Favorable effect of 6-mercaptopurine on fistulae of Crohn's disease

Medical treatment of Crohn's disease

Crohn's disease is not medically (and is rarely surgically) curable. Patients do, however, live a normal life span. The goal of therapy is to optimize the quality of life, minimize disease activity and disease-related complications, and avoid therapeutic toxicity.

Management of internal fistulas in Crohn's disease

Internal fistulas occur in 5-10% of patients with Crohn's disease. The clinical presentation of each of the three main types of internal fistulas--enteroenteric, enterovaginal, and enterovesical fistulas--is important in determining the best management. Asymptomatic fistulas usually require no treatment, but fistulas that cause severe or persistent symptoms necessitate intervention. Previously regarded as a surgical condition requiring resection, some internal fistulas are amenable to a more conservative approach involving medical therapy, surgical repair, or both. So far, there have not been any prospective studies designed specifically to assess the efficacy of a medical treatment of internal fistulas, and information about treatment results is gleaned from trials in which patients with internal fistulas have been included and from retrospective reports. Drugs that have been reported to close internal fistulas partially or completely include azathioprine, 6-mercaptopurine, mycophenolate mofetil, cyclosporine A, tacrolimus, and infliximab. Reparative surgical techniques include transrectal and transvaginal mucosal advancement flaps, cutaneous advancement flap, and anal stricturectomy in combination with a rectal mucosal advancement sleeve. Prospective trials of medical therapy and combination medical and surgical therapy for internal fistulas are needed to provide evidence to support the use of these new therapeutic approaches.

Azathioprine treatment and male fertility in inflammatory bowel disease

BACKGROUND & AIMS

Long-term treatment with azathioprine (AZA) is well established in inflammatory bowel disease (IBD). AZA is metabolized to 6-mercaptopurine (6-MP), which interacts in purine metabolism and is therefore considered to have mutagenic potentials. This is the first study to examine the influence of AZA on semen quality.

METHODS

Semen quality was examined and compared with World Health Organization (WHO) standards regarding sperm density, motility, morphology, ejaculate volume, and total sperm count in 23 IBD patients treated with AZA. In 10 of these patients, a semen sample was assessed before and during AZA treatment; in another 5, semen analysis was performed twice during at least 2 years of AZA therapy.

RESULTS

In 18 patients treated with 1.5-2 mg/kg AZA daily for at least 3 months but without sulfasalazine, sperm density was 94 +/- 84 Mio/mL (94% within WHO standard), motility was 60% +/- 20% (67% within WHO standard), the proportion of sperm with normal morphology was 44% +/- 21% (67% within WHO standard), ejaculate volume was 3.4 +/- 1.5 mL (89% within WHO standard), and total sperm count was 297 +/- 272 Mio (94% within WHO standard). No changes in semen parameters were noted after 11 +/- 5 months of AZA administration or during long-term treatment (49 +/- 14 months). Sulfasalazine administration in 5 patients was associated with markedly reduced semen morphology. During the study period, 6 patients fathered 7 healthy children.

CONCLUSIONS

Our data show that AZA does not reduce semen quality and thereby male fertility in IBD.

Review article: the treatment of inflammatory bowel disease with 6-mercaptopurine or azathioprine

