Therapeutic effect of Medilac-S combined with sulfasalazine in treatment of ulcerative colitis: an analysis of 22 cases

AIM: To evaluate the therapeutic effect of Medilac-S combined with sulfasalazine (SASP) in the treatment of ulcerative colitis (UC).

METHODS: Forty-six patients with mild or moderate UC (active phase) were divided into group A (n = 22) and B (n = 24). The patients in group A were treated with Medilac-S and SASP, while those in group B, serving as the controls, were treated with SASP. The total efficacy rate and the changes of main symptoms were statistically analyzed.

RESULTS: The overall efficacy of group A was 91.66%, which was higher than that of the controls (68.18%, P < 0.05). There was significant difference before and after treatment, as well as between the two groups (P < 0.05) in the changes of abdominal pain, diarrhea, mucus bloody stool and tenesmus (P < 0.05).

CONCLUSION: Combination of Medilac-S and SASP is superior to SASP alone in the treatment of UC.

Perinuclear anti-neutrophil cytoplasmic antibodies (p-anca) in chronic ulcerative colitis: Experience in a Mexican institution

AIM: To assess the prevalence and clinical value of p-ANCA in a sample of Mexican ulcerative colitis (UC) patients.

METHODS: In a prospective, IRB-approved protocol, p-ANCA was determined in 80 patients with UC (mean age, 32 ± 12.9 years). The severity and extension of disease were determined by clinical methods, searching a statistical association with p-ANCA status.

RESULTS: p-ANCA were detected in 41 (51%) patients. Severity of disease was the only clinical variable statistically associated with their presence (P < 0.0001; OR = 9; CI 95% = 3.2-24.7).

CONCLUSION: The prevalence of p-ANCA was similar to that reported in other countries. Their presence was associated to UC severity, but offered no more information than the obtained by clinical methods.

Effects of adacolumn selective leukocytapheresis on plasma cytokines during active disease in patients with active ulcerative colitis

AIM: To investigate the relationship between ulcerative colitis (UC) clinical activity index (CAI) and circulating levels of IL-1ra, IL-10, IL-6 and IL-18.

METHODS: Blood levels of IL-1ra, IL-10, IL-6 and IL-18 were measured in 31 patients with active UC, the mean CAI was 11.1, ranging from 5-25; and 12 healthy individuals as controls. Patients were given granulocyte and monocyte adsorptive apheresis (GMA) with Adacolumn. Leucocytes which bear the FcγR and complement receptors were adsorbed to the column leucocytapheresis carriers. Each patient could receive up to 11 GMA sessions over 8 wk.

RESULTS: We found strong correlations between CAI and IL-10 (r = 0.827, P < 0.001), IL-6 (r = 0.785, P < 0.001) and IL-18 (r = 0.791, P < 0.001). IL-1ra was not correlated with CAI. Following GMA therapy, 24 of the 31 patients achieved remission and the levels of all 4 cytokines fell to the levels in healthy controls. Further, blood levels of IL-1ra and IL-10 increased at the column outflow and inflow at 60 min suggesting release from leucocytes that adhered to the carriers.

CONCLUSION: Elevated blood levels of IL-6 and IL-18 together with peripheral blood granulocytes and monocytes/macrophages in patients with active UC show activative behaviour and increased survival time can be pro-inflammatory and the targets of GMA therapy.

Rectal nitric oxide as biomarker in the treatment of inflammatory bowel disease: Responders versus nonresponders

AIM: To explore rectal nitric oxide (NO) as biomarker of treatment response in ulcerative colitis (UC) and Crohn’s disease (CD), and examine relationships between rectal NO, mucosal expression of NO synthases (NOS), and pro-inflammatory cytokines.

METHODS: Twenty-two patients with UC and 24 with CD were monitored during steroid treatment. Rectal NO levels were measured and clinical activities were assessed on days 1, 3, 7 and 28. Mucosal presence of NOS and pro-inflammatory cytokines were analyzed by immunohistochemistry and RT-PCR.

RESULTS: Active UC and CD displayed markedly increased rectal NO levels (10 950 ± 7610 and 5 040 ± 1 280 parts per billion (ppb), respectively) as compared with the controls (154 ± 71 ppb, P < 0.001). Rectal NO correlated weakly with disease activity in both UC and CD (r = 0.34 for UC and r = 0.48 for CD, P < 0.01). In 12 patients, a steroid-refractory course led to colectomy. These patients had only slightly increased NO levels (UC: 620 ± 270 ppb; CD: 1260 ± 550 ppb) compared to those with a therapeutic response (UC: 18 860 ± 530 ppb, P < 0.001; CD: 10 060 ± 3200 ppb, P < 0.05).

CONCLUSION: Rectal NO level is a useful biomarker of treatment response in IBD as low NO levels predicts a poor clinical response to steroid treatment.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

Therapeutic mechanism of Changyanqing in treatment of colitis induced by dextran sulfate sodium

AIM: To investigate the therapeutic effects of Changyanqing on dextran sulfate sodium(DSS)-induced colitis and its mechanism.

METHODS: DSS was used to establish the model of experimental colitis in 40 mice. Then the mice were averagely randomized into 4 groups (A, B, C, and D). The mice in group A, B, and C were treated with Changyanqing, salicylazosulfapyridine (SASP), and Changyanqing + SASP, respectively, and those in group D served as controls. Changyanqing was administratered by gastric irragation at a dose of 0.2 mL/(20g•d) for 7 d. The disease activity index (DAI) and the activity of intestinal myeloperoxidase (MPO) were observed. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 mRNA were detected by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: In comparison with those in the controls, the DAI (1.413 ± 0.835 vs 2.167 ± 0.911, P < 0.05), and activity of MPO (72.4 ± 0.590 nkat/g vs 117.0 ± 0.902 nkat/g, P < 0.05), and the expression of TNF-α (0.841 ± 0.190 vs 1.320 ± 0.282, P < 0.05), IL-1β (0.641 ± 0.095 vs 0.920 ± 0.082, P < 0.05), and IL-6 (1.241 ± 0.247 vs 1.620 ± 0.312, P < 0.05) mRNA were significantly decreased in group A. The above decreases were more significant in group C (DAI: 0.608 ± 0.449; MPO: 27.3 ± 0.211; TNF-α: 0.339 ± 0.081; IL-1β: 0.239 ± 0.073; IL-6: 0.639 ± 0.141)(P < 0.01). There was marked difference between group A and B (P > 0.05).

CONCLUSION: Changyanqing is effective in the treatment of DSS-induced colitis, which may be associated with the decrease of DAI, MPO activity, and TNF-α, IL-1β and IL-6 mRNA expression.

Treatment of active steroid-refractory inflammatory bowel diseases with granulocytapheresis: Our experience with a prospective study

AIM: To report our experience with the use of granulocytapheresis (GCAP) in 14 patients with active steroid-refractory inflammatory bowel disease (IBD) in order to evaluate its efficacy in achieving remission and maintaining a long lasting symptom-free period.

METHODS: The activity of the disease was evaluated by clinical activity index (CAI) and endoscopic index (EI) in ulcerative colitis (UC), while by Crohn’s disease activity index (CDAI) in Crohn's disease (CD). The patients were treated using the Adacolumn^TM system, an adsorption column which selectively binds to granulocytes and monocytes. One session/week of GCAP was performed for 5 wk. Steroids were stopped during apheresis.

RESULTS: All the patients completed the five-week course showing no complications. At the end of the last session, 93% of patients showed a clinical remission of the disease that persisted for 6 mo. Nine months after the end of the treatment, 60% of the cases maintained remission, while 23% of the patients were still in clinical remission after 12 mo.

CONCLUSION: Even if the number of our patients with steroid-refractory IBDs was not big, we can assert that GCAP is well tolerated and effective, especially in the first six months after the treatment, in a significant percentage of cases. The rate of sustained response drops slightly after 6 mo and significantly after 12 mo, however the absence of severe side effects can be a stimulus for further evaluating new schedules of treatment.

Novel susceptibility genes in inflammatory bowel disease

The inflammatory bowel disease, Crohn’s disease and ulcerative colitis, are polygenic disorders with important environmental interactions. To date, the most widely adopted approach to identifying susceptibility genes in complex diseases has involved genome wide linkage studies followed by studies of positional candidate genes in loci of interest. This review encompasses data from studies into novel candidate genes implicated in the pathogenesis of inflammatory bowel disease. Novel techniques to identify candidate genes-genome wide association studies, yeast-two hybrid screening, microarray gene expression studies and proteomic profiling, are also reviewed and their potential role in unravelling the pathogenesis of inflammatory bowel disease are discussed.

Current concept on the pathogenesis of inflammatory bowel disease-crosstalk between genetic and microbial factors: Pathogenic bacteria and altered bacterial sensing or changes in mucosal integrity take “toll”

The pathogenesis of inflammatory bowel disease (IBD) is only partially understood. Various environmental and host (e.g. genetic-, epithelial-, immune and non-immune) factors are involved. It is a multifactorial polygenic disease with probable genetic heterogeneity. Some genes are associated with IBD itself, while others increase the risk of ulcerative colitis (UC) or Crohn’s disease (CD) or are associated with disease location and/or behaviour. This review addresses recent advances in the genetics of IBD. The article discusses the current information on the crosstalk between microbial and genetic factors (e.g. NOD2/CARD15, SLC22A46A5 and DLG5). The genetic data acquired in recent years help in understanding the pathogenesis of IBD and can identify a number of potential targets for therapeutic intervention. In the future, genetics may help more accurately diagnose and predict disease course in IBD.

