Preliminary study of ciprofloxacin in active Crohn's disease

An open-label evaluation of rifaximin in the treatment of active Crohn's disease

OBJECTIVE

This open-label study was conducted as a preliminary assessment of rifaximin (200 mg TID for 16 weeks) for the treatment of active Crohn's disease in patients (n = 29) with symptoms for at least 3 months before screening and a Crohn's Disease Activity Index (CDAI) score > 220 and < 400.

RESULTS

At the end of month 4, mean +/- CDAI score was reduced by 43% compared with baseline in the intent-to-treat population (n = 29; baseline = 278 +/- 51; month 4 = 159 +/- 102; p < 0.0001 month 4 versus baseline). A similar pattern of results was observed in the per-protocol population (i.e., patients at least 70% compliant with the treatment regimen and having no protocol violations thought to affect efficacy results; n = 16), in which mean CDAI scores at month 4 were reduced by 41% from a baseline of 262.9 +/- 38.2 to 155.6 +/- 104.5 (p = 0.0009 month 4 versus baseline). Fifty-nine percent of patients (59%) had a > or = 70-point improvement in CDAI score beginning with the first assessment at the end of month 1. By the end of the treatment period, 78% of patients had a > or = 70-point improvement in CDAI score. Clinical remission, defined as CDAI score < 150, was observed at the end of treatment months 1, 2, 3, and 4 in 41%, 56%, 56%, and 59% of patients, respectively. Twenty-three (23) patients completed the 4-month course of rifaximin therapy, and 6 prematurely withdrew. The most common adverse events were abdominal pain, fatigue, and headache.

CONCLUSION

These data, which are consistent with the possibility that rifaximin may be useful for active Crohn's disease, warrant confirmation in a randomized, double-blind, placebo-controlled trial.

Management of inflammatory bowel disease: does rifaximin offer any promise?

An increasing number of both clinical and laboratory-derived observations support the importance of luminal components in driving the inflammatory response in ulcerative colitis and Crohn's disease. Although its role is unclear, antibiotic therapy is commonly used in clinical practice for the treatment of moderately to severely active ulcerative colitis. Metronidazole and/or ciprofloxacin are currently employed in active Crohn's disease, particularly in patients with colonic involvement and with perianal disease. Rifaximin, a rifamycin-derived antibiotic, is characterized by a wide range of antibacterial activity and a very low systemic absorption. Some preliminary data show its efficacy in severe active ulcerative colitis, pouchitis and prevention of postoperative recurrence in Crohn's disease.

Perianal fistulas in Crohn's disease are predominantly colonized by skin flora: implications for antibiotic treatment?

In this study we aimed to determine the microorganisms found in perianal fistulas in Crohn's disease and whether treatment with ciprofloxacin affects these microorganisms. Thirteen patients (males/females, 7/6; median age, 34 years; range, 18-61 years) with fistulas were treated with infliximab, 5 mg/kg intravenously, at weeks 6, 8, and 12 and randomized to double-blind treatment with ciprofloxacin, 500 mg bd (n = 6), or placebo (n = 7) for 12 weeks. Samples were taken at baseline and at weeks 6 and 18. In the ciprofloxacin group 10 different genera of microorganisms were identified, while 13 genera could be identified in the placebo group. Gram-negative enteric floras were present in a small minority. The genera found in patients with perianal fistulas were predominantly gram-positive microorganisms. Therefore, antimicrobial treatment should be directed toward these microorganisms.

