Recent advances in immunomodulation in the treatment of inflammatory bowel disease

Value of colonoscopy for prediction of prognosis in patients with ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder characterized by exacerbations and remissions. Some UC patients remain refractory to conventional medical treatment while, in others, the effectiveness of drugs is limited by side-effects. Recently, cyclosporine and leukocyte removal therapy have been used for refractory UC patients. To predict the efficacy of these therapies is important for appropriate selection of treatment options and for preparation for colectomy. Endoscopy is the cornerstone for diagnosis and evaluation of UC. Endoscopic parameters in patients with severe or refractory UC may predict a clinical response to therapies, such as cyclosporine or leukocyte removal therapy. As for the patients with quiescent UC, relapse of UC is difficult to predict by routine colonoscopy. Even when routine colonoscopy suggests remission and a normal mucosal appearance, microscopic abnormalities may persist and relapse may occur later. To more accurately identify disease activity and to predict exacerbations in UC patients with clinically inactive disease is important for deciding whether medical treatment should be maintained. Magnifying colonoscopy is useful for the evaluation of disease activity and for predicting relapse in patients with UC.

A triangulation study of the clinician and patient experiences of the use of the immunosuppressant drugs azathioprine and 6-mercaptopurine for the management of inflammatory bowel disease

AIM

The aim of this study was to explore the service for patients with inflammatory bowel disease taking or having taken azathioprine or 6-mercaptopurine in the last three years, at two District General Hospitals within the same Trust.

BACKGROUND

Published data confirm that the use of azathioprine and 6-mercaptopurine is effective in the control of inflammatory bowel disease. However, there are inconsistencies in dosing regimes, blood monitoring and duration of therapy. Regimes used have been largely based on clinicians' personal preference leading to inconsistencies in practice.

METHODS

A questionnaire, designed to elicit the experience of treatment regimes, blood monitoring and access to information was sent to 130 patients taking or having taken azathioprine or 6-mercaptopurine in the last three years. A further questionnaire was sent to 94 general practitioners and interviews were conducted with 10 hospital doctors initiating treatment.

RESULTS

The study demonstrated lack of clarity in the prescribing methods, the monitoring regimes being offered, variation in information given to patients and consequent patient knowledge.

CONCLUSION

Azathioprine and 6-mercaptopurine are increasingly being used successfully in inflammatory bowel disease, sparing the use of steroids and maintaining remission over a longer period. A review of the current literature has informed and made possible a suggested blood-monitoring regime.

RELEVANCE TO CLINICAL PRACTICE

The adoption of a protocol-led service, managed by the nurse specialist, incorporating guided self-management by patients should be considered. A shared-care approach with the patient and general practitioner with rapid access to secondary care would provide a robust system.

Ameliorative effects of sodium ferulate on experimental colitis and their mechanisms in rats

AIM: To investigate the ameliorative effects of sodium ferulate (SF) on acetic acid-induced colitis and their mechanisms in rats.

METHODS: The colitis model of Sprague-Dawley rats was induced by intracolon enema with 8% (V/V) of acetic acid. The experimental animals were randomly divided into model control, 5-aminosalicylic acid therapy group and three dose of SF therapy groups. The 5 groups were treated intracolonically with normal saline, 5-aminosalicylic acid (100 mg•kg^-1), and SF at the doses of 200, 400 and 800 mg·kg^-1 respectively and daily (8: 00 am) for 7 d 24 h following the induction of colitis. A normal control group of rats clystered with normal saline instead of acetic acid was also included in the study. Pathological changes of the colonic mucosa were evaluated by the colon mucosa damage index (CMDI) and the histopathological score (HS). The insulted colonic mucosa was sampled for a variety of determinations at the end of experiment when the animals were sacrificed by decapitation. Colonic activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), and levels of malondialdehyde (MDA) and nitric oxide (NO) were assayed with ultraviolet spectrophotometry. Colonic contents of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) were determined by radioimmunoassay. The expressions of inducible nitric oxide synthase (iNOS), cyclo-oxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB) p65 proteins in the colonic tissue were detected with immunohistochemistry.

RESULTS: Enhanced colonic mucosal injury, inflammatory response and oxidative stress were observed in the animals clystered with acetic acid, which manifested as the significant increase of CMDI, HS, MPO activities, MDA and NO levels, PGE₂ and TXB₂ contents, as well as the expressions of iNOS, COX-2 and NF-κB p65 proteins in the colonic mucosa, although the colonic SOD activity was significantly decreased compared with the normal control (CMDI: 2.9 ± 0.6 vs 0.0 ± 0.0; HS: 4.3 ± 0.9 vs 0.7 ± 1.1; MPO: 98.1 ± 26.9 vs 24.8 ± 11.5; MDA: 57.53 ± 12.36 vs 9.21 ± 3.85; NO: 0.331 ± 0.092 vs 0.176 ± 0.045; PGE₂: 186.2 ± 96.2 vs 42.8 ± 32.8; TXB₂: 34.26 ± 13.51 vs 8.83 ± 3.75; iNOS: 0.365 ± 0.026 vs 0.053 ± 0.015; COX-2: 0.296 ± 0.028 vs 0.034 ± 0.013; NF-κB p65: 0.314 ± 0.026 vs 0.039 ± 0.012; SOD: 28.33 ± 1.17 vs 36.14 ± 1.91; P < 0.01). However, these parameters were found to be significantly ameliorated in rats treated locally with SF at the given dose protocols, especially at 400 mg·kg^-1 and 800 mg·kg^-1 doses (CMDI: 1.8 ± 0.8, 1.6 ± 0.9; HS: 3.3 ± 0.9, 3.1 ± 1.0; MPO: 63.8 ± 30.5, 36.2 ± 14.2; MDA: 41.84 ± 10.62, 37.34 ± 8.58; NO: 0.247 ± 0.042; 0.216 ± 0.033; PGE₂: 77.2 ± 26.9, 58.4 ± 23.9; TXB₂: 18.07 ± 14.83; 15.52 ± 8.62; iNOS:0.175 ± 0.018, 0.106 ± 0.019; COX-2: 0.064 ± 0.018, 0.056 ± 0.014; NF-κBp65: 0.215 ± 0.019, 0.189 ± 0.016; SOD: 32.15 ± 4.26, 33.24 ± 3.69; P < 0.05-0.01). Moreover, a therapeutic dose protocol of 800 mg·kg^-1 SF was observed as effective as 100 mg·kg^-1 of 5-ASA in the amelioration of colonic mucosal injury as evaluated by CMDI and HS.

CONCLUSION: Administration of SF intracolonically may have significant therapeutic effects on the rat model of colitis induced by acetic acid enema, which was probably due to the mechanism of antioxidation, inhibition of arachidonic acid metabolism and NF-κB expression.