Local application of tacrolimus in distal colitis: feasible and safe

Management of proctitis in ulcerative colitis and the place of biological therapies

INTRODUCTION

Approximately 20-30% of the patients with ulcerative colitis (UC) may present with isolated proctitis. Ulcerative proctitis (UP) is a challenging condition to manage due to its significant burden in terms of disabling symptoms.

AREAS COVERED

PubMed was searched up to March 2024 to identify relevant studies on UP. A comprehensive summary and critical appraisal of the available data on UP are provided, highlighting emerging treatments and areas for future research.

EXPERT OPINION

Patients with UP are often undertreated, and the disease burden is often underestimated in clinical practice. Treat-to-target management algorithms can be applied to UP, aiming for clinical remission in the short term, and endoscopic remission and maintenance of remission in the long term. During their disease, approximately one-third of UP patients require advanced therapies. Escalation to biologic therapy is required for refractory or steroid dependent UP. For optimal patient care and management of UP, it is necessary to include these patients in future randomized clinical trials.

Temperature-triggered in situ forming lipid mesophase gel for local treatment of ulcerative colitis

Ulcerative colitis is a chronic inflammatory bowel disease that strongly affects patient quality of life. Side effects of current therapies necessitate new treatment strategies that maximise the drug concentration at the site of inflammation, while minimizing systemic exposure. Capitalizing on the biocompatible and biodegradable structure of lipid mesophases, we present a temperature-triggered in situ forming lipid gel for topical treatment of colitis. We show that the gel is versatile and can host and release drugs of different polarities, including tofacitinib and tacrolimus, in a sustained manner. Further, we demonstrate its adherence to the colonic wall for at least 6 h, thus preventing leakage and improving drug bioavailability. Importantly, we find that loading known colitis treatment drugs into the temperature-triggered gel improves animal health in two mouse models of acute colitis. Overall, our temperature-triggered gel may prove beneficial in ameliorating colitis and decreasing adverse effects associated with systemic application of immunosuppressive treatments.

GADECCU 2022 Guideline for the treatment of Ulcerative Colitis. Adaptation and updating of the GETECCU 2020 Guideline

INTRODUCTION

Ulcerative colitis (UC) is a chronic inflammatory disease that compromises the colon, affecting the quality of life of individuals of any age. In practice, there is a wide spectrum of clinical situations. The advances made in the physio pathogenesis of UC have allowed the development of new, more effective and safer therapeutic agents.

OBJECTIVES

To update and expand the evaluation of the efficacy and safety of relevant treatments for remission induction and maintenance after a mild, moderate or severe flare of UC.

RECIPIENTS

Gastroenterologists, coloproctologists, general practitioners, family physicians and others health professionals, interested in the treatment of UC.

METHODOLOGY

GADECCU authorities obtained authorization from GETECCU to adapt and update the GETECCU 2020 Guide for the treatment of UC. Prepared with GRADE methodology. A team was formed that included authors, a panel of experts, a nurse and a patient, methodological experts, and external reviewers. GRADE methodology was used with the new information.

RESULTS

A 118-page document was prepared with the 44 GADECCU 2022 recommendations, for different clinical situations and therapeutic options, according to levels of evidence. A section was added with the new molecules that are about to be available.

CONCLUSIONS

This guideline has been made in order to facilitate decision-making regarding the treatment of UC, adapting and updating the guide prepared by GETECCU in the year 2020.

A review of the rationale for the testing of the calcineurin inhibitor tacrolimus for post-ERCP pancreatitis prevention

Endoscopic retrograde cholangiopancreatography (ERCP) is commonly performed for the management of pancreaticobiliary disorders. The most troublesome ERCP-associated adverse event is post-ERCP pancreatitis (PEP), which occurs in up to 15% of all patients undergoing ERCP. A substantial body of preclinical data support a mechanistic rationale for calcineurin inhibitors in preventing PEP. The findings are coupled with recent clinical data suggesting lower rates of PEP in patients who concurrently use the calcineurin inhibitor tacrolimus (e.g., solid organ transplant recipients). In this review, we will firstly summarize data in support of testing the use of tacrolimus for PEP prophylaxis, either in combination with rectal indomethacin or by itself. Secondly, we propose that administering tacrolimus through the rectal route could be favorable for PEP prophylaxis over other routes of administration.

When disease extent is not always a key parameter: Management of refractory ulcerative proctitis

Background

Patients with ulcerative proctitis represent a sub-group of ulcerative colitis patients with specific characteristics. Disease-related symptoms, endoscopic findings and patient's personality perspectives create a difficult-to-assess condition in certain cases.

Objectives

To summarize available evidence on the management of refractory ulcerative proctitis and provide insights in treatment options.

Results

/Conclusion: Topical therapy plays a central role due to the location of the disease. However, well-established treatment options may become exhausted in a considerable proportion of ulcerative proctitis patients, indicating the need to advance to more potent therapies in order to induce and maintain clinical response and remission in these refractory cases. Systemic corticosteroids, thiopurines, calcineurin inhibitors, biologic agents and small molecules have all been tested with variable success rates. Investigational interventions as well as surgical procedures are kept as the ultimate resort in multi-treatment resistant cases. Identifying early prognostic factors that herald a disabling disease progression will help in optimizing treatment and avoiding surgery.

Sustained Intra-Articular Release and Biocompatibility of Tacrolimus (FK506) Loaded Monospheres Composed of [PDLA-PEG1000]-b-[PLLA] Multi-Block Copolymers in Healthy Horse Joints

There is an increasing interest in controlled release systems for local therapy in the treatment of human and equine joint diseases, aiming for optimal intra-articular concentrations with no systemic side effects. In this study, the intra-articular tolerability and suitability for local and sustained release of tacrolimus (FK506) from monospheres composed of [PDLA-PEG₁₀₀₀]-b-PLLA multiblock copolymers were investigated. Unloaded and tacrolimus-loaded (18.4 mg tacrolimus/joint) monospheres were injected into the joints of six healthy horses, with saline and hyaluronic acid (HA) in the contralateral joints as controls. Blood and synovial fluid were analysed for the tacrolimus concentration and biomarkers for inflammation and cartilage metabolism. After an initial burst release, sustained intra-articular tacrolimus concentrations (>20 ng/mL) were observed during the 42 days follow-up. Whole-blood tacrolimus levels were below the detectable level (<0.5 ng/mL). A transient inflammatory reaction was observed for all substances, evidenced by increases of the synovial fluid white blood cell count and total protein. Prostaglandin and glycosaminoglycan release were increased in joints injected with unloaded monospheres, which was mitigated by tacrolimus. Both tacrolimus-loaded monospheres and HA transiently increased the concentration of collagen II cleavage products (C2C). A histologic evaluation of the joints at the endpoint showed no pathological changes in any of the conditions. Together, these results indicate the good biocompatibility of intra-articular applied tacrolimus-loaded monospheres combined with prolonged local drug release while minimising the risk of systemic side effects. Further evaluation in a clinical setting is needed to determine if tacrolimus-loaded monospheres can be beneficial in the treatment of inflammatory joint diseases in humans and animals.

