ATP-binding cassette transporter ABCG2 (BCRP) and ABCB1 (MDR1) variants are not associated with disease susceptibility, disease phenotype response to medical therapy or need for surgeryin Hungarian patients with inflammatory bowel diseases

OBJECTIVE: MDR1 (ABCB1), a member of the ATP-binding cassette (ABC) transporters, is an attractive candidate gene for the pathogenesis of inflammatory bowel diseases (IBD) and perhaps for response to therapy. Since limited data are available on MDR1 and ABCG2 polymorphisms in East European IBD patients, the aim of this study was to investigate ABCG2 and MDR1 variants and responses to medical therapy and/or disease phenotype in Hungarian patients. MATERIAL AND METHODS: A total of 414 unrelated IBD patients (Crohn's disease (CD): 265, age: 35.2+/-12.1 years, duration: 8.7+/-7.6 years and ulcerative colitis (UC): 149, age: 44.4+/-15.4 years, duration: 10.7+/-8.9 years) and 149 healthy subjects were investigated. ABCG2 G34A, C421A and MDR1 C3435T, G2677T/A single nucleotide polymorphisms (SNPs) were detected using real-time polymerase chain reaction (PCR). Detailed clinical phenotypes were determined by reviewing the medical charts. RESULTS: The frequency of the ABCG2 and MDR1 SNPs was not significantly different among IBD, CD, UC patients and controls. There was no difference in risk for steroid resistance in CD patients carrying variant ABCG2 (19.6% versus non-carriers 18.4%, p=NS) or MDR1 3435T (CC: 22.2% versus CT/TT: 17.6%) alleles. In addition, carriage of the variant allele was not associated with disease phenotype, presence of extra-intestinal manifestations, smoking, response to infliximab therapy or the need for surgery. In UC, the carriage of variant ABCG2 alleles seemed to be preventive for arthritis (15.5% versus 31.7%, OR: 0.39, 95% CI: 0.16-0.98). CONCLUSIONS: MDR1 and ABCG2 SNPs were not associated with disease susceptibility or disease phenotype in Hungarian patients, and variant alleles did not predict the response to medical therapy or the need for surgery. Further studies are needed to clarify the association between the presence of ABCG2 variants and arthritis in UC.     

Higher expression of glucocorticoid receptor in peripheral mononuclear cells in inflammatory bowel disease

OBJECTIVE: Glucocorticoids are widely used in the treatment of inflammatory bowel disease (IBD). Up- and down-regulated expression of glucocorticoid receptors (GR) has been reported for different chronic inflammatory diseases. The aim of this study was to investigate the expression of GR and their apparent dissociation constant (Kd) in patients with IBD. METHODS: Thirty-nine patients with IBD (22 with ulcerative colitis, 17 with Crohn's disease) and 35 normal controls were studied. Twenty-five patients did not receive steroids, 14 patients were treated with steroids. Peripheral blood mononuclear cells from patients and controls were isolated using the Ficoll-Hypaque gradient and a whole cell [3H]-dexamethasone binding assay and Scatchard plot analysis were performed to assess GR number and the apparent dissociation constant. Results were expressed as mean +/- standard deviation. RESULTS: Normal controls showed an expression of 3,969 +/- 1,555 GR per cell with an apparent dissociation constant of 6.16 +/- 3.8 nmol/L. IBD patients without steroids had a significant increase both in the expression of GR per cell (6,401 +/- 2,344; p < 0.0001; Wilcoxon-Mann-Whitney test) and in the apparent dissociation constant (11.02 +/- 7.57 nmol/L; p = 0.006). Expression of GR in IBD patients was suppressed to normal levels under steroid treatment (4,594 +/- 2,237; p = 0.024), but Kd remained elevated (13.56 +/- 9.05 nmol/L). Plasma cortisol levels were not different between IBD patients and the control group. CONCLUSIONS: Our data show a systemic increase in GR expression and a decrease in the affinity to the GR in IBD, in contrast to other inflammatory diseases such as rheumatoid arthritis and asthma. These changes point towards a systemic character of IBD, which might be considered in a decision between topical and systemic treatment.     

