Long-term 6-mercaptopurine treatment in adolescents with Crohn's disease

Controlled ileal release budesonide in pediatric Crohn disease: efficacy and effect on growth

BACKGROUND

Although the effectiveness of controlled ileal release (CIR) budesonide in children can be extrapolated from adult studies, there are currently no data available concerning the effects of CIR budesonide therapy on linear growth. In the absence of controlled, prospective pediatric clinical trials, we reviewed the outcomes, particularly linear growth, of children and adolescents given CIR budesonide to treat active intestinal inflammation and to maintain remission.

METHODS

Thirty-two children (20 males) aged 14.1 +/- 2.7 years with Crohn disease of the distal ileum with or without right colon involvement were treated for active Crohn disease (baseline Pediatric Crohn Disease Activity Index, 34 +/- 14) with 9 mg daily of CIR budesonide through the Hospital for Sick Children, University of Toronto, Inflammatory Bowel Diseases program.

RESULTS

At first follow-up visit 8.7 +/- 6.0 weeks later, 19 of 32 (59%) were judged by the physician to have responded. In the subset of 22 patients who had laboratory tests repeated at the first follow-up visit, their Pediatric Crohn Disease Activity Index fell from 33 +/- 14 to 22 +/- 16 (P = 0.001). The Pediatric Crohn Disease Activity Index score fell to less than 15 (cut-off score remission) in 29%. Six prepubertal responders continued to receive 6 mg CIR budesonide for 6 to 13 months. Five of the 6 experienced only mild or no gastrointestinal symptoms and gained weight. Nevertheless, their mean height velocity was only 2.3 +/- 1.0 cm/year, and none grew at a rate of more than 4cm/year whilst receiving CIR budesonide.

CONCLUSIONS

These data provide grade III evidence of modest effectiveness of CIR budesonide in children with active Crohn disease confined to the ileum with or without right colon involvement. The subnormal growth observed with continued therapy is concerning and may reflect either inadequately controlled intestinal inflammation or direct suppression of linear growth, as is observed with conventional corticosteroids. Randomized controlled pediatric trials of CIR budesonide must include parameters of linear growth as an outcome variable.

A multicenter trial of 6-mercaptopurine and prednisone in children with newly diagnosed Crohn's disease

BACKGROUND & AIMS

Clinical experience suggests that 6-mercaptopurine (6-MP) is effective therapy for children with active steroid-dependent Crohn's disease (CD). We report the results of a prospective, placebo-controlled, multicenter trial evaluating the combination of 6-MP and prednisone as therapy for children with newly diagnosed moderate-to-severe CD.

METHODS

Fifty-five children (age, 13+/-2 years) were randomized to treatment with 6-MP (1.5 mg x kg(-1) x day(-1)) or placebo within 8 weeks of initial diagnosis. Both groups also received prednisone (40 mg/day). Prednisone dosage adjustments were based on a defined schedule determined by the change in a subject's disease activity score, and steroid administration was discontinued as remission was achieved. Study treatment with 6-MP or placebo continued for 18 months.

RESULTS

Groups were comparable for age, sex, and site and activity of disease. In the 6-MP group, the duration of steroid use was shorter (P<0.001) and the cumulative steroid dose lower at 6, 12, and 18 months (P<0.01). Although remission was induced in 89% of both groups, only 9% of the remitters in the 6-MP group relapsed compared with 47% of controls (P = 0.007). Growth was comparable in both groups. No clinically significant adverse events occurred, although mild leukopenia and increases in aminotransferase activity were noted in the 6-MP group.

CONCLUSIONS

Addition of 6-MP to a regimen of corticosteroids significantly lessens the need for prednisone and improves maintenance of remission. 6-MP should be part of the initial treatment regimen for children with newly diagnosed moderate-to-severe CD.

Corticosteroids in the treatment of gastrointestinal disease

Corticosteroids remain the mainstay of anti-inflammatory and immunosuppressive therapy for many gastrointestinal conditions. We are now starting to understand their mechanism of action and the phenomenon of corticosteroid resistance. Because of the ubiquity of corticosteroid receptors in virtually all cells of the body, side effects of therapy are common and may affect multiple body sites. Newer corticosteroid analogues are being developed to minimize these complications, and concomitant use of other immunomodulatory drugs often facilitates corticosteroid dosage reduction or even withdrawal in chronic inflammatory states.

Pediatric Inflammatory Bowel Disease

The combination of an unprecedented number of new therapeutic options (Fig. 1), along with new insights in how to optimize currently available therapies and advances in our understanding of disease pathogenesis, present many exciting new aspects to the management of patients with inflammatory bowel disease (IBD). Clinical management paradigms must evolve in parallel to keep pace with these advances. Traditional pediatric IBD regimens have underutilized combination therapies (Fig. 2) and immunomodulatory agents. Increased appreciation for steroid side effects is leading to a shift away from their inclusion in maintenance regimens. Immunomodulators are being introduced earlier in the course of disease for maintenance of remission and growth promotion. Recognition that the sole signs of active disease in children and adolescents may be growth and maturational delay, despite a relative lack of gastrointestinal symptoms, should prompt earlier, more aggressive interventions. When more potent, rapidly acting interventions such as infliximab, cyclosporine (CSA), or tacrolimus are considered, they should generally be co-administered with agents such as 6-mercaptopurine (6-MP) or azathioprine (AZA) for longer-term disease suppression.

A comparison of methotrexate with placebo for the maintenance of remission in Crohn's disease. North American Crohn's Study Group Investigators

BACKGROUND

Patients with Crohn's disease often have relapses. Better treatments are needed for the maintenance of remission. Although methotrexate is an effective short-term treatment for Crohn's disease, its role in maintaining remissions is not known.