GETECCU 2020 guidelines for the treatment of ulcerative colitis. Developed using the GRADE approach

INTRODUCTION

Since the first edition of the Guidelines was published in 2013, much information has been generated around the treatment of ulcerative colitis, and new drugs and action protocols have been introduced. Clinical practice has changed substantially, warranting new approaches and a comprehensive review and update of the evidence.

MATERIAL AND METHODS

Once again, we used the GRADE approach, supported by an electronic tool (https://gradepro.org). The clinical scenarios are the same as in the previous version (induction and maintenance in severe and mild-moderate flare-ups), as are the variables and their evaluation. However, in the updated guidelines, three questions have been deleted, 14 added and 30 maintained, making a total of 44 clinical questions. After an exhaustive review of the evidence, the recommendations are now updated.

RESULTS

Of the 44 questions analysed, no recommendation could be established in two due to the very low quality of the evidence, while in the other 42, based on different degrees of quality of evidence, recommendations were made according to the GRADE system. In 25 of these questions the final recommendation is strongly in favour, in six strongly against, in seven weakly in favour and in four weakly against. According to the scenarios and recommendations, six algorithms are proposed as a simple guide for practical decision-making.

CONCLUSIONS

The aim of this update of the 2013 guidelines is to provide answers, based on the GRADE approach, to the different questions we ask ourselves daily when deciding the most appropriate treatment for our patients with ulcerative colitis in the different clinical scenarios.

Suppository treatment in ulcerative proctitis

Ulcerative proctitis (UP) is a common form of ulcerative colitis (UC), the number of patients with UP is increasing. Suppository treatment containing mesalamine is usually the first-line choice for mild to moderate UP, here, we review the publications on mesalamine suppository in UP, to better understand its dosage, duration of therapy and adverse events in both induction and maintenance phases. We also review articles on budesonide, beclomethasone, tacrolimus, herbal medicine and acetarsol suppositories in UP, to present therapeutic strategies for patients with UP refractory to mesalamine suppository.

Limosilactobacillus fermentum CECT5716: Mechanisms and Therapeutic Insights

Probiotics microorganisms exert their health-associated activities through some of the following general actions: competitive exclusion, enhancement of intestinal barrier function, production of bacteriocins, improvement of altered microbiota, and modulation of the immune response. Among them, Limosilactobacillus fermentum CECT5716 has become one of the most promising probiotics and it has been described to possess potential beneficial effects on inflammatory processes and immunological alterations. Different studies, preclinical and clinical trials, have evidenced its anti-inflammatory and immunomodulatory properties and elucidated the precise mechanisms of action involved in its beneficial effects. Therefore, the aim of this review is to provide an updated overview of the effect on host health, mechanisms, and future therapeutic approaches.

Role of topical tacrolimus in the management of proctitis, perianal manifestations in Crohn's disease, and chronic pouchitis: a systematic review

Several published studies have evaluated the safety and effectiveness of oral and intravenous tacrolimus for the management of patients with inflammatory bowel disease (IBD). However, little is known about the effectiveness of topical tacrolimus in this patient population. The aim of this systematic review was to evaluate the current state of literature to evaluate the safety and effectiveness of rectal administration of topical tacrolimus, in the form of suppository, ointment, and/or enema in patients with ulcerative proctitis, perianal Crohn's disease (CD), and chronic refractory pouchitis. Electronic database searches were conducted in international databases since their inception until February 2020. Study subjects were categorized into three groups: topical tacrolimus for patients with proctitis, perianal CD, and chronic refractory pouchitis. The primary end point of this study was the remission rate. Secondary end points were response rate and the incidence of AEs. Eleven studies were included in the final assessment in this systematic review. This provided information from 188 patients. Tacrolimus was administered topically as suppositories, ointment, or enema. Clinical remission was achieved in 57.1%, 57.14%, and 70.0% in patients with proctitis, fistulizing perianal CD, and chronic pouchitis. The most commonly reported side effect was perianal itching and burning. Reversible nephrotoxicity occurred in a single patient. No clear correlation was found between blood levels and clinical outcomes. Topical tacrolimus is effective for a subset of patients with IBD. The adverse effects were minimal and tolerable. Well-designed randomized clinical trials are warranted to establish the appropriate dose and administration method.

Intestinal stenosis in Crohn's disease shows a generalized upregulation of genes involved in collagen metabolism and recognition that could serve as novel anti-fibrotic drug targets

BACKGROUND AND AIMS

Crohn's disease (CD) can be complicated by intestinal fibrosis. Pharmacological therapies against intestinal fibrosis are not available. The aim of this study was to determine whether pathways involved in collagen metabolism are upregulated in intestinal fibrosis, and to discuss which drugs might be suitable to inhibit excessive extracellular matrix formation targeting these pathways.

METHODS

Human fibrotic and non-fibrotic terminal ileum was obtained from patients with CD undergoing ileocecal resection due to stenosis. Genes involved in collagen metabolism were analyzed using a microfluidic low-density TaqMan array. A literature search was performed to find potential anti-fibrotic drugs that target proteins/enzymes involved in collagen synthesis, its degradation and its recognition.

RESULTS

mRNA expression of collagen type I (COL1A1, 0.76 ± 0.28 versus 37.82 ± 49.85, p = 0.02) and III (COL3A1, 2.01 ± 2.61 versus 68.65 ± 84.07, p = 0.02) was increased in fibrotic CD compared with non-fibrotic CD. mRNA expression of proteins involved in both intra- and extracellular post-translational modification of collagens (prolyl- and lysyl hydroxylases, lysyl oxidases, chaperones), collagen-degrading enzymes (MMPs and cathepsin-K), and collagen receptors were upregulated in the fibrosis-affected part. A literature search on the upregulated genes revealed several potential anti-fibrotic drugs.

CONCLUSION

Expression of genes involved in collagen metabolism in intestinal fibrosis affected terminal ileum of patients with CD reveals a plethora of drug targets. Inhibition of post-translational modification and altering collagen metabolism might attenuate fibrosis formation in the intestine in CD. Which compound has the highest potential depends on a combination anti-fibrotic efficacy and safety, especially since some of the enzymes play key roles in the physiology of collagen.

