifically in T-cells isolated from colonic mucosa. Moreover, orexin-A inhibited canonical NFκB activation in an immune cell line and in intestinal epithelial cell line. These results suggest that orexin-A might represent a promising alternative to current UC therapies.

In vivo analysis of mucosal lipids reveals histological disease activity in ulcerative colitis using endoscope-coupled Raman spectroscopy

The goal of this study is to evaluate endoscopic Raman spectroscopy as a noninvasive technique to determine histological inflammatory status of colitis. Colon mucosal composition was investigated in vivo from patients with ulcerative colitis (UC) and from age- and body mass index (BMI) matched controls using endoscope-coupled Raman spectroscopy. The results were co-registered with histological assessment of inflammatory status at the same locations. Substantial decreases (50-60%) in the content of phosphotidylcholines (PCs) and total lipids were observed in inflamed colon tissue (histology grade 1, 2 and 3) compared to those from the quiescent (histology grade 0) and from the controls. No significant difference was observed in lipids or PC contents between control and grade 0, or among grades 1 - 3. The degree of lipid unsaturation increased in the inflamed tissue regardless of disease severity. The inflammation-associated alterations in lipids and PC are observed independent of BMI or the anatomical locations for data collection. Multivariate analysis using support vector machine (SVM) algorithm classified the spectra of the controls or the inactive colitis from those of inflamed tissue with a sensitivity of 83.5% and 97.1% respectively. Our results showed that mucosal lipid content is related to the microscopic disease activity, and thus could serve as a valuable spectral marker to differentiate active colitis from the quiescent.

A randomized trial comparing 4.8 vs. 2.4 g/day of oral mesalazine for maintenance of remission in ulcerative colitis

BACKGROUND

Mesalazine is used as maintenance therapy in ulcerative colitis but the optimal dosage is still controversial.

AIM

To compare the remission-maintenance efficacy and tolerability of two daily doses of oral mesalazine (4.8 g and 2.4 g) in patients with ulcerative colitis with frequent relapses in a randomized controlled trial.

METHODS

112 ulcerative colitis patients in remission were enrolled and randomly allocated to treatment for 1 year with oral mesalazine at a daily dose of 4.8 g (n=56, Group A) or 2.4 g (n=56, Group B).

RESULTS

At the end of the 12 months, intention to treat analysis revealed persistent remission in 42 (75%) in Group A and 36 (64.2%) in Group B (p=0.3). The higher daily dose (4.8 g) proved to be significantly more effective for maintaining remission in patients under 40 years of age (90.5% Group A vs. 50% Group B; Fisher's exact test, p=0.0095) and in those with extensive disease (90.9% Group A vs. 46.7% Group B; Fisher's exact test, p=0.0064).

CONCLUSIONS

In ulcerative colitis patients younger than 40 years and/or with extensive disease, a daily dose of 4.8 g oral mesalazine results in increased rates and duration of remission compared to 2.4 g.

Indian Society of Gastroenterology consensus on ulcerative colitis

In 2010, the Indian Society of Gastroenterology's Task Force on Inflammatory Bowel Diseases undertook an exercise to produce consensus statements on ulcerative colitis. This consensus, produced through a modified Delphi process, reflects our current understanding of the definition, diagnostic work up, treatment and complications of ulcerative colitis. The consensus statements are intended to serve as a reference point for teaching, clinical practice, and research in India.

Common misconceptions about 5-aminosalicylates and thiopurines in inflammatory bowel disease

Misconceptions are common in the care of patients with inflammatory bowel disease (IBD). In this paper, we state the most commonly found misconceptions in clinical practice and deal with the use of 5-aminosalicylates and thiopurines, to review the related scientific evidence, and make appropriate recommendations. Prevention of errors needs knowledge to avoid making such errors through ignorance. However, the amount of knowledge is increasing so quickly that one new danger is an overabundance of information. IBD is a model of a very complex disease and our goal with this review is to summarize the key evidence for the most common daily clinical problems. With regard to the use of 5-aminosalicylates, the best practice may to be consider abandoning the use of these drugs in patients with small bowel Crohn’ s disease. The combined approach with oral plus topical 5-aminosalicylates should be the first-line therapy in patients with active ulcerative colitis; once-daily treatment should be offered as a first choice regimen due to its better compliance and higher efficacy. With regard to thiopurines, they seem to be as effective in ulcerative colitis as in Crohn’ s disease. Underdosing of thiopurines is a form of undertreatment. Thiopurines should probably be continued indefinitely because their withdrawal is associated with a high risk of relapse. Mercaptopurine is a safe alternative in patients with digestive intolerance or hepatotoxicity due to azathioprine. Finally, thiopurine methyltransferase (TPMT) screening cannot substitute for regular monitoring because the majority of cases of myelotoxicity are not TPMT-related.