Effect of IBD sera on expression of inducible and endothelial nitric oxide synthase in human umbilical vein endothelial cells

AIM: To study the expression of endothelial and inducible nitric oxide synthases (eNOS and iNOS) and their role in inflammatory bowel disease (IBD).

METHODS: We examined the effect of sera obtained from patients with active Crohn’s disease (CD) and ulcerative colitis (UC) on the function and viability of human umbilical vein endothelial cells (HUVEC). HUVECs were cultured for 0-48 h in the presence of a medium containing pooled serum of healthy controls, or serum from patients with active CD or UC. Expression of eNOS and iNOS was visualized by immunofluorescence, and quantified by the densitometry of Western blots. Proliferation activity was assessed by computerized image analyses of Ki-67 immunoreactive cells, and also tested in the presence of the NOS inhibitor, 10^-4 mol/L L-NAME. Apoptosis and necrosis was examined by the annexin-V-biotin method and by propidium iodide staining, respectively.

RESULTS: In HUVEC immediately after exposure to UC, serum eNOS was markedly induced, reaching a peak at 12 h. In contrast, a decrease in eNOS was observed after incubation with CD sera and the eNOS level was minimal at 20 h compared to control (18% ± 16% vs 23% ± 15% P<0.01). UC or CD serum caused a significant increase in iNOS compared to control (UC: 300% ± 21%; CD: 275% ± 27% vs 108% ± 14%, P<0.01). Apoptosis/necrosis characteristics did not differ significantly in either experiment. Increased proliferation activity was detected in the presence of CD serum or after treatment with L-NAME. Cultures showed tube-like formations after 24 h treatment with CD serum.

CONCLUSION: IBD sera evoked changes in the ratio of eNOS/iNOS, whereas did not influence the viability of HUVEC. These involved down-regulation of eNOS and up-regulation of iNOS simultaneously, leading to increased proliferation activity and possibly a reduced anti-inflammatory protection of endothelial cells.

Expression of Foxp3 mRNA in peripheral blood monocytes of patients with ulcerative colitis

AIM: To investigate the level of Foxp3 mRNA in the peripheral blood monocytes (PBMCs) of patients with ulcerative colitis (UC), and its relationship with activity of UC.

METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to examine Foxp3 mRNA expression in the PBMCs from 22 cases with UC in active stage, 20 cases at stable stage, and 30 normal controls.

RESULTS: Foxp3 mRNA expression was lower in patients with UC at active stage than that in the controls (1.58 ± 0.31 vs 3.27 ± 0.40, P < 0.05), while Foxp3 mRNA expression in UC at stable stage was not significantly different from that in the controls (P = 0.104). The level of Foxp3 mRNA in the PBMCs in active UC was negatively correlated with the Walmsley renal scoring (r = -0.756, P = 0.000).

CONCLUSION: Foxp3 mRNA expression in the PBMCs may be involved in the pathogenesis and activity of UC.

Association of the HLA-DRB1*0701 allele with perinuclear anti-neutrophil cytoplasmatic antibodies in Mexican patients with severe ulcerative colitis

AIM: To determine the association between the HLA-DRB1 alleles and perinuclear anti-neutrophil cytoplasmatic antibodies (p-ANCA) positive in Mexican patients with ulcerative colitis (UC).

METHODS: Ninety Mexican mestizo patients (45 females) with UC, confirmed by biopsy, were studied. High resolution HLA typing was performed by PCR-SSO reverse dot blot and PCR-SSP. Molecular typing techniques were applied to define HLA-DRB1 alleles. Enzyme-linked immunosorbent assay and immunofluorescence techniques were used to detect p-ANCA.

RESULTS: Forty-eight (53%) UC patients were positive for p-ANCA by ELISA and IF. We found that p-ANCA-positive UC patients had a significantly increased frequency of HLA-DR7 compared with p-ANCA-negative controls (22% vs 5.1%; pC = 0.02, OR = 5.2, CI 95%: 1.06-37.82). Disease activity was scored as severe in 20 patients, moderate in 8, mild in 14 and no activity in the remaining 38 patients according to the Truelove and Witts criteria. Subgroup analysis showed a significantly increased frequency of the HLA-DRB1*07 allele in 15 of 20 UC patients with severe activity of UC and p-ANCA positivity [100% vs 0%; pC = 0.0000001; OR = 35]. No significant differences were found between p-ANCA positive patients, HLA-DR alleles and other clinical features such as extraintestinal manifestations, proctocolectomy and extension.

CONCLUSION: The HLA-DRB1*07 is associated with p-ANCA positive UC Mexican patients.

Roles of hepatocyte growth factor, c-Met and epidermal growth factor receptor in repair of colonic mucosa from patients with ulcerative colitis

AIM: To investigate the expression of hepatocyte growth factor (HGF), c-Met and epidermal growth factor receptor (EGFR) in colonic mucosa from patients with active or inactive ulcerative colitis and their clinical significances.

METHODS: Forty-two patients with ulcerative colitis were divided into 2 groups (active: n = 25; inactive: n = 17) according to the modifi-ed Williams Disease Activity Index (DAI). Health examinees from outpatient department or patients hospitalized for irritable bowel syndrome were selected as controls. All colon-ic mucosa specimens were obtained from colonoscopic examination. SABC immuno-histochemistry was used to evaluate the expres-sion of hepatocyte growth factor and c-Met, and SP immunohistochemistry was used to evaluate the expression of epidermal growth factor recep-tor and proliferating cell nuclear antigen.

RESULTS: In control group, active and inactive ulcerative colitis group, the positive rates of HGF expression were 25%, 88% and 100%, respectively, and those of c-Met expression were 25%, 92% and 100%, respectively. There were significant differences among the above three groups (HGF: χ² = 62.84, P < 0.01; c-Met: χ² = 62.34, P < 0.01). The expression of EGFR in control group, active and inactive ulcerative colitis group were 25%, 92% and 100%, respect-ively, and those of PCNA were 0, 36%, and 100%, respectively. There also existed significant differences among the above three groups (χ² = 54.34, P < 0.01; χ² = 67.50, P <0.01). In addition, the expression of HGF, c-Met and EGFR in ulcerative colitis were significantly correlated with the over-expression of PCNA (r = 0.648, P < 0.01; r = 0.645, P < 0.01; r = 0.565, P < 0.01, respectively).

CONCLUSION: HGF, c-Met and EGFR may be involved in the repair process of inflamed mucosa in ulcerative colitis.

Expression of macrophage migration inhibitory factor and activation of nuclear factor-κB in colon tissues of rats with ulcerative colitis

AIM: To detect the expression of macrophage migration inhibitory factor (MIF) and nuclear factor-κB (NF-κB) in the colon tissues of rats with ulcerative colitis, and investigate the role of MIF in pathogenesis of ulcerative colitis.

METHODS: Twenty-four Sprague-Dawley rats were randomly divided into three groups: normal group (n = 8), model groupⅠ(n = 8), model groupⅡ(n = 8); The rat in model groupⅠ and Ⅱ treated with 50 and 100 mg/kg 2,4,6-trinitrobenzene sulfonic acid (TNBS), respectively, to establish light and severe colitis model. The disease activity index (DAI) was calculated every day, and the expression of MIF in colon tissues was detected by semi-quantitative reverse transcription chain reaction (RT-PCR). The expression of NF-κB was examined by immunohistochemistry, and the myeloperoxidase (MPO) activity was detected by biochemistry.

RESULTS: In normal group, the MPO activity, DAI, NF-κB and MIF mRNA level were 0.38 ± 0.18 U/g, 0.51 ± 0.28, 0.18 ± 0.05 and 0.11 ± 0.03, respectively; in model groupⅠthey were 1.68 ± 0.45 U/g, 5.04 ± 0.73, 0.62 ± 0.08 and 0.65 ± 0.04, respectively; in model groupⅡthey were 2.70 ± 0.35 U/g, 8.13 ± 0.71, 0.78 ± 0.11 and 0.81 ± 0.05, respectively. In comparison with that in the normal controls, the expression of MIF mRNA increased significantly (P < 0.05), and the activity of NF-κB and MPO and DAI also increased significantly (P < 0.05) in model group, especially in model groupⅡ.

CONCLUSION: MIF may be involved in the pathogenesis of TNBS-induced ulcerative colitis and the mechanism may be correlated with NF-κB activation and excessive expression of inflammatory cytokine.

Pulse cyclophosphamide therapy for inflammatory bowel disease

AIM: To assess the efficacy of intravenous cyclophosphamide pulse therapy for refractory inflammatory bowel disease (IBD).

METHODS: We included in our cohort eight patients with (moderate/severe) steroid refractory IBD (4 with ulcerative colitis and 4 with Crohn’s disease). They all received 6 cycles of intravenous cyclophosphamide (800 mg) per month.

RESULTS: Patients entered into remission after the second/third cyclophosphamide pulse. Disease activity decreased. There were no side effects and toxicity. All the patients went into long lasting remission. All Crohn’s disease patients and 3 of 4 ulcerative colitis patients achieved complete remission. One patient with ulcerative colitis showed an impressive clinical response but did not enter into remission. For the maintenance, patients with Crohn’s disease were treated with methotrexate (15 mg/wk) and patients with ulcerative colitis were treated with azathioprine (2.5 mg/kg body weight/d).