The Role of Antibiotics in Inflammatory Bowel Disease

Broad-spectrum antibiotics are the mainstay of therapy for patients with Crohn's disease (CD) who present with localized peritonitis due to a microperforation bacterial overgrowth secondary to chronic strictures. They are essential adjuncts to drainage therapy for CD-associated abscesses and for complicated perineal disease. The lack of well-designed, placebo-controlled trials has led to much skepticism about the efficacy of antibiotics as primary therapy for CD. However, a careful review of the experience with antibiotics, including clinical observations and controlled trials, leads to the conclusion that antibiotics have a role as primary therapy in active uncomplicated CD. The efficacy of their response must be considered in well-defined subsets of patients. Ciprofloxacin and metronidazole, the two most widely studied antibiotics, are effective therapy for patients with active ileocolonic and colonic disease and have been shown to reduce recurrence rates after ileocolonic resection. The benefits of these drugs are less clear for patients with uncomplicated ileal disease. Additionally, ciprofloxacin and metronidazole may also serve as an adjunct to immunomodulator therapy. The role of antimycobacterial therapy in treatment of CD is an attractive alternative, and hopefully this therapy will be further clarified when results of ongoing trials become available. In toxic patients with fulminant ulcerative colitis (UC), with or without megacolon, broad-spectrum antibiotics should be a part of the treatment program. In less severely ill patients requiring hospitalization, antibiotics may be given to cover for the potential of a superimposed infection until the workup for infection, including Clostridium difficile is completed. There may be a subset of patients with severe nontoxic colitis with persistent fever and bandemia after steroid therapy who respond to antibiotics, but to date controlled trials have not shown efficacy in this group. Antibiotics should not be routinely used for mild to moderately ill patients with UC, although a trial of ciprofloxacin is not unreasonable prior to colectomy for otherwise refractory patients. The use of rifaximin in UC requires further evaluation in larger studies.

Management of Perianal Crohn's Disease

Perianal manifestations of Crohn's disease usually coexist with active inflammation of other primary sites of the disease. Although treatment of active proximal disease may sometimes alleviate perianal symptoms, it is reasonable to separately treat symptomatic perianal disease. The diversity of perianal manifestations in Crohn's disease mandates a tailored, individualized approach in every case. Medical therapy is the best treatment option for hemorrhoids and anal fissures. The medical management of patients with perianal Crohn's disease includes the use of systemic antibiotics, immunosuppressive agents, and infliximab. Infliximab is now recognized as a very efficacious agent for treating fistulizing Crohn's disease, including perianal fistulae. It may also reduce the need for surgical intervention in specific cases. Abscesses and fistulae are treated by control of sepsis, resolution of inflammation and optimal preservation of continence, and quality of life. Abscesses require surgical drainage that may need to be prolonged to achieve complete healing. Fistulae may be treated medically, especially in cases of concurrent proctitis. Refractory fistulae may require surgical treatment including an occasional need for fecal diversion or proctectomy. The role of new treatment options such as natalizumab and CDP571 is evolving and requires further investigation.

Antibiotic use and the risk of flare of inflammatory bowel disease

BACKGROUND & AIMS

Intestinal microbial flora participate in the pathogenesis of inflammatory bowel disease. Because antibiotic therapy alters intestinal microbial flora, we hypothesized that use of antibiotics might decrease the risk of flare.

METHODS

We conducted a case-crossover study by using the General Practice Research Database from 1989-1997. Flares of disease were identified by receipt of a new prescription for either corticosteroids or mesalamine medications after an interval of at least 4 months without prescriptions for either class of medication. The primary exposure was receipt of any antibiotics in the 60 days preceding the index date.

RESULTS

Among 1205 patients with Crohn's disease, exposure to antibiotics was associated with a reduced risk of flare (adjusted odds ratio [OR], 0.78; 95% confidence interval [CI], 0.64-0.96; P = .019). The effect was strongest with more recent exposure (test for trend, P < .05). Among 2230 patients with ulcerative colitis, use of any antibiotics within 60 days was not associated with flare of disease (adjusted OR, 0.96; 95% CI, 0.82-1.12; P = .581), although a potentially protective effect was observed in those patients with very recent exposure (exposure within 15 days: OR, 0.66; 95% CI, 0.51-0.85).

CONCLUSIONS

Antibiotic use within 60 days was associated with a lower risk of flare of Crohn's disease, but not ulcerative colitis. The strength of the protective effect of antibiotics in Crohn's disease wanes over time.

Medical Therapy of Crohn's Disease

There is no medical or surgical treatment that provides a permanent cure for Crohn's disease (CD). However, an evolving understanding of the pathogenesis of CD has provided clinicians with a diversity of medical treatment options for the disease. The goal of therapy is to induce and maintain clinical remission. The efficacy of immune-modifying agents such as azathioprine/6-mercaptopurine and infliximab have supported a paradigm shift in CD treatment in which maintenance agents are introduced earlier in the disease course. At the same time, it is imperative to balance the efficacy, safety, and tolerability of medical therapy. Given the variable and relapsing clinical course of CD, the physician and patient should ideally develop an ongoing relationship that allows for individualization of treatment regimens, monitoring of response and side effects, and modification of the therapeutic strategy in the absence of improvement.