Multidrug resistance 1 gene polymorphism and susceptibility to inflammatory bowel disease

BACKGROUND: Several studies have evaluated the role of the multidrug resistance 1 gene (MDR1) polymorphism, which encodes the membrane-bound efflux transporter P-glycoprotein 170, in determining susceptibility to and disease behavior in inflammatory bowel disease (IBD), but with conflicting results. METHODS: A total of 211 patients with Crohn's disease (CD), 97 patients with ulcerative colitis (UC), and 212 control subjects were investigated for the presence of MDR1 G2677T/A and C3435T polymorphisms. Genotype frequencies of CD and UC patients were compared to those observed in a control population. Genotype-phenotype correlations with major clinical features were also established and estimated risks (odds ratio [OR] with 95% confidence interval [CI]) for the mutations were calculated by a logistic regression analysis and multiple correspondent analysis. RESULTS: No significant difference was observed for genotype frequencies for both MDR1 G2677T/A and C3435T polymorphisms on overall disease susceptibility for either CD or UC patients compared with control subjects. A significant association was found between the MDR1 C3435T polymorphism and patients with ileo-colonic CD (OR = 3.34; 95% CI: 1.34-8.27). Interestingly, a negative association was found between MDR1 C3435T polymorphism in patients with a positive family history for IBD (OR = 0.44; 95% CI: 0.20-0.95) and articular manifestations (OR = 0.29; 95% CI: 0.13-0.68). Both susceptible and protective effects were identified. No significant association between G2677T/A polymorphism and any specific subphenotypes was found, nor was there any association with subphenotypic categories of UC and both single nucleotide polymorphisms. CONCLUSIONS: The results of our study suggest that MDR1 gene polymorphism could have a role in determining susceptibility to IBD. The variability of this possible effect in the several studies reported so far may be the indirect expression of the complex role played by the MDR1 gene and its product, P-glycoprotein 170, in the regulation of host-bacteria interactions and in the pathogenesis of IBD.     

Secretory immunoglobulin deficiency in a family with inflammatory bowel disease.

A family with 4 of 10 first-degree relatives affected with inflammatory bowel disease (IBD) was studied to determine whether any distinct immunological abnormalities occur in the affected members, as compared with unaffected members of the family, normal controls, and other unrelated patients with IBD. Red cell blood type and HL-A phenotypes did not distinguish between healthy and affected members, although HL-A2, 32, B27, and B12 were the predominant haplotypes in members with IBD. There was no significant difference between the two groups in the lymphocyte subpopulation counts of T cells, B cells, and cells carrying Fc or complement receptors. The in vitro mitogen response, however, to phytohemagglutinin and pokeweed mitogen were depressed in the affected members. Serum IgA and C3 levels were significantly elevated in members with IBD compared to healthy subjects with values of 232 +/- 69 (mean +/- SD) versus 148 +/- 29 mg per dl for IgA (P less than 0.05) and 173 +/- 32 versus 115 +/- 22 mg per dl for C3 (P less than 0.025), respectively. Plasma and, to a lesser extent, peripheral lymphocytes from 2 affected members who were tested were cytotoxic to allogeneic colonic epithelial cells. Salivary IgA was normal in the affected family members and unrelated patients with IBD. However, the free secretory component of salivary IgA was absent or markedly depressed in family members, as well as in unrelated patients with ulcerative colitis. This deficiency of the secretory immune system appears to characterize more frequently ulcerative colitis than Crohn's disease and may compromise mucosal host defenses in IBD.     

Clinical pharmacology of inflammatory bowel disease therapies

Knowledge about the clinical pharmacology of medical therapy of inflammatory bowel disease has incrementally advanced. Small studies with mesalamine have suggested that intestinal mucosal concentrations of mesalamine may predict clinical response to mesalamine therapy. Increased expression of glucocorticoid receptor β and increased expression of the multidrug resistance drug pump P-glycoprotein 170 have been proposed as markers of drug resistance to glucocorticoids. A baseline determination of thiopurine methyltransferase phenotype or genotype may predict early leukopenia in patients treated with azathioprine or 6-mercaptopurine. Serial measurement of erythrocyte 6-thioguanine nucleotides may be useful in tailoring the dose of these medications. A loading dose of intravenous azathioprine does not accelerate the time to response in patients with steroid-treated Crohn's disease; however, standard azathioprine may work more quickly than previously reported. Methotrexate, 15 to 25 mg/wk, is effective for the treatment of Crohn's disease (active or in remission), and there is no significant difference in the erythrocyte concentrations of methotrexate polyglutamate in patients with inflammatory bowel disease receiving 15 mg, compared with 25 mg, subcutaneously on a weekly basis.     

