Tacrolimus (FK-506) treatment of fulminant colitis in a child

Clinical outcome of ulcerative colitis with severe onset in children: a multicenter prospective cohort study

BACKGROUND

As best practices for treating children with severe-onset ulcerative colitis remain controversial in the era of biologic agents, we prospectively investigated treatments and outcomes in a multicenter cohort.

METHODS

Using a Web-based data registry maintained in Japan between October 2012 and March 2020, we compared management and treatment outcomes in an S1 group defined by a Pediatric Ulcerative Colitis Activity Index of 65 or more points at diagnosis with those in an S0 group defined by an index value below 65.

RESULTS

Three hundred one children with ulcerative colitis treated at 21 institutions were included, with follow-up for 3.6 ± 1.9 years. Among them, 75 (25.0%) were in S1; their age at diagnosis was 12.3 ± 2.9 years, and 93% had pancolitis. Colectomy free rates in S1 were 89% after 1 year, 79% after 2, and 74% after 5, significantly lower than for S0 (P = 0.0003). Calcineurin inhibitors and biologic agents, respectively, were given to 53% and 56% of S1 patients, significantly more than for S0 patients (P < 0.0001). Among S1 patients treated with calcineurin inhibitors when steroids failed, 23% required neither biologic agents nor colectomy, similarly to the S0 group (P = 0.46).

CONCLUSIONS

Children with severe ulcerative colitis are likely to require powerful agents such as calcineurin inhibitors and biologic agents; sometimes colectomy ultimately proves necessary. Need for biologic agents in steroid-resistant patients might be reduced to an extent by interposing a therapeutic trial of CI rather than turning to biologic agents or colectomy immediately.

Tacrolimus for ulcerative colitis in children: a multicenter survey in Japan

Background/Aims

Tacrolimus is effective for refractory ulcerative colitis in adults, while data for children is sparse. We aimed to evaluate the effectiveness and safety of tacrolimus for induction and maintenance therapy in Japanese children with ulcerative colitis.

Methods

We retrospectively reviewed the multicenter survey data of 67 patients with ulcerative colitis aged < 17 years treated with tacrolimus between 2000 and 2012. Patients’ characteristics, disease activity, Pediatric Ulcerative Colitis Activity Index (PUCAI) score, initial oral tacrolimus dose, short-term (2-week) and long-term (1-year) outcomes, steroid-sparing effects, and adverse events were evaluated. Clinical remission was defined as a PUCAI score < 10; treatment response was defined as a PUCAI score reduction of ≥ 20 points compared with baseline.

Results

Patients included 35 boys and 32 girls (median [interquartile range] at admission: 13 [11–15] years). Thirty-nine patients were steroid-dependent and 26 were steroidrefractory; 20 had severe colitis and 43 had moderate colitis. The initial tacrolimus dose was 0.09 mg/kg/day (range, 0.05–0.12 mg/kg/day). The short-term clinical remission rate was 47.8%, and the clinical response rate was 37.3%. The mean prednisolone dose was reduced from 19.2 mg/day at tacrolimus initiation to 5.7 mg/day at week 8 (P< 0.001). The adverse event rate was 53.7%; 6 patients required discontinuation of tacrolimus therapy.

Conclusions

Tacrolimus was a safe and effective second-line induction therapy for steroid-dependent and steroid-refractory ulcerative colitis in Japanese children.

Prolonged tacrolimus for pediatric gastrointestinal disorder: Double-edged sword?

BACKGROUND

Although tacrolimus (TAC) can induce remission in children with refractory inflammatory bowel disease (IBD) or autoimmune gastroenteropathy (AGE), its use in maintenance therapy remains controversial. The aim of this study was to investigate the potential nephrotoxic nature of prolonged TAC use.

METHODS

This retrospective study reviewed children with gastrointestinal disorder who underwent kidney biopsy for the evaluation of renal damage during TAC therapy for >1 year. The clinical and histological features of renal damage were evaluated in this single-institution cohort.

RESULTS

Eighteen of 121 children with IBD and two children with AGE followed at a national children hospital in Tokyo, Japan, received TAC between August 2006 and April 2013. Among them, five (Crohn's disease, n = 3; autoimmune gastropathy, n = 1; autoimmune enteropathy, n = 1) received TAC for >1 year, and underwent kidney biopsy. All five had achieved remission on TAC, but had histological evidence of chronic nephrotoxicity. Renal damage in one patient with relatively low TAC trough level remained mild. Estimated glomerular filtration rate (eGFR) at the time of kidney biopsy was lower than at the initiation of TAC in all four available patients. Among them, eGFR improved in one patient after the decrease or discontinuation of TAC.

