Efficacy of Lactobacillus GG in maintaining remission of ulcerative colitis

Transcription

1 Alimentary Pharmacology & Therapeutics Efficacy of Lactobacillus GG in maintaining remission of ulcerative colitis M.A.ZOCCO,L.ZILERIDALVERME,F.CREMONINI,A.C.PISCAGLIA,E.C.NISTA,M.CANDELLI, M. NOVI, D. RIGANTE*, I. A. CAZZATO, V. OJETTI, A. ARMUZZI, G. GASBARRINI & A. GASBARRINI Departments of Internal Medicine, and *Pediatrics, Catholic University of Rome, Rome, Italy Correspondence to: Dr A. Gasbarrini, Professor of Internal Medicine, Department of Medical Pathology, Catholic University of Rome, Largo Gemelli, Rome, Italy. Publication data Submitted 13 December 25 First decision 5 January 26 Resubmitted 12 March 26 Accepted 12 March 26 SUMMARY Background Aminosalicylates are the mainstay of therapy to prevent relapse of quiescent ulcerative colitis. The rationale for using probiotics is based on the evidence implicating intestinal bacteria in the pathogenesis of this disorder. Aim To evaluate the efficacy of Lactobacillus GG alone or in combination with mesalazine vs. mesalazine as maintenance treatment in ulcerative colitis. Patients and methods 187 ulcerative colitis patients with quiescent disease were randomized to receive Lactobacillus GG viable bacteria/day (65 patients), mesalazine 24 mg/day (6 patients) or Lactobacillus GG + mesalazine (62 patients). Disease activity index, endoscopic and histological scores were determined at, 6 and 12 months and in case of relapse. The primary end point was to evaluate sustained remission. Results Overall analysis showed no difference in relapse rate at 6 (P ¼.44) and 12 months (P ¼.77) among the three treatment groups. However, the treatment with Lactobacillus GG seems to be more effective than standard treatment with mesalazine in prolonging the relapse-free time (P <.5). Conclusions Lactobacillus GG seems to be effective and safe for maintaining remission in patients with ulcerative colitis, and it could represent a good therapeutic option for preventing relapse in this group of patients. Aliment Pharmacol Ther 23, ª 26 The Authors 1567 doi:1.1111/j x