T-cell co-stimulatory molecules are upregulated on intestinal macrophages from inflammatory bowel disease mucosa.

BACKGROUND AND AIMS: Macrophages play an important role during mucosal inflammation in inflammatory bowel disease (IBD). As the co-stimulatory molecules B7-1 (CD80) and B7-2 (CD86) play an integral role in the activation of T cells by antigen-presenting cells (APC) we investigated the surface expression of B7-1 and B7-2 on colonic macrophages from normal and IBD mucosa. METHODS: Intestinal macrophages were isolated from biopsies of 13 control persons and 14 patients with IBD (seven with Crohn's disease (CD); and seven with ulcerative colitis (UC)). Cells were characterized by triple fluorescence flow cytometrical analysis using CD33 as macrophage marker. RESULTS: The expression of B7-1 (CD80) (9.2% +/- 4.2%) and B7-2 (CD86) (15.1% +/- 7.3%) was low on colonic macrophages from normal mucosa, indicating only a low antigen presenting potential. However, on macrophages from IBD colon there was a significant increase in the expression of co-stimulatory molecules (CD80, 33.8% +/- 8.9%, P = 0.00005 vs. control; CD86, 39.9% +/- 8.8%, P = 0.00002). There was no significant difference between CD and UC in the expression of CD80 (CD, 31.3% +/- 6.7%; UC, 34.4% +/- 13.3%) and CD86 (CD, 41.9% +/- 3.8%; UC, 35.6% +/- 13.8%). While in normal mucosa only 10.6% +/- 4.9% of the macrophages expressed CD14, more than 90% of the CD86/CD80 positive cells of the inflamed mucosa were positive for CD14. CONCLUSION: Colonic macrophages from normal mucosa rarely express the co-stimulatory molecules CD80 and CD86. In IBD a new macrophage population is found with high expression of co-stimulatory molecules presumably responsible for the perpetuated immune response.     

Analysis of the cellular basis of keratinocyte growth factor overexpression in inflammatory bowel disease

BACKGROUND: Keratinocyte growth factor (KGF) stimulates gastrointestinal epithelial cells in vivo, and is protective against gastrointestinal injury and colitis. Endogenous KGF is increased in inflammatory bowel disease (IBD), and may be an important mediator of mucosal repair. KGF is expressed by mesenchymal cells and activated intraepithelial lymphocytes (IEL). AIMS: To investigate the relative contributions of these cellular sources of KGF expression in IBD. METHODS: IELs and lamina propria lymphocytes (LPL) were isolated from inflamed and uninflamed IBD tissues. mRNA expression was determined by ribonuclease protection assay. In situ hybridisation was combined with immunohistochemistry to determine whether KGF mRNA was expressed by specific cell types in vivo. RESULTS: Low levels of KGF mRNA expression were detected in three of five IEL samples derived from inflamed tissue, but not in two IEL samples from uninflamed tissue. No KGF expression was detected in LPLs from either inflamed or uninflamed tissue. In contrast, KGF was expressed by primary cultures of human intestinal fibroblasts, and was induced by treatment with interleukin 1. CONCLUSIONS: The major source of KGF expression in IBD was lamina propria cells of non-immune origin, most likely fibroblasts and/or smooth muscle cells. Compared with these cell types, relatively little KGF synthesis was associated with IELs in inflamed IBD tissue.     

Characterization of epithelial IL-8 response to inflammatory bowel disease mucosal E. coli and its inhibition by mesalamine

BACKGROUND: Mucosally adherent E. coli are found in inflammatory bowel disease (IBD) and colon cancer. They promote release of the proinflammatory cytokine interleukin-8 (IL-8). We explored mechanisms for this release and its inhibition by drugs. METHODS: IL-8 release from colon epithelial cells in response to mucosal E. coli isolates from IBD, colon cancer, and controls was characterized at the cellular and molecular level. RESULTS: IL-8 response of HT29 cells was greater with Crohn's disease (689 +/- 298 [mean +/- SD] pg IL-8/mL at 4 hours, n = 7) and colon cancer isolates (532 +/- 415 pg/mL, n = 14) than with ulcerative colitis (236 +/- 58 pg/mL, n = 6) or control isolates (236 +/- 100 pg/mL, n = 6, P < 0.0001). Bacterial supernatants contained shed flagellin that triggered IL-8 release. For whole bacteria the IL-8 response to E. coli that agglutinate red blood cells (548 +/- 428 pg IL-8/mL, n = 16), a function that correlates with epithelial invasion, was greater than for nonhemagglutinators (281 +/- 253 pg/mL, n = 17; P < 0.0001). This was particularly marked among E. coli that, although flagellate, could not release IL-8 from TLR5-transfected HEK293 cells. IL-8 release was mediated by extracellular-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) and inhibited by mesalamine, but not hydrocortisone, at therapeutic concentrations. CONCLUSIONS: Mucosa-associated E. coli shed flagellin that elicits epithelial IL-8 release but this may only become relevant when the mucosal barrier is weakened to expose basolateral TLR5. Adherent and invasive IBD and colon cancer E. coli isolates also elicit a flagellin-independent IL-8 response that may be relevant when the mucosal barrier is intact. The IL-8 release is MAPK-dependent and inhibited by mesalamine.     