CONCLUSION: Remission was maintained in all patients for 6 mo on the average. The drug was well tolerated. These findings suggest that aggressive immunosuppressive therapy may be useful in some refractory patients and further controlled study should be considered in order to fully evaluate this type of treatment as a potential therapy for IBD..

Relationships between mucinous gastric carcinoma, MUC2 expression and survival

AIM: Pouchitis develops in ileoanal pouches in up to 50% of patients with ulcerative colitis during the first 10 years after pouch surgery while being rare in patients after proctocolectomy for familial adenomatous polyposis coli (FAP) syndrome. Defensins are major components of the innate immune system and play a significant role in gastrointestinal microbial homeostasis. Pouch defensin and cytokine expression were correlated with states of pouch inflammation to study their role in pouchitis.

METHODS: Patients with ulcerative colitis and FAP syndrome were stratified into groups with pouches after surgery, pouches without or with pouchitis. Biopsies from terminal ileum from a healthy intestine or from normal terminal ileum of patients with ulcerative colitis served as controls. mRNA from pouches and controls was analysed for defensin and cytokine expression.

RESULTS: Expression of defensins was increased in all pouches immediately after surgery, compared to ileum of controls. Initially, pouches in ulcerative colitis revealed higher defensin expression than FAP pouches. Defensin expression declined in both patient groups and increased again slightly in pouchitis in patients with ulcerative colitis. FAP pouches without pouchitis had strong expression of β-defensin hBD-1, while all other defensins remained at low levels. Cytokine expression in ulcerative colitis pouches was high, while FAP pouches showed moderately elevated cytokines only after surgery.

CONCLUSION: Development of pouchitis correlates with decreased defensin expression in ulcerative colitis in addition to high expression of cytokines. The low incidence of pouchitis in FAP pouches correlates with increased expression of hBD-1 β- defensin in association with low cytokine levels.

Severity of ulcerative colitis is associated with a polymorphism at diamine oxidase gene but not at histamine N-methyltransferase gene

AIM: To analyse the role of two common polymorphisms in genes coding for histamine metabolising enzymes as it relates to the risk to develop ulcerative colitis (UC) and the clinical course of these patients.

METHODS: A cohort of 229 unrelated patients with UC recruited from a single centre and 261 healthy volunteers were analysed for the presence of Thr105Ile and His645Asp amino acid substitutions at histamine N-methyltransferase (HNMT) and diamine oxidase (ABP1) enzymes, respectively, by amplification-restriction procedures. All patients were phenotyped and followed up for at least 2 years (mean time 11 years).

RESULTS: There were no significant differences in the distribution of ABP1 alleles between ulcerative colitis patients and healthy individuals [OR (95% CI) for variant alleles = 1.22 (0.91-1.61)]. However, mutated ABP1 alleles were present with higher frequency among the 58 patients that required immunosuppresive drugs [OR (95 % CI) for carriers of mutated alleles 2.41 (1.21-4.83; P = 0.006)], with a significant gene-dose effect (P = 0.0038). In agreement with the predominant role of ABP1 versus HNMT on local histamine metabolism in human bowel, the frequencies for carriers of HNMT genotypes or mutated alleles were similar among patients, regardless clinical evolution, and control individuals.

CONCLUSION: The His645Asp polymorphism of the histamine metabolising enzyme ABP1 is related to severity of ulcerative colitis.

Safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis therapy for ulcerative colitis

Active ulcerative colitis (UC) is frequently associated with infiltration of a large number of leukocytes into the bowel mucosa. Therefore, removal of activated circulating leukocytes by apheresis has the potential for improving UC. In Japan, since April 2000, leukocytapheresis using Adacolumn has been approved as the treatment for active UC by the Ministry of Health and Welfare. The Adacolumn is an extracorporeal leukocyte apheresis device filled with cellulose acetate beads, and selectively adsorbs granulocytes and monocytes/macrophages. To assess the safety and clinical efficacy of granulocyte and monocyte adsorptive apheresis (GMCAP) for UC, we reviewed 10 open trials of the use of GMCAP to treat UC. One apheresis session (session time, 60 min) per week for five consecutive weeks (a total of five apheresis sessions) has been a standard protocol. Several studies used modified protocols with two sessions per week, with 90-min session, or with a total of 10 apheresis sessions. Typical adverse reactions were dizziness, nausea, headache, flushing, and fever. No serious adverse effects were reported during and after GMCAP therapy, and almost all the patients could complete the treatment course. GMCAP is safe and well-tolerated. In the majority of patients, GMCAP therapy achieved clinical remission or improvement. GMCAP is a useful alternative therapy for patients with steroid-refractory or -dependent UC. GMCAP should have the potential to allow tapering the dose of steroids, and is useful for shortening the time to remission and avoiding re-administration of steroids at the time of relapse. Furthermore, GMCAP may have efficacy as the first-line therapy for steroid-naive patients or patients who have the first attack of UC. However, most of the previous studies were uncontrolled trials. To assess a definite efficacy of GMCAP, randomized, double-blind, sham-controlled trials are necessary. A serious problem with GMCAP is cost; a single session costs ¥145 000 ($1 300). However, if this treatment prevents hospital admission, re-administration of steroids and surgery, and improves a quality of life of the patients, GMCAP may prove to be cost-effective.

Role of nuclear factor-kappa B expression in steroid-resistant ulcerative colitis

AIM: To investigate the relationship between nuclear factor-kappa B (NF-κB) and the occurrence of ulcerative colitis (UC), and to explore the role of NF-κB expression in steroid resistance of UC.

METHODS: The activation of NF-κB was investigated in the UC biopsies from 15 steroid-resistant cases of the 20 steroid-sensitive patients with an acute episode of moderate or severe UC. Sixteen normal persons were used as controls.

RESULTS: Before the steroid treatment, the expression of NF-κB p65 were significantly different between the steroid-resistant patients and the normal controls (6.1 ± 2.9 vs 1.1 ± 0.8, P < 0.01), as well as between the steroid-sensitive patients and the normal controls (5.9 ± 2.7 vs 1.1 ± 0.8, P < 0.01). There was no significant difference between the steroid-sensitive group and the steroid-resistant group before the steroid treatment (P > 0.05), while there was significant difference between them after the steroid treatment (1.3 ± 0.8 vs 5.4 ± 2.4, P < 0.01). The expression of NF-κB p65 in the steroid-sensitive group has significant difference before and after the steroid treatment (5.9 ± 2.7 vs 1.3 ± 0.8, P < 0.01), while no significant difference in the steroid-resistant group (P > 0.05).

CONCLUSION: The expression of NF-κB p65 is closely related with the occurrence and development of UC. The changes of NF-κB expression before and after the steroid treatment may be helpful for the identification of steroid resistance and can be used as an index for the early recognition of steroid resistance.

Effects of rhubarb polysacchrides on apoptosis of colonic epithelial cells and peripheral blood polymorphonuclear neutrophils in mice with ulcerative colitis

AIM: To investigate the effects of rhubarb polysac-chrides (RP) on the apoptosis of colonic epithelial cells and peripheral blood polymorphonuclear neutrophils (PMN) in mice with ulcerative colitis, and to explore the mechanisms of RP in the treatment of ulcerative colitis.

METHODS: A mouse mode1 of ulcerative colitis was induced with 2, 4, 6-trinitrobenzene sulfonic acid (TNBS) by enema. The mice were divided into three groups: nomal control, model, and RP treatment (400 mg/kg) group. TUNEL method was used to investigate the apoptosis of cells in colon, and the expression of Fas and FasL protein were measured by Western-blot. The level of Caspase 3 expression was detected by immunohistochemistry. Meanwhile, flow cytometry was used to examine the apoptosis of PMN.

RESULTS: The apoptosis level of colonic epithelial cells was dramatically higher in the model mice than that in the normal controls, while the rate of PMN apoptosis was significantly lower in the former (40.5 ± 7.8% vs 57.7 ± 8.2%, P < 0.01). However, the apoptosis level of colonic epithelial cells in RP treated mice was markedly lower than that in the model group, while the rate of PMN apoptosis was notably higher in the former (46.3 ± 6.5% vs 40.5 ± 7.8%, P < 0.01). In model group, the expression of Caspase 3, Fas, and FasL protein were significantly increased in comparison with those in the normal controls, but 3 d after treatment with RP, the expression of Caspase 3, Fas, and FasL protein were remarkably decreased as compared with those in the model mice.

CONCLUSION: Rhubarb polysacchrides can protect the intestinal tract against ischemic inflammation by down-regulation of Caspase-3 expression, which leads to the inhibition of apoptosis induced by Fas/FasL pathway.

Effects of rosiglitazone on expression of NF-κB and ICAM-1 in rats with ulcerative colitis

AIM: To investigate the effect of rosiglitazone on the expression of nuclear factor-kappa B (NF-κB) and intercellular adhesion molecule-1 (ICAM-1) in the colon mucosa of rats with ulcerative colitis.

METHODS: The rat colitis model was induced by the combined enema of trinitrobenzene sulphonic acid (TNB) and ethanol. The experimental animals were randomly divided into six groups: normal group, model group, Sulfasalazine (SASP) group (100 mg/kg), and 3 rosiglitazone groups (2, 4, 8 mg/kg). The saline, SASP, and different concentrations of rosiglitazone were administered by gastric irrigation daily, respectively, from 24 h after the establishment of model to the end of experiment. The disease activity index (DAI) and colon mucosa damage index (CMDI) of the rats were observed and evaluated. The activity of myeloperoxidase (MPO) was measured by biochemical method. The expression of NF-κBp65 and ICAM-1 protein were detected by immunohistochemistry.

