Crohn Disease: Croitoru K

Sadowski DC, Bernstein CN, Bitton A, Croitoru K, Fedorak RN, Griffiths A, Anonymous00036. · Royal Alexandra Hospital, Edmonton, Canada. · Can J Gastroenterol. · Pubmed #19319383 No free full text.

Abstract: BACKGROUND: Guidelines regarding the use of infliximab in Crohn's disease were previously published by the Canadian Association of Gastroenterology in 2004. However, recent clinical findings and drug developments warrant a review and update of these guidelines. OBJECTIVE: To review and update Canadian guidelines regarding the use of tumour necrosis factor-alpha antibody therapy in both luminal and fistulizing Crohn's disease. METHODS: A consensus group of 25 voting participants developed a series of recommendation statements that addressed pertinent clinical questions and gaps in existing knowledge. An iterative voting and feedback process was used in advance of the consensus meeting in conjunction with a systematic literature review to refine the voting statements. These statements were brought to a formal consensus meeting held in Montreal, Quebec (March 2008), wherein each statement underwent discussion, reformulation, voting and subsequent revision until group consensus was obtained (at least 80% agreement). OUTCOME: The 47 voting statements addressed three themes: induction therapy, maintenance therapy and safety issues. As a result of the iterative process, 23 statements achieved consensus and were submitted for publication. CONCLUSION: In the past five years, tumour necrosis factor-alpha antagonist therapy has become a cornerstone in the management of moderate-to-severe Crohn's disease refractory to conventional treatment algorithms. The evidentiary base supporting the use of these drugs in Crohn's disease is substantial and strengthened by results from longterm clinical and molecular studies. However, significant gaps in knowledge exist, particularly with regard to treatment failure. Confidence in the safety of these drugs is increasing, provided that therapy is administered in a clinical setting in which potential complications can be readily recognized and treated.

Panaccione R, Fedorak RN, Aumais G, Bernstein CN, Bitton A, Croitoru K, Enns R, Feagan B, Fishman M, Greenberg G, Griffiths A, Marshall JK, Rasul I, Sadowski D, Seidman E, Steinhart H, Sutherland L, Walli E, Wild G, Williams CN, Zachos M, Anonymous00234. · University of Calgary, Calgary, Canada. · Can J Gastroenterol. · Pubmed #15372114 links to  free full text

This publication has no abstract.

Mow WS, Landers CJ, Steinhart AH, Feagan BG, Croitoru K, Seidman E, Greenberg GR, Targan SR. · Inflammatory Bowel Disease Center, Division of Gastroenterology, Cedars-Sinai Medical Center and UCLA School of Medicine, Los Angeles, California 90048, USA. · Dig Dis Sci. · Pubmed #15387358 No free full text.

Abstract: In Crohn's disease, antibiotics are used with variable efficacy, suggesting that some patients are more likely to respond. The aim of this study was to determine whether Crohn's patients with predominant serum antibody reactivity toward bacterial antigens OmpC and/or I2 were more likely to achieve remission with antibiotics. Patients with ileal or ileal with right-sided colonic Crohn's disease were studied in a double-blind trial of budesonide alone or budesonide plus metronidazole and ciprofloxacin. In the budesonide plus metronidazole and ciprofloxacin group, patients with OmpC/I2 predominant profiles had the highest remission rate, whereas the group with no antibody predominant profiles had the lowest rate. In the budesonide group, patients with the OmpC/I2 predominant profile had the lowest remission rate, and the no-antibody group rate was higher. Although not statistically significant, these results support further testing to determine whether predominant serum reactivity to certain bacterial antigens may be a marker for efficacious use of antibiotics.

Steinhart AH, Feagan BG, Wong CJ, Vandervoort M, Mikolainis S, Croitoru K, Seidman E, Leddin DJ, Bitton A, Drouin E, Cohen A, Greenberg GR. · Department of Medicine, Mount Sinai Hospital, Toronto, Ontario, Canada. · Gastroenterology. · Pubmed #12105831 No free full text.

Abstract: BACKGROUND & AIMS: Although antibiotics are frequently used to treat Crohn's disease, this practice is not supported by strong evidence from randomized trials. METHODS: We conducted a double-blind multicenter study of patients with active Crohn's disease of the ileum, right colon, or both. Patients were randomized to receive oral ciprofloxacin and metronidazole, both 500 mg twice daily, or placebo for 8 weeks. All patients received oral budesonide 9 mg once daily. The primary efficacy measure was the proportion of patients in remission at week 8. RESULTS: Of the 134 patients who were randomized, 130 were evaluated for efficacy; 66 received placebo, and 64 received antibiotics. At week 8, 21 patients (33%) assigned to antibiotics were in remission as compared with 25 patients (38%) in the placebo group (P = 0.55; absolute difference, -5%; 95% confidence interval, -21% to 11%). An interaction (P = 0.025) between treatment allocation and disease location on treatment response was identified. Among patients with disease of the colon, 9 of 17 (53%) were in remission after treatment with antibiotics, compared with 4 of 16 (25%) of those who received placebo (P = 0.10). Discontinuation of therapy because of adverse events occurred in 13 of 66 (20%) patients treated with antibiotics, compared with 0 of 68 in the group who received placebo (P < 0.001). CONCLUSIONS: In patients with active Crohn's disease of the ileum, the addition of ciprofloxacin and metronidazole to budesonide is an ineffective intervention, but this antibiotic combination may improve outcome when there is involvement of the colon.