Randomized,controlled trial evaluating the effect of multi-strain probiotic on the mucosal microbiota in canine idiopathic inflammatory bowel disease

The intestinal microbiota is increasingly linked to the pathogenesis of idiopathic inflammatory bowel disease (IBD) in dogs. While studies have reported alterations in fecal (luminal) microbial populations, only limited information is available about the mucosal microbiota of IBD dogs at diagnosis and following medical therapy. Our aim was to characterize the mucosal microbiota and determine the clinical, microbiological, and mucosal homeostatic effects of probiotic treatment in dogs with IBD. Thirty four IBD dogs were randomized to receive standard therapy (ST = diet + prednisone) with or without probiotic. Tissue sections from endoscopic biopsies were evaluated by fluorescence in situ hybridization (FISH) on a quantifiable basis. Disease activity and changes in mucosal microbiota and tight junction protein (TJP) expression were assessed before and after 8 weeks of IBD therapy. ST and ST/probiotic therapy modulated the number of mucosal bacteria of IBD dogs in a similar fashion. Both treatments increased the numbers of total bacteria and individual species residing within adherent mucus, with ST therapy increasing Bifidobacterium spp. and ST/probiotic therapy increasing Lactobacillus spp (P < 0.05 for both), respectively. Both treatments were associated with rapid clinical remission but not improvement in histopathologic inflammation. Probiotic therapy was associated with upregulated (P < 0.05) expression of TJPs E-cadherin, occludin, and zonulin versus ST. The probiotic effect on mucosal bacteria is similar to that of IBD dogs receiving ST. IBD dogs fed probiotic had increased TJP expression suggesting that probiotic may have beneficial effects on mucosal homeostasis.     

Immunoglobulin coating of faecal bacteria in inflammatory bowel disease

OBJECTIVE: An inappropriate mucosal immune response to the commensal bacterial flora may play a role in the pathogenesis of inflammatory bowel disease (IBD). In this study we determined the percentage of immunoglobulin-coated bacteria in the stools of patients and controls. METHODS: Faecal samples were obtained from 18 patients with IBD (one sample during exacerbation and one shortly after remission was achieved), 15 healthy volunteers, eight infectious colitis patients, and 13 IBD patients in long-term remission. Bacterial immunoglobulin coating was determined by flow-cytometry analysis. Faecal alpha-1-antitrypsin concentrations were determined by radial immune diffusion. RESULTS: IBD patients had 69 +/- 19% immunoglobulin A (IgA)-, 56 +/- 32% immunoglobulin G (IgG)- and 56 +/- 29% immunoglobulin M (IgM)-coated bacteria in their faeces. Healthy controls had less immunoglobulin coating, respectively 36 +/- 12%, 11 +/- 4% and 11 +/- 7%. Infectious colitis patients had 57 +/- 14% IgA, 31 +/- 13% IgG, and 42 +/-16% IgM; however, they had higher faecal alpha-1-antitrypsin concentrations than IBD patients. Shortly after remission, IBD patients had 65 +/- 20% IgA, 32 +/- 18% IgG and 40 +/- 21% IgM. Long-term-remission IBD patients had normal IgG and IgM but increased IgA (50 +/- 16%) coating. CONCLUSIONS: Compared with healthy controls, patients with IBD had an increased percentage of immunoglobulin-coated faecal anaerobic bacteria, both in active disease and shortly after remission. These results support the concept that there may be a breakdown of mucosal tolerance to the commensal gut flora in IBD.     