3D printed tacrolimus suppositories for the treatment of ulcerative colitis

Ulcerative colitis is a global health problem, affecting millions of individuals worldwide. As an inflammatory condition localised in the large intestine, rectal delivery of immunosuppressive therapies such as tacrolimus is a promising strategy to maximise drug concentration at the site of action whilst minimising systemic side effects. Here, for the first time, self-supporting 3D-printed tacrolimus suppositories were prepared without the aid of moulds using a pharmaceutical semi-solid extrusion (SSE) 3D printer. The suppositories were printed vertically in three different sizes using combinations of two lipid pharmaceutical excipients (Gelucire 44/14 or Gelucire 48/16) and coconut oil. Although both suppository formulations had the appropriate viscosity characteristics for printing, the Gel 44 formulation required less energy and force for extrusion compared to the Gel 48 system. The Gel 44 disintegrated more rapidly but released tacrolimus more slowly than the Gel 48 suppositories. Although the tacrolimus release profiles were significantly different, both suppository systems released more than 80% drug within 120 min. DSC and XRD analysis was inconclusive in determining the solid-state properties of the drug in the suppositories. In summary, this article reports on the fabrication of 3D printed self-supporting suppositories to deliver personalised doses of a narrow therapeutic index drug, with potential benefits for patients with ulcerative colitis.

No Superiority of Tacrolimus Suppositories vs Beclomethasone Suppositories in a Randomized Trial of Patients With Refractory Ulcerative Proctitis

BACKGROUND & AIMS

Ulcerative proctitis (UP) refractory to 5-aminosalicylic acid (5-ASA) suppositories is a challenge to treat, often requiring step up to immunomodulator or biological therapy. Topical tacrolimus is effective and safe in patients with refractory UP. However, it is not clear how tacrolimus suppositories fit into in the treatment algorithm of UP.

METHODS

We performed a randomized controlled, double-blind study at 8 hospitals in the Netherlands and Belgium from 2014 through 2017. Eighty-five patients with refractory UP (65% women) were randomly assigned to groups given once daily tacrolimus suppositories (2 mg; n = 43) or beclomethasone (3 mg; n = 42) for 4 weeks. The primary outcome was clinical response (decrease in Mayo score of 3 or more). Secondary outcomes included clinical remission, endoscopic response and remission, adverse events and quality of life. Outcomes were compared using Fisher's exact test and Mann-Whitney U test.

RESULTS

Proportions of patients with clinical responses were 63% in the tacrolimus group and 59% in the beclomethasone group (P = .812); proportions of patients in clinical remission were 46% and 38%, respectively (P = .638). Proportions of patients with an endoscopic response were 68% and 60% in the tacrolimus group and in the beclomethasone group (P = .636); proportions in endoscopic remission rates were 30% and 13%, respectively (P = .092) Median increases in the inflammatory bowel disease questionnaire score were 18.0 in the tacrolimus group and 20.5 in the beclomethasone group (P = .395). Adverse event rates did not differ significantly between groups.

CONCLUSIONS

In a 4-week randomized controlled trial, tacrolimus and beclomethasone suppositories induce comparable clinical and endoscopic responses in patients with UP refractory to 5-ASA. There were no significant differences in adverse events rates. Tacrolimus and beclomethasone suppositories are therefore each safe and effective treatment options for 5-ASA refractory disease. EUDRACT 2013-001259-11; Netherlands Trial Register NL4205/NTR4416.

CYP3A5 Genotype as a Potential Pharmacodynamic Biomarker for Tacrolimus Therapy in Ulcerative Colitis in Japanese Patients

Tacrolimus has been used to induce remission in patients with steroid-refractory ulcerative colitis. It poses a problem of large individual differences in dosage necessary to attain target blood concentration and, often, this leads to drug inefficacy. We examined the difference in mRNA expression levels of ATP binding cassette transporter B1 (ABCB1) between inflamed and non-inflamed tissues, and the influence of CYP3A5 genotype on tacrolimus therapy. The mRNA expression of CYP3A4 in colonic mucosa and that of cytochrome p450 3A5 (CYP3A5) and ABCB1 in inflamed and non-inflamed areas were examined in 14 subjects. The mRNA expression levels of CYP3A5 were higher than that of CYP3A4. The mRNA expression of ABCB1 was lower in the inflamed than in the non-inflamed mucosa, despite that of CYP3A5 mRNA level being not significantly changed. Hence, the deterioration of the disease is related to the reduction of the barrier in the inflamed mucosa. The relationship between CYP3A5 genotype and blood concentration, dose, and concentration/dose (C/D) ratio of tacrolimus in 15 subjects was studied. The tacrolimus dose to maintain equivalent blood concentrations was lower in CYP3A5*3/*3 than in CYP3A5*1 carriers, and the C/D ratio was significantly higher in the latter. Thus, CYP3A5 polymorphism information played a role in determining the initial dose of tacrolimus. Furthermore, since the effect of tacrolimus appears earlier in CYP3A5*3/*3 than in CYP3A5*1/*1 and *1/*3, it seems necessary to change the evaluation time of therapeutic effect by CYP3A5 genotype. Additionally, the relationship between CYP3A5 genotype and C/D ratio of tacrolimus in colonic mucosa was investigated in 10 subjects. Tacrolimus concentration in the mucosa was two-fold higher in CYP3A5*3/*3 than in CYP3A5*1 carriers, although no significant difference in tacrolimus-blood levels was observed. Therefore, the local concentration of tacrolimus affected by CYP3A5 polymorphism might be related to its therapeutic effect.

Simple water-based tacrolimus enemas for refractory proctitis

Background and Aims

Rectal ulcerative colitis (UC) and Crohn's disease (CD) often do not respond to conventional therapies. Oral and suppository tacrolimus are effective but often poorly tolerated or are complex to formulate. Tacrolimus is topically active, water soluble, and has minimal systemic toxicity when administered rectally; we therefore tested a simple tap water‐based enema formulation.

Methods

Tacrolimus powder from 1 mg capsules and tap water in a 60 mL syringe were delivered rectally. The primary end‐point was endoscopic response (UC: MAYO score reduction by one point; CD: improvement in ulcer number and severity). Secondary end‐points included endoscopic remission, clinical response, stool frequency, and rectal bleeding.

Results

Seventeen patients [12 UC, five CD, nine female, median age 31 years] with refractory rectal disease were treated. The majority of patients had failed immunosuppressive therapy [88% thiopurine; 71% biologic therapy]. Initial enemas included 1–4 mg tacrolimus daily and 1–3 mg tacrolimus maintenance three times a week for a median of 20 weeks (range 3–204). Concomitant thiopurine or biologic therapy continued. 94% tolerated therapy. Of 12 UC patients, eight (67%) achieved endoscopic remission, one further patient achieved endoscopic response, and median partial MAYO scores decreased (pre:4 vs. post:2; P = 0.010). Of five CD patients, three (60%) achieved endoscopic response, two (40%) endoscopic remission, and three (60%) clinical response. Stool frequency, rectal bleeding, and C‐reactive protein levels improved. Strictures became endoscopically passable in all four affected patients. No major adverse events were reported, and four patients had disease flare.

