Pouchitis: result of microbial imbalance?

Changes in bacterial enzymes and PCR profiles of fecal bacteria from a patient with ulcerative colitis before and after antimicrobial treatments

A 26-year-old female patient, suffering from recurrent attacks of ulcerative colitis accompanied by extraintestinal symptoms (erythema nodosum and pyoderma gangrenosum), was evaluated for the effect of antibacterial agents on the intestinal bacteria and their enzymatic activities. The enzymes were assayed both at the onset of disease symptoms and after treatment with each of five drug regimens (fluconazole and cefadroxil, cefuroxime axetil and cestriaxone sodium, ciprofloxacin and cestriaxone sodium, ciprofloxacin alone, and ciprofloxacin, metronidazole, and cephalexin). The activities of azoreductase, nitroreductase, oxidoreductase, glucuronidase, and sulfatase were generally lower following all of the treatments, especially when ciprofloxacin was included. The DNA from each sample was amplified by PCR, using random primers. Profiles of amplified DNA on agarose gels showed different patterns, indicating differences in the microflora before and after the antimicrobial treatments. The clinical response to antibacterial therapy was consistent with the decreased bacterial enzymatic activities and changes in the microbial population. Ciprofloxacin, which was associated with the most dramatic falls in enzymatic activity, also had the best clinical results. We conclude that intestinal bacteria and their enzymes play important roles in ulcerative colitis and that population changes can be monitored using PCR profiles.

A rat model of ileal pouch-rectal anastomosis

After colectomy and ileal pouch-rectal anastomosis, pouchitis may occur. Pouchitis is a poorly defined condition with unknown etiology. The aim of this study was to develop an animal model of pouchitis. Ileal pouch-rectal anastomosis was created in Lewis and Sprague-Dawley rats. Rats were studied 4 and 8 weeks after surgery, and pouchitis was assessed by stool output, histology, and tissue myeloperoxidase (MPO) levels. Some rats were treated with allopurinol or metronidazole beginning the day of surgery. Rats with pouches demonstrated inflammation with a monocytic infiltration, luminal exudate, mucosal ulcerations, and serosal inflammation. Rats with pouches had increased anaerobic bacterial flora compared with normal ileum. After creation of pouches, Lewis rats (histology score = 8.4 +/- 1.6; MPO = 17.3 +/- 3.6, mean +/- SD) developed more severe inflammation than Sprague-Dawley rats did (histology score = 4.3 +/- 1.8; MPO = 5.5 +/- 3.6) within 4 weeks, p < 0.001 and 8 weeks after surgery, p < 0.05. Stool output was also greater in Lewis (55 +/- 7 g/kg/day) compared with Sprague-Dawley rats with pouches (43 +/- 5 g/kg/day), p < 0.05. Metronidazole treatment reduced histology score (6.0 +/- 0.5) p < 0.05 and MPO (5.9 +/- 1.6) p < 0.001 in rats with pouches compared with rats with pouches that had no treatment. Allopurinol treatment in rats with pouches reduced histology score (4.0 +/- 1.7) and MPO (3.9 +/- 1.6), p < 0.001, compared with rats with pouches that had no treatment. Ileal pouch-rectal anastomosis in rats induced inflammation within 4 weeks, demonstrated differential host genetic susceptibility, and was associated with increased number of pouch bacteria. Anaerobes, especially bacteroides sp. and free radical, may mediate inflammation. Ileal pouch-rectal anastomosis surgery in rats may be a useful animal model for the study pouchitis.

Proctocolectomy with jejunal pouch-distal rectal anastomosis: an alternative to ileal pouch reconstruction

The aim of this study was to determine whether a jejunal pouch would have a lower resting pressure, be more distensible, and have more interdigestive migrating myoelectric complexes and less fecal bacterial overgrowth than would an ileal pouch after proctocolectomy and pouch-distal rectal anastomosis. In six conscious dogs with a jejunal pouch-distal rectal anastomosis and six with an ileal pouch-distal rectal anastomosis (controls), pouch distensibility and motility were measured using a barostat and perfused pressure-sensitive catheters passed per anum, pouch electrical activity was recorded using chronically implanted electrodes, and the number of bacteria per gram of stool was assessed by culture. Dogs with a jejunal pouch had lower resting pouch pressures, more distensible pouches, faster frequencies of pacesetter potentials in the pouch, more phase 3 intervals of the interdigesive migrating myoelectric complex reaching the pouch, but similar numbers and types of bacteria in their stools compared to the dogs with an ileal pouch. We concluded that jejunal pouches have a lower resting pressure, are more distensible, have more cleansing contractions, but a similar fecal flora compared to ileal pouches. A jejunal pouch has features that make it an attractive alternative to an ileal pouch for pouch-distal rectal or pouch-anal canal anastomosis after proctocolectomy.