细胞毒性T淋巴细胞相关抗原4基因微卫星多态性与炎症性肠病的关系

目的探讨细胞毒性T淋巴细胞相关抗原4（CTLA-4）基因微卫星多态性与浙江省炎症性肠病（IBD）患者的相关性。方法对118例无血缘关系的IBD患者（99例溃疡性结肠炎，19例克罗恩病）以及140例正常对照者，采用特异性等位基因PCR方法，检测CTLA-4外显子4的3′非翻译区包含（AT）。重复序列的等位基因。扩增产物用12％非变性聚丙烯酰胺凝胶电泳，硝酸银染色。结果CTLA-4微卫星共有20种等位基因。与正常对照组比较，122bp等位基因频率在溃疡性结肠炎患者（P=0.0001／Pc=0．0025，OR=11.393，95％CI：2．574～50．429）和克罗恩病患者（P=0．0003／Pc=0.0050，OR=21.061，95％CI：3，927～112．94）中均显著增高。结论CTLA-4基因微卫星多态性与浙江省IBD患者显著相关。     

Fecal calprotectin is useful in predicting disease relapse in pediatric inflammatory bowel disease

BACKGROUND: Fecal calprotectin (FC) has been proposed as a noninvasive surrogate marker to determine the degree of intestinal inflammation and predicting relapse in patients with inflammatory bowel disease (IBD). The aim was to compare FC levels in IBD and healthy controls, to correlate FC levels with clinical disease activity, and to assess whether FC levels can be used to predict clinical relapse in children with IBD. METHODS: Enzyme-linked immunosorbent assay (ELISA) determined levels of FC were measured in more than 1 stool samples (n) from 32 IBD patients (n = 97) and from 34 healthy controls (n = 37). Disease activity was assessed by the Harvey-Bradshaw index in Crohn's disease (CD) and by Physician's Global Assessment (PGA) in both CD and ulcerative colitis (UC). Clinical events were recorded up to 9 months following stool collection in CD patients. Wilcoxon rank sum test and Fisher's exact tests were used to compare FC levels in IBD patients and in control. Kaplan-Meyer analysis was used to determine a risk of clinical relapse in relation to FC levels. RESULTS: The IBD group had higher FC levels (range 17-7500 g/g) compared with control (16-750 g/g, P < 0.0001). FC levels were higher during relapse (CD, 3214 +/- 2186; UC, 2819 +/- 1610) compared to remission (CD, 1373 +/- 1630; UC, 764 +/- 869; P < 0.0001). Among those with clinical relapse, 90% had FC levels more than 400 mug/g in CD. Eighty-nine percent of CD encounters with FC levels less than 400 mug/g remained in clinical remission. CONCLUSIONS: FC levels differentiate active IBD from controls. Among children with CD and in remission, FC levels may be useful in predicting impending clinical relapse.     

Plasma thrombin-activatable fibrinolysis inhibitor and plasminogen activator inhibitor-1 levels in inflammatory bowel disease

BACKGROUND: Patients with inflammatory bowel disease (IBD) have an increased risk of thromboembolic events. Imbalance of fibrinolysis has been suggested as one of the possible pathogenetic mechanisms. As plasminogen activator inhibitor-1 (PAI-1) and thrombin-activatable fibrinolysis inhibitor (TAFI) are inhibitors of fibrinolysis, we studied TAFI as well as PAI-1 plasma levels in IBD patients compared with healthy controls. METHODS: A total of 132 IBD patients [68 ulcerative colitis (UC) and 64 Crohn's disease (CD)] and 50 healthy controls were enrolled. PAI-1 and TAFI plasma levels were assessed by commercially available enzyme-linked immunosorbent assay kits. Their relationship with clinical parameters of UC and CD was assessed. RESULTS: Mean plasma PAI-1 levels were significantly higher in both UC patients (3.9+/-1.3 IU/ml) and CD patients (4.0+/-1.5 IU/ml) compared with healthy controls (3.1+/-1.1 IU/ml) (P=0.01). On the other hand, mean plasma TAFI levels were significantly lower in both UC patients (14.7+/-3.1 microg/ml) and CD patients (13.3+/-3.4 microg/ml) compared with healthy controls (17.4+/-3.0 microg/ml) (P<0.0001). Patients with active disease had significantly higher PAI-1 levels compared with patients with inactive disease for both diseases (P=0.03 and P=0.01, respectively). No significant association between plasma TAFI levels and disease activity was also found. Plasma TAFI levels were significantly lower in patients with ileal CD compared with patients with colonic CD. CONCLUSION: PAI-1 plasma levels are increased whereas TAFI levels are decreased in IBD patients. These results suggest an imbalance of fibrinolysis in IBD.     