The thioguanine derivative, azathioprine, is a prodrug of 6-mercaptopurine that is further metabolized by various enzymes present in the liver and gut. Azathioprine and 6-mercaptopurine have been used in the treatment of inflammatory bowel disease, i.e. ulcerative colitis and Crohn's disease, for more than 30 years. However, widespread use of azathioprine or 6-mercaptopurine in inflammatory bowel disease is of more recent origin, the primary reason being a long-standing debate on the efficacy of these agents in inflammatory bowel disease. Both drugs are slow acting, which is why clinical efficacy cannot be expected until several weeks or even months of treatment have elapsed. Consequently, azathioprine and 6-mercaptopurine have no place as monotherapy in the treatment of acute relapsing inflammatory bowel disease. Today, azathioprine and 6-mercaptopurine are the most commonly used immunomodulatory drugs in the treatment of inflammatory bowel disease. Their clinical effects are probably identical, although their exact mode of action is still unknown. The mode of action of azathioprine is thought to be multifactorial, including conversion to 6-mercaptopurine (which acts as a purine antimetabolite), possible blockade of thiol groups by alkylation, inhibition of several pathways in nucleic acid biosynthesis (preventing proliferation of cells involved in the determination and amplification of the immune response) and damage to DNA through the incorporation of thiopurine analogues. However, 6-thioguanine nucleotides may accumulate in toxic doses in myeloid precursor cells, resulting in life-threatening myelosuppression. Azathioprine and 6-mercaptopurine are further known to alter lymphocyte function, reduce the number of lamina propria plasma cells and affect natural killer cell function. The purpose of this comprehensive review is to suggest guidelines for the application of azathioprine and 6-mercaptopurine in the treatment of inflammatory bowel disease.

An open-label pilot study using thioguanine as a therapeutic alternative in Crohn's disease patients resistant to 6-mercaptopurine therapy

BACKGROUND AND AIMS

A substantial number of patients with inflammatory bowel disease (IBD) fail to achieve a complete clinical response with 6-mercaptopurine (6-MP) and azathioprine (AZA). Inability to achieve therapeutic 6-thioguanine nucleotide (6-TGN) levels due to the preferential overproduction of 6-methylmercaptopurine ribonucleotides (6-MMPR) upon dose escalation characterizes a newly described subgroup of IBD patients resistant to 6-MP/AZA therapy. Treatment with 6-thioguanine (6-TG), a related thiopurine, which forms 6-TGNs more directly may be beneficial in such patients. This pilot study evaluated the safety, tolerance, and efficacy of 6-TG in the subgroup of Crohn's disease (CD) patients failing to attain adequate disease control with traditional 6-MP/AZA therapy.

METHODS

Ten CD patients with preferential 6-MMPR production upon 6-MP/AZA dose escalation were enrolled in an open-label pilot study. Seven of 10 patients had experienced dose-related 6-MP toxicities.

RESULTS

Seventy percent of the patients (7 of 10) responded or were in remission at week 16. Clinical response was evident by week 4 in most. 6-TGN levels were nine-fold higher with 6-TG treatment than with 6-MP, whereas 6-MMPR levels were undetectable. No patient developed a recurrence of hepatic or hematological toxicity.

CONCLUSIONS

6-TG was a safer and more efficacious thiopurine in this subgroup of IBD patients resistant to 6-MP therapy. Larger controlled trials are warranted to further evaluate both the short- and long-term safety and efficacy in this subgroup of patients as well as a broader spectrum of IBD patients.

Cost-utility of initial medical management for Crohn's disease perianal fistulae

BACKGROUND & AIMS

The cost-utility of infliximab is unknown. The aim of this study was to determine the incremental cost-utility (CU(inc)) of medical therapy for Crohn's disease (CD) perianal fistula.

METHODS

A Markov model was used to simulate a 1-year treatment period with the following: 6-mercaptopurine and metronidazole [6MP/met] (comparator), 3 infliximab infusions + 6MP/met as second-line therapy (intervention I), infliximab with episodic reinfusion (intervention II), and 6MP/met + infliximab as second-line therapy (intervention III). Utilities were elicited from patients with CD and healthy individuals by standard gamble, and costs were obtained from hospital billing data. Uncertainty was assessed by sensitivity analysis.

RESULTS

All strategies had similar effectiveness. Interventions I, II, and III were slightly more effective, but also more costly than 6MP/met (Intervention I: CU(inc) = $355,450/quality-adjusted life-years [QALY]; Intervention II: CU(inc) = $360,900/QALY; Intervention III: CU(inc) = $377,000/QALY). If the cost of infliximab were reduced to $304 per infusion, the CU(inc) for intervention II would be $54,050/QALY.