Pouchitis

Pouchitis is a major long-term complication of the continent ileostomy as well as the ileoanal pouch anastomosis. When diagnosed on the basis of clinical, endoscopic and histologic features, this syndrome has been demonstrated almost exclusively in patients with ulcerative colitis. The clinical course, the endoscopic findings and the histologic abnormalities resemble those of ulcerative colitis. The association with extra-intestinal manifestations further supports the hypothesis that pouchitis represents ulcerative colitis in the small bowel. All ileal reservoirs show bacterial overgrowth, especially of anaerobes. As a response to this altered intraluminal environment chronic inflammation and incomplete colonic metaplasia occur. The efficiency of metronidazole does suggest that bacteriological factors play an important role in the pathogenesis of pouchitis.

Nitrate-reducing bacteria in diversion colitis: a clue to inflammation?

A pathogenic role of nitric oxide has been suggested in acute and chronic intestinal inflammation. We took the opportunity offered by studies in patients with excluded colon, which represents a model of chronic intestinal inflammation with no exogenous nitrite or nitrate supply, to evaluate the quantity and the quality of nitrate reducers in diversion colitis. Thirty patients (17 men, 13 women, mean age 45 years) having an excluded colon for various reasons were sampled by rectal swabs and compared to 30 healthy controls (11 men, 19 women, mean age 28 years). The percentage of nitrate-reducers among the total count of subcultured bacteria was 46 +/- 41% (mean +/- SD) in patients with diversion colitis as compared to 19 +/- 24% in healthy controls. This difference was significant (P < 0.05) despite great heterogeneity in individual values. In patients with diversion colitis, 75/254 (29.5%) different isolated bacterial strains were nitrate-reducers as compared to 61/294 (21%) (P < 0.05) in controls. Among the 75 nitrate-reducing strains isolated from patients with diversion colitis, 55 were aerobes. Pseudomonas species were only encountered in this population. The predominant group was enterobacteria with a high isolation rate of species belonging to the genera Proteus, Providencia, and Morganella. In healthy controls nitrate-reducing anaerobes were nearly as frequent as aerobes. The most frequent species was Eubacterium lentum, followed by Clostridium perfringens. It could be suggested that nitric oxide synthase might produce a bacterial substrate increasing the growth of bacteria with a high pathogenic potential, creating conditions for chronic inflammation and infection in patients with excluded colon.

Crohn's-like complications in patients with ulcerative colitis after total proctocolectomy and ileal pouch-anal anastomosis

Total proctocolectomy with ileal pouch-anal anastomosis (IPAA) has become an established surgical procedure for ulcerative colitis. Occasional patients who have undergone IPAA develop persistent or recurrent episodes of pouchitis (chronic pouchitis), from which a subset also develop gastrointestinal and systemic complications that are identical to those seen in Crohn's disease. These complications include enteric stenoses or fistulas in the pouch or pouch inlet segment, perianal fistulas or abscesses, pouch fistulas, arthritis, iridocyclitis, and pyoderma gangrenosum. The development of Crohn's-like gastrointestinal complications in a patient with chronic pouchitis frequently engenders concern that the pathologist misinterpreted the proctocolectomy specimen as ulcerative colitis instead of Crohn's disease. We describe eight patients who developed chronic pouchitis and Crohn's-like complications after IPAA and total proctocolectomy. In each case, concern was voiced about misinterpretation of the proctocolectomy specimen as ulcerative colitis instead of Crohn's disease after the development of the Crohn's-like complications. Preoperatively, all eight patients had characteristic clinical, radiographic, and pathologic features of ulcerative colitis. Review of the pathology specimens indicated that all eight had ulcerative colitis. Crohn's-like complications are most likely related to chronic pouchitis, which probably is a form of recrudescent ulcerative colitis within the novel environment of the pouch. A diagnosis of Crohn's disease after IPAA surgery should only be made when reexamination of the original proctocolectomy specimen shows typical pathologic features of Crohn's disease, Crohn's disease arises in parts of the gastrointestinal tract distant from the pouch, pouch biopsies contain active enteritis with granulomas, or excised pouches show the characteristic features of Crohn's disease, including granulomas. There were no histologic differences in the total colectomy specimens between the eight ulcerative colitis study patients and 16 control ulcerative colitis patients who had a favorable clinical outcome after IPAA surgery groups. Crohn's-like complications and chronic pouchitis does not necessarily imply an incorrect original interpretation of ulcerative colitis by the pathologist.