High-sensitivity C-reactive protein in paediatric inflammatory bowel disease

AIM:To study whether high-sensitivity C-reactive protein(hs-CRP) measurement can aid the assessment of disease activity and glucocorticoid treatment in paediatric inflammatory bowel disease(IBD).METHODS:CRP levels were measured in 39 children with IBD undergoing colonoscopy [median age 12.8 years,Crohn's disease(CD) n=20],in 22 other children with IBD followed for acute response to glucocorticoids,and in 33 paediatric non-IBD patients.When standard CRP level was below detection limit(<5mg/L),hs-CRP was anal...     

Serum tenascin-C is an indicator of inflammatory bowel disease activity

Tenascin-C is a multifunctional matrix protein that is induced in inflammation and neoplasia. In the colonic mucosa of ulcerative colitis patients tenascin-C indicates tissue repair, and mucosal concentrations are correlated with local disease activity. We prospectively examined the relationship between serum concentrations of tenascin-C parameters of disease activity in surgically treated patients with ulcerative colitis and patients with inflammatory bowel disease (IBD). Perioperative serum concentrations were quantified by ELISA in 58 patients admitted for restorative proctocolectomy; controls were 37 patients with familial adenomatous polyposis receiving the same treatment. We also measured tenascin-C serum levels in 47 patients with ulcerative colitis and Crohn's disease who were receiving nonsurgical treatment. Preoperative serum tenascin-C levels were significantly higher in ulcerative colitis patients than in controls (17.2 +/- 14.6 microg/ml vs. 3.2 +/- 1.7 microg/ml) and were significantly correlated with clinical and histological parameters of disease activity; levels decreased significantly after restorative proctocolectomy. Serum tenascin-C levels were also correlated with the course of disease activity in conservatively treated IBD patients. Tenascin-C is thus not disease-specific. However, it does indicate the activity of IBD and may reflect the degree of tissue remodeling. The tenascin-C levels therefore offers a novel serum parameter for assessing disease activity and monitoring therapy in patients with IBD.     

The effect of infliximab on circulating levels of leptin, adiponectin and resistin in patients with inflammatory bowel disease

BACKGROUND: Tumour necrosis factor alpha is a critical mediator of inflammation-related altered metabolism in inflammatory bowel disease (IBD), possibly through its interaction with adipokines, which play an important role in IBD. Infliximab is a well established antitumour necrosis factor alpha treatment in IBD. AIM AND METHODS: We studied serum levels of leptin, adiponectin and resistin in 20 IBD patients before and after infliximab treatment using commercially available enzyme-linked immunosorbent assays. The results were correlated with alterations of disease activity, BMI and C-reactive protein. RESULTS: Infliximab induced clinical response or remission in 18 out of 20 treated IBD patients. Mean serum-leptin levels were 4.6+/-0.5 and 5.1+/-0.5 ng/ml (P=0.41), mean serum-adiponectin levels were 10513.9+/-1216.9 and 9653.5+/-1031.5 ng/ml (P=0.36) and mean serum-resistin levels were 26.3+/-4.1 and 13.9+/-1.4 ng/ml (P=0.004), before and after infliximab treatment, respectively. No significant correlation between the changes of BMI, C-reactive protein or the clinical indices of activity and alterations of the examined adipokines was found. CONCLUSIONS: Serum levels of leptin and adiponectin had no significant alterations, whereas serum-resistin levels are significantly decreased after infliximab therapy in IBD patients, suggesting a possible proinflammatory status for resistin in IBD and a role as a marker of successful therapy.     

Human colonic intraepithelial and lamina proprial lymphocytes: cytotoxicity in vitro and the potential effects of the isolation method on their functional properties.