RESULTS: As compared with the normal group, the DAI, CMDI, and the activity of MPO in the colon tissues of the rats in the model group were significantly increased (2.11 ± 1.29 vs 0.11 ± 0.17; 2.67 ± 0.82 vs 0.33 ± 0.52; 1.26 ± 0.36 U/g vs 0.27 ± 0.07 U/g; all P < 0.01). The expression of NF-κBp65 and ICAM-1 in the rat colon mucosa were significantly increased (0.7 081 ± 0.0 671 vs 0.2 293 ± 0.0 474; 0.4 846 ± 0.0 366 vs 0.1 783 ± 0.0 201, both P < 0.01). The DAI, CMDI, and the activity of MPO in the 4 mg/kg and 8 mg/kg rosiglitazone group were significantly decreased (DAI: 1.11 ± 0.50, 0.61 ± 0.25 vs 2.11 ± 1.29, P < 0.05; CMDI: 1.67 ± 0.52, 1.17 ± 0.75 vs 2.67 ± 0.82, P < 0.05; 0.82 ± 0.13, 0.51 ± 0.10 U/g vs 1.26 ± 0.36 U/g, P< 0.01) in comparison with those in the model group, and the expression of NF-κB and ICAM-1 were also decreased (NF-κB: 0.4 544 ± 0.0 379, 0.2 577 ± 0.0 131 vs 0.7 081 ± 0.0 671, P < 0.01; ICAM-1: 0.3 854 ± 0.0 277, 0.2 830 ± 0.0 234 vs 0.4 846 ± 0.0 366, P < 0.01). The expression of NF-κBp65 and ICAM-1 in rat colon mucosa was positively correlated (r = 0.927, P < 0.01), and the expression of ICAM-1 and the activity of MPO was also positively correlated with each other (r = 0.580, P < 0.01).

CONCLUSION: Rosiglitazone has protective effect against rat ulcerative colitis, and its mechanism may be related with the inhibition of the NF-κB activation, reduction of the ICAM-1, and decreasing of neutrophil invasion.

Changes of plasma fasting carnitine ester profile in patients with ulcerative colitis

AIM: To determine the plasma carnitine ester profile in adult patients with ulcerative culitis (UC) and compared with healthy control subjects.

METHOD: Using ESI triple quadrupole tandem mass spectrometry, the carnitine ester profile was measured in 44 patients with UC and 44 age- and sex-matched healthy controls.

RESULTS: There was no significant difference in the fasting free carnitine level between the patients with UC and the healthy controls. The fasting propionyl- (0.331 ± 0.019 vs 0.392 ± 0.017 μmol/L), butyryl- (0.219 ± 0.014 vs 0.265 ± 0.012), and isovalerylcarnitine (0.111 ± 0.008 vs 0.134 ± 0.008) levels were decreased in the UC patients. By contrast, the level of octanoyl- (0.147 ± 0.009 vs 0.114 ± 0.008), decanoyl- (0.180 ± 0.012 vs 0.137 ± 0.008), myristoyl- (0.048 ± 0.003 vs 0.039 ± 0.003), palmitoyl- (0.128 ± 0.006 vs 0.109 ± 0.004), palmitoleyl- (0.042 ± 0.003 vs 0.031 ± 0.002) and oleylcarnitine (0.183 ± 0.007 vs 0.163 ± 0.007; P < 0.05 in all comparisons) were increased in the patients with UC.

CONCLUSION: Our data suggest selective involvement of the carnitine esters in UC patients, probably due to their altered metabolism.

Activity of cytokines in dinitrochlorobenzene-induced colitis in mice

AIM: To observe the changes of serum pro-inflammatory and anti-inflammatory cytokine activities in mice with experimental colitis.

METHODS: A total of 33 BALB/c mice were randomly divided into control (n = 15) and experiment group(n = 18). After sensitized by 2, 4-dinitrochlorobenzene (DNCB) smeared on the abdominal skin, the mice in the experiment group were challenged with DNCB enema, while those in the control group were treated with ethanol. The body weight, stool viscosity and hematochezia were observed and accumulated as disease active index (DAI) score; the colon pathological score was achieved by macropathology and HE staining of section prepared for microscopy. The activity of serum IL-1, TNFa, IL-6, IL-4 and IL-10 was determined.

RESULTS: The percentage of diarrhea was 59% in the experiment mice 24 h after DNCB treatment, and serious weight loss was found, 20% mice died. Pathologically, the mice in the control group had normal histological structures and glands, and no ulcer was found except for occasional light mucosal congestion. However, the decrease in the number of glands and disturbance of tissue structure were observed in the mice of experiment group. Moreover, erosion, hemorrhage, necrosis as well as deeper ulcers were easily seen. As compared with those in the control mice, the DAI (3.82 ± 2.77 vs 1.25 ± 1.65, P <0.05), pathologic score (2.47 ± 1.33 vs 0.38 ± 0.72, P <0.05) were significantly increased in the experiment mice. The activities of pro-inflammatory cytokines such as IL-1(112.9 ± 8.3 ng/L vs 81.2 ± 16.3 ng/L, P <0.01), TNF-a(137.9 ±36.7 ng/L vs 110.3 ± 22.4 ng/L, P <0.05), and IL-6(48.2 ± 4.3 ng/L vs 36.1 ± 7.2 ng/L, P <0.01) were significantly increased, while the activities of anti-inflammatory cytokines such as IL-4 (96.7 ± 16.5 ng/L vs 130.1 ± 13.1 ng/L, P <0.01) and IL-10(107.3 ± 31.2 ng/L vs 149.8 ± 45.1 ng/L, P <0.01) were markedly lowered.

CONCLUSION: The pathological progress of colitis induced by DNCB is possiblely related with the increased activities of pro-inflammatory cytokines and decreased activities of anti-inflammatory cytokines.

Experimental research on treatment of ulcerative colitis with integrative traditional Chinese and Western medicine

AIM: To explore the effect of the clyster treatment with integrated traditional Chinese and Western medicine on ulcerative colitis (UC), and to investigate its mechanism.

METHODS: The mouse model of UC was established, and then the rats were treated (clyster) with the combination of tin-like powder, dexamethasone, gentamicin, and berberine. Then the therapeutic effect was observed, and the mechanism of the treatment was analyzed.

RESULTS: The disease active index (DAI) and histopathologic score (HPS) of the low dose (DAI: 5.10±4.07, HPS: 8.00±6.38), the moderate dose (DAI: 0.80±1.87, HPS: 1.30±1.49), the high dose (DAI: 1.00±1.94, HPS: 0.90±1.45), and the positive control group (DAI: 5.30±4.37, HPS: 8.00±5.12) were markedly lower than those of the negative control group (DAI: 8.60±1.26, HPS: 13.20±1.69) (all P <0.05). The DAI and HPS of the moderate dose group were markedly lower than those of the low dose group and the positive control group (all P <0.05), but there was no significant difference between the moderate and high dose group (P >0.05). The levels of interleukin-4 (IL-4) of the low, moderate, and high dose group, and the positive control group were markedly lower than those of the negative control group (32.33±15.30, 25.79±6.33, 29.92±12.81, 28.45±9.30 vs 63.89±11.31, all P <0.05), but the levels of interferon-γ (IFN-γ) were markedly higher than those of the negative control group (198.38±31.46, 187.49±13.04, 188.14±14.11, 207.64±41.44 vs 127.41±21.47, all P <0.05).

CONCLUSION: The combination enema of tin-like powder, dexamethasone, gentamicin, and berberine has definite therapeutic effect on UC, which may be related with its regulation on IL-4 and IFN-γ level.

Favorable response to subcutaneous administration of infliximab in rats with experimental colitis

AIM: To investigate the influence of infliximab (Remicade) on experimental colitis produced by 2,4,6,trinitrobenzene sulfonic acid (TNBS) in rats.

METHODS: Thirty-six Wistar rats were allocated into four groups (three groups of six animals each and a fourth of 12 animals). Six more healthy animals served as normal controls (Group 5). Group 1: colitis was induced by intracolonic installation of 25 mg of TNBS dissolved in 0.25 mL of 50% ethanol and infliximab was subcutaneously administered at a dose of 5 mg/kg BW; Group 2: colitis was induced and infliximab was subcutaneously administered at a dose of 10 mg/kg BW; Group 3: colitis was induced and infliximab was subcutaneously administered at a dose of 15 mg/kg BW; Group 4: colitis was induced without treatment with infliximab. Infliximab was administered on d 2–6. On the 7^th d, all animals were killed. The colon was fixed in 10% buffered formalin and examined by light microscopy for the presence and activity of colitis and the extent of tissue damage. Tumor necrosis factor-alpha (TNF-α) and malondialdehyde (MDA) were also measured.

RESULTS: Significant differences concerning the presence of reparable lesions and the extent of bowel mucosa without active inflammation in all groups of animals treated with infliximab compared with controls were found. Significant reduction of the tissue levels of TNF-α in all groups of treated animals as compared with the untreated ones was found (0.47±0.44, 1.09±0.86, 0.43±0.31 vs 18.73±10.53 respectively). Significant reduction in the tissue levels of MDA was noticed in group 1 as compared to group 4, as well as between groups 2 and 4.