Antibiotics for inflammatory bowel disease: do they work?

A growing amount of evidence indicates that the intestinal flora plays a pathogenic role in inflammatory bowel disease (IBD): hence, the use of anti-bacterial agents as ancillary treatment in patients with ulcerative colitis, or Crohn's disease. While the results with anti-tubercular agents remain inconclusive, antibiotic treatment in IBD is usually carried out with either metronidazole or ciprofloxacin, or both. Controlled trials are scarce and, although both antibiotics appear to provide clinical benefit, definitive conclusions cannot be drawn and precise therapeutic guidelines cannot be suggested. The best results are achieved in the long-term treatment of Crohn's disease and in the management of pouchitis, or of perianal Crohn's disease. Long-term tolerability of antibiotic treatment may be poor due to the appearance of systemic side-effects. The use of non-absorbable anti-bacterial agents such as rifaximin deserves further investigation.

Advances in medical therapy for Crohn's disease

Therapeutic research in Crohn's disease has been intensified in recent years. This has led to many novel approaches and insights into the mechanism of action of "classic" drugs. Antibiotics remain valuable but do not offer benefit when used in addition to corticosteroids. Immunomodulators remain the cornerstone for maintenance therapy, although certain corticosteroid-dependent patients can be switched to maintenance therapy with topical steroids. Azathioprine and 6-mercaptopurine remain efficient beyond 4 years in patients with relapses and elevated C-reactive protein in spite of this therapy. Infliximab has shown efficiency in maintenance of active and fistulizing Crohn's disease. In addition, "automatic reinfusion" was found to be superior to "on-demand" treatment. Infusion reactions and loss of response, most often caused by antibodies against infliximab, can be prevented with immunomodulators and corticosteroid infusions before dosing. Such alternative anti-tumor necrosis factor agents as adalimumab or CDP-870 may be less immunogenic. Other biologic agents, such as the anti-integrin monoclonal antibody natalizumab, were shown to be effective in maintaining remission and somewhat less so in induction of remission. Finally, much attention is being paid to alteration of the luminal flora with probiotics and helminth ova. Extracorporeal apheresis and even stem cell transplantation were found to be effective in isolated patients, but these therapies warrant further prospective and controlled investigation.

Sero-reactivity to microbial components in Crohn's disease is associated with disease severity and progression, but not NOD2/CARD15 genotype

BACKGROUND AND AIMS

Antibodies directed against the porin protein C of Escherichia coli (anti-OmpC) and Pseudomonas fluorescens (anti-I2) have recently been described in Crohn's disease (CD). Those directed against Saccharomyces cerevisiae (ASCA) and the perinuclear component of neutrophils (pANCA) have been more widely studied and may be of diagnostic importance. We aimed to assess the frequency of anti-OmpC, anti-I2, ASCA, and pANCA, in an independent Scottish CD cohort, establish phenotypic associations, and compare with a U.S. cohort.

METHODS

One hundred and forty-two well-characterized CD patients (76 females, median age 39 yr (17-88)) were studied. CD was classified by the Vienna classification. Sera were assayed for anti-OmpC, anti-I2, ASCA, and pANCA. Allele specific primers were used for NOD2/CARD15 genotyping.

RESULTS

Anti-OmpC, anti-I2, ASCA, and pANCA were present in sera from 37%, 52%, 39%, and 14% of CD patients, respectively. Multivariate analysis demonstrated independent associations of anti-OmpC to be progression of disease type (p= 0.005) and long disease duration (p= 0.002), and those of anti-I2 to be long disease duration (p= 0.002) and the need for surgery (p= 0.033). ASCA were associated with disease progression (p < 0.001). When the presence and magnitude of all antibody responses were considered, reactivity to microbial components was associated with long disease duration (p < 0.001), progression of disease type (p < 0.001), penetrating disease (p= 0.008), small bowel disease (p < 0.02), and the need for surgery (p < 0.001). There was no association of antibody status to NOD2/CARD15 genotype.