CONCLUSIONS

TAC appeared to be effective in children with refractory gastrointestinal disorder, but long-term use seems to cause irreversible renal damage. Rigorous monitoring of eGFR and kidney biopsy in selected cases should be considered for the proper adjustment of TAC.

Oral tacrolimus for pediatric steroid-resistant ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) occurring during childhood is generally extensive and is associated with severe flares that may require intravenous steroid treatment. In cases of corticosteroid resistance is necessary to introduce a second-line treatment to avoid or delay surgery.

AIMS

To describe the efficacy and safety of oral tacrolimus for the treatment of severe steroid-resistant UC.

METHODS

We performed a retrospective study that included all patients under age 18 suffering from severe steroid-resistant UC treated with oral tacrolimus during the period January 1998 to October 2012 and with a follow-up period after treatment of 24 months or more.

RESULTS

A total of ten patients were included. The age at baseline was 9.4±4.9 years, and the time from diagnosis was 1.3 months (IQR, 1-5.7). Seven of the patients were in their first flare of disease. All of them received an oral dose of 0.12 mg/kg/day of tacrolimus divided in two doses. Trough plasma levels of tacrolimus were maintained between 4 and 13 ng/ml. Response was seen in 5/10 patients at 12 months, colectomy was eventually performed in 60% of patients during the follow-up period.

CONCLUSIONS

Tacrolimus is useful in inducing remission in patients with severe steroid-resistant UC, preventing or delaying colectomy, and allowing the patient and family to prepare for a probable surgery. Tacrolimus may also be used as a treatment bridge for corticosteroid-dependent patients until the new maintenance therapy takes effect.

Predictive value of the Pediatric Ulcerative Colitis Activity Index in the surgical management of ulcerative colitis

PURPOSE

The primary purpose of this study was to investigate the relationship between Pediatric Ulcerative Colitis Activity Index (PUCAI) and operative management. We also specifically evaluated those patients receiving tacrolimus for their disease.

METHODS

A retrospective review (1/06-1/11) identified ulcerative colitis patients (≤21 years old) undergoing restorative proctocolectomy with rectal mucosectomy and ileal pouch-anal anastomosis. Main outcomes included pre-operative PUCAI, combined versus staged procedure, and postoperative complications. Patients receiving tacrolimus within 3 months of surgical intervention were identified. PUCAI at tacrolimus induction and medication side effects were also noted.

RESULTS

Sixty patients were identified. Forty-two (70%) underwent combined and 18 (30%) had staged procedures. Pre-operative PUCAI was lower for combined versus staged patients (p = < 0.001). Furthermore, a higher pre-operative PUCAI strongly correlated with the likelihood of undergoing a staged procedure (p < 0.001). Forty-four patients (73%) received tacrolimus. Significant improvement in their PUCAI was noted from induction to pre-operative evaluation (p < 0.001). Minor and reversible side effects occurred in 46% of patients receiving tacrolimus, but complication rates were not significantly different.

CONCLUSIONS

There is a very strong correlation between the PUCAI and the likelihood of undergoing a staged procedure. A significant improvement in PUCAI occurs following preoperative tacrolimus therapy.

Outcomes and adverse events in children and young adults undergoing tacrolimus therapy for steroid-refractory colitis

BACKGROUND

Children with severe corticosteroid-resistant ulcerative colitis either need to undergo surgery or be treated with more intensive immunosuppression. Our aim was to characterize the short- and long-term outcomes and adverse events associated with the use of tacrolimus in a steroid-refractory pediatric population.

METHODS

We retrospectively reviewed the medical records of 46 children with steroid-refractory colitis treated with tacrolimus at Children's Hospital Boston between 1994 and 2008. Oral tacrolimus was initiated at a dose of 0.1 mg/kg twice a day and titrated to yield trough levels of 10-15 ng/mL for induction, and 5-10 ng/mL once in remission. The Pediatric Ulcerative Colitis Activity Index (PUCAI) and other measures of disease activity, adverse events, and long-term outcomes were assessed. Statistical analysis of outcomes was performed using SAS statistical software.

RESULTS

Ninety-three percent of patients were discharged without undergoing surgery. The median length of stay after starting tacrolimus was 10 days (range 4-37 days). The mean PUCAI score was 68 ± 13 prior to initiating tacrolimus, and 27 ± 18 at the time of hospital discharge. The probability of avoiding colectomy after starting tacrolimus was 40% at 26 months. The most common adverse events included hypertension (52%) and tremor (44%). There was one seizure and no deaths.

CONCLUSIONS

Tacrolimus is useful as induction therapy in pediatric patients with corticosteroid-refractory colitis and side effects are generally mild and reversible. Despite these findings, many patients develop exacerbations of colitis upon transition to maintenance therapies. The long-term colectomy rate in this challenging population remains ≈60% over time.