2 1568 M. A. ZOCCO et al. INTRODUCTION Crohn s disease (CD) and ulcerative colitis (UC), collectively referred to as inflammatory bowel diseases (IBD), represent chronic disorders, affecting approximately 35 55/1 people in western Europe. The current leading hypothesis for the aetiology of UC, emphasizes genetic predisposition to dysregulation of the gastrointestinal immune system. However, descriptive epidemiological studies highlight differences in incidence of UC across age, time and geographic region, suggesting that the environmental factors can significantly modify the expression of these conditions. 1 Classically, the natural history of UC includes periods of disease flare-up and remission, and the goal of the currently available treatments was to induce and to maintain remission of both symptoms and mucosal inflammation, improving patients quality of life. Once remission is achieved with any of the therapeutic schemes available, up to 7% of the patients given no treatment are expected to relapse within a 1-year period. 2 Aminosalicylates remain the mainstay of therapy for remission induction in mild to moderately active UC and to prevent relapse of quiescent disease. 3, 4 Although doctors have the possibility to target the treatment on the basis of site and extent of the disease with new formulations, relapse rate in patients administered mesalazine is still assessed to be around 2% within the first year. In addition, potential side-effects, costs and a poor compliance to a life-long therapy have led investigators to search for novel therapeutic approaches. In particular, manipulation of the enteric flora with probiotics could be an appealing alternative. 5 Probiotics are live micro-organisms that, when ingested in adequate amount, have a beneficial effect on health, altering the enteric microflora. The rationale for using probiotics in IBD is based on the evidence implicating intestinal bacteria in the pathogenesis of these disorders that involves genetically influenced dysregulation of the mucosal immune response to antigens present in the normal bacterial flora. 6 The disturbance of balance among the host s overall genetic background, bowel mucosal immunity and enteric microflora, seems to be at the basis of tissue damage. Such imbalance results in an abnormal reactivity of the host defence system towards organisms represented in the normal gut flora, bacterial overgrowth within crucial anatomical sites and a decreased ratio of aerobic to anaerobic bacteria. 7, 8 Several observations, both on humans and animal models, emphasized the importance of bacterial flora in IBD pathogenesis, justifying the current interest towards emerging antibiotic and probiotic therapies aimed at the manipulation of enteral flora. 9 Probiotic therapeutic efficacy has been demonstrated in experimental murine models, including interleukin (IL)-1 knock-out mice and lymphocyte transfer models Controlled data in human IBD are limited. A nonpathogenic strain of Escherichia coli has been found in different studies to be as effective as mesalazine in patients with UC Besides, a cocktail of bacteria in patients with pouchitis has been impressive. 16 Lactobacillus rhamnosus is the most extensively used probiotic in clinical trials and is represented in 17, 18 the bowel of healthy individuals. Lactobacillus rhamnosus GG strain () has been shown to improve common conditions such as traveller s diarrhoea, antibiotic-associated diarrhoea and relapsing Clostridium difficile colitis. 19 The beneficial effect seems to be related to a large number of mechanisms, including resistance to acid and bile, adherence to intestinal cells and bowel colonization 2 and modulation of mucosal immune response. 21, 22 Oral bacteriotherapy with this specific strain has not been shown to affect remission rates in patients with pouchitis. 23 The efficacy of supplementation vs. standard mesalazine for maintaining disease remission in UC patients is still unknown. The aim of the present prospective, open-label, randomized trail was to evaluate the efficacy of an oral probiotic preparation of alone or combined with mesalazine vs. standard mesalazine in maintaining remission of patients affected by UC. MATERIAL AND METHODS Patients From June 21 to December 24, 187 consecutive patients (14 men and 83 women) participated in this randomized open-label trial, performed at the Inflammatory Bowel Diseases Centre of the Catholic University in Rome. Patients were eligible if they had UC in clinical, laboratory and endoscopic remission of no longer than 12 months before admission. Clinical remission was defined by a Colitis Activity Index (CAI) lower than Endoscopic and histological remission were defined according to Baron et al. 25 and Truelove Richard s 26 scoring systems respectively. Each patient was