Croitoru K, Zhou P. · Intestinal Diseases Research Program, Division of Gastroenterology, McMaster University, Hamilton, Ontario, Canada. · Curr Opin Gastroenterol. · Pubmed #15703686 No free full text.

Abstract: PURPOSE OF REVIEW: T cells are central to most inflammatory disorders of the intestine, particularly Celiac disease, graft vs. host disease, Crohn disease, and ulcerative colitis. The mechanisms by which T cells contribute to mucosal damage in these disorders have been explored using both in vitro and in vivo models. This review will highlight recent studies directed at understanding the mechanisms by which T cells are involved in the induction of mucosal damage. RECENT FINDINGS: The recent studies of in vivo T-cell activation using monoclonal anti-CD3 antibody have shown that a number of cytotoxic T-cell pathways are required and involved in the induction of mucosal damage and in particular in the induction of epithelial cell apoptosis. These include the Fas/FasL and perforin pathways. Other mediators of T-cell-induced cytotoxicity, such as TNFalpha and IFNgamma may contribute to mucosal damage but are not required for the induction of mucosal damage in vivo. In addition, several studies have tried to identify the role of regulatory mucosal T cells and the physiologically relevant triggers for T-cell-induced mucosal damage. SUMMARY: It is now clear that there are significant redundancies in the mechanisms that lead to immune-mediated mucosal damage and that the mechanisms that operate in vivo may not be predicted by in vitro experiments. These investigations are improving our understanding of the pathogenesis of immune-mediated enteropathies and will hopefully lead to new approaches to the management of these disorders.

Söderholm JD, Streutker C, Yang PC, Paterson C, Singh PK, McKay DM, Sherman PM, Croitoru K, Perdue MH. · Department of Surgery, University Hospital, SE-581 85 Linköping, Sweden. · Gut. · Pubmed #15542521 links to  free full text

Abstract: BACKGROUND AND AIMS: The exact nature of the epithelial barrier defect in Crohn's disease remains to be elucidated. Previously we showed increased permeability to proteins in ileal Crohn's disease. Our aims were to study if this barrier defect (a) involves endocytotic uptake of antigens and (b) is related to low grade inflammation not detectable by histology. METHODS: Macroscopically normal segments of distal ileum of Crohn's disease patients (n = 10) were subgrouped into non-inflamed (histologically unaffected) and slightly inflamed tissues and studied in Ussing chambers, with normal ileal specimens from colon cancer patients (n = 9) as controls. Endocytotic uptake into enterocytes of the protein antigen horseradish peroxidase was assessed by measuring the area of horseradish peroxidase containing endosomes in electron photomicrographs. Mucosal tumour necrosis factor alpha (TNF-alpha) mRNA was quantified using real time polymerase chain reaction. For comparison, the effects of low doses of TNF-alpha on endosomal uptake of horseradish peroxidase were studied in cultured T84 cells grown on filter supports. RESULTS: The area of horseradish peroxidase containing endosomes was increased (p<0.001) in enterocytes of non-inflamed ileum of Crohn's disease (2.8 (0.7) mum(2)/300 mum(2)) compared with control ileum (0.6 (0.06)). In non-inflamed mucosa, a significant association between endosomal uptake and mucosal expression of TNF-alpha mRNA (p = 0.03) was found. Low concentrations of TNF-alpha (0.25-1.0 ng/ml) enhanced the endosomal uptake of horseradish peroxidase in polarised T84 cells, without affecting transepithelial electrical resistance. CONCLUSIONS: Our findings suggest increased endosomal uptake of antigens in ileal Crohn's disease that may be mediated by TNF-alpha. These data highlight the transcellular route of antigen uptake in barrier dysfunction and implicate the interaction between epithelial cells and the innate immune system in the development of mucosal inflammation.

Collins SM, McHugh K, Croitoru K, Howorth M. · Division of Gastroenterology, McMaster University Medical Centre, Hamilton, Ontario, Canada. · Can J Gastroenterol. · Pubmed #12605247 links to  free full text

Abstract: The Crohn's and Colitis Foundation of Canada (CCFC) has established a national bank for tissue, serum and blood from patients with inflammatory bowel disease (IBD). Investigators from across the country submit material to the bank together with clinical data. Investigators may access their own patient information from the bank for their own study purposes, but the distribution of tissue is restricted to specific CCFC-funded projects. Currently, tissues are being collected from newly diagnosed, untreated IBD patients to support a recent initiative aimed at characterizing microbes in colonic and ileal biopsies from such patients. In the future, criteria for the submission of tissue will be tailored to specific research questions. This bank is believed to be the first national bank of its kind dedicated to research in Crohn's disease and ulcerative colitis