CONCLUSION

Reactivity to microbial components is associated with severe CD characterized by small bowel involvement, frequent disease progression, longer disease duration, and greater need for intestinal surgery.

Crohn's is not a 6-week disease: lifelong management of mild to moderate Crohn's disease

Crohn's disease is an idiopathic, chronic inflammatory disorder of the digestive tract with heterogeneous clinical presentations. Crohn's is currently not a curable disease, and patients are faced with a lifetime of recurrent disease flare-ups and remissions. Management strategies for Crohn's must therefore be targeted toward lifelong management, taking into consideration not only the short-term but also the long-term aspects of the disease. With this in mind, here we review the classifications and natural history of Crohn's disease and discuss possible predictive factors for the disease evolution in a patient. Here we also evaluate the current preferable treatment practices, based on scientifically valid research and collective clinical experience, for the management of mild to moderate Crohn's disease.

Treatment of inflammatory bowel disease with antibiotics

Although antibiotics are clearly recognized as having a role in treating the infectious complications of inflammatory bowel diseases (IBD), their impact in the primary treatment of IBD has long been an area of speculation. Over the past decade there is increasing evidence that luminal gut bacteria play a role in the pathogenesis of IBD, particularly Crohn's disease. Compelling evidence that normal commensal bacteria induce chronic intestinal inflammation in susceptible rodents provides an excellent rationale for treatment of human IBD with antibiotics. This article summarizes published studies of antibiotics in IBD patients and reviews available data for the use of antibiotic therapy in Crohn's disease and ulcerative colitis.

Successful management of histiocytic ulcerative colitis with enrofloxacin in two Boxer dogs

Two Boxer dogs with histologically confirmed histiocytic ulcerative colitis were treated with enrofloxacin, one as sole therapy and one in conjunction with prednisolone, after failure of standard therapy. Clinical remission occurred rapidly in both dogs after commencement of enrofloxacin and in one case where repeat colonoscopy was performed the endoscopic appearance of the mucosa was normal within 2 weeks. Histological examination of the colonic mucosa in this dog after 7 months showed resolution of the cellular infiltration characteristic of histiocytic ulcerative colitis. Histological improvement following therapy in Boxer dogs with histiocytic ulcerative colitis has not been reported previously.

Antibiotics should be used as first-line therapy for Crohn's disease

The etiology of Crohn's disease remains uncertain, and to date no therapy is curative. Recent experimental evidence suggests that an altered immune response to commensal enteric flora in a genetically susceptible host plays a key role in both the development and perpetuation of the intestinal inflammation of Crohn's disease. Thus, incorporation of antibiotics into the therapeutic armamentarium for Crohn's disease, either as first-line therapy or combined with immunomodulatory drugs, would seem to be a rational strategy. Indeed, most IBD clinicians would attest to the marked benefit of antibiotic therapy in individual patients. Skepticism surrounding this approach arises because evidenced-based analyses' show that the few clinical trials evaluating the efficacy of antibiotics for Crohn's disease have produced equivocal or negative results or have methodological deficiencies, including small number of patients and absence of a placebo group. However, by undertaking an analysis that integrates information from both basic and clinical spheres of study, the dichotomy between experimental and clinical observations tends to merge. This approach underscores certain key factors that determine an optimal response to antibiotics, emphasizes the requirement for assessment in well-defined subsets of patients, and leads to the conclusion that antibiotics do provide benefit for Crohn's disease.

Therapeutic manipulation of the enteric microflora in inflammatory bowel diseases: antibiotics, probiotics, and prebiotics