Enteropathies of Infancy and Childhood

Intestinal biopsies constitute an ever-increasing portion of the pathologist's workload, accounting for nearly two-thirds of specimens accessioned yearly by the pathology department at The Children's Hospital of Philadelphia. The widespread use of endoscopy and gastrointestinal biopsies in current clinical practice presents the pathologist with a diversity of intestinal mucosal appearances corresponding to disease states of variable clinical severity, requiring close collaboration between clinician and pathologist for optimal interpretation. Many of the entities resulting in severe diarrhea of infancy have been recognized only in the last several decades, and although rare, the study of these disorders, especially when combined with the powerful methods of present-day genetics and molecular biology, has afforded important insights into enterocyte development and function, and intestinal immunity and tolerance. Other conditions once considered infrequent, such as celiac disease, have now been recognized to be much more common and can present with a wide range of pathologic features.

Tacrolimus (FK506) for induction of remission in refractory ulcerative colitis

BACKGROUND

There are a limited number of treatment options for patients with refractory ulcerative colitis. Animal models of inflammatory bowel disease and uncontrolled studies in humans suggest that tacrolimus may be effective treatment for ulcerative colitis.

OBJECTIVES

This review aims to evaluate the efficacy of tacrolimus for induction of remission in patients with corticosteroid refractory ulcerative colitis.

SEARCH STRATEGY

MEDLINE (PubMed), The Cochrane Central Register of Controlled Trials, the IBD/FBD review group specialized register and the ISI-Research Institute were searched (January 1997 to November 2007) to identify relevant studies all randomized trials.

SELECTION CRITERIA

Each author independently reviewed potentially relevant studies to determine eligibility based on the pre-specified criteria.

DATA COLLECTION AND ANALYSIS

A data extraction form was developed and used to extract data from included studies. Two authors independently extracted data. Data were analyzed using Review Manager (RevMan 4.2.9). The primary outcomes were induction of remission and clinical improvement, as defined by the studies and expressed as a percentage of the patients randomized (intention to treat analysis).

MAIN RESULTS

One randomized controlled trial comparing high target serum concentration and low target serum concentration tacrolimus versus placebo was identified and included in the review. Clinical remission was observed in 19% (4/21) of patients in the high target serum concentration group, in 9% (2/22) in the low target serum concentration group and in 5% (1/20) in the placebo group (OR 2.27; 95% CI 0.35 to 14.75). A statistically significant benefit for clinical improvement at two weeks was observed. Clinical improvement was observed in 62% (13/21) of patients in the high target serum concentration group, in 36% (8/22) in the low target serum concentration group and in 10% (2/20) in the placebo group (OR 8.66; 95% CI 1.79 to 42.00; RD 0.39; 95% CI 0.20 to 0.59; NNT = 3). Patients in the high serum target concentration group were significantly more likely than placebo patients to experience adverse events related to treatment (P = 0.043). Finger tremor (n = 6) was the most common adverse event in the tacrolimus group. Other adverse events included: gastroenteritis, sepsis, sleepiness, hot flush, headache, queasiness and stomach discomfort.

AUTHORS' CONCLUSIONS

Tacrolimus may be effective for short-term clinical improvement in patients with refractory ulcerative colitis. However, these results should be interpreted with caution due to the small number of patients enrolled in the trial and other study limitations. Insufficient treatment and follow-up intervals prevent any conclusions with regard to long term safety and efficacy. The use of tacrolimus in the clinical setting requires careful consideration of risks versus benefits as well as close monitoring for adverse events. More data from well designed and controlled studies are needed to determine the long-term efficacy and safety of tacrolimus.

Therapeutic effect of a new immunosuppressive agent, everolimus, on interleukin-10 gene-deficient mice with colitis

A limited number of therapeutic strategies are currently available for patients with inflammatory bowel disease (IBD). In particular, the maintenance therapy after remission in Crohn's disease (CD) is not satisfactory and new approaches are needed. Interleukin-10 gene-deficient (IL-10-/-) mice, a well-characterized experimental model of CD, develop severe chronic colitis due to an aberrant Th1 immune response. Everolimus, an inhibitor of the mammalian target of rapamycin (mTOR), a new immunosuppressive reagent, has been used successfully in animal models for heart, liver, lung and kidney transplantation. In the present study, we examined the efficacy of everolimus in the treatment of chronic colitis in an IL-10-/- mouse model. Everolimus was administered orally for a period of 4 weeks to IL-10-/- mice with clinical signs of colitis. The gross and histological appearances of the colon and the numbers, phenotype and cytokine production of lymphocytes were compared with these characteristics in a control group. The 4-week administration of everolimus resulted in a significant decrease in the severity of colitis, together with a significant reduction in the number of CD4+ T cells in the colonic lamina propria as well as IFN-gamma production in colonic lymphocytes. Everolimus treatment of established colitis in IL-10-/- mice ameliorated the colitis, probably as a result of decreasing the number of CD4+ T cells in the colonic mucosa and an associated reduction in IFN-gamma production.