CONCLUSION: Subcutaneous administration of infliximab reduces the inflammatory activity as well as tissue TNF-α and MDA levels in chemical colitis in rats. Infliximab at a dose of 5 mg/kg BW achieves better histological results and produces higher reduction of the levels of TNF-α than at a dose of 10 mg/kg BW. Infliximab at a dose of 5 mg/kg BW produces higher reduction of tissue MDA levels than at a dose of 15 mg/kg BW.

Expression of matrix metalloproteinase-2 and matrix metalloproteinase-9 protein in colonic carcinoma

AIM: To analyze the correlation of matrix metallopro-teinase-2(MMP-2) and MMP-9 protein expression with the pathological factors in colonic carcinoma, and to investigate the clinical significance of matrix metallo-proteinases in the occurrence of colonic carcinoma.

METHODS: The expression of MMP-2 and MMP-9 protein were measured by immunohistochemistry in the resected specimens from 31 patients with colonic carcinoma, and their relations with clinicopathologic factors were analyzed by SPSS 10.0 for Windows software. The specimens from ulcerative colitis (n = 20), colon adenoma (n = 21), and normal colon (n = 10) tissues were used as the controls.

RESULTS: The positive rate of MMP-2 protein expres-sion was significantly different between colonic carcinoma and normal colon tissues (10.0% vs 54.8%, P <0.05), while no significant difference was found between other groups. The positive rates of MMP-2 and MMP-9 expression tended to increase in ulcerative colitis, colon adenoma, and colonic carcinoma gradually. The positive rates of MMP-2 and MMP-9 protein expression were significantly correlated with the Dukes's staging and lymph node metastasis (C-D stage vs A-B stage: 76.9% vs 38.9%, P <0.05; 84.6% vs 27.8%, P <0.05; metastasis vs non-metastasis: 76.9% vs 38.9%, P <0.05; 84.6% vs 27.8%, P <0.05).

CONCLUSION: Over-expression of MMP-2 and MMP-9 protein play important roles in the carcinogenesis and metastasis of colonic carcinoma.

Prevalence of cholelithiasis in patients with chronic inflammatory bowel disease

AIM: To investigate the effect of chronic inflammatory bowel disease (CIBD) specific risk factors for cholecystolithiasis, as duration and involvement pattern of the disease and prior surgery in patients with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS: A total of 222 patients with CD (135 females, 87 males; average age, 35.8 ± 11.8 years; range 17-81 years) and 88 patients with UC (39 females, 49 males; average age, 37.2 ± 13.6 years; range 16-81 years) underwent clinical and ultrasound examinations. Besides age, sex and degree of obesity, patients? CIBD specific parameters, including duration and extent of disease and prior operations were documented and evaluated statistically using logistic regression.

RESULTS: The overall prevalence of gallbladder stone disease in patients with CD was 13% (n = 30). Only age could be shown to be an independent risk factor (P = 0.014). Compared to a collective representative for the general population in the same geographic region, the prevalence of cholecystolithiasis was higher in all corresponding age groups. Patients with UC showed an overall prevalence of gallbladder stone disease of only 4.6%.

CONCLUSION: Only age but not disease-specific factors such as duration and extent of disease, and prior surgery are independent risk factors for the development of cholecystolithiasis in patients with CIBD.

Effects of Huoxue, Jianpi and Bushen recipe on expression of TNF-α and its mRNA in mice with colitis

AIM: To observe the expression of tumor necrosis factor-a (TNF-α) and its mRNA in colitis mice, and to explore the effects of Huoxue Jianpi Bushen recipe on it.

METHODS: The mouse model of ulcerative colitis was induced by dextran sulfate sodium (DSS). The mice were randomly divided into six groups: normal control, model, sulfasalazine (SASP), Huoxun, Jianpi, and Bushen group. The expression of TNF-α and its mRNA in the mice were examined by immunohistochemistry and in situ hybridization.

RESULTS: The colonic histological scores (for inflam-mation, depth of the illness, damage of the recess) of the mice in the model group were 4.85±2.1, 5.77±2.2, and 7.76±2.4, respectively, which were significantly higher than those in Huoxue group (2.24±2.4, 2.53±2.5, 3.49±2.3), Jianpi group (2.76±2.2, 2.89±2.4, 3.87±2.3), and Bushen group (2.12±2.3, 2.33±2.2, 3.44±2.4) (all P < 0.05). The expression of TNF-α (integral after staining, mean optical density, mean grey) in model group (6.8±1.4, 0.35±0.03, 78.6±4.4) was significantly different from those in Huoxue group (3.7±1.1, 0.18±0.05, 137.9±6.7), Jianpi group (3.4±1.3, 0.16±0.03, 155.1±8.8), and Bushen group (3.1±1.5, 0.17±0.04, 145.62±7.6)(all P < 0.05).

CONCLUSION: TNF-α plays an important role in the occurrence of ulcerative colitis induced by DSS, and the recipe of Huoxue, Jianpi, and Bushen can prevent and cure this disease by down-regulating the expression of TNF-α.

Effects of olsalazine sodium on expression of nitric oxide synthase in patients with ulcerative colitis: an analysis of 36 cases

AIM: To explore the effects of olsalazine sodium on the expression of nitric oxide synthase (NOS) in patients with ulcerative colitis (UC).

METHODS: The colonic mucosa specimens were collected from 36 patients with active ulcerative colitis. The expression of inducible NOS (iNOS), epithelial NOS(eNOS), and nitrotyrosine were detected by immunohistochemistry before and after the patients were treated with olsalazine sodium.

RESULTS: eNOS was expressed in the mucosal epithelial cells of the inflammatory area in 4 patients, but not expressed in the inflammatory cells. iNOS was expressed in the mucosal epithelial cells of all the 36 (100%) samples (13 strong positive and 23 light positive) taken from inflammatory area. iNOS light positive staining in acinar cells of colonic epithelium was detected in 1 patient only. Inflammatory cells in the lamina propria expressed iNOS in 18 (50%) cases. After the treatment of olsalazine sodium, iNOS was lightly and positively expressed in the mucosal epithelial cells of only 5 patients, and no iNOS was expressed in non-inflammatory areas. Nitrotyrosine was detected in the mucosal epithelial cells of inflammatory areas in 5 patients, of which only 1 was accompanied by light and positive expression of nitrotyrosine in the acinar epithelial cells. No nitrotyrosine expression was found in the inflammatory cells of the lamina propria and non-inflammatory areas.

CONCLUSION: Olsalazine sodium can inhibit the expression of iNOS, alleviate the inflammation, and promote the healing of the ulcer.

Hyperhomocysteinemia in ulcerative colitis is related to folate levels

AIM: To study the prevalence and clinical significance of hyperhomocysteinemia (hHcys), an independent factor for arterial and venous thrombosis, in a group of patients with ulcerative colitis (UC).

METHODS: Fasting homocysteine (Hcys), folate, and vitamin B12 serum levels were measured in 40 UC patients and 50 healthy controls. Clinical data regarding UC were gathered.

RESULTS: Median serum Hcys levels in UC patients were similar to those in controls (12.26 µmol/L vs 12.32 µmol/L), but the prevalence of hHcys was higher in UC patients than in controls (30% vs 10%, P = 0.028). UC significantly increased the risk of hHcys (adjusted odds ratio: 4.125; 95%CI: 1.26-13.44). Multivariate regression analysis showed that male sex, folate and vitamin B12 deficiency or lower serum values were significant independent predictors of higher Hcys levels in UC patients (r² = 0.4; P<0.001).

CONCLUSION: hHcys is common in UC patients and it is related to folate and vitamin B12 deficiency or lower serum values. It would be reasonable for patients with UC to receive folate and vitamin B complex supplements as a prophylactic measure.

Ulcerative colitis in a multiracial Asian country: Racial differences and clinical presentation among Malaysian patients

AIM: TO determine the prevalence of ulcerative colitis (UC) in Malaysian patients and to establish the spectrum of the disease seen in Malaysian patients.

METHODS: Data were obtained retrospectively from a review of the medical records of in- and out-patients with a diagnosis of UC at the University Hospital, Kuala Lumpur between 1985 and 1998.

RESULTS: There were 45 confirmed cases of UC, of which 3 were foreigners, who were excluded from analysis. Thirty new cases of UC were diagnosed during the study period. Their mean age at presentation was 33.0 ± 10.0 years. The highest prevalence of UC was 17.9/100 000 hospital admissions in the Indians, followed by 11.2/100 000 hospital admissions in the Chinese. The lowest prevalence was 3.7/100 000 hospital admissions in the Malays. The prevalence of UC was significantly higher in the Indians and the Chinese when compared with the Malays with an OR of 4.89 (CI = 2.02-12.24; c2 = 15.45,P < 0.001) and 3.06 (CI = 1.24-7.78; c2 = 6.30; P = 0.012) respectively. The extent of colonic disease was similar in the Malay and Indian patients. In contrast, distal or left-sided colitis predominated in the Chinese with an OR of 8.17 (95%CI = 1.31-64.87; c2 = 5.53, P = 0.02). Extraintestinal manifestations were uncommon (11.9%).

CONCLUSION: UC is an uncommon disease in Malaysia, but racial differences exist. The Indians had the highest prevalence of UC with the Chinese demonstrating the least extensive disease.

On tolerability and safety of a maintenance treatment with 6-thioguanine in azathioprine or 6-mercaptopurine intolerant IBD patients

AIM: To determine the tolerability and safety profile of a low-dose maintenance therapy with 6-TG in azathioprine (AZA) or 6-mercaptopurine (6-MP) intolerant inflammatory bowel disease (IBD) patients over a treatment period of at least 1 year.

METHODS: Database analysis.