CONCLUSIONS

Based on available data, all strategies had similar effectiveness in our model, but infliximab was much more expensive than 6MP/met. The incremental benefit of infliximab for treating CD perianal fistulae over a 1-year period may not justify the higher cost. Prospective studies directly comparing 6MP/met and infliximab are warranted.

Immunomodulator Therapy in Inflammatory Bowel Disease

6-Mercaptopurine and its prodrug counterpart, azathioprine, have proven efficacy in the induction and maintenance of remission, fistula closure, and steroid sparing in patients with Crohn's disease. Long-term follow-up has demonstrated the safety of the purine analogues, with no increased risk of malignancy. For patients with Crohn's disease intolerant or unresponsive to azathioprine or 6-mercaptopurine, methotrexate has emerged as an effective alternative. In patients with severe ulcerative colitis, intravenous cyclosporine is highly efficacious in the short term, and with the addition of azathioprine or 6-mercaptopurine to oral cyclosporine, long-term remission rates of 60% to 70% can be achieved. Azathioprine or 6-mercaptopurine therapy is effective in patients with steroid-dependent or steroid-refractory colitis and is valuable in maintaining remission. Neither methotrexate nor cyclosporine has been shown to be effective for maintenance therapy in patients with ulcerative colitis. Current data are insufficient to recommend routine use of genetic or enzymatic testing of thiopurine methyltransferase or measurements of blood 6-thioguanine metabolites to guide 6-mercaptopurine or azathioprine dosing.

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

Various medications are used to control the symptoms of Crohn's disease. This article reviews the traditional medical therapies of Crohn's disease, including aminosalicylates and corticosteroids, and the broad armamentarium of immune modulators and biologic agents that are becoming increasingly important in the management of Crohn's disease.

Anorectal Crohn's disease

Anorectal disease affects many patients with Crohn's disease. Clinical manifestations vary from asymptomatic skin tags to severe, debilitating perineal destruction and sepsis. Surgical management needs to be conservative and must focus on draining septic sites, preserving sphincter function, and palliating symptoms. Medical management has had some success in improving symptoms, but as yet, it has not been able to ameliorate most perianal complaints quickly and enduringly. Many new and exciting treatment modalities are being investigated with the hope that more effective approaches to these complex and difficult problems can be realized.

Update in medical treatment of Crohn's disease

Crohn's disease is an inflammatory bowel disorder that has no known cause. The goal of medical treatment is to control active disease, induce and maintain clinical remission, and treat complications. Anti-inflammatory medications and immunomodulatory therapies are the primary treatment modalities for Crohn's disease. The categories of standard treatment include the 5-aminosalicylic acid compounds, corticosteroids, antibiotics, and immunomodulators. New biologic therapy has been developed to better target the immune mediators that are active in Crohn's disease. Infliximab is the first of the biologic agents approved for the treatment of fistulizing and active Crohn's disease. Despite medical advances in treatment, there is still no cure for Crohn's disease.

Treatment of fistulizing Crohn's disease

The appropriate treatment of patients with fistulas in the setting of Crohn's disease requires a knowledge of the specific medical and surgical literature of fistulizing Crohn's. The patient with symptomatic fistulizing Crohn's disease may respond differently to specific medical therapy than a patient with symptomatic obstructing Crohn's disease. Certain medications that are useful for the treatment of patients with obstructive Crohn's disease may not be helpful in the treatment of fistulas in patients with fistulizing Crohn's disease (e.g., corticosteroids and mesalamine); in fact, some medications are believed to be detrimental (e.g., corticosteroids). Few studies have been performed to assess the efficacy of specific medications on fistulas directly. To date, there has been only one published prospective randomized controlled trial that was designed to assess the efficacy and safety of a specific medication on fistulas in patients with Crohn's disease; it showed clinical efficacy over placebo in a statistically significant manner. The judicious use of surgery remains an integral part of the management of certain presentations of fistulizing Crohn's disease, and the appropriate integration of surgical and medical therapy is of paramount importance in the management of these patients. This review provides an overview of pertinent medical and surgical literature as it pertains to management of patients with fistulizing Crohn's disease.

Azathioprine or 6-mercaptopurine for inflammatory bowel disease: do risks outweigh benefits?