METHODS

We conducted a double-blind, placebo-controlled, multicenter study of patients with chronically active Crohn's disease who had entered remission after 16 to 24 weeks of treatment with 25 mg of methotrexate given intramuscularly once weekly. Patients were randomly assigned to receive either methotrexate at a dose of 15 mg intramuscularly once weekly or placebo for 40 weeks. No other treatments for Crohn's disease were permitted. We compared the efficacy of treatment by analyzing the proportion of patients who remained in remission at week 40. Remission was defined as a score of 150 or less on the Crohn's Disease Activity Index.

RESULTS

Forty patients received methotrexate, and 36 received placebo. At week 40, 26 patients (65 percent) were in remission in the methotrexate group, as compared with 14 (39 percent) in the placebo group (P=0.04; absolute reduction in the risk of relapse, 26.1 percent; 95 percent confidence interval, 4.4 percent to 47.8 percent). Fewer patients in the methotrexate group than in the placebo group required prednisone for relapse (11 of 40 [28 percent] vs. 21 of 36 [58 percent], P=0.01). None of the patients who received methotrexate had a severe adverse event; one patient in this group withdrew because of nausea.

CONCLUSIONS

In patients with Crohn's disease who enter remission after treatment with methotrexate, a low dose of methotrexate maintains remission.

Therapy of Crohn's disease in childhood

Crohn's disease in childhood is a chronic relapsing condition with a high morbidity. Growth failure is common. The aim of therapy is to induce and then maintain disease remission and thereby promote well-being and normal growth and development. Enteral nutrition (either polymeric or elemental) is effective and used as initial therapy. This is employed as sole therapy over a 6- to 8-week period followed by a period of controlled food reintroduction. The relapse rate is high and further courses of enteral nutrition or alternative therapies are frequently required. Corticosteroids are also effective as initial therapy and are required in difficult cases but there are problems with their long term use, particularly their adverse effects on growth. Many patients develop either corticosteroid-dependent or corticosteroid-resistant disease. In this instance, additional immunosuppression, such as azathioprine, can be used. Surgery is required for those patients with disease resistant to medical therapy and this will result in remission; however, the relapse rate with surgery is high. There are many areas for future research. Very little is known about why enteral nutrition works, how long it should be given or its role as maintenance therapy. Newer immunosuppressive strategies based on cytokine modulation may be helpful in children once more experience is gained from their use in adults.

Azathioprine and 6-mercaptopurine for the treatment of perianal Crohn's disease in children

Numerous adult studies show a 30-65% response rate to azathioprine (AZA) or 6-mercaptopurine (6-MP) for significant perianal Crohn's disease. The aim of this study was to evaluate whether these drugs healed pediatric perianal Crohn's disease. Records of pediatric Crohn's patients were retrospectively reviewed for significant perianal disease treated with AZA or 6-MP for > or =6 months. The patient's perianal disease was reviewed and evaluated for fistulas, drainage, induration, and tenderness. In addition, the patients were given a score using the Irvine Perianal Disease Activity Index (PDAI). Patients were retrospectively scored upon initiation of treatment and after six months of therapy. Possible scores ranged from 0-20. Twenty patients met the study criteria. Five patients were considered treatment failures. One patient required a colostomy after 1.5 months of therapy, one developed pancreatitis, and three were noncompliant with therapy. Of the remaining 15 patients who were treated for > or =6 months, 67% had an improvement in drainage, 73% in tenderness, 60% in induration, and 40% in fistula closure. The mean Irvine PDAI was 7.67 +/- 2.19 initially and 4.40 +/- 1.72 after six months of therapy. The improvement was statistically significant (p < 0.001). AZA and 6-MP are effective treatments for healing significant perianal Crohn's disease in pediatrics.

Pharmacogenomics and metabolite measurement for 6-mercaptopurine therapy in inflammatory bowel disease

BACKGROUND & AIMS

The effects of 6-mercaptopurine (6-MP) are mediated via its intracellular conversion to 6-thioguanine (6-TG) and 6-methylmercaptopurine (6-MMP) nucleotide metabolites, the latter genetically controlled by thiopurine methyltransferase (TPMT). We sought to determine optimal therapeutic 6-MP metabolite levels and their correlation with medication-induced toxicity and TPMT genotype.

METHODS

Therapeutic response was determined in 92 pediatric patients with inflammatory bowel disease coincidentally with hematologic, pancreatic, and hepatic laboratory parameters, and compared with erythrocyte metabolite levels and TPMT genotype.

RESULTS

Clinical response was highly correlated with 6-TG levels (P < 0.0001) but not with any other variable, including 6-MMP levels, drug dose, gender, and concurrent medications. The frequency of therapeutic response increased at 6-TG levels > 235 pmol/8 x 10(8) erythrocytes (P < 0.001). Hepatotoxicity correlated with elevated 6-MMP levels (>5700 pmol/8 x 10(8) erythrocytes; P < 0.05). Although leukopenia was associated with higher 6-TG levels (P < 0.03), it was observed in only 8% of responders. Patients heterozygous for TPMT (8/92) had higher 6-TG levels (P < 0.0001), and all responded to therapy.

CONCLUSIONS

6-MP metabolite levels and TPMT genotyping may assist clinicians in optimizing therapeutic response to 6-MP and identifying individuals at increased risk for drug-induced toxicity.