Meta-analysis: the efficacy of azathioprine and mercaptopurine in ulcerative colitis

BACKGROUND

Debate exists regarding to whether thiopurine therapy is as effective in ulcerative colitis (UC) as it is in Crohn's disease.

AIM

To review systematically the efficacy of azathioprine (AZA) and mercaptopurine (MP) in UC, and to conduct a meta-analysis of randomized clinical trials evaluating the efficacy of AZA/MP for the induction or maintenance of UC clinical remission.

SELECTION OF STUDIES

Evaluating AZA/MP for induction and/or maintenance of clinical remission of UC. Randomized-controlled-trials comparing AZA/MP with placebo/5-aminosalicylates were included in the meta-analysis.

SEARCH STRATEGY

Electronic and manual. Study quality: Independently assessed by two reviewers.

DATA SYNTHESIS

By 'intention-to-treat'.

RESULTS

Thirty noncontrolled studies (1632 patients) were included in the systematic review. Mean efficacy of AZA/MP was 65% for induction and 76% for maintenance of the remission. Seven controlled studies were included in the meta-analysis. (i) Induction of remission: four studies (89 AZA/MP-treated patients) showed mean efficacy of 73% vs. 64% in controls (OR = 1.59; 95% CI = 0.59-4.29). (ii) Maintenance of remission: six studies (124 AZA/MP-treated patients) showed mean efficacy of 60% vs. 37% in controls (OR = 2.56; 95% CI = 1.51-4.34). When only studies comparing AZA/MP vs. placebo were considered, OR was 2.59 (95% CI = 1.26-5.3), absolute risk reduction was 23% and number-needed-to-treat (NNT) to prevent one recurrence was 5.

CONCLUSION

Thiopurine drugs (AZA/MP) are more effective than placebo for the prevention of relapse in UC, with an NNT of 5 and an absolute risk reduction of 23%.

Inhibition of cell proliferation and invasion in a human colon cancer cell line by 5-aminosalicylic acid

BACKGROUND

5-Aminosalicylic acid lacks the well-known side effects associated with the long-term use of non-steroidal anti-inflammatory drugs. We investigated anti-carcinogenic mechanisms of 5-aminosalicylic acid on a colon cancer cell line.

METHODS

MTT analysis was performed for various colon cancer cell lines. The expression of NF-kappaB and metalloproteinases was examined in either HT-29 cells treated with IL-1beta and/or 5-aminosalicylic acid. Matrigel assay was used to evaluate invasive potential of HT-29 cells. Analysis of a cDNA microarray containing 8700 genes was performed to identify the alteration of gene expression in response to treatment to 5-aminosalicylic acid.

RESULTS

The use of MTT analysis showed that 5-aminosalicylic acid suppressed the growth of HT-29 cells. The activity of NF-kappaB was also decreased by combined-treatment with IL-1beta and 5-aminosalicylic acid. The use of an ELISA and zymography demonstrated that MMP-2 and MMP-9 enzyme activity were decreased in HT-29 cells by treatment with various concentration of 5-aminosalicylic acid. A matrigel analysis demonstrated that 5-aminosalicylic acid treatment on HT-29 significantly inhibited the invasiveness of the cells. In cDNA microarray, 163 genes following 5-aminosalicylic acid exposure showed altered expression.

CONCLUSIONS

This study indicated that 5-aminosalicylic acid suppresses the growth of human colon cancer cells and is able to inhibit MMPs expression via NF-kappaB mediated cell signals and invasiveness.

Rectal administration of d-alpha tocopherol for active ulcerative colitis: A preliminary report

AIM: To investigate the anti-oxidant and anti-neutrophil recruitment effects of rectal d-alpha (d-α) tocopherol administration on mild and moderately active ulcerative colitis (UC).

METHODS: Fifteen patients with mild and moderately active ulcerative colitis were enrolled in an open-label study of d-α tocopherol enema (8000 U/d) for 12 wk. All patients were receiving concomitant therapy with 5-aminosalicylic acid derivatives (5-ASA) and/or immunomodulator medications. Endoscopic evaluation was performed at baseline and after 4th and 12th weeks. Disease activity was measured with the Mayo disease activity index (DAI) and remission was defined as DAI of ≤ 2 with no blood in stool. Clinical response was defined as a DAI reduction of ≥ 2.