Conclusions

Tacrolimus enemas are easy to prepare, well tolerated, effective, and safe. They should be included in the treatment armamentarium for inflammatory bowel disease‐related refractory proctitis.

A comprehensive review and update on ulcerative colitis. Dis Mon 2019;65:100851. [PMID: 30837080 DOI: 10.1016/j.disamonth.2019.02.004]

Ulcerative colitis (UC) is a chronic idiopathic inflammatory bowel disorder of the colon that causes continuous mucosal inflammation extending from the rectum to the more proximal colon, with variable extents. UC is characterized by a relapsing and remitting course. UC was first described by Samuel Wilks in 1859 and it is more common than Crohn's disease worldwide. The overall incidence and prevalence of UC is reported to be 1.2-20.3 and 7.6-245 cases per 100,000 persons/year respectively. UC has a bimodal age distribution with an incidence peak in the 2nd or 3rd decades and followed by second peak between 50 and 80 years of age. The key risk factors for UC include genetics, environmental factors, autoimmunity and gut microbiota. The classic presentation of UC include bloody diarrhea with or without mucus, rectal urgency, tenesmus, and variable degrees of abdominal pain that is often relieved by defecation. UC is diagnosed based on the combination of clinical presentation, endoscopic findings, histology, and the absence of alternative diagnoses. In addition to confirming the diagnosis of UC, it is also important to define the extent and severity of inflammation, which aids in the selection of appropriate treatment and for predicting the patient's prognosis. Ileocolonoscopy with biopsy is the only way to make a definitive diagnosis of UC. A pathognomonic finding of UC is the presence of continuous colonic inflammation characterized by erythema, loss of normal vascular pattern, granularity, erosions, friability, bleeding, and ulcerations, with distinct demarcation between inflamed and non-inflamed bowel. Histopathology is the definitive tool in diagnosing UC, assessing the disease severity and identifying intraepithelial neoplasia (dysplasia) or cancer. The classical histological changes in UC include decreased crypt density, crypt architectural distortion, irregular mucosal surface and heavy diffuse transmucosal inflammation, in the absence of genuine granulomas. Abdominal computed tomographic (CT) scanning is the preferred initial radiographic imaging study in UC patients with acute abdominal symptoms. The hallmark CT finding of UC is mural thickening with a mean wall thickness of 8 mm, as opposed to a 2-3 mm mean wall thickness of the normal colon. The Mayo scoring system is a commonly used index to assess disease severity and monitor patients during therapy. The goals of treatment in UC are three fold-improve quality of life, achieve steroid free remission and minimize the risk of cancer. The choice of treatment depends on disease extent, severity and the course of the disease. For proctitis, topical 5-aminosalicylic acid (5-ASA) drugs are used as the first line agents. UC patients with more extensive or severe disease should be treated with a combination of oral and topical 5-ASA drugs +/- corticosteroids to induce remission. Patients with severe UC need to be hospitalized for treatment. The options in these patients include intravenous steroids and if refractory, calcineurin inhibitors (cyclosporine, tacrolimus) or tumor necrosis factor-α antibodies (infliximab) are utilized. Once remission is induced, patients are then continued on appropriate medications to maintain remission. Indications for emergency surgery include refractory toxic megacolon, colonic perforation, or severe colorectal bleeding.

Tacrolimus Suppositories in Therapy-Resistant Ulcerative Proctitis

Background

Ulcerative proctitis may often be managed with topical salicylates or steroids alone, but in some patients, symptoms are persistent and severe. We analyzed the efficacy of tacrolimus suppositories in patients who had proven refractory to combined topical and systemic treatment.

Methods

In this retrospective analysis, ulcerative colitis activity index (CAI), side effects, co-medication and drug levels were assessed in 43 patients with distal ulcerative colitis who received suppositories containing 2 mg of tacrolimus b.i.d. as add-on medication.

Results

A total of 23 patients with ulcerative proctitis presented to follow-up within ≤50 days (mean 27.0 days) after suppositories were started. A decrease in CAI (from 8.0 to 5.5 points) was observed and 52.3% reached clinical remission (CAI ≤4). In total, 43 patients were available for analysis, of whom 9 had inflammation of the sigmoid colon as well. For the entire cohort, the median treatment duration was 76 days; 60% were in remission on the last documented visit. Serum measurements revealed a substantial tacrolimus level with a mean of 5.5 ng/mL. We observed one case of mild reversible acute kidney injury.

Conclusions

In ulcerative proctitis, adding tacrolimus suppositories can be an effective and safe option when topical mesalazine, corticoid formulations and concomitant oral or parenteral medications have failed.

Algorithms to facilitate shared decision-making for the management of mild-to-moderate ulcerative colitis

Nonadherence has been a key barrier to the efficacy of medical treatments in ulcerative colitis (UC). Engaging patients in their IBD care via shared decision-making (SDM) to facilitate self-management may improve adherence to therapy. Areas covered: This review aims to summarize the most recent trial evidence from 2012 to 2017 for mild-to-moderate UC in order to develop clinical algorithms that guide SDM to facilitate self-management. A structured literature search via multiple electronic databases was performed using the search terms 'ulcerative colitis,' 'treatment,' 'management,' 'medication,' 'maintenance,' 'remission,' '5-ASA,' and 'inflammatory bowel disease. Expert commentary: Novel formulations of existing oral and topical medications have expanded the treatment options available for the induction and maintenance therapy for mild-to-moderate UC. Daily dosing of 5-ASA therapy is equivalent to twice daily dosing. The combination therapies of oral plus topical 5-ASA therapy and 5-ASA plus corticosteroid therapy are more effective than monotherapy. Budesonide MMX now plays a role in the management of mild-to-moderate UC. This review collates the evidence on drug efficacy and safety, adherence and tolerability, and noninvasive monitoring of mild-to-moderate UC into SDM-orientated algorithms to facilitate self-management.

The treatment of refractory ulcerative colitis

Ulcerative proctitis is defined as a mucosal inflammation limited to the rectum. Ulcerative proctitis is responsible for distressing symptoms and alteration of patient quality of life. Effective treatment is important to prevent or delay proximal extension of the disease and to improve quality of life. Refractory ulcerative proctitis is defined as the failure of topical and oral 5-aminosalicylic acid and corticosteroids. Medical management of refractory ulcerative proctitis may be challenging as there is little evidence regarding drug efficacy in this clinical situation. Data are currently available for azathioprine, topical tacrolimus and anti-TNF monoclonal antibodies as rescue treatment for refractory ulcerative proctitis. Other biologics may be of benefit despite a lack of dedicated clinical trials. Ultimately, experimental therapies such as epidermal growth factor enemas, appendectomy or fecal transplantation may be tried before restorative proctocolectomy with J pouch anastomosis, which has demonstrated good results with regards to clinical remission and quality of life.