Outcome of pregnancies when fathers are treated with 6-mercaptopurine for inflammatory bowel disease

OBJECTIVE

The outcomes of pregnancies after maternal use of 6-mercaptopurine (6-MP) for inflammatory bowel disease (IBD) during pregnancy have been reported, but data are lacking for outcomes when the fathers use this drug.

METHODS

Subjects were male patients with IBD seen at one center between 1970 and 1997. Patients and their wives were interviewed. Group 1 comprised pregnancies fathered by men who were taking 6-MP. This group was further subdivided into those conceived within 3 months of 6-MP use and those conceived at least 3 months after 6-MP was stopped. Group 2 comprised pregnancies fathered by men with IBD, similar in characteristics to group 1, who had not taken 6-MP before fertilization. Information was collected regarding the fathers, the mothers, and the pregnancies, as well as the health of the children, in a historical cohort study.

RESULTS

There were 50 pregnancies in group 1 (13 in 1A and 37 in 1B) and 90 pregnancies in group 2. Four of the 13 pregnancies in group 1A were associated with complications. There were two spontaneous abortions, and two congenital anomalies including a missing thumb in one and acrania with multiple digital and limb abnormalities in the other. Risk of complications was significantly increased when compared with group 1B (p < 0.013) and group 2 (p < 0.002).

CONCLUSION

The incidence of pregnancy-related complications was significantly increased when the fathers used 6-MP within 3 months of conception.

Azathioprine or 6-mercaptopurine for inducing remission of Crohn's disease

OBJECTIVES

To determine the effectiveness of azathioprine and 6-mercaptopurine in inducing remission of active Crohn's disease.

SEARCH STRATEGY

Studies were selected using the MEDLINE data base (1966 - December 1997), abstracts from major gastrointestinal meetings and references from published articles and reviews. The Cochrane Controlled Trials Register and the Inflammatory Bowel Disease Review Group Trials Register was also searched.

SELECTION CRITERIA

Eight randomized placebo controlled trials of azathioprine and 6-mercaptopurine therapy in adult patients were identified: five dealt with active disease and three had multiple therapeutic arms.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers based on the intention to treat principle. Each study was given a quality score based on predetermined criteria. Extracted data were converted to 2X2 tables (response versus no response and antimetabolite versus placebo) and then synthesized into a summary test statistic using the pooled odds ratio and 95% confidence intervals as described by Cochran and Mantel and Haenszel ('Odds Ratio' in MetaView).

MAIN RESULTS

The odds ratio of a response to azathioprine or 6-mercaptopurine therapy compared with placebo in active Crohn's disease was 2.36 (95% CI 1.57-3.53). This corresponded to a number needed to treat of about 5 to observe an effect of therapy in one patient. When the two trials using 6-mercaptopurine in active disease were excluded from the analysis, the odds ratio of response was 2.04 (CI 1.24 - 3.35). Treatment >/= 17 weeks increased the odds ratio of a response to 2.51 (CI 1.63-3. 88). A steroid sparing effect was seen with an odds ratio of 3.86 (CI 2.14 - 6.96), corresponding to a number needed to treat of about 3 to observe steroid sparing in one patient. Adverse events requiring withdrawal from a trial, principally allergy, leukopenia, pancreatitis, and nausea were increased on therapy with an odds ratio of 3.01 (CI 1.30 - 6.96). The number needed to treat to observe one adverse event in one patient treated with azathioprine or 6-mercaptopurine was 14.

REVIEWER'S CONCLUSIONS

Azathioprine and 6-mercaptopurine are effective therapy for inducing remission in active Crohn's disease. The odds ratio of response increases after >/= 17 weeks of therapy, suggesting that there is a minimum length of time for a trial of azathioprine or 6-mercaptopurine therapy. Adverse events were more common among patients on therapy.

Azathioprine for maintaining remission of Crohn's disease

OBJECTIVES

To assess the effectiveness of azathioprine in maintaining remission of quiescent Crohn's disease.

SEARCH STRATEGY

Pertinent studies were selected using the MEDLINE data base (1966 - May 1998), the Cochrane Controlled Trials Register, the Inflammatory Bowel Disease Trials Register, as well as abstracts from major gastrointestinal research meetings and references from published articles and reviews.

SELECTION CRITERIA

Five randomized, double-blind, placebo-controlled trials of azathioprine therapy were identified. Two of these trials consisted solely of patients with quiescent Crohn's disease. Three trials had multiple therapeutic arms for both induction of remission and maintenance of remission.

DATA COLLECTION AND ANALYSIS

Data were extracted by three independent observers (GRM, GF, LRS) based on the intention to treat principle. Peto odds ratios for the overall maintenance of remission, steroid sparing, and withdrawals due to adverse effects were calculated, and from these, 95% confidence intervals were derived. Numbers needed to treat or harm (NNT, NNH respectively) for the maintenance of remission, steroid sparing, and withdrawals due to adverse effects were also determined.

MAIN RESULTS

Azathioprine had a positive effect on maintaining remission. The Peto odds ratio for maintenance of remission was 2.16 (CI 1.35 - 3.47) with an NNT of 7. A higher dose improved response. A steroid sparing effect was noted, with a Peto odds ratio of 5.22 (CI 1.06 - 25.68) and NNT of 3 for quiescent disease. The Peto odds ratio for withdrawals due to adverse events was 4.36 (CI 1.63 - 11.67), the NNH (Number Needed to Harm) was 19.

REVIEWER'S CONCLUSIONS

Azathioprine is effective in maintaining remission. There is evidence for a steroid sparing effect.