RESULTS: At the end of 12th week, the average DAI score significantly decreased compared to the beginning of the study (2.3 ± 0.37 vs 8 ± 0.48, P < 0.0001). One patient was withdrawn after 3 wk for being unavailable to follow-up. On the 4th week of therapy, 12 patients showed clinical response, 3 of whom (21.4%) achieving remission. After 12 wk, all 14 patients responded clinically to the therapy and remission was induced in 9 of them (64%). No patient reported adverse events or was hospitalized due to worsened disease activity.

CONCLUSION: This preliminary report suggests that rectal d-α tocopherol may represent a novel therapy for mild and moderately active UC. The observed results might be due to the anti-inflammatory and anti-oxidative properties of vitamin E.

Comparison of two different daily dosages (2.4 vs. 1.2 g) of oral mesalazine in maintenance of remission in ulcerative colitis patients: 1-year follow-up study

BACKGROUND

Mesalazine as maintenance therapy in ulcerative colitis is used worldwide and has been proven to be effective. However, the optimal dosage remains to be defined.

AIM

To establish whether daily treatment with 2.4 g of oral mesalazine is more effective than 1.2 g in preventing disease relapse.

METHODS

A total of 156 patients with ulcerative colitis in remission were randomly treated for 1 year with 2.4 (n = 80) or 1.2 (n = 76) g/day of mesalazine. Activity of disease was assessed by periodical clinical, endoscopic and histological examinations.

RESULTS

After 12 months, 24 of 80 patients (30%) on 2.4 g and 20 of 76 patients (26%) on 1.2 g were still in remission (P = N.S.). Patients in 2.4 g group remained in remission for a longer time than those in 1.2 g group (P < 0.001). Among clinical variables considered in the study, course of disease prior to enrollment (< or = 3 or > 3 relapses/year) was found to influence response to therapy.

CONCLUSIONS

A daily dosage of 2.4 g of oral mesalazine seems to better at preventing and delaying relapses of ulcerative colitis than 1.2 g. The course of disease seems to be crucial in choosing the optimal dosage of mesalazine in a maintenance regimen.

Long-term risk of cancer in ulcerative colitis: a population-based cohort study from Copenhagen County

BACKGROUND & AIMS

Ulcerative colitis (UC) is associated with an increased risk for colorectal cancer (CRC) and possibly also increased risk for cancers outside the intestinal tract. We followed-up a population-based cohort of 1160 patients with UC diagnosed in Copenhagen County between 1962 and 1987 for up to 36 years to analyze the overall and site-specific cancer risk.

METHODS

Observed vs. expected cancers were presented as standardized morbidity ratio (SMR) with 95% exact confidence intervals (CI) calculated by using individual person-years at risk and sex- and age-specific incidence rates for the Danish background population in 1995.

RESULTS

The cohort was followed-up for a median of 19 years, or 22,290 person-years. A total of 124 malignancies were observed compared with 139.85 expected (SMR, .89; 95% CI, .74-1.07). The observed number of CRCs was almost exactly equal to expected: 13 cases vs. 12.42 (SMR, 1.05; 95% CI, .56-1.79). The cumulative probability of CRC was .4% by 10 years, 1.1% by 20 years, and 2.1% by 30 years of disease. Among men, melanoma was increased (SMR, 3.45; 95% CI, 1.38-7.10); otherwise, no increased risk for cancer could be detected. No hepatobiliary cancers and no increased risk for lymphoma or leukemia were found.

CONCLUSIONS

Neither the overall cancer risk, nor the CRC risk, were increased in this population-based cohort after a median of 19 years of follow-up evaluation. An active surgical approach in medical treatment failures and long-term use of 5-aminosalicylic acid (5-ASA) as relapse prevention may explain this remarkable result.

Infliximab for acute, not steroid-refractory ulcerative colitis: a randomized pilot study

OBJECTIVE

Therapeutic alternatives for patients with acute ulcerative colitis in whom steroids would usually be contraindicated are rare. The antibody to tumor necrosis factor alpha, infliximab, has shown to be effective in the treatment of steroid-refractory ulcerative colitis in pilot studies. We therefore evaluated whether infliximab can achieve remission in patients with acute ulcerative pancolitis who were not steroid-refractory.