The treatment of Crohn's disease and ulcerative colitis has evolved and has improved the quality of life of patients afflicted with these disorders. Immune modulators such as azathioprine and 6-mercaptopurine are an important class of medications used for the treatment of patients with inflammatory bowel disease. Controlled studies have demonstrated their efficacy in both induction and maintenance of remission in Crohn's disease, and similarly, for the induction and maintenance of remission in patients with ulcerative colitis. These agents have had an increasing importance in the management of steroid-resistant, steroid-dependent diseases, and fistulizing Crohn's disease. The primary limitations to these agents have been their slow onset of action and their side effect profile. Despite these limitations, these agents have demonstrated efficacy and have become paramount to the management of patients with these incurable potentially disabling disorders. The precise role of azathioprine/6-mercaptopurine, their limitations and their safety are reviewed in this paper.

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.

Oral tacrolimus (FK 506) in Crohn's disease complicated by fistulae of the perineum

We describe the cases of two patients with Crohn's disease affected by severe perineal fistulae resistant to conventional therapies, successfully treated with FK 506, a new immunomodulatory drug. It is well absorbed from diseased bowel and preliminary experiences have indicated its short-term use in complicated Crohn's disease. The first patient was a 24-year-old male with perineal fistula and severe skin ulceration (8 cm of external opening diameter). He had undergone colectomy and ileostomy because of severe pancolitis refractory to medical treatment and had been treated with azathioprine and metronidazole. Two months after starting FK 506, a dramatic improvement made further surgical operation unnecessary. Local and general benefit was observed during the following 26 months, until FK 506 was withdrawn. The second patient was a 28-year-old male with a diagnosis of ulcerative pancolitis changed to Crohn's disease two months after the onset of a perineal fistula, recurring despite drainage procedures, steroid therapy, and total parenteral nutrition. FK 506 was administered for two months with a complete healing of fistula. Successively, it was stopped and corticosteroids (associated to enteral nutrition) were given because of recurrent rectal bleeding. Our experience encourages the use of oral FK 506 in complicated Crohn's disease and suggests the possibility of a long-term primary therapy other than the use as a "bridge" to other treatments.

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.

How to do without steroids in inflammatory bowel disease

This review covers the use of steroids in the treatment of both ulcerative colitis and Crohn's disease. It looks at controlled trials and uncontrolled trials as to the benefits of this agent in both inducing and maintaining remission. The review also stresses the high incidence of toxicity with prolonged use of steroids and the fact that controlled trials have clearly shown that steroids do not maintain remission in either disorder. Alternatives to initiating steroids in mild to moderately active ulcerative colitis and Crohn's disease are presented. The use of steroids in fistulizing versus nonfistulizing Crohn's is also covered. Finally, there is a review of data and discussion of the role of antibiotics, immunosuppressives, and combination therapy for both ulcerative colitis and Crohn's disease. The expectation is that the reader will consider alternatives to initiating and maintaining steroids for prolonged periods of time in the treatment of inflammatory bowel disease.

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.

Successful management of Crohn's disease of the ileoanal pouch with infliximab

This study reports the clinical benefit and safety of the murine chimeric anti-tumor necrosis factor (TNF)-alpha monoclonal antibody, infliximab, in the treatment of patients who developed findings compatible with Crohn's disease after undergoing colectomy with ileal-pouch anal anastomosis (IPAA) for an original diagnosis of ulcerative colitis. Medical records of 7 patients with Crohn's disease and an IPAA treated with infliximab were reviewed. Clinical response was classified as complete response, partial response, and no response. Concurrent treatment with immune modifier agents and/or antibiotics was recorded. Seven patients with active inflammatory or fistulizing Crohn's disease and an IPAA performed for diagnosis of ulcerative colitis were treated with infliximab after they had no response to conventional therapies. Patients received 1-4 infliximab infusions at a dose of 5 mg/kg. All patients improved clinically. Six patients had a complete response, and 1 had a partial response. Four of the 5 patients with complex perianal and fistulizing disease had closure of all fistula tracts, and 1 patient improved temporarily. Six of the 7 patients underwent concurrent treatment with immune modifier drugs. One patient had myalgias and malaise after the first infliximab infusion and flu-like symptoms after the second one. No other adverse effects were observed. This case series demonstrates that the murine chimeric anti-TNF-alpha monoclonal antibody, infliximab, can be used successfully to treat patients with Crohn's disease involving an IPAA who are refractory to conventional therapies.