Optimum duration of treatment with 6-mercaptopurine for Crohn's disease

OBJECTIVE

6-Mercaptopurine (6MP) and azathioprine are immunomodulators used in the treatment of refractory Crohn's disease. Studies have confirmed their efficacy and value in maintenance of remission, but it is our purpose to determine how long 6MP/azathioprine should be continued once remission has been accomplished.

METHODS

Careful follow-up was accomplished in patients with Crohn's disease seen at one medical center who were treated with 6MP for > or = 6 months, who achieved remission within 1 yr of initiation of therapy, and who were in prolonged clinical remission (> or = 6 months without steroids). The time-to-relapse was calculated in those who continued treatment, in those who stopped treatment for reasons other than a relapse, and in the whole sample, taking into account that they could be treated with the drug, or could not, as a function of time. The influence of concomitant variables on the time-to-relapse rate was evaluated.

RESULTS

A total of 120 patients met the inclusion criteria. The cumulative probabilities of relapse at 1, 2, 3, and 5 yr for those who continued to take 6MP and for those who stopped the therapy for reasons other than a relapse are as follows: Patients maintained on 6MP (n = 84): 1 yr, 29%; 2 yr, 45%; 3 yr, 55%; 5 yr, 61%. Patients who terminated 6MP (n = 36): 1 yr, 36%; 2 yr, 71%; 3 yr, 85%; 5 yr, 85%. Sex, distribution of disease, duration of disease, time to remission on 6MP, and concomitant 5-ASA use did not influence the relapse rates. Younger age was associated with a higher rate of relapse in patients who were maintained on 6MP. A higher daily dose of 6MP was associated with a higher relapse rate.

CONCLUSIONS

Discontinuation of 6MP, while Crohn's disease is in remission, leads to higher relapse rates and continuation of 6MP reduces the likelihood of relapse. Therefore, we favor the indefinite use of 6MP once remission has been achieved.

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.

Allergic reactions to 6-mercaptopurine during treatment of inflammatory bowel disease

Hypersensitivity reactions to 6-mercaptopurine (6-MP) or azathioprine occur during the treatment of inflammatory bowel disease (IBD), raising significant diagnostic and therapeutic challenges. Charts of 591 patient with IBD treated with 6-MP in a single center were retrospectively reviewed. All allergic reactions were recorded along with results of rechallenge, desensitization, and subsequent course of IBD. Sixteen (2.7%) allergic reactions to 6-MP were noted, with fever being the most common (14 cases). Nine of these were rechallenged with 6-MP with recurrence of the same symptoms. Azathioprine was tried in six patients and in five the same symptoms recurred. Four patients underwent successful desensitization to either 6-MP or azathioprine; all four plus another patient who tolerated direct switch to azathioprine entered long-term remission. Among the remaining 11, 5 required surgery, 2 are well on methotrexate, and 4 have chronic symptoms while being treated with other medications. If an allergic reaction to 6-MP occurs during the treatment of IBD, direct switching to azathioprine is probably not justified. Instead, desensitization to either 6-MP or azathioprine should be attempted. Patients who can tolerate these medications after previous allergic reactions have improved outcomes compared with patients who resort to other forms of treatment.

Shingles during the course of treatment with 6-mercaptopurine for inflammatory bowel disease

OBJECTIVE

Our aim was to study the frequency, severity, and outcome of patients with Crohn's disease and ulcerative colitis treated with 6-mercaptopurine (6MP) who developed shingles during treatment, and to recommend management. While varicella can be severe in young people immunocompromised by steroids, the incidence of herpes zoster in older people with inflammatory bowel disease (IBD) and whether its severity is influenced by 6MP and azathioprine are unknown.

METHODS

Data were collected from our IBD Center on 550 patients with IBD to identify those who developed shingles while on 6MP, its severity, the dose and duration of 6MP, and the management of the 6MP.

RESULTS

Twelve of 550 patients with IBD treated with 6MP developed shingles. In two with herpes zoster ophthalmicus the pain was prolonged, and one patient developed encephalitis which was brief and uncomplicated; in nine patients the course was benign. Acyclovir should be the treatment of choice even though it was available in only three cases.

CONCLUSIONS

Shingles occurs more often in IBD patients treated with 6MP than in those who are not, but the course is usually benign and there has been no mortality. The 6MP should be stopped temporarily until severity is established but if the underlying disease warrants further treatment the 6MP should be restarted.

Safety of azathioprine and 6-mercaptopurine in pediatric patients with inflammatory bowel disease

BACKGROUND & AIMS

Azathioprine (AZA) and 6-mercaptopurine (6-MP) are used in pediatric patients with ulcerative colitis and Crohn's disease to reduce disease activity, maintain remission, prevent relapse, and lower corticosteroid dosage, but their long-term side effects remain to be studied. The aim of this study was to analyze the safety of AZA and 6-MP and steroid reduction in this age group.

METHODS

The investigators' database identified 118 patients who received either drug; 23 were excluded (single visit, noncompliance, or therapy < 1 week), leaving 95 patients, with a mean (+/-SD) age of 14.2 +/- 4.4 years. Medical files were reviewed for adverse side effects: fever, pancreatitis, infections, gastrointestinal intolerance, aminotransferase level increase, leukopenia, and thrombocytopenia. Prednisone doses before and after immunomodulatory therapy were compared.

RESULTS

AZA or 6-MP was tolerated in 51 of 95 patients (54%) without adverse reaction; 27 of 95 (28%) experienced side effects that responded to dose reduction (23 patients) or spontaneously (4 patients), most commonly increased aminotransferase level (13.7%). Cessation of therapy was needed in 17 of 95 patients (18%), including recurrent fever (4), pancreatitis (4), gastrointestinal intolerance (4), and recurrent infections (3). Mean prednisone dose decreased from 24.3 to 8.6 mg/day.