Topical tacrolimus in the treatment of perianal Crohn's disease: exploratory randomized controlled trial

BACKGROUND

The aim of this study is to evaluate the efficacy of topical tacrolimus in treating perianal Crohn's disease.

METHODS

Nineteen patients, stratified into 7 with ulcerating, and 12 with fistulizing, perianal Crohn's disease were randomized to topical tacrolimus 1 mg/g (1 g ointment twice a day [bid]) or placebo for 12 weeks. Sixteen patients had been on, or were currently taking, azathioprine/6-MP, and 6 had received infliximab. The primary outcome in ulcerating disease was global improvement in perianal/anal lesions, as assessed by the attending physician; for fistulas, it was reduction of > or =50% of actively draining fistulas on 2 consecutive visits. Blood tacrolimus levels and adverse events were assessed.

RESULTS

Three of 4 patients treated with topical tacrolimus for ulcerating disease improved compared with none of 3 in the placebo group. Complete healing was not achieved. In fistulizing disease, topical tacrolimus was not beneficial. Two tacrolimus-treated patients developed perianal abscesses, 1 after improvement in fistula drainage. Adverse events were otherwise infrequent and mild. Whole blood tacrolimus levels were detectable in only 2 patients and were low.

CONCLUSIONS

These preliminary data suggest that topical tacrolimus is effective and safe in the treatment of perianal or anal ulcerating Crohn's disease. This therapy is unlikely to be beneficial in fistulizing perianal Crohn's disease, although a larger study is required to confirm this.

Current therapy of inflammatory bowel disease in children

Ulcerative colitis (UC) and Crohn disease (CD) are chronic intestinal inflammatory diseases that can present as bloody diarrhea, abdominal pain, and malnutrition. Collectively, these disorders are referred to as inflammatory bowel disease (IBD). All patients with IBD share a common pathophysiology. However, there are a number of developmental, psychosocial, and physiologic issues that are unique to the approximate, equals 20% of patients that present during childhood or adolescence. These include the possibility of disease-induced delays in linear growth or physical development, differences in drug dosing, and the changes in social and cognitive development that occur as children move from school-age years into adolescence and early adulthood. Gastroenterologists caring for these children must therefore develop an optimal regimen of pharmacologic therapies, nutritional management, psychologic support, and properly timed surgery (when necessary) that will maintain disease remission, minimize disease and drug-induced adverse effects, and optimize growth and development. This article reviews current approaches to the management of patients with UC and CD and highlights issues specific to the treatment of children with IBD. The principal medical therapies used to induce disease remission in patients with UC are aminosalicylates (for mild disease), corticosteroids (for moderate disease), and cyclosporine (ciclosporin) (for severe disease). If a patient responds to the induction regimen, maintenance therapies that are used to prevent disease relapse include aminosalicylates, mercaptopurine, and azathioprine. Colectomy with creation of an ileal pouch anal anastomosis (J pouch) has become the standard of care for patients with severe or refractory colitis and results in an improved quality of life in most patients. Therefore, the risks associated with using increasingly potent immunosuppressant agents must be balanced in each case against a patient's desire to retain their colon and avoid a temporary or potentially permanent ileostomy. Decisions about drug therapy in the management of patients with CD are more complex and depend on both the location (e.g. gastroduodenal vs small intestinal vs colonic), as well as the behavior of the disease (inflammatory/mucosal vs stricturing vs perforating) in a given patient. Induction therapies for CD typically include aminosalicylates and antibiotics (for mild mucosal disease), nutritional therapy (including elemental or polymeric formulas), corticosteroids (for moderate disease), and infliximab (for corticosteroid-resistant or fistulizing disease). Aminosalicylates, mercaptopurine, azathioprine, methotrexate, and infliximab can be used as maintenance therapies. Because surgical treatment of CD is not curative, it is typically reserved for those patients either with persistent symptoms and disease limited to a small section of the intestine (e.g. the terminal ileum and cecum) or for the management of complications of the disease including stricture or abdominal abscess. When surgery is necessary, maintenance medications administered postoperatively will postpone recurrence. Patients with UC and CD are at risk for the development of micronutrient deficiencies (including folate, iron, and vitamin D deficiencies) and require close nutritional monitoring. In addition, patients with UC and CD involving the colon are at increased risk of developing colon cancer, and should be enrolled into a colonoscopy surveillance program after 8-10 years of disease duration.