Long-term efficacy of bismuth carbomer enemas in patients with treatment-resistant chronic pouchitis

BACKGROUND

Mucosal inflammation of the ileal pouch (pouchitis) is the major long-term complication after ileal pouch-anal anastomosis for ulcerative colitis. Broad-spectrum antibiotics are the mainstay of treatment, however, 15% of patients with pouchitis have a chronic, treatment-resistant disease.

AIM

To determine the safety and efficacy of bismuth carbomer enemas in achieving and maintaining remission in treatment-resistant chronic pouchitis.

METHODS

Twelve patients with treatment-resistant chronic pouchitis were treated nightly for 45 days with enemas containing elemental bismuth complexed with carbomer. Diagnosis of pouchitis and response to treatment were evaluated with the Pouchitis Disease Activity Index (PDAI), which includes clinical, sigmoidoscopic and histological criteria. Serum bismuth concentrations were determined by atomic absorption.

RESULTS

Ten of 12 patients (83%) went into remission, with a significant decrease of mean total PDAI score from 12 (range 9-15) to 6 (4-15) (P < 0.002), and were continued on bismuth carbomer enemas administered every third night for 12 months. Patients were monitored clinically, sigmoidoscopically and histologically every 2 months for evidence of recurrence (increase > or = 2 in the clinical symptom portion of the PDAI). Six of 10 patients (60%) were able to maintain remission throughout the 12-month trial; 4/10 had an exacerbation, two of which occurred soon after discontinuing daily treatment. Serum bismuth levels were negligible in all patients and no side-effects were registered.

CONCLUSIONS

Our findings suggest that bismuth carbomer enemas are safe and effective in achieving and maintaining remission in patients with treatment-resistant chronic pouchitis.

Functional results after restorative proctocolectomy complicated by pouchitis

This study aimed to examine the incidence and cumulative risk of pouchitis after restorative proctocolectomy for ulcerative colitis and to evaluate the clinical and functional results in patients with pouchitis.

METHODS

A total of 291 patients had proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis between January 1985 and January 1996. During follow-up, 65 patients had one or more episodes of pouchitis based on clinical, histologic, and endoscopic criteria. Functional results and patient satisfaction in these patients were compared with those of 65 matched control patients who had experienced no episodes of pouchitis.

RESULTS

Pouchitis developed in 65 patients (22 percent), giving rise to a cumulative frequency of 28 percent at 11 years after the operation. Only 13 patients (4.5 percent) had chronic pouchitis that required long-lasting treatment. A permanent ileostomy had to be constructed in one patient (0.3 percent) because of pouchitis. During the last year (1995), 60 percent of patients with pouchitis had medication, most often metronidazole and/or corticosteroids. Defecation frequency per 24 hours was 6.7 for all patients with pouchitis, 8.2 for those with chronic pouchitis (P < 0.05), and 6.3 for patients without pouchitis. Nighttime defecation occurred in 44 (80 percent) patients with pouchitis, compared with 37 (67 percent) of those without pouchitis (P > 0.05). Frequencies of soiling or flatus incontinence did not differ between the two groups. During the last year, 43 (80 percent) of the pouchitis patients, who answered the questionnaire, were working all the year or were on sick-leave less than one month.

CONCLUSIONS

Episodic pouchitis is easily treated and causes minimum functional consequences, whereas chronic pouchitis increases defecation frequency and needs prolonged medication. Pouchitis seems not to be a major threat to preventing the use of restorative proctocolectomy in ulcerative colitis, but still the small group of chronic pouchitis patients remains a problem.

Ileal pouches: adaptation and inflammation

Ileal pouch-anal anastomosis (IPAA) has become the operation of choice following proctocolectomy for ulcerative colitis (UC) and familial adenomatous polyposis. Functioning ileal pouch mucosa undergoes histological changes resembling the colon (colonic metaplasia). The possible role of stasis and luminal factors--bile acids, short-chain fatty acids and bacteria--are discussed. It seems likely that colonic metaplasia is an adaptive response to the new luminal environment in IPAA. Inflammation in the ileal reservoir ('pouchitis') is the most significant late complication in IPAA. It occurs in 20-30% of patients and is virtually confined to those with prior UC. The clinical picture in pouchitis is highly variable; however, it can be easily categorized into three groups. Nevertheless, in most cases it is likely to represent recurrent UC in the ileal pouch. Current treatments and possible preventative strategies for pouchitis have been outlined.

Azoreductase and nitroreductase activity of bacteria in feces from patients with an ileal reservoir

Azoreductase and nitroreductase activities of bacteria in feces of five patients with ileal reservoirs were evaluated, both at the onset of symptoms of pouchitis and following recovery after treatment with drugs. All stool samples tested had bacteria with azoreductase and nitroreductase activities. Azoreductase and nitroreductase activities were higher after recovery than during attacks of pouchitis. During reestablishment of the normal microflora in the ileal reservoirs after pouchitis, the anaerobic bacteria increased and the aerobic bacteria decreased.