Colonic mucosal lymphoid cells, selectively enriched for intraepithelial (IEL) or lamina proprial lymphocytes (LPL), were isolated by sequential EDTA-collagenase treatment of resected human colons. Cytotoxic activities of colonic and peripheral blood lymphoid cells (PBL) were tested in three different assays, using chicken erythrocytes (CRBC) and Chang cells as targets. Antibody-dependent cell-mediated cytotoxicity (ADCC) and PHA-induced cytotoxicity (MICC) for both targets were shown by all the isolates of PBL, as was spontaneous cell-mediated cytotoxicity (SCMC) for Chang cells. However, no SCMC or ADCC for Chang cells was found with LPL, and IEL showed minimal or no activity in either assay. PBL, LPL and IEL demonstrated MICC for Chang cells but, contrasting with PBL and LPL, IEL showed no MCC for CRBC. No significant differences were found between the cytotoxic capabilities of colonic lymphoid cells from patients with inflammatory bowel disease and those from patients with other colonic diseases. Importantly, control studies with PBL showed that SCMC for Chang cells and ADCC for CRBC and Chang cells were reduced by collagenase treatment used in the isolation, of LPL. Also, SCMC for Chang cells was reduced by the treatment of PBL with EDTA. In contrast, neither EDTA nor collagenase reduced MICC for CRBC or Chang cells. Both forms of treatment induced variable degrees of cell losses in the PBL. By analogy, it can be implied that the isolation of intestinal mononuclear cells using EDTA and collagenase may influence some of their cytotoxic activities in vitro. This raises an important caveat in the interpretation of such studies.     

Reduced plasma antioxidant concentrations and increased oxidative DNA damage in inflammatory bowel disease.

BACKGROUND: Oxidative stress is believed to play a key role in the pathogenesis of inflammatory bowel disease (IBD)-related intestinal damage. Circulating antioxidants may have a role to play in preventing free radical-mediated tissue injury. METHODS: Plasma vitamin A, E and carotenoid concentrations, leukocytic genomic damage and 8-hydroxy-deoxy-guanosine (8-OHdG) concentration were determined in 46 ulcerative colitis (UC) patients, 37 Crohn disease (CD) patients and 386 controls. A 20 ml blood sample was taken from each subject for antioxidant and 8-OHdG measurements. A food frequency questionnaire was administered to a sample of subjects from each group to evaluate daily intake of dietary compounds. RESULTS: Antioxidant concentration was significantly reduced in IBD patients, particularly in those with active disease, with respect to controls (P < 0.0001). 8-OHdG concentrations were significantly increased in IBD patients compared to controls, independent of disease activity (P < 0.05). No correlation was found between antioxidant and 8-OHdG concentrations. Carotenoid concentrations were significantly reduced in malnourished IBD patients (0.89 +/- 0.14 micromol/l) compared to patients with normal or high body mass index (1.83 +/- 0.12 micromol/l; P < 0.05), independent of disease activity or extension. Protein, fruit and vegetable intakes of IBD patients were significantly lower than those of controls. CONCLUSIONS: Depletion of antioxidants is likely to be important in the pathophysiology of IBD: UC and CD patients show increased free radical peripheral leukocyte DNA damage and decreased plasma antioxidant defenses. These results indicate the necessity of further studies to establish whether optimal vitamin status may improve the clinical course of UC and CD.     

Impact of inflammatory bowel disease and ursodeoxycholic acid therapy on small-duct primary sclerosing cholangitis

A longitudinal, cohort study was performed to characterize the clinical features of patients with small-duct primary sclerosing cholangitis (PSC) occurring with and without inflammatory bowel disease (IBD) and to determine the influence of IBD and the effect of ursodeoxycholic acid (UDCA) therapy on the course of the liver disease. Forty-two patients with small-duct PSC (14 women and 28 men; mean age, 36.7 +/- 13.3 years) were followed for up to 24.9 years. At presentation, prevalence of signs of liver disease (none versus 35%, P = 0.002), gastroesophageal varices (5% versus 30%, P = 0.03), and stage III/IV disease (9% versus 45%, P = 0.008) were lower in those with IBD versus those without IBD. During follow-up, 6 patients underwent liver transplantation, and another died of cirrhosis. Using the Cox proportional hazard analysis, concomitant IBD was not associated with liver death or transplant, whereas the revised Mayo risk score for PSC was the only prognostic factor associated with liver-related outcomes (relative risk, 6.47; 95% confidence interval, 1.75-137.5). UDCA (13-15 mg/kg/day) therapy for an average of 40 months showed biochemical improvement (P < 0.001) in UDCA-treated patients, while no significant change occurred in untreated patients. UDCA therapy had no effect on delaying progression of disease (relative risk, 0.95; 95% confidence interval, 0.38-2.36). CONCLUSION: Small-duct PSC often is recognized at an early stage in patients with IBD; however, IBD has no impact on long-term prognosis. Although UDCA therapy improves liver biochemistries, it may not delay disease progression during the short period of treatment.