[Tacrolimus in the treatment of refractory moderate-to-severe inflammatory bowel disease]

INTRODUCTION

The primary endpoint of this study was to evaluate the efficacy of oral tacrolimus in patients with active moderate-to-severe luminal IBD, mainly those refractory to steroids. Secondary endpoints were surgery requirements during follow-up, the percentage of patients achieving steroid withdrawal, and treatment safety.

PATIENTS AND METHOD

Nineteen patients were included. The main indication for tacrolimus therapy was steroid resistance. The mean duration of treatment was 11 (range 3- 13) and 15 (range 4-44) months in patients with UC and CD, respectively. Remission was evaluated at weeks 4, 8 and 24 from the start of treatment, using the Harvey-Bradshaw index and the Truelove-Witts criteria for CD and UC patients, respectively, and acute- phase reactants (Serum erythrocyte sedimentation rate and C-reactive protein). Steroid withdrawal, need for surgery, and previous and concomitant medication were also evaluated.

RESULTS

Overall, 47%, 66% and 41% of the patients were in complete remission at weeks 4, 8 and 24, respectively. Steroid withdrawal was achieved in 50% of the patients. Among patients who could not undergo complete steroid withdrawal, steroid therapy was reduced to a mean prednisone dose of 12.5 mg /day (range 10-15 mg). Surgery was required in 16% (mean follow-up of 38 months). Adverse effects occurred in 63% patients, who improved with dose reduction; none of the patients required tacrolimus withdrawal.

CONCLUSIONS

Oral tacrolimus could be a safe, effective and useful option in patients with refractory IBD.

Tacrolimus is safe and effective in patients with severe steroid-refractory or steroid-dependent inflammatory bowel disease--a long-term follow-up

OBJECTIVE

We and others have reported the use of tacrolimus in refractory inflammatory bowel disease (IBD). Little is known about its long-term efficacy and safety.

METHODS

In this retrospective, observational single center study the charts of 53 adult patients with steroid-dependent (n = 18) or steroid-refractory (n = 35) IBD, Crohn's disease (CD) (n = 11), ulcerative colitis (UC) (n = 40), or pouchitis (PC) (n = 2) were reviewed. Tacrolimus (0.1 mg/kg body weight per day) was administered orally in all and initially intravenously in 2 patients (0.01 mg/kg body weight per day), aiming for serum trough levels of 4-8 ng/mL. Forty-one of 53 (77.1%) patients were receiving concomitant azathioprine. The mean treatment duration was 25.2 +/- 4.6 SD months (0.43-164 months). Patients were followed for a mean of 39 +/- 4.1 SD months (5-164 months). Response was evaluated using a modified clinical activity index (M-CAI).

RESULTS

Thirty-one UC (78%), 10 CD (90.1%), and both PC (100%) patients experienced an immediate clinical response or went into remission at 30 days. A statistically significant drop on the M-CAI was documented for UC and CD patients. Nine UC patients (22.5%) underwent colectomy between 1.6 and 41.3 months following initiation. Mean colectomy-free survival was 104.8 +/- 15.5 (95% CI 74.4-135.2) months (limited to 164.4 months). Cumulative colectomy-free survival was estimated 56.5% at 43.8 months. Steroids were reduced or discontinued in 40 of 45 UC and CD patients (90%) taking steroids. Side effects included a temporary rise of creatinine (n = 4, 7.6%), tremor or paresthesias (n = 5, 9.4%), hyperkalemia (n = 1, 1.9%), hypertension (n = 1, 1.9%), and opportunistic infections (n = 2, 3.8%).

CONCLUSION

Long-term tacrolimus therapy appears safe and effective in refractory IBD.

Successful therapy of refractory pyoderma gangrenosum and periorbital phlegmona with tacrolimus (FK506) in ulcerative colitis

We describe two male patients with ulcerative colitis and refractory pyoderma gangrenosum including periorbital phlegmona in one case. Both patients were successfully managed with low dose oral tacrolimus (0.1 mg/kg bodyweight per day). Serum trough levels were closely monitored and maintained between 4 and 6 ng/mL. A rapid response was noted in both cases. Complete non-scarring skin restitution without side effects was accomplished in both cases. Low dose oral tacrolimus provides a valuable alternative treatment option for IBD patients with refractory pyoderma gangrenosum.

Rescue therapy with tacrolimus is effective in patients with severe and refractory inflammatory bowel disease

BACKGROUND

Oral tacrolimus, approved for the prophylaxis of organ rejection in liver or kidney transplants, has been reported to be effective in anecdotal cases of refractory inflammatory bowel disease.

AIM

To evaluate the usefulness of low-dose oral tacrolimus in refractory inflammatory bowel disease.