CONCLUSIONS

AZA and 6-MP were well tolerated in 82% of patients; of these, prednisone reduction occurred in 87%. However, 18% required discontinuation because of hypersensitivity or infectious side effects.

Methotrexate in patients with Crohn's disease after 6-mercaptopurine

OBJECTIVE

The objective of this study was to describe the clinical outcome of children with Crohn's disease treated with subcutaneous methotrexate.

SUBJECTS/METHODS

Fourteen patients (10 boys) with extensive Crohn's disease diagnosed at a mean age of 10.6 +/- 3.6 years had previously received various medical therapies for 4.3 +/- 4.0 years. Because of the severity of their disease, 6-mercaptopurine had been introduced but discontinued because of the patients' failure to respond (n = 11) or the development of pancreatitis (n = 3). Subsequently, low-dose, weekly, subcutaneous methotrexate was initiated. Pediatric Crohn's Disease Activity Index scores and prednisone requirement were followed as outcome measures.

RESULTS

Overall, 9 (64%) of the 14 patients showed improvement, including 6 (55%) of 11 patients who had previously received an adequate trial of 6-mercaptopurine and all three patients who were intolerant of 6-mercaptopurine. Improvement in clinical and laboratory measures occurred by 4 weeks and were similar whether (n = 8) or not (n = 6) the dose of corticosteroids was increased before the start of subcutaneous methotrexate. Three patients were tapered from their initial methotrexate dose after the minimization of corticosteroids and remain well. One patient receiving daily corticosteroids died suddenly after acute onset of illness. Among patients responding, methotrexate was discontinued because of side effects (n = 2) or electively (n = 2). Of the latter two patients, one has resumed methotrexate after disease relapse, whereas the other patient has had a sustained remission.

CONCLUSIONS

Low-dose, weekly, subcutaneous methotrexate can induce remission in some pediatric patients with Crohn's disease who fail to adequately respond to other immunomodulator medications.

Crohn's disease in adolescents

The clinical features of Crohn's disease manifest during adolescence are varied as in adults. The potential complication of growth impairment and concomitant delay in pubertal development is unique to this population. Cytokines released from the inflamed bowel and chronic nutritional insufficiency are the major factors in the pathophysiology of growth inhibition. Hence reduction of intestinal inflammation and consistent provision of adequate nutrition are of paramount importance in management. Drug treatment mirrors that of adults; few specifically paediatric clinical trials have been conducted. Enteral nutrition is an important therapeutic alternative for young patients. There is evidence that it constitutes both a primary therapy of inflammation and a means of providing the calories needed for growth. In the setting of extensive disease, dependency on corticosteroids should be minimized through judicious administration of immunosuppressive drugs. For an adolescent with localized stenotic disease, optimal management includes a timely referral for intestinal resection as a means of providing an asymptomatic interval during which growth and pubertal development can normalize.

Medical therapy of active Crohn's disease

Active Crohn's disease constitutes a major problem in gastroenterology. Symptoms vary with site, extent and local complications of the disease as well as with the absence or presence of extraintestinal manifestations. Due to the troublesome consequences of the disease new treatments have continuously been tried. However, the results have varied and no definite breakthrough has occurred in the medical treatment of active Crohn's disease during the last years. The new salicylates have shown some effect using higher doses, but have not fulfilled the expectations once connected with their development. The new steroids have compared well to, but not exceeded, the older corticosteroid preparations in terms of therapeutic efficacy but they have a better side-effect profile. The role of the purine analogs azathioprine/6-mercaptopurine has been further evaluated. The onset of their effect is slow, an intravenous loading dose might shorten this time span, and they are steroid sparing. The controlled data on methotrexate are limited and the long-term effects not well studied and there is concern about toxicity. Even the use of cyclosporine in active Crohn's disease is controversial and connected with serious adverse events. Studies on the new immune modulating therapies such as anti-TNF-alpha antibodies, anti-CD4 antibodies, interleukin-10 and interferon have been encouraging but large scale studies are still awaited before the effect and the spectra of side-effects can be fully evaluated. The aim of this chapter is to summarize the present knowledge of medical treatment of active Crohn's disease and to point towards the directions of new therapeutic options.

Controversies in Crohn's disease

Despite recent advances in the medical therapy of Crohn's disease, surgery continues to play a central role in the treatment of the disease. The strategy for surgical management of Crohn's disease continues to evolve. This chapter reviews many of the controversies surrounding surgical palliation of complications of Crohn's disease. Included is a discussion of indications for strictureplasty in treatment of intractable intestinal obstruction. Factors influencing long-term outcome with sphincter-saving resection in the treatment of Crohn's colitis are reviewed. Experience with definitive treatment of anal Crohn's disease and repair of rectovaginal fistulas is examined. Finally, recent experience supporting ileocolic resection when acute Crohn's ileitis is identified during laparotomy for right lower quadrant pain is critically evaluated. These controversial aspects of the surgical treatment of Crohn's disease reflect an improved understanding of the natural history of the disease as well as refinement in surgical techniques and better definition of criteria for surgical intervention.

6-Mercaptopurine metabolism in Crohn's disease: correlation with efficacy and toxicity

BACKGROUND

6-Mercaptopurine (6-MP) has confirmed short and longterm efficacy in the treatment of IBD. However, the relation between its metabolism, efficacy, and side effects is not well understood.

AIMS

To assay 6-MP metabolites and to correlate levels with drug compliance, disease activity, and adverse effects of treatment.