3 LACTOBACILLUS GG AS MAINTENANCE TREATMENT FOR ULCERATIVE COLITIS 1569 evaluated for demographic data (age, sex, smoking behaviour) and prestudy clinical features (CAI, disease duration and extension, previous treatment, number of flare ups). Patients with active disease or complications, severe accompanying illness or major colonic surgery, gastrointestinal infections, serious concomitant diseases (renal or hepatic failure, severe hypertension), diabetes mellitus, immunosuppressive treatment being administered currently or in the month before enrolment, mesalazine intolerance, and pregnant or lactating woman were excluded from the study. Oral or rectal treatment with antibiotic or steroid medications, apart from the study drugs, was not allowed during the trial. The study was performed in accordance with the Declaration of Helsinki and was approved by the ethical committee of the Catholic University of Rome. Written informed consent was obtained from all the participants, before entry into the study. Study design The study was performed as a single centre, prospective, open-label randomized trial. Eligible patients were randomized to receive one of the following treatments: 1 Lactobacillus GG (Giflorex, Errekappa, Euroterapici SpA, Milan, Italy) viable bacteria/day divided into two oral administrations ( group, 65 patients). 2 8 mg tablets (mesalazine Errekappa, Euroterapici SpA), three tablets (24 mg) daily (MES group, 6 patients). 3 Lactobacillus GG viable bacteria/day plus mesalazine 24 mg daily ( + MES group, 62 patients). Patients were treated for 12 months; the treatment was interrupted in case of disease relapse, occurrence of side-effects, poor compliance and inability to attend follow-up visit. Full clinical evaluation with symptoms assessment and physical examination was performed at baseline and every 3 months for all the 12-month study period. Patients were asked to fill in a diary card with daily record of symptoms (e.g. stool frequency, presence of blood and mucus, abdominal pain) during the week before every examination. At each visit all patients underwent blood analysis (haemoglobin, total cell count, C-reactive protein and erythrocyte sedimentation rate) and the clinical activity index was calculated. Each patient was given a telephone number to contact the investigators at the first sign of relapse. Compliance with the study drugs was checked by the investigator by counting the number of empty bags returned at each visit. Full colonoscopy with mucosal biopsies and histological evaluation were performed at baseline and after 6 and 12 months or in the case of clinical relapse. Treatment failure during the study period was defined as the appearance of UC symptoms and/or signs which needed additional medical treatment. Failure was also defined as an increase in CAI to more than 4 points. In the event of treatment failure, endoscopy with biopsies was performed to confirm recurrence. End points The primary end point of this study was to compare the number of patients suffering a relapse of UC during the 12-month observation period among the three different groups. Secondary end points were to evaluate the variations of clinical, endoscopic and histological scores over the period of the study and the relapse-free time as an index of drug efficacy. Statistical analysis All the patients who received the study treatment were included in the analysis. STATA software (version 8.) and SPSS (version 13.) were used for data management and statistical analysis. We estimated a total sample size of 59 subjects per treatment group to obtain an 8% power to detect a clinically significant difference on 2% in relapse rate between groups, with an a of.5, assuming a proportion of patients in remission of 75% at 1 year in the conventionally treated group. Wilcoxon s rank and chi-square tests were used to evaluate the comparability of the three treatment groups at baseline. The clinical, endoscopic and histological scores at, 6 and 12 months of the three different groups were analysed using ANOVA test. The relapse rate and in the three groups of treatment were compared using chisquared test. Logistic regression was used to calculate odds ratios (OR) for relapse and 95% confidence interval (CI) adjusted for age, sex, disease duration and extent in the probiotics and probiotics + mesalazine groups vs. the mesalazine group (used as comparison group). Finally, we computed person-time of follow-up for each participant from the date of enrolment to the end

4 157 M. A. ZOCCO et al. (n ¼ 65) (n ¼ 6) + mesalazine (n ¼ 62) Table 1. Baseline characteristic of the study groups Male/female 36/29 34/26 34/28 Age (years; mean s.d.) Smokers Disease duration (years; mean s.d) Disease extension n ¼ 25 n ¼ 23 n ¼ 24 Proctosigmoiditis Left colon Total/subtotal CAI (UC; mean s.d.) CAI, Colitis Activity Index; UC, ulcerative colitis;, Lactobacillus GG. of the study or the date of relapse. Relapse rates were computed by dividing the number of relapsed patients by the number of person-months in each treatment group and compared using chi-square test. A P-value of <.5 was considered statistically significant. respectively, 91% and 85% for the group, 87% and 8% for the mesalazine group and 94% and 84% for the combined treatment group. Chi-squared test obtained comparing clinical relapse rates among the three groups was not significant at 6 and 12 months RESULTS One hundred and eighty-seven patients who fulfilled the enrolment criteria were randomly assigned to receive, mesalazine, + mesalazine. Demographic and prestudy clinical characteristics did not differ significantly among the three groups (Table 1). The time gap between the end of the last relapse before the study and entry into the study was no longer than 4 weeks in 12% of patients receiving, in 1% of patients receiving mesalazine and in 11% of patients receiving the combined treatment, and no longer than 3 months in 26%, 26% and 25% of, mesalazine and + mesalazine patients respectively. No significant side-effects was reported. Premature discontinuation of the study for reasons other than relapse did not occur. Disease relapse rates Ten patients receiving, 12 patients receiving mesalazine and 1 patients receiving both drugs relapsed during the observation period. In the group six patients had signs of clinical relapse in the first 6 months compared with eight patients of the mesalazine group and four of the combined treatment group. All other parameters were not altered among the three groups. The percentage of subjects maintaining clinical remission after 6 and 12 months of treatment was, % % CAI 6 months -MES MES CAI 12 months -MES MES Remission Relapse Remission Relapse Figure 1. Outcome of patients with ulcerative colitis expressed as percentage of remission and relapse at 6 and 12 months for the three treatment groups (P ¼.44 and.77 respectively).