Crohn's disease, ulcerative colitis, and pouchitis are caused by overly aggressive immune responses to a subset of commensal (nonpathogenic) enteric bacteria in genetically predisposed individuals. Clinical and experimental studies suggest that the relative balance of aggressive and protective bacterial species is altered in these disorders. Antibiotics can selectively decrease tissue invasion and eliminate aggressive bacterial species or globally decrease luminal and mucosal bacterial concentrations, depending on their spectrum of activity. Alternatively, administration of beneficial bacterial species (probiotics), poorly absorbed dietary oligosaccharides (prebiotics), or combined probiotics and prebiotics (synbiotics) can restore a predominance of beneficial Lactobacillus and Bifidobacterium species. Current clinical trials do not fulfill evidence-based criteria for using these agents in inflammatory bowel diseases (IBD), but multiple nonrigorous studies and widespread clinical experience suggest that metronidazole and/or ciprofloxacin can treat Crohn's colitis and ileocolitis (but not isolated ileal disease), perianal fistulae and pouchitis, whereas selected probiotic preparations prevent relapse of quiescent ulcerative colitis and relapsing pouchitis. These physiologic approaches offer considerable promise for treating IBD, but must be supported by rigorous controlled therapeutic trials that consider clinical disease before their widespread clinical acceptance. These agents likely will become an integral component of treating IBD in combination with traditional anti-inflammatory and immunosuppressive agents.

Crohn's disease: the cold chain hypothesis

Crohn's disease is the result of an abnormal immune response of the gut mucosa triggered by one or more environmental risk factors in people with predisposing gene variations, including CARD15 mutations. Epidemiological data allow assessment of familial environmental risk factors related to western lifestyle, diet, bacteria, and domestic hygiene. All findings point to refrigeration as a potential risk factor for Crohn's disease. Furthermore, cold-chain development paralleled the outbreak of Crohn's disease during the 20th century. The cold chain hypothesis suggests that psychrotrophic bacteria such as Yersinia spp and Listeria spp contribute to the disease. These bacteria have been identified in Crohn's disease lesions and we discuss their pathogenic properties with respect to our knowledge of the disease. From a molecular perspective, we postulate that the disease is a result of a defect in host recognition by pathogenic bacterial components that usually escape the immune response (eg, Yop molecules), which results in an excessive host response to these bacteria.

Antibiotics and azathioprine for the treatment of perianal fistulas in Crohn's disease

BACKGROUND

Antibiotics and thiopurines have been employed in the management of fistulizing Crohn's disease, although evidence of their efficacy is rare.

AIM

To evaluate, in a prospective, open-label study, the influence of antibiotics and azathioprine on the clinical outcome of perianal fistulas in patients with Crohn's disease.

METHODS

Fifty-two patients entered the study, starting with an 8-week regimen of ciprofloxacin (500-1000 mg/day) and/or metronidazole (1000-1500 mg/day). Seventeen patients had already received daily azathioprine (2-2.5 mg/kg) at enrollment, whereas in 14 patients azathioprine was initiated after 8 weeks of antibiotic treatment. Outcome was evaluated by Fistula Drainage Assessment and the Perianal Disease Activity Index at weeks 8 and 20.

RESULTS

Overall, 26 patients (50%) responded to antibiotic treatment, with complete healing in 25% of patients at week 8. The Perianal Disease Activity Index decreased significantly from 8.4 +/- 2.9 to 6.0 +/- 4.0 (P < 0.0001). At week 20, the outcome was assessed in 49 patients (94%), 29 of whom (59%) had received azathioprine. Response was noted in 17 of the 49 patients (35%), with complete healing in nine patients (18%). Patients who received azathioprine were more likely to achieve a response (48%) than those without immunosuppression (15%) (P = 0.03). The Perianal Disease Activity Index was closely associated with treatment response and perianal disease activity.

CONCLUSION

Antibiotics are useful to induce a short-term response in perianal Crohn's disease, and may provide a bridging strategy to azathioprine, which seems to be essential for the maintenance of fistula improvement.

Review article: mild to moderate Crohn's disease--defining the basis for a new treatment algorithm

Previously, clinicians have had few choices in treating mild to moderate Crohn's disease. They currently treat these Crohn's disease patients with oral mesalamine and antibiotics. This treatment approach is based on the safety of these agents, and the perception that they are effective. This perception regarding efficacy may be influenced by publication bias. This review examines the efficacy and safety data of the conventional corticosteroids, mesalamine, sulfasalazine, budesonide and antibiotics for inducing the remission of mild to moderate Crohn's disease from randomized controlled trials, and proposes an evidence-based treatment approach. Sulfasalazine has demonstrated modest efficacy when Crohn's disease is confined to the colon. Mesalamine has no clear benefit over placebo in treating active Crohn's disease. Conventional corticosteroids effectively induce remission but are associated with unwanted adverse effects. Budesonide has similar efficacy to conventional steroids with far fewer adverse effects. Antibiotics have not consistently demonstrated efficacy. We propose a new evidence-based approach which suggests inducing remission of mild to moderate Crohn's disease with budesonide 9 mg/day for patients with ileal and/or right colonic involvement; sulfasalazine for those with disease limited to the colon; and conventional steroids for high disease activity, those who failed budesonide and those with left-sided disease who are allergic or intolerant to sulfasalazine.