Efficacy of Rectal Tacrolimus for Induction Therapy in Patients With Resistant Ulcerative Proctitis

BACKGROUND & AIMS

Resistant ulcerative proctitis can be extremely difficult to manage. Topically administered tacrolimus, however, may be effective in difficult-to-treat proctitis. This was a randomized, double-blind, placebo-controlled induction trial of rectal tacrolimus in patients with active ulcerative colitis.

METHODS

Eleven patients received rectal tacrolimus (0.5 mg/mL), and 10 placebo, for 8 weeks. The primary endpoint was clinical response by using the Mayo Clinic score.

RESULTS

A planned interim analysis after 20 patients had completed the study demonstrated highly significant differences between the groups and the study was closed because of ethical considerations with patients already recruited allowed to complete the study. The primary endpoint was met in 8 of 11 patients receiving rectal tacrolimus and 1 of 10 patients receiving placebo (73% vs 10%; P = .004). Of the secondary endpoints, 5 patients with rectal tacrolimus achieved clinical remission compared with none receiving placebo (45% vs 0%; P = .015). Mucosal healing at Week 8 was achieved in 8 patients receiving rectal tacrolimus compared with 1 (73% vs 10%) receiving placebo (P = .004). The Inflammatory Bowel Disease Questionnaire increased ≥16 points over baseline in 5 of the tacrolimus and 2 (45% vs 20%) of the placebo patients (P = .36). Finally, the average partial Mayo score was numerically lower in the tacrolimus-treated group compared with placebo at Week 2 (4.3 ± 0.74 vs 5.8 ± 0.64; P = .15) and Week 4 (3.7 ± 0.96 vs 5.8 ± 0.6; P = .08) but was significantly lower at Week 8 (3.3 ± 1.2 vs 6.7 ± 0.62; P = .01). There were no safety issues identified with rectal tacrolimus use.

CONCLUSIONS

Rectal tacrolimus was more effective than placebo for induction of a clinical response, clinical remission, and mucosal healing in resistant ulcerative proctitis (Clinicaltrials.gov registration: NCT01418131).

Azathioprine for refractory ulcerative proctitis: A retrospective multicenter study

BACKGROUND

Efficacy of azathioprine (AZA) in refractory ulcerative proctitis (UP) is unknown.

METHODS

All patients treated with AZA for refractory UP in three referral centers between 2002 and 2012 were included. "Treatment success" in the long-term was defined as the absence of colectomy during follow-up, no need for anti-TNF during follow-up, no ongoing systemic steroids use, no adverse event leading to AZA withdrawal, and clinically quiescent disease at last follow-up.

RESULTS

Of the 1279 adult patients with ulcerative colitis, 25 patients were treated with AZA for refractory UP (median disease duration 4.9 years). Of these, 4 had no short-term clinical assessment. Of the remaining 21, 4 were primary non responders to AZA, 7 discontinued AZA for adverse events and 10 showed clinical improvement. At the long-term assessment at last follow up after a median of 46 months, 5 patients had treatment success and were still on AZA treatment, the remaining 20 were treatment failures. Of these, 5 discontinued AZA for adverse events and 15 were treated with infliximab (clinical response in 11 patients, primary non-response in one patient, and 3 underwent colectomy).

CONCLUSION

AZA may be efficacious in maintaining clinical response in one-fifth of patients with refractory UP in a real-life setting.

Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel diseases are common in Europe, with prevalences as high as 1 in 198 persons (ulcerative colitis) and 1 in 310 persons (Crohn's disease).

METHODS

This review is based on pertinent articles retrieved by a search in PubMed and in German and European guidelines and Cochrane reviews of controlled trials.

RESULTS

Typically, the main clinical features of inflammatory bowel diseases are diarrhea, abdominal pain, and, in the case of ulcerative colitis, peranal bleeding. These diseases are due to a complex immunological disturbance with both genetic and environmental causes. A defective mucosal barrier against commensal bowel flora plays a major role in their pathogenesis. The diagnosis is based on laboratory testing, ultrasonography, imaging studies, and, above all, gastrointestinal endoscopy. Most patients with Crohn's disease respond to budesonide or systemic steroids; aminosalicylates are less effective. Refractory exacerbations may be treated with antibodies against tumor necrosis factor (TNF) or, more recently, antibodies against integrin, a protein of the cell membrane. In ulcerative colitis, aminosalicylates are given first; if necessary, steroids or antibodies against TNF-α or integrin are added. Maintenance therapy to prevent further relapses often involves immunosuppression with thiopurines and/or antibodies. Once all conservative treatment options have been exhausted, surgery may be necessary.

CONCLUSION

The treatment of chronic inflammatory bowel diseases requires individually designed therapeutic strategies and the close interdisciplinary collaboration of internists and surgeons.

Rectal and sublingual administration of tacrolimus: a single-dose pharmacokinetic study in healthy volunteers

AIMS

The immunosuppressant tacrolimus is usually administered orally. When this is not feasible, other routes of administration may be useful. Previous research suggested that tacrolimus may be applied sublingually or rectally. Pharmacokinetic data are sparse. The aim of this study was to investigate and compare the pharmacokinetics of these alternative formulations with orally administered tacrolimus.

METHODS

Three single, fixed-dose formulations of tacrolimus were administered in a random sequence in 18 healthy subjects, using a cross-over study design. For sublingual administration, 3 mg of powder obtained from oral capsules was applied under the tongue for a period of 15 min without swallowing, with mouth rinsing afterwards. For rectal administration, a suppository containing 15 mg of the oral powder was used. Oral administration consisted of 7 mg of instant-release tacrolimus capsules (Prograf). Main pharmacokinetic outcome parameters were compared by anova.

RESULTS

Sublingual administration showed no clinically significant exposure, contrary to rectal administration, where all subjects had clinically relevant exposure, with a lower relative bioavailability (78%), a lower maximal blood concentration and a later time of maximal blood concentration compared with oral administration.

CONCLUSIONS

Sublingual administration of a single dose of tacrolimus does not result in systemic exposure if care is taken not to swallow saliva and to rinse the oral cavity afterwards. Rectal administration of tacrolimus results in clinically relevant systemic exposure and might represent an alternative formulation in case oral administration is not feasible. When used as a topical agent, systemic side-effects should be considered.

Systematic Review: Rectal Therapies for the Treatment of Distal Forms of Ulcerative Colitis

BACKGROUND

Many therapeutic options are available for patients with distal forms of ulcerative colitis (UC). Rectal therapies (e.g., suppositories, foams, gels, and enemas) may be recommended either alone or in combination with oral treatment. Compared with oral therapies, rectal therapies are underused in patients with distal forms of UC, although rectal therapies have favorable efficacy and safety profiles.