PATIENTS

Heparinised blood was obtained prior to daily administration of 6-MP in 25 adolescent Crohn's disease patients (14 ileocolitis, 11 colitis) receiving 1.2 (range 0.4-1.6) mg/kg/day for a mean of 17 (range 4-65) months.

METHODS

Erythrocyte free bases 6-thioguanine (6-TG) and 6-methyl-mercaptopurine (6-MMP) were measured (pmol/8 x 10(8) red blood cells) using reverse phase high performance liquid chromatography.

RESULTS

Disease activity (modified Harvey-Bradshaw index) improved significantly with 6-MP (p = 0.001). Clinical remission was achieved in 72% of patients, who stopped taking prednisone, or were successfully weaned to a low alternate day dose (< 0.4 mg/kg/OD). Remission correlated well with erythrocyte 6-TG (p < 0.05), but not 6-MMP levels. Neutropenia was associated with 6-MP use (p < 0.005), but did not correlate with erythrocyte 6-MP metabolite levels. One patient refractory to 6-MP had 6-TG, but no measureable 6-MMP production, suggesting deficient thiopurine methyl-transferase activity or poor compliance. 6-MP induced complications (hepatitis, pancreatitis, and marrow suppression) were generally associated with increased 6-MMP levels.

CONCLUSIONS

These results suggest that high performance liquid chromatography measurement of erythrocyte 6-MP metabolites may provide a quantitative assessment of patient responsiveness and compliance to treatment. The data support an immunosuppressive role for 6-TG, and potential cytotoxicity of raised 6-MMP levels.

Combined use of cyclosporine and azathioprine or 6-mercaptopurine in pediatric inflammatory bowel disease

The aim of this study was to assess whether in steroid-resistant patients with pediatric inflammatory bowel disease (IBD) a combination of cyclosporine and azathioprine (or 6-mercaptopurine) could induce remission and subsequently permit maintenance on azathioprine/6-mercaptopurine as the sole immunosuppressive agent. Two boys and six girls (six with ulcerative colitis and two with Crohn's disease; ages 3-17 years) received 100-200 micrograms/kg/day cyclosporine intravenously and then 4-10 mg/kg/day orally. Doses were adjusted to achieve trough serum cyclosporine levels of 100-200 mu/L (Abbott's TDX assay). Seven of the eight patients received azathioprine/6-mercaptopurine, and all were given a 5-aminosalicylate preparation and corticosteroids. The latter drugs were continued and then tapered off as clinical status allowed. Cyclosporine was continued for 3-10 months in those who responded. In seven of eight patients, there was a rapid clinical response; one patient showed a transient response, but recurrent bleeding led to total colectomy 9 days after starting cyclosporine. Of the seven responders, three were able to discontinue prednisone and cyclosporine and are doing well on azathioprine at long-term follow-up (2-5 years). One who did not receive azathioprine/6-mercaptopurine maintained remission for 2 years after cyclosporine was stopped, one experienced a disease flare-up 5 months after start of cyclosporine treatment and required colectomy, one who did not tolerate 6-mercaptopurine had a flare-up during cyclosporine tapering and underwent surgery at 6 months, and one started to flare up with cyclosporine tapering at 6 months and was scheduled for surgery. No significant complications of treatment were observed. Seven patients had an initial response and four of them have so far not required surgery. These preliminary findings suggest that azathioprine/6-mercaptopurine can be used safely to maintain cyclosporine-induced remission in children with IBD.

Ulcerative colitis in children

Chronic nonspecific ulcerative colitis remains a disease of unknown etiology, although much new information continues to be gleaned from basic research and clinical trials. In most instances, ulcerative colitis responds to medical therapy. Selecting appropriate drug therapy for a specific child depends on the extent and severity of the colitis. This article summarizes the clinical information, diagnostic studies, and approaches to management that should be considered when evaluating a child for ulcerative colitis.

Crohn's disease in children

Crohn's disease is a chronic inflammatory condition that may affect any part of the gastrointestinal system and multiple extraintestinal organs. Although its exact pathogenesis remains unknown, increasing evidence suggests an abnormality in the control of "physiologic" inflammation caused by bacterial and other antigens. Diagnosis starts with a careful history and physical examination, and confirmation rests with radiologic and histologic studies. Newer treatments are more specifically targeting the cascade of cytokine-mediated events that perpetuate inflammation.

Long-term follow-up of patients with Crohn's disease treated with azathioprine or 6-mercaptopurine

BACKGROUND

Crohn's ulcerative gastrointestinal disease is presently managed through a variety of medical interventions, including-according to severity of illness-anti-inflammatory, immunosuppressive, and corticosteroid agents; and with remedial surgery to correct anatomical abnormalities caused by disease processes. The immunosuppressant azathioprine (or its metabolite, 6-mercaptopurine) is considered an efficient maintenance therapy for Crohn's, but there is always concern about bone-marrow suppression, liver damage, and other adverse effects. For how long persons with this disease should be given these drugs has not been determined.

METHODS

Patients who were treated with azathioprine or 6-mercaptopurine for more than 6 months, and who were in prolonged clinical remission (> 6 months without steroids) were followed. The time-to-relapse was analysed in those on treatment, in those who stopped treatment for reasons other than a relapse, and in the whole sample, taking into account that they could be treated with the drugs or not, as a function of time. The influence of concomitant variables on time-to-relapse rate was examined using the Cox proportional hazard model.