RESULTS: Twenty out of ninety-five (21%) patients discontinued 6-TG (mean dose 24.6 mg; mean 6-TGN level 540 pmol/8×108 RBC) within 1 year. Reasons for discontinuation were GI complaints (31%), malaise (15%) and hepatotoxicity (15%). Hematological events occurred in three patients, one discontinued treatment. In the 6-TG-tolerant group, 9% (7/75) could be classified as hepatotoxicity. An abdominal ultrasound was performed in 54% of patients, one patient had splenomegaly.

CONCLUSION: The majority of AZA or 6-MP-intolerant IBD patients (79%) is able to tolerate maintenance treatment with 6-TG (dosages between 0.3 and 0.4 mg/kg per d). 6-TG may still be considered as an escape maintenance immunosuppressant in this difficult to treat group of patients, taking into account potential toxicity and efficacy of other alternatives. The recently reported hepatotoxicity is worrisome and 6-TG should therefore be administered only in prospective trials.

Persistence of high CD40 and CD40L expression after restorative proctocolectomy for ulcerative colitis

AIM: To focus on the role of CD40 and CD40L in their pathogenesis.

METHODS: We analyzed by immunohistochemistry the CD40 and CD40L expression in the pouch mucosa of 28 patients who had undergone RPC for UC, in the terminal ileum of 6 patients with UC and 11 healthy subjects. We also examined by flow cytometry the expression of CD40 by B lymphocytes and monocytes in the peripheral blood of 20 pouch patients, 15 UC patients and 11 healthy controls.

RESULTS: Ileal pouch mucosa leukocytes presented a significantly higher expression of CD40 and CD40L as compared to controls. This alteration correlated with pouchitis, but was also present in the healthy pouch and in the terminal ileum of UC patients. CD40 expression of peripheral B lymphocytes was significantly higher in patients with UC and pouch, respect to controls. Increased CD40 levels in blood B cells of pouch patients correlated with the presence of spondyloarthropathy, but not with pouchitis, or inflammatory indices.

CONCLUSION: High CD40 expression in the ileal pouch mucosa could be implied in the pathogenesis of pouchitis following proctocolectomy for UC, whereas its increased levels on peripheral blood B lymphocytes are associated with the presence of extraintestinal manifestations.

Refractory ulcerative colitis accompanied with cytomegalovirus colitis and multiple liver abscesses: A case report

Various hepato-biliary complications are an increased incidence in patients with inflammatory bowel disease, and portal bacteremia is well documented in patients with ulcerative colitis (UC). However, few reports mention UC in association with liver abscesses. Recently, there are several reports describing cytomegalovirus (CMV) infection in association with disease exacerbation and steroid refractoriness in patients with UC. Here we present a case of refractory UC accompanied with multiple liver abscesses and CMV colitis. The patient, a 72-year-old male, with a five-year history of repeated admissions to our hospital for UC, presented with an exacerbation of his UC. Sigmoidoscopy performed on admission suggested that his UC was exacerbated, then he was given prednisolone and mesalazine orally, and betamethasone enemas. However, he had exacerbated symptoms. Repeat sigmoidoscopy revealed multiple longitudinal ulcers and pseudopolyps in the rectosigmoid colon. Although immunohistochemical staining of biopsy specimens and the serum testing for antigenemia were negative on admission and after the repeat sigmoidoscopy, they became histologically positive for CMV. Nonetheless, the patient developed spiking fevers, soon after ganciclovir was administered. Laboratory studies revealed an increased white cell count with left shift, and Enterococcus fecalis grew in blood cultures. An abdominal computed tomography (CT) scan was obtained and the diagnosis of liver abscesses associated with UC was made, based on CT results. The hepatic abscesses were successfully treated with intravenous meropenem for 6 wk, without further percutaneous drainage. To our knowledge, this is the first reported case of multiple liver abscesses that develop during UC exacerbation complicated by CMV colitis.

Persistence of gene expression changes in noninflamed and inflamed colonic mucosa in ulcerative colitis and their presence in colonic carcinoma

AIM: A few studies have applied genomic-wide gene expression analysis in inflamed colon tissue sample in ulcerative colitis (UC). We reported the first study of non-inflamed mucosal gene expression in UC and explored its clinical implication.

METHODS: Non-inflamed mucosa was obtained from 6 UC patients who received total colectomy. The gene expression of UC in noninflamed mucosa was monitored with a microarray. For a selected gene, RT-PCR was performed to verify array results and to further examine expression pattern in inflamed mucosa of UC, colorectal cancer tissue and normal mucosa using additional matched pairs.

RESULTS: Two genes showing 2.5-fold decreased expression with significance set at in UC samples were homeo box a4 (HOXa4) and mads box transcription enhancer factor 2, polypeptide B (MEF2b). RT-PCR showed that MEF2b expression in non-inflamed mucosa was significantly downregulated, whereas the expression of MEF2b increased in accordance with the severity of mucosal inflammation. HOXa4 expression both in inflamed and non-inflamed mucosa in UC was consistently downregulated, and the downregulation of HOXa4 was also found in colorectal carcinoma.

CONCLUSION: It is suggested that the MEF2b expression in UC which increase in accordance with inflammation may be induced by the inflammatory mediator. In contrast the downregulation of HOXa4 may be partly involved in the pathogenesis of disease including UC and UC-related carcinogenesis.

Appendix is a priming site in the development of ulcerative colitis

AIM: The role of the appendix has been highlighted in the pathogenesis of ulcerative colitis (UC). The aims of this study were to elucidate the immuno-imbalances in the appendix of UC patients, and to clarify the role of the appendix in the development of UC.

METHODS: Colonoscopic biopsy specimens of the appendix, transverse colon, and rectum were obtained from 86 patients with UC: active pancolitis (A-Pan; n = 15), active left-sided colitis (A-Lt; n = 25), A-Lt with appendiceal involvement (A-Lt/Ap; n = 10), inactive pancolitis (I-Pan; n = 14), and inactive left-sided colitis (I-Lt; n = 22), and from controls. In the isolated mucosal T cells, the CD4/CD8 ratio and proportion of activated CD4+ T cells were investigated, and compared with controls.

RESULTS: In the appendix, the CD4/CD8 ratio significantly increased in A-Lt and A-Lt/Ap. The ratio in the appendix also tended to increase in A-Pan. In the rectum, the ratio significantly increased in all UC groups. In the appendix, the proportion of CD4+CD69+ (early activation antigen) T cells significantly increased in all UC groups. In the rectum, the proportion of CD4+CD69+ T cells significantly increased only in A-Pan. The proportion of CD4+HLA-DR+ (mature activation antigen) T cells significantly increased only in the rectum of A-Pan, but not in the other areas of any groups.

CONCLUSION: The increased CD4/CD8 ratio and predominant infiltration of CD4+CD69+ T cells in the appendix suggest that the appendix is a priming site in the development of UC.

Effects of four regulating-intestine prescriptions on pathology and ultrastructure of colon tissue in rats with ulcerative colitis

AIM: To observe different histomorphologic changes of ulcerative colitis (UC) rats that were treated with four regulating-intestine prescriptions (FRIP), to investigate the curative effects of FRIP and to analyze their treatment mechanism.

METHODS: The UC rat model was made by the method of 2,4-dinitro chloro benzene (DNCB) immunity and acetic acid local enema. Ninety-eight SD rats were randomly divided into seven groups, namely, the normal control group, model group, salicylazosulfapyridine (SASP) group, Wumeiwan (WMW) group, Baitouwengtang (BTWT) group, Senglingbaishusan (SLBSS) group, and Tongxieyaofang (TXYF) group. Each group had 14 rats (with equal ratio of male and female). The six animal model groups of UC -SASP, TXYF, WMW, BTWT, SLBSS, TXYF-were treated by distilled water except the normal control group. Changes of the rat’s general conditions after treatment were respectively observed, the colon tissue damage scores were given out, the pathology of colonic mucosa and changes of ultrastructure were analyzed.

RESULTS: Different pathological changes on histology were shown after treatment by FRIP. The colon tissue damage score in model group was higher than that of FRIP groups and SASP group (q = 4.59, 4.77, P<0.05 or q = 5.48, 6.25, 5.97, P<0.01). The scores of WMW group, BTWT group and SLBSS group were lower than that of SASP (q = 4.13, P<0.05 or q = 5.31, 5.12, P<0.01). There was no remarkable difference between the damage score of TXYF group and SASP group (q = 3.75, P>0.05). In addition, some apoptosis cells were found in the pathologic control group.

CONCLUSION: The model made with DNCB and acetic acid was successful, and FRIP had better curative effect and WMW was the best curative effect, BTW, SLBSS and TXYF were similar to SASP, and we discovered that apoptosis was possibly related to UC.

Effects of garlicin on apoptosis in rat model of colitis

AIM: To investigate the effects of garlicin on apoptosis and expression of bcl-2 and bax in lymphocytes in rat model of ulcerative colitis (UC).

METHODS: Healthy adult Sprague-Dawley rats of both sexes, weighing 180±30 g, were employed in the present study. The rat model of UC was induced by 2,4,6-trinitr-obenzene sulfonic acid (TNBS) enema. The experimental animals were randomly divided into garlicin treatment group (including high and low concentration), model control group, and normal control group. Rats in garlicin treatment group and model control group received intracolic garlicin daily at doses of 10.0 and 30.0 mg/kg and equal amount of saline respectively 24 h after colitis model was induced by alcohol and TNBS co-enema. Rats in normal control group received neither alcohol nor only TNBS but only saline enema in this study. On the 28^th d of the experiment, rats were executed, the expression of bcl-2 and bax protein was determined immunohistochemically and the apoptotic cells were detected by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. At the same time, the rat colon mucosal damage index (CMDI) was calculated.