METHODS

This systematic review identified 48 articles for inclusion after a comprehensive PubMed search and the identification of additional relevant articles through other sources. Inclusion criteria were clinical studies examining efficacy and safety of 5-aminosalicylic acid, corticosteroid, and non-5-aminosalicylic acid rectal therapies (suppositories, foams, gels, and enemas) that induce or maintain remission in patients with ulcerative proctitis, ulcerative proctosigmoiditis, or left-sided colitis (i.e., distal forms of UC). The quality of the evidence presented was evaluated using the GRADE system.

RESULTS

Overall, a greater percentage of patients with distal forms of UC receiving 5-aminosalicylic acids or corticosteroid rectal formulations derived greater therapeutic benefit after treatment compared with patients receiving placebo. Furthermore, most uncontrolled studies of rectal therapies reported that patients with distal forms of UC had marked improvement from baseline after treatment. The overall safety profile of rectal therapies was favorable. Treatment with second-generation corticosteroids, such as budesonide and beclomethasone dipropionate, did not increase the incidence of steroid-related adverse effects.

CONCLUSIONS

The current literature supports the use of rectal therapies for both induction and maintenance of remission in patients with distal forms of UC.

Tacrolimus for the Treatment of Ulcerative Colitis

Tacrolimus is a calcineurin inhibitor used for the treatment of corticosteroid-refractory ulcerative colitis (UC). Two randomized controlled trials and a number of retrospective studies have assessed the therapeutic effect of tacrolimus in UC patients. These studies showed that tacrolimus has excellent short-term efficacy in corticosteroid-refractory patients, with the rates of clinical response ranging from 61% to 96%. However, the long-term prognosis of patients treated with tacrolimus is disappointing, and almost 50% of patients eventually underwent colectomy in long-term follow-up. Tacrolimus can achieve mucosal healing in 40-50% of patients, and this is associated with a favorable long-term prognosis. Anti-tumor necrosis factor (TNF)-α antibodies are another therapeutic option in corticosteroid-refractory patients. A prospective head-to-head comparative study of tacrolimus and infliximab is currently being performed to determine which treatment is more effective in corticosteroid-refractory patients. Several retrospective studies have demonstrated that switching between tacrolimus and anti-TNF-α antibody therapy was effective in patients who were refractory to one of the treatments. Most adverse events of tacrolimus are mild; however, opportunistic infections, especially pneumocystis pneumonia, are the most important adverse events, and these should be carefully considered during treatment. Several issues on tacrolimus treatment in UC patients remain unsolved (e.g., use of tacrolimus as remission maintenance therapy). Further controlled studies are needed to optimize the use of tacrolimus for the treatment of UC.

An integrated microfluidic device for screening the effective concentration of locally applied tacrolimus for peripheral nerve regeneration

The effectiveness of tacrolimus (FK506) for the promotion of nerve regeneration is known. However, at present, due to the fact that systemic application may lead to opportunistic infections and tumors, and that the treatment of peripheral nerve injury with systemic immunosuppression is not generally accepted, FK506 has not been widely used for the treatment of simple or peripheral nerve injury. In this study, a pyramid-shaped microfluidic device was designed and fabricated that was able to analyze the effective concentration of locally applied FK506. After testing the effectiveness of the microfluidic device by measuring the fluorescence intensity of fluorescein isothiocyanate-dextran, rat Schwann cells (SCs) were loaded into the device and cultured for 9 days in the presence of different concentrations of FK506. SC proliferation in the presence of FK506 was concentration-dependent between 0 and 2.5±0.003 ng/ml. The proliferation rate reached a maximum at 1.786±0.014 ng/ml, which was statistically significantly different from the proliferation rate at lower FK506 concentrations. There was no statistically significant difference in the proliferation rate between the 1.786 ng/ml group and groups of higher FK506 concentrations. Furthermore, the SCs in the microfluidic device and a 96-well plate continued to proliferate as the culture time increased. No statistically significant differences were identified between the microfluidic device and a 96-well plate with regard to the proliferation rates in each corresponding group. The results obtained in this study demonstrated that the microfluidic device can be used as an excellent platform for the study of drug concentration at the cellular level, and the effective FK506 concentration for local application is 1.786±0.014 ng/ml.

Managing intractable proctitis and the problematic pouch

Proctitis accounts for a significant proportion of cases of ulcerative colitis (UC), and some patients subsequently develop more extensive disease. However, most patients continue to have limited inflammation, although the changes in the distal colon and rectum can occasionally be severe, and symptoms of increased frequency, rectal bleeding and urgency can be as disabling as they are for patients with more extensive colitis. Furthermore, although symptoms are typically well controlled with standard medications, medically refractory proctitis poses particular problems. Patients generally are not systemically unwell, and there is no added fear of cancer. Therefore, the prospect of colectomy for such limited disease is resisted by patients, physicians and surgeons alike. Unusual therapies, often delivered locally by enema or suppository, have been tested in small case series without definitive outcomes. The pathogenesis of such limited, yet intractable inflammation remains unclear, and the differential diagnosis should be carefully reviewed to ensure that local disease, whether it is infectious, vascular, or a result of injury or degeneration, is not overlooked. Ileo-anal pouch formation is the surgery of choice for about 20% of patients with UC who undergo colectomy. In the majority of cases, this surgery results in an acceptable quality of life and freedom from a stoma. However, in a sizeable minority of cases, pouch dysfunction can cause intractable problems. The causes of pouch dysfunction are varied and must all be considered carefully, particularly in refractory cases. Pouchitis is a common issue and is usually transient and easily treated. However, refractory and chronic pouchitis can be challenging. Ischaemia, injury, infection and Crohn's disease can all cause refractory pouch dysfunction. In a minority of cases, there appears to be no apparent organic pathology, and the presumptive diagnosis is that of a functional pouch disorder. Although it is much rarer, neoplastic changes in the pouch must also be considered, and the risk managed appropriately. The management of both intractable proctitis and the problematic pouch is made more challenging by the wide differential diagnosis that must be considered and by the paucity of high-quality clinical trials to support any one therapy. Key strategies to overcoming these limitations include methodical and systematic investigation and review, and a willingness to tailor therapy to the individual patient. Clinical trials of new treatments should be supported, and data from the experience with small cohorts of patients should be meticulously collected, critically analysed and widely disseminated.

What is left when anti-tumour necrosis factor therapy in inflammatory bowel diseases fails?