METHODS AND DESIGN

Patients were eligible if they had acute disease with a modified Truelove and Witts activity score of more than 10 for at least 2 weeks and if they were currently not receiving immunomodulators or more than 10 mg/day prednisolone. Patients were randomly assigned to receive either three intravenous infusions of infliximab at 5 mg/kg (group A) or high-dose prednisolone (1.5 mg/kg body weight) daily for 2 weeks, followed by 1 mg/kg for 1 week, followed by a weekly reduction of 5 mg (group B). Therapy success was defined as clinical response in terms of a decrease of more than 5 points from the baseline score and to less than 10 points total after 3 weeks as well as after 13 weeks.

RESULTS

Thirteen patients (seven women, six men) were randomized (six for group A and seven for group B). The median baseline activity scores were 13.5 (12-18) in group A and 14.0 (11-18) in group B. Five of six patients in group A and six of seven patients in group B showed therapy success after 3 weeks as well as after 13 weeks.

CONCLUSIONS

Infliximab could be effective in the treatment of acute moderate or severe ulcerative colitis. The obtained data call for larger controlled trials.

Review article: the long-term management of ulcerative colitis

After the induction of remission, the second priority of therapy for ulcerative colitis is sustained clinical remission, defined as the absence of inflammatory symptoms (diarrhoea, bleeding, rectal urgency) and the maintenance of an intact mucosa, with the absence of ulcers, friability or significant granularity at endoscopy. The 'optimal' maintenance strategy will depend on the therapy needed to induce remission. Thus, the transition from induction to maintenance therapy will be determined by the intensity of acute therapy necessary to induce remission and the duration of therapy required to complete the resolution of clinical symptoms. There are few controlled clinical trials pertaining to maintenance after each induction regimen. However, experience dictates that aminosalicylates are efficacious after aminosalicylate-induced remissions, that steroids should be tapered according to the time required to induce remission, that patients requiring ciclosporin will benefit from the addition of long-term immunomodulation with azathioprine or mercaptopurine, and that many patients with distal colitis who require topical mesalazine (mesalamine) will continue to need topical therapy to maintain remission, albeit at reduced frequency. The expectations for maintenance therapy require patient adherence to the prescribed treatment regimen. Patients require education with regard to the long-term goals of maintenance therapy (e.g. prevention of relapse, reduction of long-term complications of disease activity or risks of acute therapy with steroids), and should be warned against the use of nonsteroidal anti-inflammatory drugs and cautioned about the cessation of smoking, when applicable, due to potential risks of relapse or chronic activity.

Medical approaches and future options in chronic active ulcerative colitis

BACKGROUND

Immunosuppressive therapy employing purine analogues is the therapeutic mainstay in patients with chronic active ulcerative colitis. However, despite therapeutic optimization according to thiopurine-methyltransferase activity or red blood cell 6-thioguanine levels, a substantial proportion of patients does not tolerate azathioprine or 6-mercaptopurine or relapses during this treatment. In the latter multiple therapeutic regimens comprising 6-thioguanine, cyclosporin or tacrolimus, methotrexate, cyclophosphamide, infliximab, interferons, heparin, leukocyte apheresis, and various other regimens might be considered aiming at long-term remission. Many of these treatment forms have only been evaluated in small mostly uncontrolled trials.

OBJECTIVE

In this review existing treatment modalities and future options for patients with chronic active ulcerative colitis will be discussed focusing on immunomodulating approaches.

Review article: Oral, modified-release mesalazine formulations--proprietary versus generic

Products containing mesalazine have been used in the treatment of inflammatory bowel disease for many years. Many of the oral, modified-release products are reaching the point of patent expiration, and it is expected that several new 'generic' versions will be developed. As mesalazine acts topically, the drug needs to be available at the site of inflammation to be effective. For this reason, the currently available products have been developed with individual formulations so that physicians have a choice when matching the different release profiles to the site and extent of disease. As such, the current guidelines state that oral, delayed-release mesalazine formulations are not interchangeable and should be prescribed by their proprietary (brand) name. The standard regulatory assessment process for generic or 'copy' products, using systemic bioequivalence data, does not appear to be sufficient when evaluating topically acting, oral, modified-release products. We therefore recommend that the regulatory bodies should require that new, oral mesalazine products should be assessed by a combination of dissolution, bioequivalence and (a minimum of one) adequately powered, comparative trial to determine therapeutic equivalence. Of most importance here is that the assessment of new modified-release products is sufficiently rigorous to allow patients and physicians to be confident in their use.