Aetiology and pathogenesis of chronic inflammatory bowel disease

No potential causal link between HP infection and IBD: A 2way Mendelian randomization study

Recent epidemiological research suggests a possible negative correlation between Helicobacter pylori infection and inflammatory bowel disease (IBD). However, conflicting studies have provided unclear evidence regarding these causal relationships. Therefore, recommending specific prevention and treatment strategies for H. pylori infection and IBD is challenging. We used various antibodies (anti-H. pylori IgG, VacA, and GroEl) related to H. pylori infection as indicators. We acquired relevant genetic variants from public databases within the Genome-wide Association Studies (GWAS) dataset using IBDs tool variables from 2 different GWAS datasets. We thoroughly examined the data and screened for IVs that fulfilled these criteria. Subsequently, Bidirectional Mendelian randomization (MR) was conducted to predict the potential causality between the 2. To ensure the accuracy and robustness of our results, we conducted a series of sensitivity analyses. Based on our comprehensive MR analysis, no potential causal relationship was observed between H. pylori infection and IBD. Across various methodologies, including IVW, MR-Egger, and weighted median, our findings showed P values > .05. The only exception was observed in the reverse MR analysis using the MR-Egger method, which yielded a P value of < .05. However, because the IVW method is considered the most statistically significant method for MR, and its P value was > .05, we do not believe that a potential causal relationship exists between them. Our sensitivity analysis did not suggest significant horizontal pleiotropism. Although heterogeneity was detected in the analysis of IBD (IIBDGC source) versus H. pylori GroEL antibody levels (MR-Egger, Qp = 0.038; IVW, Qp = 0.043), the results remained reliable because we selected IVW as a random-effects model in our MR analysis method. Based on our MR research, no direct correlation was observed between H. pylori infection and IBD risk. This implies that eradicating H. pylori may not provide substantial benefits in preventing or treating regional IBD, and vice versa. Nevertheless, the use of H. pylori serological index substitution has limitations, and further research using histological diagnosis and additional MR studies is required to comprehensively assess the link between H. pylori infection and IBD.

Hydrogen sulfide toxicity in the gut environment: Meta-analysis of sulfate-reducing and lactic acid bacteria in inflammatory processes

BACKGROUND

Hydrogen sulfide is the final product of sulfate-reducing bacteria metabolism. Its high concentration in the gut can affect adversely bowel environment and intestinal microbiota by toxicity and pH lowering.

AIM OF REVIEW

The aim of the review was to give observations related to the properties of bacterial communities inhabiting the gut, with the emphasis on sulfate-reducing bacteria and lactic acid bacteria.

KEY SCIENTIFIC CONCEPTS OF REVIEW

The conduction of meta-analysis was another goal, since it gave statistical observation of the relevant studies. The review literature consisted of more than 160 studies, published from 1945 to 2019. Meta-analysis included 16 studies and they were chosen from the Web of Science database. The systematic review gave important information about the development of gut inflammation, with emphasis on sulfate-reducing and lactic acid bacteria. Oppositely from sulfate-reducing bacteria, probiotic properties of lactic acid bacteria are effective inhibitors against inflammatory bowel disease development, including ulcerative colitis. These facts were confirmed by the conducted meta-analysis. The results and observations gained from the systematic review represent the emphasized importance of gut microbiota for bowel inflammation. On the other side, it should be stated that more studies in the future will provide even better confirmations.

Beneficial effect of Amorphophallus paeoniifolius tuber on experimental ulcerative colitis in rats

CONTEXT

The tuber of Amorphophallus paeoniifolius (Dennst.) Nicolson (Araceae), commonly called Suran or Jimmikand, has high medicinal value and is used ethnomedicinally for the treatment of different gastrointestinal and inflammatory disorders.

OBJECTIVE

The present study evaluated the effects of extracts of Amorphophallus paeoniifolius tubers on acetic acid-induced ulcerative colitis (UC) in rats.