The inflammatory bowel diseases (IBDs) are chronic incurable conditions that primarily present in young patients. Being incurable, the IBDs may be part of the patient’s life for many years and these conditions require therapies that will be effective over the long-term. Surgery in Crohn’s disease does not cure the disease with endoscopic recurrent in up to 70% of patients 1 year post resection. This means that, the patient will require many years of medications and the goal of the treating physician is to induce and maintain long-term remission without side effects. The development of the anti-tumour necrosis factor alpha (TNFα) agents has been a magnificent clinical advance in IBD, but they are not always effective, with loss of response overtime and, at times, discontinuation is required secondary to side effects. So what options are available if of the anti-TNFα agents can no longer be used? This review aims to provide other options for the physician, to remind them of the older established medications like azathioprine/6-mercaptopurine and methotrexate, the less established medications like mycophenolate mofetil and tacrolimus as well as newer therapeutic options like the anti-integins, which block the trafficking of leukocytes into the intestinal mucosa. The location of the intestinal inflammation must also be considered, as topical therapeutic agents may also be worthwhile to consider in the long-term management of the more challenging IBD patient. The more options that are available the more likely the patient will be able to have tailored therapy to treat their disease and a better long-term outcome.

Topical tacrolimus therapy for antibiotic-refractory pouchitis

BACKGROUND

Pouchitis is the most common complication after restorative proctocolectomy for ulcerative colitis, and it leads to pouch failure. The administration of oral antibiotics is the main treatment for pouchitis; however, in some cases, antibiotic-refractory pouchitis may develop, which requires further medical therapy.

OBJECTIVE

We investigated the applicability of topical tacrolimus for refractory pouchitis.

DESIGN

We performed a prospective pilot study. The study protocols were registered with the University Hospital Medical Information Network Clinical Trials Registry, 000006658.

SETTING

This study was conducted in the Surgical Department of Hyogo College of Medicine.

PATIENTS

Patients with antibiotic-refractory pouchitis were treated for 8 weeks with a tacrolimus enema.

MAIN OUTCOME MEASURES

The efficacy was assessed by comparing Pouchitis Disease Activity Index scores. Safety was assessed by measuring whole blood tacrolimus trough levels.

RESULTS

Ten patients with refractory pouchitis were enrolled. No severe adverse events occurred. The mean scores decreased from 15.9 ± 0.8 to 7.8 ± 0.8 during 8 weeks of treatment (p < 0.01). Specifically, the clinical symptom, endoscopic finding, and histological finding subscores decreased to 0.8 ± 0.6, 3.9 ± 0.2, and 2.9 ± 0.4. Nine patients recovered from their clinical symptoms, and 3 patients recovered from pouchitis.

LIMITATIONS

This small study was neither blinded nor randomized.

CONCLUSIONS

This study demonstrates that the use of topical tacrolimus for the treatment of refractory pouchitis is safe and effective in the short term for clinical symptoms. Although complete endoscopic healing was not achieved, this treatment may have early rescue efficacy in the treatment of antibiotic-refractory pouchitis.

Placebo controlled evaluation of Xilei San, a herbal preparation in patients with intractable ulcerative proctitis

BACKGROUND AND AIM

Topical mesalamine or corticosteroid has shown efficacy in patients with ulcerative proctitis, but patients often become refractory to these interventions. Xilei San is a herbal preparation with evidence of anti-inflammatory effects. We evaluated the efficacy of topical Xilei San in ulcerative proctitis patients.

METHODS

In a double blind setting, 30 patients with intractable ulcerative proctitis despite ≥ 4 weeks of topical mesalamine or corticosteroid were randomly assigned to True (n = 15) and placebo (n = 15). Patients in True received suppository Xilei San (0.1 g/dose per day of Xilei San), the other 15 received placebo suppository. The initial efficacy was evaluated on day 14. Primary endpoint of the trial was avoiding relapse during 180 days, relapse meant recurrence of active disease. Riley's index was applied for endoscopic and histological evaluations, while patients' quality of life was evaluated by an inflammatory bowel disease questionnaire.

RESULTS

On day 14, the number of patients who achieved remission, clinical activity index ≤ 4 in True was significantly higher versus placebo (P < 0.04). Likewise, at day 180, an 81.8% of patients in True were without relapse versus 16.7% in placebo (P < 0.001). Further, significant endoscopic (P < 0.01), histological (P < 0.02) and inflammatory bowel disease questionnaire (P < 0.04) improvements were observed in True, but not in placebo.

CONCLUSIONS

This is the first controlled investigation showing significant clinical and endoscopic efficacy for Xilei San in patients with intractable ulcerative proctitis. Topical Xilei San was well tolerated, and was without safety concerns.

ABCB1 single-nucleotide polymorphisms determine tacrolimus response in patients with ulcerative colitis

Tacrolimus (Tac) is effective in the treatment of steroid-refractory ulcerative colitis (UC); however, nonresponse and unpredictable side effects are major limitations. Because Tac response in patients who have undergone solid-organ transplantation has been associated with the presence of variants in CYP3A and ABCB1, we elucidated the contributions of CYP3A4*1B and CYP3A5*3 and of ABCB1 1236C>T, 2677G>T,A, and 3435C>T polymorphisms to Tac response in 89 patients with UC. Short-term remission and response were achieved in 61 and 14% of the patients, respectively, and were associated with colectomy-free survival. In a linear logistic regression model, patients with homozygous variants for one of the three ABCB1 alleles showed significantly higher short-term remission rates as compared with those of other genotypes. The effects held true after multivariate analysis including multiple comparisons and were more pronounced after correction for dose-adjusted Tac blood trough levels. We suggest that ABCB1, but not CYP3A5, may predict short-term remission of Tac in steroid-refractory UC.

Review article: the role of non-biological drugs in refractory inflammatory bowel disease

BACKGROUND

Up to one-third of patients with inflammatory bowel disease (IBD) do not respond to, or are intolerant of conventional immunosuppressive drugs. Although biological agents are alternative treatments, they may not be suitable or available to some patients.

AIM

To review the evidence for use of nonbiological drugs in the treatment of patients with IBD refractory to corticosteroids or thiopurines.

METHODS

A literature search was performed using PubMed for English language publications with predetermined search criteria to identify relevant studies.

RESULTS

Published evidence from uncontrolled series and controlled clinical trials has been used to produce a practical approach relevant to clinical practice which incorporates the indication, optimal dose, and side effects of various therapies including tacrolimus, methotrexate, thalidomide, tioguanine, mycophenolate mofotil, leucocyte apheresis, nutritional therapy, antibiotics, probiotics, allopurinol, rectal acetarsol and ciclosporin in the treatment of patients with refractory ulcerative colitis and Crohn's disease. Approaches to optimise thiopurine efficacy are also discussed.

CONCLUSIONS

Patients with IBD refractory to corticosteroids or thiopurines may respond to alternative anti-inflammatory chemical molecules, but the evidence base for many of these alternatives is limited and further trials are needed.