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.

Medical therapy of specific clinical presentations

A pluridisciplinary approach that integrates medical therapy with surgery and other aspects of patient care, such as nutritional and psychosocial support, is essential to the management of patients with inflammatory bowel disease (IBD). Despite new medical therapies, such as 5-amino-salicylic acid compounds, steroids, and immunomodulators, the treatment of patients with IBD remains challenging. Success depends on the appropriate use of the available medications in relation to the severity and localization of the disease. The introduction of novel immunomodulating agents such as antitumor necrosis factor alpha is likely to have a major influence on the current therapeutic strategies. This article describes the use of the available medications in the most common clinical presentations of IBD.

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.

Appropriate nutritional support in acute and complicated Crohn's disease

Crohn's disease is frequently complicated by protein-calorie malnutrition. Four common clinical presentations of Crohn's disease include acute exacerbations or flares of disease, intestinal obstruction, fistulizing disease, and perianal disease. In this review, we examine the role of nutritional support in these clinical scenarios. Nutritional support is important for maintaining functional status and preventing loss of lean tissue. Determinants of lean-tissue loss include severity of underlying injury, baseline nutritional status, and duration of inadequate nutrition. One of the clinically useful measures of nutritional status is the nutritional risk index (NRI) defined on the basis of the serum albumin and weight loss. Nutritional support is important in severely malnourished patients (NRI < 83). Enteral nutrition is the route of choice, provided there are no contraindications to using the gastrointestinal tract. In acute exacerbations of Crohn's disease, enteral nutrition also has a role in the primary management of disease although it is not as effective as corticosteroids in inducing remission. The mechanisms are poorly understood and the most effective enteral formulation needs to be determined. Total parenteral nutrition is justified in severely malnourished Crohn's disease patients who are unable to tolerate enteral feeding or in whom enteral feeding is contraindicated. More clinical studies are needed on the assessment of malnutrition in Crohn's disease, the effects of nutritional management on functional status, and the timing of nutritional intervention.

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.

Clinical outcome following treatment of refractory inflammatory and fistulizing Crohn's disease with intravenous cyclosporine

OBJECTIVE

To determine outcome following treatment of refractory Crohn's disease with intravenous (i.v.) cyclosporine (CYA).

METHODS

The medical records of 18 patients with refractory Crohn's disease treated with i.v. CYA were reviewed. Nine patients had refractory inflammatory Crohn's disease and nine patients had complex fistulizing Crohn's disease. All patients were initially treated with i.v. CYA (4 mg/kg/day). Patients who responded were converted to standard oral CYA. Patient outcomes were classified as complete response, partial response, or nonresponse.

RESULTS

Four of nine patients with severe inflammatory Crohn's disease and seven of nine patients with fistulizing Crohn's disease had a partial response to i.v. CYA. Four of four responding patients in the inflammatory group and four of six responding patients in the fistulizing group (plus one initial nonresponder) maintained or improved their response during oral CYA therapy. After discontinuing oral CYA, all four patients in the inflammatory group and five of seven patients in the fistulizing group relapsed despite 1-17 wk of concomitant treatment with azathioprine or 6-mercaptopurine (AZA/6MP). Two patients who received overlapping CYA and AZA/6MP for 17 and 23 wk maintained long-term responses. CYA toxicity was minimal: reversible nephrotoxicity (n = 2), headache (n = 2), oral candidiasis (n = 1), paresthesia (n = 2).