METHODS

Thirty-one adult Caucasian patients with steroid-dependent (n = 15) or steroid-refractory (n = 16) inflammatory bowel disease (Crohn's disease, n = 6; ulcerative colitis, n = 23; pouchitis, n = 2) were enrolled. Tacrolimus (0.1 mg/kg body weight per day) was administered orally in 30 patients and initially intravenously in one patient (0.01 mg/kg body weight per day), aiming for serum trough levels of 4-6 ng/mL. The median treatment duration was 12 months (range, 1-137 months).

RESULTS

Twenty-eight patients (90.3%) experienced a clinical and laboratory response and 20 (64.5%) went into remission. One ulcerative colitis patient and two Crohn's disease patients did not improve. Three ulcerative colitis patients (9.7%) were colectomized at 1, 12 and 24 months after tacrolimus initiation. In 19 of 23 patients (82.6%) taking steroids, steroids were reduced or discontinued. Side-effects included a temporary rise of creatinine (n = 3, 9.7%), tremor or paraesthesias (n = 3, 9.7%), hyperkalaemia (n = 1, 3.2%), hypertension (n = 1, 3.2%) and an opportunistic infection (n = 1, 3.2%).

CONCLUSION

Oral tacrolimus is safe and effective in refractory inflammatory bowel disease.

Treatment of inflammatory bowel disease in childhood: best available evidence

The physician treating children with inflammatory bowel disease is confronted with a number of specific problems, one of them being the lack of randomized, controlled drug trials in children. In this review, the role of nutritional therapy is discussed with a focus on primary treatment, especially for children with Crohn's disease. Then, the available medical therapies are highlighted, reviewing the evidence of effectiveness and side effects in children, as compared with what is known in adults. Nutritional therapy has proven to be effective in inducing and maintaining remission in Crohn's disease while promoting linear growth. Conventional treatment consists of aminosalicylates and corticosteroids, whereas the early introduction of immunosuppressives (such as azathioprine or 6-mercaptopurine) is advocated as maintenance treatment. If these drugs are not tolerated or are ineffective, methotrexate may serve as an alternative in Crohn's disease. Cyclosporine is an effective rescue therapy in severe ulcerative colitis, but only will postpone surgery. A novel strategy to treat Crohn's disease is offered by infliximab, a monoclonal antibody to the proinflammatory cytokine tumor necrosis factor (TNF)-alpha. Based on the best-available evidence, suggested usage is provided for separate drugs with respect to dosage and monitoring of side effects in children.

Inflammatory bowel disease: new insights into pathogenesis and treatment

Despite all the advances in our understanding of the pathophysiology of inflammatory bowel disease (IBD), we do not know the cause. Some of the most recently available data have been discussed here and yet it is now becoming increasingly accepted that immunogenetics play an important role in the predisposition, modulation, and perpetuation of IBD. The mucosal immune system is the central effector of intestinal inflammation and injury, with cytokines playing a central role in modulating inflammation. The role of intestinal milium, and enteric flora in particular, appears to be of greater significance than previously held. A review is made of the main areas of research exploring the mechanisms more intimately associated with the development of IBD, providing advances in the agents currently used, and identifying a host of new therapeutic agents potentially interacting with or interrupting specific targets in the genesis of IBD.

Immunomodulatory therapy for pediatric inflammatory bowel disease: changing patterns of use, 1990-2000

OBJECTIVE

To identify changes over the past decade in physicians' attitudes regarding the use of immunomodulatory agents for the treatment of children with inflammatory bowel disease (IBD), we surveyed the membership of the North American Society for Pediatric Gastroenterology and Nutrition and compared the responses to those from an identical survey performed in 1990.

METHODS

Surveys were mailed to 718 physicians in January, 2000. All surveys returned by mid-February were analyzed, and results compared to those obtained in the 1990 survey.

RESULTS

Thirty-nine percent (278/718) of surveys were returned, compared to 27% (105/385) in 1990. Overall, 93% of the current survey's respondents agreed with the statement "immunomodulatory agents are effective in the treatment of children and adolescents with IBD." Compared to 1990, significant increases (p < 0.0001) were noted in the percentage of respondents who prescribe immunomodulatory agents to children with all forms of IBD. Indications for immunomodulation that showed significant increases (p < 0.001) since 1990 included treatment of perianal and non-perianal fistulae; growth failure; use as initial, primary therapy; and use as prophylaxis against postoperative recurrence. 6-Mercaptopurine and azathioprine continue to be the agents prescribed by the greatest percentage of respondents. More physicians are willing to use immunomodulatory agents in children younger than 5 yr, and duration of use is longer than in 1990. Currently, physicians seem to favor the use of immunomodulatory agents over colectomy for children with either intractable ulcerative or Crohn's colitis. Most respondents remain concerned about potential bone marrow and immune suppression, but concerns regarding malignancy, teratogenicity, and infertility have lessened.