FINDINGS

In the 157 patients who continued to take the therapy, cumulative probabilities of relapse at 1 and 5 years were 11% and 32% respectively. Female gender, younger age, and a time for achieving remission more than 6 months were associated with a higher risk of relapse. In 42 patients who stopped therapy, probabilities of relapse at 1 and 5 years were 38% and 75%, respectively. Male gender, younger age and duration of remission less than 4 years were associated with a higher risk of relapse. After 4 years of remission on these drugs, the risk of relapse appeared to be similar, whether the therapy was maintained or stopped.

INTERPRETATION

Taking into account the potential risks of long-term immunosuppressive therapy, the usefulness of maintaining azathioprine or 6-mercaptopurine in patients who have been in remission for more than 4 years is questionable.

Cyclosporine for the treatment of fulminant ulcerative colitis in children. Immediate response, long-term results, and impact on surgery

PURPOSE

Emergency surgery for fulminant colitis is often complicated by high-dose steroid therapy, poor nutrition, and psychologic maladjustment. Cyclosporine is effective for fulminant ulcerative colitis in adults, resulting in avoidance of immediate surgery in 75 percent of patients and a 55 percent long-term remission rate. Over the last five years, we studied the effectiveness of cyclosporine in children with fulminant colitis.

METHODS

Fourteen patients with ulcerative colitis (age, 7-20 years) received cyclosporine after satisfying the following criteria: 1) greater than five bloody diarrheal stools per day; 2) severe abdominal pain; 3) no improvement after ten days of bowel rest, 4) intravenous methylprednisolone (1-2 mg/kg/day); and 5) parenteral nutrition. Treatment was begun with oral cyclosporine (4.6-9.6 mg/kg/day), and the dose was adjusted to achieve whole blood trough levels measured with a monoclonal radioimmunoassay between 150 and 300 ng/ml. If improved, patients were discharged on oral cyclosporine, prednisone, and a regular diet.

RESULTS

Eleven of 14 patients (78 percent) responded within two to nine days and were able to consume a normal diet, had three or less soft stools per day, and had no pain. One did not respond after ten days and underwent an ileal pouch-anal anastomosis procedure. Two patients elected surgery after 20 days of therapy and a partial response. Of 11 patients who left the hospital, 4 had recurrent symptoms after 2 to 11 months of taking therapeutic doses of cyclosporine and 3 flare ups while weaning from cyclosporine after 4 to 8 months. Three patients have been weaned from cyclosporine after 8 to 13 months and have remained in remission from six months to five years. One patient is about to complete a six-month course of cyclosporine. Overall ten (72 percent) have undergone surgery, including 7 of 11 who responded initially to cyclosporine and left the hospital. Weight (P < 0.001), albumin (P < 0.01), erythrocyte sedimentation rate (P > 0.05), and prednisone dose (P < 0.001) improved significantly in the seven patients on cyclosporine who responded initially, left the hospital, and subsequently underwent surgery.

CONCLUSIONS

Cyclosporine is effective in achieving clinical remission in 80 percent of children with refractory fulminant colitis; however, within one year, most initial responders will require colectomy because of a flare up of the disease. In a majority of patients, the role of cyclosporine therapy is to rapidly ameliorate symptoms and prevent precipitous colectomy, improve nutrition and psychologic adaptation, and reduce the steroid dose leading to surgery in a well-prepared patient.

Mechanisms of growth retardation, drug therapy, and nutritional support in pediatric inflammatory bowel disease: a workshop sponsored by the north american and European societies for pediatric gastroenterology and nutrition

: Growth retardation is common in children with inflammatory bowel disease (IBD). The most sensitive measure of impaired growth, growth velocity, is abnormal in 65% of children with Crohn's disease. With treatment, growth velocity may return to normal, but catch-up growth is often incomplete and ultimate height lower than predicted. In some patients delayed puberty may compensate for poor growth earlier in life, and there is good evidence that even after menarche, significant growth can occur. Surgery may have a favorable impact on growth in the short term, but final height often remains reduced. The mechanism for growth failure in IBD is thought to be related to both prolonged periods of suboptimal nutritional intake and persistent inflammation. Growth throughout childhood is dependent on growth hormone and insulin-like growth factors (IGF). At puberty, androgens and estrogens also play a significant role in normal growth. Both malnutrition and inflammatory bowel disease result in low levels of IGF-1. With recovery, levels return to normal. Although little work has been done to measure the effects of chronic maintenance drug therapy on growth, it is known that children taking alternate-day prednisone grow normally and can exhibit catch-up growth. Nutritional therapy with tube feeding of elemental diets also improves nutrition and decreases inflammation. Children with either small-bowel Crohn's or Crohn's ileocolitis respond to tube feedings of both elemental or semielemental diets.

Immunomodulator therapy in inflammatory bowel disease

The introduction of immunomodulator therapy in the treatment of patients with inflammatory bowel disease (IBD) has provided an important tool in modifying the mucosal immune system thought to be important in the pathogenesis of IBD. Currently available immunomodulating agents include azathioprine, 6-mercaptopurine, cyclosporin, and methotrexate. Recent clinical trials have demonstrated that these agents have an important therapeutic role in the treatment of patients who are either refractory or intolerant to traditional medical therapy. They are useful in the induction and maintenance of remission for both ulcerative colitis and Crohn's disease. However, these agents have significant toxicities and limited efficacy. In addition, potential risks of malignancy and infection limit their indiscriminate use. Thus, with the better understanding of the molecular basis of mucosal immunity, innovative immune-modifying therapies, such as antagonists of cytokines and inhibitors of T-cell activation, are being developed. It is likely that these exciting developments will soon result in specific immune modulating therapy with improved efficacy and reduced toxicity in the treatment of patients with IBD.