CONCLUSIONS

I.v. CYA appears to benefit both refractory inflammatory and fistulizing Crohn's disease. Most patients who respond to i.v. CYA will maintain their response during oral CYA therapy. However, the majority of these patients relapse when oral CYA is discontinued, probably because of inadequate duration of overlap with the slow acting maintenance drugs, AZA/6MP.

[Perineal lesions in childhood Crohn disease]

BACKGROUND

Perineal lesions (PAL) usually evolve together with bowel disease and often constitute a serious and disabling complication of Crohn's disease.

PATIENTS

Forty-three children (47%) with Crohn's disease developed PAL in a retrospective study of 92 patients ranging in age from 4 to 20 years.

RESULTS

PAL occurred at the mean age of 11.4 +/- 0.7 years, prior to diagnosis in 25% or subsequently in 21%. PAL were severe: complex fistulae (15%), rectovaginal fistulae (2%), anal raggedness (13%); moderate: subcutaneous fistulae (11%), abscesses (19%), cavitating ulcers (9.5%) and stricture formations (5.7%); or mild: eczema (6.7%), fissures (57%) and skin tags (17%). An association with these various features has been observed in 31%. The extent of involvement of the gastrointestinal tract was rectosigmoid (72%), ileal and colonic (41%), ileal with pancolitis (12%). Two PAL course profiles were observed: one with exacerbation and remissions (52%), the other without remission (48%), especially anal raggedness (100%), cavitating ulcers (80%) and skin tags (61%). Medical treatment included steroids (54%), metronidazole (53%), salicylates (51%), nutritional support (44%), azathioprine (17%). PAL healed in 41%. Surgical treatment was performed in 27% with 83% of healing. Relapses occurred in 35% after medical treatment and 86% after surgery.

Complicated anorectal sepsis

These complex anorectal conditions are difficult to diagnose because clinical features overlap. In general, an aggressive approach is reserved for hidradenitis suppurativa and necrotizing infections. Patients with Crohn's disease, hematologic disorders, or AIDS are often treated more conservatively, but the correct timing and degree of aggressiveness of surgical intervention may considerably improve the overall outcome. The increasing incidence of AIDS and the frequency with which infected patients present to surgical clinics make it imperative that all surgeons have a working knowledge of the conditions associated with this syndrome. Expertise is required not only to diagnose and treat these conditions but also to protect oneself and others from being inadvertently infected with the HIV. A high index of suspicion and constant vigilance permit the successful resolution of many of these challenging problems.

Newer treatments for inflammatory bowel disease

Despite intense investigative efforts, the causes of ulcerative colitis and Crohn's disease remain elusive. The mainstay of medical therapy focuses on inhibition of the effects of the inflammatory mediators operant in inflammatory bowel disease because the causes of these two chronic disorders are unknown. During recent years, the physician's armamentarium for medical treatment of inflammatory bowel disease has increased substantially. In this article, the current standard medical therapies available for treatment of patients with inflammatory bowel disease are reviewed along with their efficacy; the side effects and status of other investigative drugs also are reviewed.

Laparoscopically assisted ileocecal resection for Crohn's disease associated with intestinal stenosis and ileovesical fistula

We describe a 22-year-old man with Crohn's ileocolitis accompanied by intestinal stenosis and ileovesical fistula in whom laparoscopically-assisted surgery was successfully performed after thorough nutritional therapy. Laparoscopic procedures are characterized by minimal access and minimal invasion, features which can contribute to the early recovery of patients who undergo surgery. It is suggested that laparoscopic (or laparoscopically-assisted) surgery after strict nutritional therapy can be effective in the treatment of patients with Crohn's disease who have intestinal complications.

An intravenous loading dose of azathioprine decreases the time to response in patients with Crohn's disease

BACKGROUND & AIMS

Azathioprine, an effective therapy for Crohn's disease, is limited by a prolonged time to response. The aim of this study was to determine the safety and utility of a loading dose of azathioprine to decrease the time to response in patients with Crohn's disease.