CONCLUSION

These survey findings document that pediatric gastroenterologists have widely accepted the use of immunomodulators in the treatment of children and adolescents with IBD.

Abrupt increase of tacrolimus blood levels during an episode of Shigella infection in a child after liver transplantation

The authors report the case of an 8-year-old girl who underwent a liver transplant at the age of 18 months because of biliary atresia. She was treated with cyclosporin for more than 5 years. Increased hirsutism prompted a change to tacrolimus therapy. During 11 months the mean tacrolimus level was 8.2 ng/mL. The patient was hospitalized because of an episode of Shigella infection and a threefold increase in tacrolimus level was measured. Despite a reduction of tacrolimus dose, the trough tacrolimus levels were in the range of 16.5 to 22.0 ng/mL during the subsequent 2 weeks. On resolution of the diarrhea, tacrolimus levels returned to those observed before the Shigella infection. It is suggested that the marked increase in tacrolimus levels observed in this patient is a direct result of the damage produced to the gastrointestinal mucosa by the Shigella infection.

Recent advances in inflammatory bowel disease

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Oral tacrolimus treatment of severe colitis in children

OBJECTIVE

To evaluate the efficacy of oral tacrolimus as an induction agent in steroid-refractory severe colitis.

STUDY DESIGN

Open-label, multicenter trial of oral tacrolimus in patients with severe colitis. Patients not responding to conventional therapy received tacrolimus, 0.1 mg/kg/dose given twice a day, and the dosage was adjusted to achieve blood levels between 10 and 15 ng/mL. Response was defined as improvement in a number of clinical parameters (including abdominal pain, diarrhea, rectal bleeding, and cessation of transfusions). Patients who responded by 14 days continued to receive tacrolimus, and 6-mercaptopurine or azathioprine was added as a steroid-sparing agent 4 to 6 weeks after the tacrolimus was instituted.

RESULTS

Fourteen patients were enrolled in the study. One patient elected to withdraw after 48 hours. Of the 13 remaining, 9 (69%) responded and were discharged. Tacrolimus was continued for 2 to 3 months in the responders, except for 1 patient who was given tacrolimus for 11 months. After 1 year of follow-up, only 5 (38%) patients were receiving maintenance therapy; the other 4 responders had undergone colectomy.

CONCLUSION

Although tacrolimus is effective induction therapy for severe ulcerative or Crohn's colitis, fewer than 50% of patients treated will successfully achieve a long-term remission.

Therapy for Crohn disease

Medical therapy for Crohn disease has advanced incrementally: Small, non-definitive controlled trials of mesalamine continue to be reported, but the results are not sufficient to change the conclusion of a large meta-analysis that shows only marginal benefit of mesalamine in Crohn disease. Low-dose, controlled ileal-release budesonide is not effective for preventing postoperative recurrence of Crohn disease. A loading dose of intravenous azathioprine does not accelerate the time to response in patients with steroid-treated Crohn disease; however, standard azathioprine may work more quickly than previously reported. Mycophenolate mofetil may be therapeutically equivalent to azathioprine for active Crohn disease. There is a trend toward benefit of oral methotrexate (15 mg/wk) for active Crohn disease, and there is no significant difference in the blood concentrations of methotrexate in patients with inflammatory bowel disease who receive methotrexate (15 or 25 mg weekly) administered subcutaneously. Results in a pilot study suggest that tacrolimus may close perianal fistulas in patients with Crohn disease. The anti-tumor necrosis factor antibody infliximab is effective in closing perianal and enterocutaneous fistulas and in maintaining remission in patients with Crohn disease. Infliximab also leads to endoscopic and histologic remission. There is a trend toward benefit of subcutaneous recombinant interleukin-11 for active Crohn disease. Two pilot studies have shown that thalidomide may be of benefit in patients with refractory Crohn disease.

Therapy of inflammatory bowel disease

In the last decade, substantial gains have been made in the treatment of inflammatory bowel disease (IBD). Refinements in drug formulation have provided the ability to target distinct sites of delivery, enhancing the safety and efficacy of older agents. Immunosuppressive agents beyond corticosteroids have assumed a routine part in the care of patients with IBD. Moreover, as the century closes, we stand at the threshold of unprecedented advances in knowledge of the pathogenesis of ulcerative colitis and Crohn's disease. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This review covers agents currently used in the treatment of IBD and seeks to provide an overview of emerging therapies.