RESULTS: In garlicin treatment group, the positive expression of bcl-2 in lymphocytes decreased and the number of apoptotic cells was more than that in model control group, CMDI was lower than that in model control group. The positive expression of bax in lymphocytes had no significant difference.

CONCLUSION: Garlicin can protect colonic mucosa against damage in rat model of UC induced by TNBS enema.

Antibody to eosinophil cationic protein suppresses dextran sulfate sodium-induced colitis in rats

AIM: To produce an antibody against rat eosinophil cationic protein (ECP) and to examine the effects of the antibody in rats with dextran sulfate sodium (DSS)-induced colitis.

METHODS: An antibody was raised against rat ECP. Rats were treated with 3% DSS in drinking water for 7 d and received the antibody or normal serum. The colons were examined histologically and correlated with clinical symptoms. Immunohistochemistry and Western blot analysis were estimated as a grade of inflammation.

RESULTS: The ECP antibody stained the activated eosinophils around the injured crypts in the colonic mucosa. Antibody treatment reduced the severity of colonic ulceration and acute clinical symptoms (diarrhea and/or blood-stained stool). Body weight gain was significantly greater and the colon length was significantly longer in anti-ECP-treated rats than in normal serum-treated rats. Expression of ECP in activated eosinophils was associated with the presence of erosions and inflammation. The number of Ki-67-positive cells in the regenerated surface epithelium increased in anti-ECP-treated rats compared with normal serum-treated rats. Western blot analysis revealed reduced expression of macrophage migration inhibitory factor (MIF) in anti-ECP-treated rats.

CONCLUSION: Our results indicate that treatment with ECP antibody, improved DSS-induced colitis in rats, possibly by increasing the regenerative activity of the colonic epithelium and downregulation of the immune response, and suggest that anti-ECP may promote intestinal wound healing in patients with ulcerative colitis (UC).

Effects of sulfasalazine on biopsy mucosal pathologies and histological grading of patients with active ulcerative colitis

AIM: To investigate the mechanisms of sulfasalazine (SASP) in the treatment of ulcerative colitis (UC).

METHODS: Changes of pathological signs and histological grading of 106 patients with active UC were observed before and after the treatment with SASP, 1 g, thrice daily for 6 wk.

RESULTS: The effect of SASP on the vasculitis in lamina propria was 48.2% and 17.4% in the mild active UC (P < 0.001) and 68% and 26.7% in the moderate active UC (P < 0.001) before and after treatment. Fibroid necrosis of vessel wall was found in one case of mild UC and two cases of moderate UC before treatment and was not found after treatment. No thrombosis was found in mild UC before and after treatment, while thrombosis was found in one case of moderate UC before treatment. The effect on mucosal glandular abnormality was 30.4% and 13.0% in mild UC (P < 0.05), and 42% and 40% in moderate UC (P > 0.05) before and after treatment. The rate of eosinophil infiltration was 98.2% and 80.4% in mild UC (P < 0.01), and 100% and 91.1% in moderate UC (P < 0.05) before and after treatment. The effect on crypt abscess was 21.4% and 4.4% in mild UC (P < 0.05), and 48% and 13.3% in moderate UC (P < 0.001) before and after treatment. The effect on mucosal pathohistological grading was 2.00 ± 0.84 and 0.91 ± 0.46 in mild UC (P < 0.001), and 2.49 ± 0.84 and 1.31 ± 0.75 in moderate UC (P < 0.001) before and after treatment.

CONCLUSION: SASP can improve small vessel lesions and crypt abscesses and reduce neutrophilic and eosinophilic leukocyte infiltration in inflammatory mucosa of UC.

Association of polymorphic alleles of CTLA4 with inflammatory bowel disease in the Japanese

AIM: To examine an association between the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene that plays a role in downregulation of T-cell activation and inflammatory bowel disease consisting of ulcerative colitis (UC) and Crohn’s disease (CD) in the Japanese.

METHODS: We studied 108 patients with UC, 79 patients with CD, and 200 sex-matched healthy controls, with respect to three single nucleotide polymorphisms (SNPs) in CTLA4, such as C-318T in the promoter region, A+49G in exon 1 and G+6230A in the 3’ untranslated region (3’-UTR) by a PCR-restriction fragment length polymorphism method, and to an (AT)_n repeat polymorphism in 3’-UTR by fragment analysis with fluorescence-labeling on denaturing sequence gels. Frequency of alleles and genotypes and their distribution were compared statistically between patients and controls and among subgroups of patients, using χ² and Fisher exact tests.

RESULTS: The frequency of “A/A” genotype at the G+6230A SNP site was statistically lower in UC patients than in controls (3.7% vs 11.0%, P = 0.047, odds ratio (OR = 0.311). Moreover, the frequency of “G/G” genotype at the A+49G SNP site was significantly higher in CD patients with fistula (48.6%) than those without it (26.2%) (P = 0.0388, OR=2.67).

CONCLUSION: The results suggest that CTLA4 located at 2q33 is a determinant of UC and responsible for fistula formation in CD in the Japanese.

Effects of Changtai granules, a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats

AIM: To study the effects of Changtai granules (CTG), a traditional compound Chinese medicine, on chronic trinitrobenzene sulfonic acid-induced colitis in rats.

METHODS: Healthy adult Sprague-Dawley (SD) rats of both sexes, weighing 250-300 g, were employed in the present study. The rat colitis models were induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enemas at a concentration of 100 mg/kg in 50% ethanol. The experimental animals were randomly divided into dexamethasone (DX) treatment, CTG treatment, and model control groups, which were intracolicly treated daily with DX (0.2 mg/kg), CTG at doses of 2.9, 5.7 and 11.4 g crude drug/kg, and the equal amount of saline respectively from 6 h following induction of the colitis in rats inflicted with TNBS to the end of study. A normal control group of rats treated without TNBS but saline enema was also included in the study. After 3 wk of treatment, the animals were assessed for colonal inflammatory and ulcerative responses with respect to mortality, frequency of diarrhea, histology and myeloperoxidase activity (MPO).

RESULTS: The therapeutic effect of CTG on ulcerative colitis (UC) was better than DX. CTG effectively inhibited the activity of granulocytes, macrophages and monocytes in a dose-dependent manner. Also it reduced MPO and formation of inflammation in colonic mucosal tissue. Furthermore, administration of CTG significantly prevented body mass loss and death, and decreased frequency of diarrhea in UC rats, when compared with the model control group rats.

CONCLUSION: CTG would prove to be an ideal drug for chronic UC, and is warranted to be studied further.

Decrease of reactive-oxygen-producing granulocytes and release of IL-10 into the peripheral blood following leukocytapheresis in patients with active ulcerative colitis

AIM: To investigate the clinical efficacy of leukocytapheresis (LCAP) in patients with active ulcerative colitis (UC), and to elucidate the mechanisms by determining the changes in the cytokine levels in the peripheral blood and of the functions of the peripheral blood leukocytes in these patients.

METHODS: The subjects were 19 patients with active UC, with a mean clinical activity index (CAI) of 9.2. The LCAP was conducted using Cellsorba E. In each session of LCAP, 2-3 L of blood at the flow rate of 30-50 mL/min was processed. The treatment was carried out in approximately 1-h sessions, once a week, for 5-10 wk. Blood samples for determination of the cytokine levels were collected from the inflow side of the column (site of dehematization; at the start of LCAP) and outflow side of the column (at the end of LCAP). Blood samples for the determination of reactive-oxygen-producing cells were collected from the peripheral blood before and after LCAP.

RESULTS: LCAP resulted in clinical improvement in all the 19 patients of UC recruited for this study. Remission (CAI: ≤4) was noted in 15 (79%) of the 19 patients. The blood level of the pro-inflammatory cytokine IL-6 was found to be decreased following treatment by LCAP, and the level of the anti-inflammatory cytokine IL-10 at the outflow side of the LCAP column was found to be significantly elevated as compared to that at the inflow side of the column. The reactive-oxygen-producing granulocytes in the peripheral blood of UC patients was increased as compared to that in healthy persons and the increase was found to be decreased following treatment by LCAP.

CONCLUSION: LCAP exerted a high therapeutic efficacy in patients with active UC. Our findings suggest that LCAP is associated with enhanced production of the inhibitory cytokine IL-10 to indirectly inhibit the functions of the inflammatory leukocytes, and that inflammation is also considerably attenuated by the direct removal of reactive-oxygen-producing neutrophils from the peripheral blood.

Characteristics and therapeutic efficacy of sulfasalazine in patients with mildly and moderately active ulcerative colitis

AIM: To investigate the characteristics and short-term efficacy of sulfasalazine (SASP) in patients with mildly and moderately active ulcerative colitis (UC).

METHODS: Two hundred and twenty-eight patients with mildly and moderately active UC were recruited, 106 patients in 1993-1995, and 122 patients in 2000-2002, they were assigned as the 1990s group (n = 106) and the 2000s group (n = 122), prospectively. The general characteristics, clinical manifestations, colonoscopic and histological data were compared between the two groups. The short-term efficacy and safety of SASP 3 g per d were evaluated.