MATERIALS AND METHODS

Wistar rats were orally administered methanol extract (APME) or aqueous extract (APAE) (250 and 500 mg/kg) or standard drug, prednisolone (PRDS) (4 mg/kg) for 7 days. On 6th day of treatment, UC was induced by transrectal instillation of 4% acetic acid (AA) and after 48 h colitis was assessed by measuring colitis parameters, biochemical estimations and histology of colon.

RESULTS

APME or APAE pretreatment significantly (p < .05-.001) prevented AA-induced reduction in body weight and increase in colitis parameters viz. stool consistency, colon weight/length ratio and ulcer score, area and index. Extracts treatment attenuated (p < .001) increase in alkaline phosphatase and lactate dehydrogenase in serum and myeloperoxidase activity and cytokines in colon tissue due to AA administration. Extracts treatment prevented AA-induced elevation in lipid peroxidation and decline in activities of superoxide dismutase and catalase and reduced-glutathione content (p < .05-.001) along with histopathological alterations. PRDS also showed similar ameliorative effect on colitis.

DISCUSSION AND CONCLUSION

APME and APAE showed a preventive effect on UC, and ameliorated inflammation and oxidative damage in colon. The effects may be attributed to presence of phytochemicals, betulinic acid, β-sitosterol, and glucomannan. In conclusion, the tuber of Amorphophallus paeoniifolius exhibited an anticolitic effect through anti-inflammatory and antioxidant action.

Regulatory effects of glycyrrhizae radix extract on DSS-induced ulcerative colitis

BACKGROUND

Glycyrrhizae Radix (GR) is a Korean traditional herb medicine that is widely-used in clinical health care. The clinical functions of GR include relief of toxicity, anti-cancer, regulating blood cholesterol and anti-inflammation. This study investigated the role of GR on ulcerative colitis in a dextran sulfate sodium (DSS)-induced mouse model of colitis.

METHOD

Western blot analysis and enzyme-linked immunosorbent assay (ELISA) analyses were done on male BALB/c mice administered 5 % DSS during the experimental period. Ethanol extracts of GR were orally administered at same time daily to control mice. The severity of colitis was measured by body weight change and colon length.

RESULT

DSS-treated mice displayed weight loss and shortened colon length compared with control mice. Mice were administered GR showed less weight loss and longer colon length than the DSS-treated group. Inflammatory cytokines were decreased by GR treatment. Treatment also reduced DSS-induced microscopic damage to colon tissue. GR regulated the phosphorylation of transcription factors such as NF-κB p65 and IκB α.

CONCLUSIONS

GR has beneficial effects in a colitis model. GR might be a useful herb medicine in the treatment of ulcerative colitis.

Glycyrrhetic Acid Ameliorates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Vivo

Glycyrrhizae Radix (GR) is a Korean traditional herb medicine that is widely used in clinical health care. Glycyrrhetic acid (GA) is an aglycone saponin extracted from GR that has anti-inflammatory, anti-cancer, and anti-viral effects. However, the anti-inflammatory effects of GA in colitis have not been reported. This study investigated the role of GA on ulcerative colitis in a dextran sulfate sodium (DSS)-induced mouse colitis model. DSS-treated mice displayed weight loss and shortened colon length compared with control mice. Mice administered GA showed less weight loss and longer colon length than the DSS-treated group. Interleukin (IL)-6, IL-1β, and tumor necrosis factor-alpha were decreased by GA treatment. GA treatment also reduced DSS-induced microscopic damage to colon tissue. GA regulates the phosphorylation of transcription factors including nuclear factor-kappa B (NF-κB) and IκB alpha, and regulates the expression of cycloxygenase-2 and prostaglandin E₂. GA thus showed beneficial effects in a mouse model of colitis, implicating GA might be a useful herb-derived medicine in the treatment of ulcerative colitis.