METHODS

Twelve patients were studied: 6 with 13 fistulae and 6 with inflammatory disease. All patients received an intravenous infusion of azathioprine (50 mg/h for 36 hours). Response was determined by physical and radiographic examination for fistulae and by the Crohn's Disease Activity Index for inflammatory disease. Erythrocyte concentrations of azathioprine metabolites were measured by chromatography.

RESULTS

Seven of 13 fistulae closed by week 4, and three had a temporary decrease in drainage. One fistula improved at week 16. Two fistulae failed to improve. Four of 6 patients with inflammatory disease achieved remission, and 1 improved temporarily. Improvement was rapid (< or = 4 weeks). Peak concentrations of azathioprine metabolites occurred within 3 days. Clinical response did not correlate with azathioprine metabolite concentrations at the azathioprine dose studied. No adverse events occurred.

CONCLUSIONS

An 1800-mg intravenous loading dose of azathioprine is safe and may decrease the time to response to < or = 4 weeks in patients with Crohn's disease. Correlation between clinical response and azathioprine metabolite concentrations at larger azathioprine doses should be determined.

A controlled double blind study of azathioprine in the management of Crohn's disease

While immunosuppressive agents are used widely in the management of Crohn's disease, their efficacy has not been well established in randomised controlled trials. This study was designed to examine whether azathioprine increases remission rate when used in conjunction with a diminishing dose regimen of prednisolone over a period of 12 weeks. It further examined whether azathioprine offers any therapeutic advantage over placebo in the maintenance of remission in Crohn's disease over a period of 15 months. Sixty three patients with active Crohn's disease were treated with a 12 weeks diminishing dose of prednisolone and at the same time entered into a randomised, double blind 15 month trial of either azathioprine (2.5 mg/kg) or placebo. Remission rates between the two groups were compared at 12 weeks and at 15 months. There was no significant difference in the proportion of patients who had achieved and maintained remission by week 12 but at 15 months there was a highly significant difference in the proportion of patients in remission (42% receiving azathioprine v 7% receiving placebo), p = 0.001. Using life tables this beneficial effect was reflected as the difference in the median number of days on the trial (p = 0.02). There were significantly greater decreases over the trial period in the median erythrocyte sedimentation rate, C reactive protein, and leucocyte count in the azathioprine group. There were no cases of severe bone marrow suppression or clinical pancreatitis. In conclusion, azathioprine offers a therapeutic advantage over placebo in the maintenance of remission in Crohn's disease.

Clinical course of perianal fistulas in Crohn's disease

The clinical course of perianal fistulas and associated abscesses was evaluated prospectively in 90 patients with Crohn's disease. Fistula type, rectal disease, faecal diversion, and immunosuppression were examined as prognostic indicators for fistula healing and recurrence. Median follow up was 22 months. The outcome was evaluated with life table analysis. Prognostic factors were analysed by multiple regression. Inactivation was achieved in all patients. The risks of recurrent fistula activity were 48% at one year and 59% at two years. Fistulas were healed in 51% after two years but reopened in 44% within 18 months of healing. Faecal diversion and absence of rectal disease decreased recurrence rates (p = 0.019/0.04) and increased healing rates (p = 0.005/0.017). The outcome in patients with trans-sphincteric fistulas was better than that in those with ischiorectal fistulas but worse than in patients with subcutaneous fistulas (p = 0.015 for healing; p = 0.007 for recurrent fistula activity). After initial treatment about 20% of the patients were symptomatic and about 10% had painful events per six month period. Incontinence was rare and did not increase during the study period. Perianal fistulas and associated abscesses can be controlled safely by simple drainage of pus collections. Frequent reinfection and re-opening after healing of fistulas are characteristic. Fistula type, rectal disease, and stool contamination influence the clinical course. Only a few patients, however, have continuous symptoms from perianal fistulas.

Hyperbaric oxygenation in severe perineal Crohn's disease

PURPOSE

Perineal involvement in Crohn's disease is a common and distressing condition, often refractory to medical or surgical treatments. Recent reports suggest the efficacy of hyperbaric oxygenation (HBO) in the healing of perineal lesions. We evaluated HBO in severe patients with perineal Crohn's disease.