RESULTS: Between 2000s and 1990s groups, the gender ratio of men to women was 1:1.18 and 1:1.04, 57.4% and 50.9% of the patients were between 30 and 49 years old. The gender ratio and age of UC patients were not sign-ificantly different. The total course of 50.0% and 37.1% of UC patients was less than 1 year (P<0.05), 10.6% and 31.2% of the cases had a duration of more than 5 years (P<0.05) in 2000s and 1990s groups, respectively. The most common clinical type was first episode in 2000s group and chronic relapse in 1990s group. The patients showed a higher frequency of abdominal pain and tenderness in 1990s group than in 2000s group. Erosions were found in 84.4% and 67.9% of patients in 2000s and 1990s groups (P<0.05). Rough and granular mucosa (67.9% vs 43.4%, P<0.05) and polyps (47.2% vs 32.8%, P<0.05) were identified in 1990s group more than in 2000s group. There were no significant differences in clinical, colonoscopic and histological classifications. After SASP (1 g thrice per d) treatment for 6 wk, the clinical, colonoscopic and histo-logical remission rates were 71.8%, 21.8% and 16.4%, respectively. In 79 patients with clinical remission, 58.2% and 67.1% remained grade 1 in colonoscopic and histological findings, respectively. The overall effects in first episode type (complete remission in 10, 18.9%, partial remission in 28, 52.8%, and improvement in 9, 17.0%) were better than in chronic relapse type (complete remission in 3, 7.5%; partial remission in 16, 40.0%; and improvement in 15, 37.5%) and chronic persistent type (complete remission in 1, 5.9%; partial remission in 6, 35.3%; and improvement in 6, 35.3%) respectively (P<0.05). In 110 patients treated with SASP, 18 patients (16.4%) had adverse reactions. Except for two cases of urticaria and one case of WBC decrease, none of the patients had to stop the treatment because of severe adverse reactions.

CONCLUSION: Patients with mildly and moderately active UC in 2000s group had a shorter disease course, milder clinical manifestations, more first episode type and higher frequency of acute mucosal lesions in colonoscopy than in 1990s group. The patients in 1990s group had higher proportion of chronic relapse type and chronic mucosal change in colonoscopy than in 2000s group. The short-term efficacy of SASP could be mainly remission of clinical manifestations. But more than half of the patients still had light inflammation in colonoscopy and histology. The overall effects of SASP in first episode type were better than those in other types. SASP was a safe and effective drug to treat mildly and moderately active UC.

Radical induction theory of ulcerative colitis

To propose a new pathogenesis called Radical Induction to explain the genesis and progression of ulcerative colitis (UC). UC is an inflammatory bowel disease. Colonic inflammation in UC is mediated by a buildup of white blood cells (WBCs) within the colonic mucosal lining; however, to date there is no answer for why WBCs initially enter the colonic mucosa to begin with. A new pathogenesis termed “Radical Induction Theory” is proposed to explain this and states that excess un-neutralized hydrogen peroxide, produced within colonic epithelial cells as a result of aberrant cellular metabolism, diffuses through cell membranes to the extracellular space where it is converted to the highly damaging hydroxyl radical resulting in oxidative damage to structures comprising the colonic epithelial barrier. Once damaged, the barrier is unable to exclude highly immunogenic fecal bacterial antigens from invading the normally sterile submucosa. This antigenic exposure provokes an initial immune response of WBC infiltration into the colonic mucosa. Once present in the mucosa, WBCs are stimulated to secrete toxins by direct exposure to fecal bacteria leading to mucosal ulceration and bloody diarrhea characteristic of this disease.

Expression and significance of nuclear factor κB p65 in colon tissues of rats with TNBS-induced colitis

AIM: To investigate the role of NF-κB in the pathogenesis of TNBS-induced colitis in rats.

METHODS: Thirty-two healthy adult Sprague-Dawley (SD) rats were randomly divided into four groups of eight each: normal, NS, model I, model II groups in our study. Rat colitis model was established through 2-,4-,6-trinitrobenzene sulfonic acid (TNBS) enema. At the end of four weeks, the macroscopical and histological changes of the colon were examined and mucosa myeloperoxidase (MPO) activities assayed. NF-κB p65 expression was determined by Western blot assessment in cytoplasmic and nuclear extracts of colon tissue, and the expressions of TNF-α and ICAM-1 protein in colon tissue were examined by immunohistochemistry. The relativities between expression of NF-κB p65 and other parameters were analyzed.

RESULTS: TNBS enema resulted in pronounced pathological changes of colonic mucosa in model II group (macroscopic and histological injury indices 6.25±1.39 and 6.24±1.04, respectively), which were in accordance with the significantly elevated MPO activity (1.69±0.11). And the nuclear level of NF-κB and expression of TNF-α, ICAM-1 in rats of model II group were higher than that of normal control (9.7±1.96 vs 1.7±0.15, 84.09±14.52 vs 16.03±6.21, 77.69±8.09 vs 13.41±4.91 P<0.01), Linear correlation analysis revealed that there were strong correlations between the nuclear level of NF-κB and the tissue positive expression of TNF-α and ICAM-1, MPO activities, macroscopical and histological indices in TNBS-induced colitis, respectively (r = 0.8235, 0.8780, 0.8572, 0.9152, 0.8247; P<0.05).

CONCLUSION: NF-κB plays a pivotal role in the pathogenesis of ulcerative colitis, which might account for the up-regulation the expression of TNF-α and ICAM-1.

Significance of glucocorticoid receptor expression in colonic mucosal cells of patients with ulcerative colitis

AIM: Glucocorticoid (GC) resistant ulcerative colitis (UC) remains a serious disease and is difficult to manage. Although the molecular basis of GC insensitivity is still unknown, GC receptors (GRα and GRβ) may play an important role in it. This study was aimed to investigate the relationship between the expression of GRα and GRβ in colonic mucosal cells of patients with UC, the efficacy of GC therapy and the intensity of inflammation.

METHODS: Twenty-five cases of UC were classified into: GC sensitive (n = 16) and GC resistant (n = 9) cases. Patients consisted of mild (n = 6), moderate (n = 8) and severe (n = 11) cases. GRα and GRβ expression in colonic mucosal specimens were investigated by immunohistochemistry, and compared between GC resistant and sensitive groups, and also among various degrees of inflammation.

RESULTS: All cases were positive for GRα and GRβ expression. Both positive association between GRα expression and the response of UC to GC and strong negative association between GRβ expression and the response of UC to GC were identified. There was no significant association between GRα/GRβ expression and the degree of inflammation of UC.

CONCLUSION: These findings suggest that both GRα and GRβ may play an important role in the action of GC, and that GRβ functions as a dominant negative inhibitor of GRα. Expression of GRα and GRβ in colonic mucosal cells of patients with UC may serve as predictors of glucocorticoid response, but can not function as markers of inflammatory intensity.

Incidence of ulcerative colitis in Central Greece: A prospective study

AIM: To study the incidence of ulcerative colitis UC in the prefecture of Trikala, Central Greece.

METHODS: A prospective and population based epidemiological study of UC from 1990 to the end of 1994 was conducted. Trikala is a semirural prefecture of Central Greece with a population of 138946 (census 1991). Three gastroenterologists (one hospital based, two private doctors) of the prefecture participated in this study.

RESULTS: During the study period, 66 new histologically verified cases of UC were recorded. The mean annual incidence of the disease in 1990-1994 was 11.2 per 10⁵ inhabitants (95%CI: 8.7-14.3). There was no difference between men and women (annual incidence: 10.5 and 12.0 per 10⁵ inhabitants respectively), either among urban, semirural or rural populations (annual incidence: 11.7, 17.1 and 9.9 per 10⁵ inhabitants respectively). The majority (56%) of the patients never smoked and a quarter were ex-smokers. About a half of all cases had proctitis.

CONCLUSION: UC is common in Central Greece and its incidence is similar to that in North-Western European countries.

IBD5 polymorphisms in inflammatory bowel disease: Association with response to infliximab

AIM: Inflammatory bowel diseases (IBD) are multifactorial pathologies of unknown etiology. One susceptibility locus, IBD5, has been mapped to chromosome 5q31. We analyzed our Spanish cohorts of Crohn’s disease (CD) and ulcerative colitis (UC) patients to determine whether this locus is associated with IBD, and to ascertain the main clinical phenotype influenced by this risk factor. The kind of interaction, either genetic heterogeneity or epistasis, between this IBD5 susceptibility region and the NOD2/CARD15 gene mutations was studied as well. Finally, we assessed whether this locus can predict response to infliximab therapy.

METHODS: A case control study was performed with 274 CD and 211 UC patients recruited from a single center and 511 healthy ethnically matched controls. Two polymorphisms were genotyped in the IBD5 locus and three in the CARD15/NOD2 gene.

RESULTS: Our results evidence association only with CD especially with the fistulizing phenotype and in the absence of NOD2/CARD15 variants (mutant allele frequency in patients vs controls: OR = 2.03, 95% CI = 1.35-3.06, P<0.01). The frequency of the IBD5 homozygous mutant genotype significantly increased in CD patients lacking response to infliximab (RR = 3.88, 95% CI = 1.18-12.0, P<0.05). UC patients overall do not show association with 5q31 polymorphisms, although a similar trend to the one observed in CD is found within the worse prognosis group.

CONCLUSION: The IBD5 variants may enhance an individual carrier’s risk for CD, mainly in the absence of the NOD2/CARD15 mutations and in fistulizing patients. The data presented suggest the potential role of the 5q31 polymorphisms as markers of response to infliximab.