Combination therapy with oral tacrolimus (FK506) and azathioprine or 6-mercaptopurine for treatment-refractory Crohn's disease perianal fistulae

Our aim was to report the clinical experience with combination treatment using tacrolimus and either azathioprine (AZA) or 6-mercaptopurine (6MP) in patients with Crohn's disease (CD) perianal fistulae. The medical records of all patients with Crohn's disease perianal fistulae seen at the Mayo Clinic from 1996-1998 who were treated with tacrolimus were reviewed. Clinical response was classified as: complete response, partial response, and nonresponse. Eleven patients were treated with oral tacrolimus for a mean duration of 22 weeks. The initial oral dose of tacrolimus ranged from 0.15 to 0.31 mg/kg/day. Azathioprine or 6MP was continued in combination with tacrolimus in seven patients and initiated simultaneously with tacrolimus in four patients. All patients improved clinically, seven had a complete response, and four had a partial response. The mean time to initial improvement was 2.4 weeks, and the mean time to complete response was 12.2 weeks. The most frequent adverse events were nausea, paresthesias, nephrotoxicity, and tremor. Patients with nephrotoxicity had a significantly higher mean initial tacrolimus dose (0.31 mg/kg/day) compared with patients who did not have nephrotoxicity (0.25 mg/kg/day) (p = 0.035); however, there was not a statistically significant association between the starting dose or mean blood level and clinical response. Combination therapy with oral tacrolimus and AZA or 6MP may be effective treatment for CD perianal fistulae. Higher initial tacrolimus doses increase the risk of nephrotoxicity without improving clinical response.

Novel therapies for inflammatory bowel disease

Looking back at successes and failures in newer approaches to treating IBD, it is tempting--although still difficult--to draw conclusions about pathogenesis. When a therapy proves effective, do clinicians truly know how it works? Even with a therapy as specific as anti-TNF antibody, it is not clear if the benefit is attributable to simple binding and clearance of TNF-alpha or to binding on the cell surface and subsequent deletion of the activated macrophage. When a drug appears to be less effective than preclinical models suggest, can failures in effectiveness from delivery or dosing be differentiated? The disappointing results of clinical trials with IL-10--so at odds with the prediction of benefit from animal models--bring into question the validity of those models as well as the soundness of design of the clinical trials on which efficacy of IL-10 is judged. The variability of response even to the most narrowly targeted agents suggests that these diseases are far more heterogeneous in humans than in their murine counterparts. Clinicians are only just beginning to recognize subclinical markers of response, and it may soon be possible to predict response on the basis of genetic composition. For the moment, however, the field of pharmacogenetics is embryonic. Challenges in developing new therapeutic strategies include not only identifying novel agents, but also improving the definitions of clinical endpoints and defining efficacy at the biologic level. Only through considered evaluation of clinical evidence may clinicians determine which therapies should remain novelties and which should become an accepted part of the armamentarium.

Severe Ulcerative Colitis

Patients with severe ulcerative colitis should be hospitalized and treated with intravenous corticosteroids for 7 to 10 days. Patients who fail to respond may be offered colectomy or rescue therapy with intravenous cyclosporine. Risks of cyclosporine therapy, including a 1% to 2% risk of death from opportunistic infection and a 50% failure rate after 6 months of follow-up, should be discussed with the patient. Because of the high rate of relapse, patients who elect to be treated with cyclosporine should receive overlapping therapy with prednisone, cyclosporine and azathioprine or 6-mercaptopurine. Azathioprine or 6-mercaptopurine should then be continued long-term for maintenance of remission.

Steroid-unresponsive acute attacks of inflammatory bowel disease: immunomodulation by tacrolimus (FK506)

OBJECTIVE

Steroid treatment failure in acute Crohn's disease and ulcerative colitis frequently necessitates surgical intervention. Several alternative therapeutic strategies have been raised. The most promising so far has been intravenous cyclosporine, but the results in the long term have been discouraging. We assessed the efficacy and safety of the new macrolide immunomodulator tacrolimus as an alternative to cyclosporine A.

METHODS

Eleven patients with steroid-refractory disease (six ulcerative colitis, two indeterminate colitis, two Crohn's disease, one pouchitis) and severe activity according to the Truelove and Witts criteria or Crohn's disease activity index > 150, respectively, were eligible for the study. All patients were treated with intravenous tacrolimus for 7-10 days followed by oral treatment over a median period of 7 months (range 0.25-16). Azathioprine and mesalamine were given concomitantly. Steroids were tapered according to clinical activity.

RESULTS

Seven of 11 patients achieved remission rapidly, whereas a modest improvement was noted in two. Only two patients required an early and one a delayed colectomy. Moreover, a rectovaginal fistula closure in a case of Crohn's disease and an improvement of pouchitis was observed. A tapering to low dose steroids was possible during oral tacrolimus therapy in all nine responders and remission was maintained in five of them (mean follow-up 9.2 months). The drug was well tolerated and side effects were managed conservatively.

CONCLUSION

Tacrolimus induced rapid remission in steroid resistant inflammatory bowel disease in the majority of cases. It appears to be an effective treatment modality that may be superior to cyclosporine with respect to maintenance of remission.