5 LACTOBACILLUS GG AS MAINTENANCE TREATMENT FOR ULCERATIVE COLITIS 1571 OR at 6 months.74 ( ) +MES.88 ( ) Better than Equivalent to Worse than OR at 12 months.78 ( ) +MES.9 ( ) Better than Equivalent to Worse than Figure 2. Odds ratios (OR) for relapse and 95% CI adjusted for age, sex, disease duration and extent in the probiotics and probiotics + mesalazine groups vs. the mesalazine group (used as comparison group) at 6 and 12 months. (P ¼.44 and.77, respectively) resulting in equivalent efficacy of the different therapeutic schemes (Figure 1a). Compared with the clinical, the endoscopic relapse rates were slightly higher at both 6 and 12 months of treatment; also in this case, the differences among the three groups were not statistically significant (P ¼.39 and.46 at 6 and 12 months, respectively; Figure 1b). Logistic regression and OR (95% CI) for relapse in patients receiving Lactobacillus GG alone or in combination with mesalazine vs. patients receiving standard treatment (mesalazine alone) at 6 and 12 months are illustrated in Figure 2. When we compared with MES we found an OR of.74 ( ) and.78 ( ), respectively, at 6 and 12 months. The OR for the combined treatment vs. standard therapy was.88 ( ) at 6 months and.9 ( ) at 12 months. At both time points the proportion of patients in remission was similar in the three treatment groups. Clinical, endoscopic and histological scores The variations in clinical, endoscopic and histological scores are illustrated in Figure 3. Colitis Activity Index increased in all patients over the study period, showing a slightly larger increase in the mesalazine group than in the group. A similar trend was observed when we considered the endoscopic or histological index between the start and end of the study. However, no statistically significant differences were noted at 6 and 12 months among the three therapeutic schemes.

6 1572 M. A. ZOCCO et al MES MES CAI T CAI T6 CAI T12 CAI T CAI T6 CAI T12 -MES MES MES MES ENDO T ENDO T6 ENDO T12 ENDO T ENDO T6 ENDO T12 -MES MES MES MES -MES MES ISTO T ISTO T6 ISTO T12 ISTO T ISTO T6 ISTO T Figure 3. Variations in clinical, endoscopic and histological scores. Person-time During the clinical follow-up, we noticed that mesalazine-treated patients had the tendency to relapse earlier than the -treated groups. Considering the person-time of follow-up, the relapse rates at 12 months were 136/1 person-months, 181/ 1 person-months and 142/1 person-months for, MES and + MES groups respectively. The chi-squared test demonstrated that the treatment with alone or in association with mesalazine was more effective than mesalazine alone in prolonging the relapse-free time (P ¼.1 and P ¼.3 for and + MES, respectively). No advantage seemed to result from the combination of with mesalazine respect to probiotic alone (P >.5). DISCUSSION Therapeutic efficacy is usually demonstrated by superiority in a placebo-controlled trial. However, in serious disease when effective therapy exists that has already been tested by comparison with placebo, additional placebocontrolled trials may be considered unethical. It can been stated that mesalazine is the standard treatment used to prevent UC relapses and thus it qualifies as a control in an equivalence trial. 2, 3 The present study shows that a probiotic may have the same efficacy of mesalazine on 1-year maintenance of remission in IBD. We demonstrated that is not inferior to the established gold standard mesalazine and can provide significantly better efficacy in delaying relapses of UC. Previous studies have suggested that luminal bacteria may be relevant in the modulation of inflammatory response in IBD. 27 The hypothesis that the onset of inflammation could be associated with a disturbance of the normal equilibrium in the intestinal microflora with relative predominance of aggressive bacteria and insufficient loads of protective species is strengthened by the observation that probiotics positively affect gut inflammation in animal models of colitis Human studies have shown alterations in gut flora composition in UC patients (e.g. decrease in Lactobacillus spp.) 33 and pouchitis patients (e.g. decreased ratio of anaerobic to aerobic bacteria, reduced faecal loads of lactobacilli and bifidobacteria and an increase in luminal ph). 34