METHODS

Ten consecutive patients (8 women, 2 men; mean age, 30 years) were studied. There were four superficial fissures, four cavitating ulcers, six low or superficial fistulas, two high fistulas, and one irreversible anal stenosis. All patients had received one or more medical treatments without healing the perineal lesions, and all had had previous surgery for perineal lesions.

RESULTS

Two patients discontinued HBO after a few sessions and did not complete treatment. Eight patients completed at least 30 HBO sessions and were evaluable. At the end of the procedure, six of eight patients treated were healed, three completely and three partially. All patients who healed completely received HBO as an additional treatment to local perineal surgery.

CONCLUSION

HBO might be useful as a last resort treatment of chronic perineal Crohn's disease, resistant to other treatments or as a complement to surgery.

Medical therapy of inflammatory bowel disease

Despite advances in pharmacologic approaches, the treatment of ulcerative colitis and Crohn's disease remains a challenge. Prior standards of therapy, sulfasalazine and corticosteroids, are gradually being replaced by mesalamine and alternative immune modulating agents. This article discusses the important pharmacologic properties, mechanisms of action, indications, and complications necessary to apply the expanding armamentarium in clinical practice.

Surgical treatment of inflammatory bowel disease

Surgery continues to play an important role in the overall treatment strategy for patients with Crohn's disease and ulcerative colitis. Innovative techniques have greatly facilitated the operative approach in patients with both disorders.

Efficacy of cyclosporine in treatment of fistula of Crohn's disease

Sixteen Crohn's disease patients with active fistula who had failed standard medical therapy were treated with intravenous cyclosporine. Ten patients had perirectal disease, four had enterocutaneous fistula, and two had rectovaginal fistula. Patients were initially treated with intravenous cyclosporine, 4 mg/kg/day, and then switched to oral cyclosporine, 6-8 mg/kg/day. Improvement was graded using the Present-Korelitz criteria, and success was defined as moderate to total closure of the fistula. Fourteen of 16 patients (88%) responded in the acute phase to parenteral cyclosporine. Closure of fistula occurred in seven (44%) with moderate improvement in the remaining seven (44%). Subsequently, five patients (36%) relapsed to some degree on oral cyclosporine (three severe and two mild relapses). Nine (64%) patients maintained their improvement in the chronic phase. Chronic steroids could be discontinued in 6/8 (75%) of patients. Mild side effects were common [paresthesias (75%) and hirsutism (19%)]. A single patient had severe paresthesias requiring discontinuation of therapy. Mild hypertension was noted in four (25%) and one patient (6%) had to be withdrawn because of nephrotoxicity, which reversed after stopping cyclosporine. We conclude that intravenous cyclosporine is effective therapy for perianal, rectovaginal, and enterocutaneous fistula in Crohn's disease. Its future role awaits controlled trials as well as determination of the risk-benefit ratio.

[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.

Surgical management of perineal and metastatic cutaneous Crohn's disease

Skin lesions are the commonest extraintestinal manifestation of Crohn's disease. Lesions that develop at sites remote from the gastrointestinal tract and have granulomas on histological examination are termed metastatic cutaneous Crohn's disease. Management is difficult as medical treatment is often ineffective. This report describes the use of surgical debridement of areas of perineal metastatic cutaneous Crohn's disease in five patients, all of whom had failed to improve after a variety of medical treatments. One patient had a poor result with continuing mild perineal discharge and four had a good outcome with complete resolution of symptoms and satisfactory cosmetic results.

Crohn's disease of the colon, rectum, and anus

The varied presentations and complexities of Crohn's disease involving the colon, rectum, and anus mandate decisions that can challenge even the most experienced surgeon. Symptomatic large-bowel disease, with its number of operative indications, is often amenable to resection that maintains intestinal continuity with acceptable rates of recurrence. Disease of the anus, occurring with or without proximal disease, typically is treated in a conservative manner, although occasional definitive treatment may yield improved results. As Crohn's disease is recognized as incurable, the treatment options discussed focus on the amelioration of symptoms while optimizing function without risking excessive morbidity.