Topical agents for idiopathic distal colitis and proctitis

Rectally administered topical agents have demonstrated efficacy in the maintenance of distal colitis (DC) and proctitis and as they are rarely associated with significant blood drug levels, side effects are infrequent. The topical 5-aminosalicylic acid (5-ASA) suppositories and enemas target different regions of the distal colon and are effective for proctitis and DC, respectively. They demonstrate clinical results that are better than oral 5-ASAs and are preferred to topical steroids with better clinical, endoscopic and histological outcomes, without the risk of adrenal suppression. Disease resistant to topical agents, however, can be extremely difficult to manage. The addition of oral 5ASAs, steroids, immunosuppressants and the anti-tumor necrosis factor-α agents may be effective, but can result in significant side effects and not all patients will respond to the therapies. It is for these patients that new and novel therapies are required. Novel topical agents have been proposed for the management of resistant DC. These agents included butyrate, cyclosporine, and nicotine enemas, as well as tacrolimus suppositories, and tacrolimus, ecabet sodium, arsenic, lidocaine, bismuth, rebamipide and thromboxane enemas. While some of these agents appear to demonstrate impressive outcomes, the majority have only been examined in small open-labeled studies. There is thus a desperate need for more randomized double-blinded placebo controlled studies to investigate the clinical utility of these topical therapies. This review summarizes the efficacy of the established topical therapies, and explores the available data on the new and novel topical agents for the management of DC and proctitis.

Novel topical therapies for distal colitis

Distal colitis (DC) can be effectively treated with topical 5ASA agents. Suppositories target the rectum while enemas can reliably reach the splenic flexure. Used in combination with oral 5ASAs, the control of the inflammation is even more effective. Unfortunately, resistant DC does occur and can be extremely challenging to manage. In these patients, the use of steroids, immunosuppressants and the anti-tumor necrosis factor α agents are often required. These, however, can be associated with systemic side effects and are not always effective. The investigation of new topical therapeutic agents is thus required as they are rarely associated with significant blood drug levels and side effects are infrequent. Some of the agents that have been proposed for use in resistant distal colitis include butyrate, cyclosporine and nicotine enemas as well as tacrolimus suppositories and tacrolimus, ecabet sodium, arsenic, lidocaine, rebamipide and Ridogrel^® enemas. Some of these agents have demonstrated impressive results but the majority of the agents have only been assessed in small open-labelled patient cohorts. Further work is thus required with the investigation of promising agents in the context of randomized double-blinded placebo controlled trials. This review aims to highlight those potentially effective therapies in the management of resistant distal colitis and to promote interest in furthering their investigation.

Infliximab for refractory ulcerative proctitis

BACKGROUND

Efficacy of infliximab in treating ulcerative proctitis remains unknown.

AIM

To evaluate the clinical, biological and endoscopic efficacy of infliximab therapy in refractory proctitis.

METHODS

The charts of 420 patients treated with infliximab for ulcerative colitis were reviewed. Thirteen patients were treated with infliximab for refractory ulcerative proctitis in six referral centres between 2005 and 2009.

RESULTS

Following infliximab therapy induction, 9/13 patients (69%) had a complete response (defined as absence of diarrhoea and blood), 2/13 (15%) had a partial response and 2/13 (15%) were primary nonresponders. The median follow-up was 17 months (range, 3-48). Among the 11 patients with clinical response after infliximab induction therapy, 9 (82%) patients maintained response at last follow-up. Disappearance of rectal disorders was observed in all nine patients who maintained clinical response at last follow-up. Following infliximab induction therapy, the mean CRP level fell from 12.8 mg/L to 4.7 mg/L. Endoscopic evaluation was performed before and after infliximab in seven patients, showing an improvement in mucosal lesions in four patients, persistent mild endoscopic activity in two patients and no improvement in one patient. One patient underwent proctocolectomy.

CONCLUSION

Infliximab therapy seems to be effective in inducing and maintaining a clinical response in refractory ulcerative proctitis.

T-cell regulation of neutrophil infiltrate at the early stages of a murine colitis model

BACKGROUND

T-cells are a main target for antiinflammatory drugs in inflammatory bowel disease. As the innate immune system is also implicated in the pathogenesis of these diseases, T-cell suppressors may not only inhibit T-cell-dependent production of proinflammatory mediators but also affect innate immune cell function. Specifically, these drugs may impair innate immune cell recruitment and activation through inhibition of T-cells or act independent of T-cell modulation. We explored the extent of immune modulation by the T-cell inhibitor tacrolimus in a murine colitis model.

METHODS

We assessed the effects of tacrolimus on trinitro-benzene sulphonic acid (TNBS) colitis in wildtype and Rag2-deficient mice. The severity of colitis was assessed by means of histological scores and weight loss. We further characterized the inflammation using immunohistochemistry and by analysis of isolated intestinal leukocytes at various stages of disease.

RESULTS

Tacrolimus-treated wildtype mice were less sensitive to colitis and had fewer activated T-cells. Inhibition of T-cell function was associated with strongly diminished recruitment of infiltrating neutrophils in the colon at the early stages of this model. In agreement, immunohistochemistry demonstrated that tacrolimus inhibited production of the neutrophil chemoattractants CXCL1 and CXCL2. Rag2-deficient mice displayed an enhanced baseline level of lamina propria neutrophils that was moderately increased in TNBS colitis and remained unaffected by tacrolimus.

CONCLUSIONS

Both the innate and the adaptive mucosal immune system contribute to TNBS colitis. Tacrolimus suppresses colitis directly through inhibition of T-cell activation and by suppression of T-cell-mediated recruitment of neutrophils.

Local immune regulation of mucosal inflammation by tacrolimus

PURPOSE

Tacrolimus is a potent immunomodulator that is effective in the treatment of inflammatory bowel disease (IBD). However, potential toxicity and systemic effects with oral intake limit its use. Local tacrolimus treatment is effective in a subgroup of proctitis patients. This study aimed to evaluate whether colonic mucosal immune cells are susceptible to locally applied tacrolimus in vitro. Our in vivo studies aimed at evaluating whether local tacrolimus treatment in mice would bring about local immune suppression and to compare colonic and systemic tacrolimus levels after locally and systemically applied tacrolimus.

RESULTS

In vitro tacrolimus inhibited the activation of multiple cell types present in colonic tissue; lamina propria T cells, NKT cells, and both classical- and non- classical antigen presenting cells. However, the cytokine production of epithelial cells was not inhibited by tacrolimus at these concentrations. After rectal administration in mice, tacrolimus blood levels were comparable to those obtained by oral intake. However, rectally treated mice exhibited a 14-fold higher concentration of tacrolimus within their colonic tissue than orally treated mice. Moreover, rectally applied tacrolimus resulted in a local but not a systemic immune suppression in mice.

CONCLUSIONS

Tacrolimus inhibits activation of several pivotal immune cells of the intestinal mucosa. Murine studies indicate that colonic application of tacrolimus induces local rather than systemic immune suppression.