7 LACTOBACILLUS GG AS MAINTENANCE TREATMENT FOR ULCERATIVE COLITIS 1573 In double-blind, placebo-controlled trials, a multistrain probiotic therapy (VSL#3) resulted more effective than placebo as maintenance treatment in patients with chronic pouchitis and in the prophylaxis of pouchitis onset. 34, 35 The same probiotic mixture was also able to induce remission in patients with active UC. 36 Other studies have shown no differences between mesalazine and non-pathogenic E. coli strain 13 15, 37 in maintaining remission of UC. Conversely, clinical trials using Lactobacillus GG failed to show effectiveness compared with placebo in improving pouch inflammation 23 even if the same probiotic has been reported to be effective in delaying the first onset of pouchitis. 38 The mechanisms by which probiotic bacteria might exert their beneficial effects and protect against IBD relapse include direct effects on local bacteria and stimulation of protective immune responses. 19 Furthermore, several probiotic species have been shown to influence the integrity of the epithelium by sequestering toxins, stimulating mucus production and inducing synthesis of anti-inflammatory cytokines. 39 One of the strength of the present study is the use of a single probiotic species. While cocktails of probiotics may offer convenience for combining several strain-specific properties, clarification of the efficacy and of the mechanism of actions of the single strains could be important to drive the clinician towards the optimal choice of probiotic in a rapidly growing market. When we consider, in vitro studies and some clinical trials have revealed that this probiotic induces a Th1 chemokines production and downregulates some proinflammatory cytokines. 39 Besides, is able to induce substances such as cyclo-oxygenase (COX)-2 and glutathione transferase, which play a central role in the cellular defence against endogenous compounds and xenobiotics. Recently, according to microarray analysis, a global screening of the probiotic s regulated genes has allowed the analysis of the complex bacteria host interplay. The results have revealed that modulates the expression of a large quantity of genes implicated in the immune and inflammatory responses, as well as molecules participating in cell adhesion and cell cell signalling which could explain the benefices of their consumption to the reinforcement of the epithelial barrier by competing with the fixation of pathogenic micro-organisms. 4 These features could explain the efficacy of oral bacteriotherapy with as UC maintenance treatment, with results comparable with that of standard therapy in 1-year observation period. Moreover, the anti-inflammatory properties together with the reinforcement of the epithelial barrier can justify its ability to significantly prolong the relapse-free time compared with mesalazine alone, potentially improving the quality of life of individual patients. It is not clear why the combination of with mesalazine does not result in a clinical advantage. It can be assumed that mesalazine can interfere with mucosal adherence and colonization but surely we need further studies that take into account this aspect. In conclusion, this new therapeutic approach is quite appealing because of the promising results, the lack of toxicity and the enthusiasm of patients wishing to use natural physiological approaches to treating IBD. It should not be assumed, however, that the same probiotic is equally suitable for all individuals, and the heterogeneity of clinical disorders such as UC suggests that strain-specific properties may be required for different patient categories. The optimal composition, dose and length of treatment in various IBD clinical settings need to be determined by large, well-designed, prospective trials. Moreover, future advances in the understanding of probiotics as therapeutic tools in IBD will likely include the testing of genetically modified probiotic species, such as those engineered to produce antiinflammatory cytokines. ACKNOWLEDGEMENT No external funding was received for this study. REFERENCES 1 Loftus EV. Clinical epidemiology of inflammatory bowel diseases: incidence, prevalence and environmental influences. Gastroenterology 24; 126: Hanauer SB. Medical therapy for ulcerative colitis 24. Gastroenterology 24; 126: Sutherland LR, Roth DE, Beck PL. Alternatives to sulafaslazine: a metanalysis od 5-ASA in the treatment of ulcerative colitis. Inflamm Bowel Dis 1997; 3:

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