[Treatment of Crohn disease in adults]

Corticosteroids are an efficient treatment for active Crohn's disease. The treatment has to be undertaken with a daily intake equivalent to 1 mg/kg per day of prednisolone for a 3 to 7 week period. Immunosuppressive agents are indicated in case of corticodependency or in case of large intestinal resection. Artificial nutrition (enteral or parenteral) is proposed in corticoresistant forms, and is usually followed by an immunosuppressive therapy. Surgical management is reserved for complications, including resistance to all medical therapy. Surgical resection has to be limited in order to avoid a short bowel syndrome. Surgery should not be considered as the ideal therapy as it has been demonstrated that recurrence after surgery increases at distance. 5-aminosalycilates compounds are an alternative therapy in mild attacks. Mesalazine may reduce the recurrence and could be considered as a possible maintenance treatment.

Review article: immunosuppressive therapy for inflammatory bowel disease

Refractory inflammatory bowel disease can be treated by surgery or using nutritional supplementation or replacement. Immunosuppressive agents may also play a role for refractory disease; they have gained widespread acceptance, due not only to trials that demonstrate efficacy but also to the realization that these side-effects are minor compared to those associated with long-term, high-dose corticosteroids. To date, 6-mercaptopurine and azathioprine remain the drugs of choice based upon extensive clinical experience, but both methotrexate and cyclosporin are promising immunosuppressants for otherwise refractory disease.

Current management of inflammatory bowel disease

The aetiology of ulcerative colitis and Crohn's disease remains unknown. While this remains so, treatment must be directed towards pathogenetic mechanisms. Corticosteroids, sulphasalazine and the new salicylates, the immunosuppressants azathioprine, 6-MP and, more recently, cyclosporin and metronidazole have become the accepted and standard forms of treatment. The importance of maintaining nutritional status is often overlooked but must be considered in every patient. Recognition of the occurrence of disease in all age groups, and in particular in children and adolescents, is also important, as is an appreciation of the special problems involved. The possibility of surgery at some stage of the disease should be raised with the patient. As the pathogenetic mechanisms of inflammatory bowel disease are further elucidated, new forms of treatment will be developed. This is already happening, with studies looking at such agents as immunoglobulin G, eicosapentaenoic acid and a new specific inhibitor of 5-lipoxygenase. These offer hope of more potent drugs with low side-effect profiles that may complement or replace the currently available agents used in the management of inflammatory bowel disease.

Medical therapy in Crohn's disease

Traditionally, sulfasalazine and corticosteroids have been used to treat Crohn's disease. However, therapy has been expanded to include other drugs, and several newer agents show clinical promise. The authors discuss the therapeutic options now available and describe results of several drug trials. Despite the apparent benefits of newer therapies, caution must be used in choosing appropriate treatment.

New developments in the pharmacotherapy of inflammatory bowel disease

In this article the clinical features and aetiology of inflammatory bowel diseases are described and current pharmacotherapeutic possibilities are explored. Also reviewed are recent developments and future prospects for the pharmacotherapy of inflammatory bowel diseases, including aminosalicylates, corticosteroids, immunosuppressants, lipoxygenase inhibitors, fish oil, sucralfate, bismuth compounds, free radical scavengers, (hydroxy)chloroquine, sodium cromoglycate and methotrexate.

Risk factors for small bowel cancer in Crohn's disease

Suspected risk factors for adenocarcinoma of the small bowel in Crohn's disease include surgically excluded small bowel loops, chronic fistulous disease, and male sex. Review of all seven University of Chicago cases failed to confirm any suspected risk factor. A case-control study was performed to identify possible alternatives. Each case was matched to four randomly selected controls from an inflammatory bowel disease registry matched for year of birth, sex, and confirmed small bowel Crohn's disease. Three factors were significantly associated with the development of cancer: (1) Four cancers developed in the jejunum, and jejunal Crohn's disease was associated with the development of cancer [odds ratio (OR) 8.0, 95% confidence interval (CI) 1.6-39.3]. (2) There was an association between the development of cancer and occupations known to be associated with an increased colorectal cancer risk (OR 20.3, CI 2.7-150.5). Three cases (a chemist with exposure to halogenated aromatic compounds and aliphatic amines, a pipefitter with exposure to asbestos, and a machinist with exposures to cutting oils, solvents, and abrasives) and one of 28 controls (a fireman with multiple hazardous exposures) had an occupational risk factor. (3) Among medications taken for at least six months, only 6-mercaptopurine use was associated with cancer (OR 10.8, CI 1.1-108.7). In conclusion, proximal small bowel disease, 6-mercaptopurine use, and hazardous occupations are associated with cancer of the small bowel in patients with Crohn's disease and can be added to the list of suspected risk factors.

6-mercaptopurine therapy in selected cases of corticosteroid-dependent Crohn's disease

Nineteen patients (12 children and 7 adults) with severe Crohn's disease, all of whom were dependent on corticosteroids, were treated with 6-mercaptopurine. All patients received a daily dose of 6-mercaptopurine of 50 mg; in two pediatric patients with a poor response after 2 months, the dosage was increased to 75 mg/day. A complete or partial response to 6-mercaptopurine therapy was noted in 47% of patients, and therapy failed in 53%. The age of the patients, prior resection, or initial symptoms did not influence the response. The clinical response was better in male than in female patients and in patients with involvement of both the small intestine and the colon than in those with only enteritis. 6-Mercaptopurine is a possible alternative to long-term corticosteroid therapy or surgical treatment in selected patients with severe Crohn's disease.