Targeting enteric bacteria in treatment of inflammatory bowel diseases: why, how, and when

PURPOSE

This review discusses the role of bacterial adjuvants and antigens in induction and reactivation of chronic intestinal inflammation in susceptible hosts; discusses the results of recent therapeutic trials of antibiotics, probiotics, and prebiotics; and suggests future treatment strategies.

RECENT FINDINGS

Bacterial adjuvants, including peptidoglycan, lipopolysaccharide, and DNA (CpG) bind to membrane-bound toll-like receptors (TLR-2, 4, and 9. respectively) or cytoplasmic (NOD1 and NOD2) receptors (pattern recognition receptors) that activate nuclear factor-kappaB and transcription of many proinflammatory cytokines and adhesion, costimulatory, and major histocompatibility complex class II molecules. Experimental enterocolitis does not occur in a sterile (germ-free) environment and is prevented and treated by broad-spectrum antibiotics. Individual nonpathogenic intestinal bacterial species selectively induce experimental colitis, with host specificity. Crohn disease and ulcerative colitis patients exhibit pathogenic immune responses (loss of immunologic tolerance) to multiple normal enteric bacterial species and serologic responses to Mycobacterium paratuberculosis. Metronidazole and ciprofloxacin selectively treat colonic Crohn disease, but not ulcerative colitis or ileal Crohn disease, and may prevent recurrence of postoperative Crohn disease. Certain probiotic species decrease relapse of ulcerative colitis and chronic pouchitis and delay onset of pouchitis.

SUMMARY

Normal, nonpathogenic enteric bacteria induce and perpetuate chronic intestinal inflammation in genetically susceptible hosts with defective immunoregulation, bacterial clearance, or mucosal barrier function. Altering the composition and decreasing mucosal adherence/invasion of commensal bacteria with antibiotics, probiotics, and prebiotics can potentially prevent and treat Crohn disease, pouchitis, and possibly ulcerative colitis, but optimal treatments have not yet been identified.

Crohn's disease: a defensin deficiency syndrome?

This comprehensive review promotes the novel concept that a defensin deficiency, i.e. lack of mucosal peptide antibiotics, may play a pivotal role in the aetiopathogenesis of Crohn's disease. Such an impaired function of this chemical barrier is consistent with the epidemiological relationship of good domestic hygiene with the incidence of inflammatory bowel diseases. The disregulated adaptive immune system, formerly believed to be the major cause in the development of Crohn's disease, may reflect only the primary break of the mucosal defence since the immune response is mostly directed against lumenal bacteria. Recent work has identified five different defensins expressed in colonic mucosa. In contrast to ulcerative colitis, Crohn's disease is characterised by an impaired induction of human beta defensins 2 and 3. This deficient induction may be due to changes in the intracellular transcription by NFkappaB and the intracellular peptidoglycan receptor NOD2, mutated in Crohn's disease. These findings are consistent with the mucosal attachment of lumenal bacteria in inflammatory bowel diseases and the frequent occurrence of other infectious agents. The hypothesis of an impaired mucosal antibacterial activity is also consistent with the benefit from antibiotic or probiotic treatment in certain inflammatory bowel disease states.

Therapy of Crohn's disease in childhood

Crohn's disease in childhood is a chronic relapsing and remitting condition that can significantly impact on normal growth and development. This influences the choice of both initial and ongoing management. The goal of therapy is to induce and maintain remission with minimal side effects. Enteral nutrition as the sole therapy for active disease is effective in some children, thus avoiding the use of corticosteroids. In disease that is resistant to conventional treatment, immunosuppression or anti-tumour necrosis factor therapy is indicated. We review the use of these treatments and discuss the new therapies being developed, including antibodies, cytokines and probiotics.