Prognostic factors for postoperative recurrence of Crohn's disease. Gruppo Italiano per lo Studio del Colon e del Retto (GISC)

Prognostic factors for postoperative recurrence of Crohn's disease (CD) have been widely investigated but not yet clearly identified.

PURPOSE

Aim of this study was, therefore, to analyze the association between demographic, clinical, laboratory, and surgical characteristics of patients and the cumulative probability of endoscopic postoperative recurrence.

METHODS

The study was performed in 110 patients who were enrolled in the Italian multicenter, randomized, controlled trial on the effectiveness of 5-aminosalicylic acid (5-ASA) in the prevention of postoperative recurrence in CD. Patients had undergone their first intestinal resection for CD of the terminal ileum with or without involvement of cecum ascending colon. Recurrence was defined on the basis of endoscopy. The following variables were evaluated as potential prognostic factors: gender, age, years since diagnosis, clinical course (perforative and non-perforative), Crohn's Disease Activity Index score, white blood count, erythrocyte sedimentation rate, C-reactive protein, and orosomucoids assessed before the operation. Timing of operation (elective or urgent), type of anastomosis (end-to-end, end-to-side, side-to-side), and prophylactic treatment were also evaluated. Colon ileoscopy was performed at 6, 12, 24, and 36 months after operation. The association between variables and the cumulative proportion of recurrence was analyzed both by univariate analysis (life table method, log-rank test) and multivariate regression analysis (Cox's model, stepwise procedure).

RESULTS

Results of this study indicate that, of the features considered before surgery, only leukocytosis (white blood count, >9,000 ml) was significantly associated with an increased risk of recurrence (P < 0.05) at univariate analysis. This finding was not confirmed by multivariate analysis. A trend toward a higher risk of recurrence for patients who have had a resection with end-to-end anastomosis compared with those who have had a resection and other types of anastomosis was also observed. This trend reached significantly in the group of patients submitted to treatment with 5-ASA. The multivariate analysis showed that 5-ASA-treated patients with end-to-end had a risk of recurrence more than threefold higher than those with other types of anastomosis (relative risk, 3.40; 95 percent confidence interval, 1.00-11.96; P < 0.03).

CONCLUSIONS

From a practical point of view, it has been estimated that the combination of intestinal resection plus side-to-side or end-to-side anastomosis with oral 5-ASA treatment reduces by 64 percent the postoperative recurrence rate in CD at three years follow-up.

Inability of Lactobacillus casei strain GG, L. acidophilus, and Bifidobacterium bifidum to degrade intestinal mucus glycoproteins

BACKGROUND

Lactic acid bacteria have been suggested for use in the prevention of relapse of ulcerative colitis and of recurrent pouchitis. These strains may not damage the protective intestinal mucus glycoproteins.

METHODS

Lactobacillus casei strain GG and strains isolated from a commercial fermented product (Lactobacillus acidophilus, Bifidobacterium bifidum, and a mesophylic lactic culture) were cultured in vitro on hog gastric mucin and human intestinal glycoproteins. Furthermore, germ-free rats were mono-associated with Lactobacillus GG and poly-associated with the other strains. Glycoproteins were isolated from rat distal ileum, cecum, and colon. Mucus degradation was established by assaying carbohydrates (hexosamines, hexoses, pentoses), proteins, and blood group antigenicity.

RESULTS

All strains colonized the intestinal mucus but were not found in the deep crypts. Degradation of mucus glycoproteins was observed neither in vitro nor in vivo.

CONCLUSION

The tested strains do not break down intestinal mucus glycoproteins and thus far are safe to use for therapy.

Clinical and physiological aspects of ileal pouch-anal anastomosis

Proctocolectomy with ileal pouch-anal anastomosis is the surgical treatment of choice for severe chronic ulcerative colitis and familial polyposis coli because the entire colonic mucosa is removed while anal function can be preserved and the necessity for permanent ileostomy is eliminated. Long-term functional results are generally gratifying, as defecation frequency and degree of incontinence are acceptable in most patients. Pouchitis, however, a non-specific inflammation of the ileal reservoir, is a major long-term complication occurring in a considerable number of patients. The etiology of pouchitis is unknown. Since pouchitis occurs more frequently or even exclusively in ulcerative colitis patients it is assumed that pouchitis is a novel manifestation of inflammatory bowel disease. However, bacterial overgrowth in the ileal pouch may also play a pathogenetic role. Chronic inflammation and villous atrophy of varying severity is found in virtually all pouches. Acute inflammatory changes and ulceration are associated with pouchitis.