Immunoprotective Effect of Probiotic Dahi Containing Lactobacillus acidophilus and Bifidobacterium bifidum on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice

In the present study, probiotic Dahi (LaBb Dahi) containing Lactobacillus acidophilus LaVK2 and Bifidobacterium bifidum BbVK3 was selected as a probiotic therapy to investigate its protective effect on dextran sodium sulfate (DSS)-induced ulcerative colitis model in mice that mimics the picture in human. LaBb Dahi was prepared by co-culturing Dahi bacteria (Lactococcus lactis ssp. cremoris NCDC-86 and Lactococcus lactis ssp. lactis biovar diacetylactis NCDC-60) along with selected strain of L. acidophilus LaVK2 and B. bifidum BbVK3 in buffalo milk (3% fat). Four groups of swiss albino male mice (12 each) were fed buffalo milk (3% fat), buffalo milk (3% fat) plus DSS, Dahi plus DSS, and LaBb Dahi plus DSS, respectively, for 17 days with basal diet. The myeloperoxidase (MPO) activity, levels of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interferon (IFN-γ) were assessed as inflammatory markers, and the histopathological picture of the colon of mice was studied. DSS-induced colitis appeared to induce significant increase in MPO activity, levels of TNF-α, IL-6 and IFN-γ. Feeding with LaBb Dahi offered significant reduction in MPO activity, levels of TNF-α, IL-6 and IFN-γ when compared to either buffalo milk group or group III (Dahi). The present study suggests that LaBb probiotic Dahi can be used to combat DSS-induced biochemical and histological changes and to achieve more effective treatment for ulcerative colitis.

Helicobacter pylori infection and inflammatory bowel disease: Is there a link?

Helicobacter pylori (H. pylori) infection is one of the most widely spread infectious diseases in humans. It can cause chronic gastritis, peptic ulcer disease and gastric malignancies and has been associated with extra-gastric disorders. H. pylori elicit a chronic systemic inflammatory response which, under certain conditions, may trigger autoimmune reactions and may be implicated in the pathogenesis of autoimmune diseases. Although the pathogenesis of inflammatory bowel disease (IBD) is unknown, it is thought to result from complex interactions between environmental factors and microbiota in the gut of individuals who are genetically susceptible. Several bacterial and viral agents have been implicated in the aetiology of IBD. In theory, H. pylori infection could be involved in the pathogenesis of IBD by inducing alterations in gastric and/or intestinal permeability or by causing immunological derangements resulting in absorption of antigenic material and autoimmunity via various immunological pathways. Similar mechanisms may also be responsible for the co-existence of IBD with other autoimmune diseases and/or extra-intestinal manifestations. However, the epidemiological data fail to support this association. In fact, various studies indicate that the prevalence of H. pylori infection is low in patients with IBD, suggesting a protective role for this infection in the development of IBD. In this report, we aim to shed light on proposed mechanisms and confounding factors underlying the potential link between H. pylori infection and IBD.

Effect of aqueous extract of Aegle marmelos unripe fruit on inflammatory bowel disease

Objective:

The present study was designed to evaluate the effect of Aegle marmelos unripe fruit extract (AMFE) on inflammatory bowel disease (IBD) in Wistar albino rats.

Materials and Methods:

Effect of AMFE was studied on acetic acid induced ulcerative colitis (1 ml of 4% acetic acid solution, transrectal) and indomethacin-induced enterocolitis (10 mg/kg, single dose, p.o) in Wistar albino rats. The extract was administered orally at different dose of 150, 200 and 250 mg/kg body weight. Disease pathogenesis was assessed by measuring disease activity index (DAI), macroscopic score, microscopic score, mesenteric mast cell protection, superoxide dismutase (SOD), and malonaldehyde (MDA) levels in the above two models.

Results:

The results showed a dose dependent decrease in intestinal inflammation following treatment with AMFE. Significant protection in mast cell degranulation was observed in acetic acid and indomethacin-induced IBD models. Treatment with AMFE significantly decreased the MDA levels and increased SOD activity.

Conclusion:

In our study, AMFE produced anti-inflammatory, antioxidant, and mast cell stabilizing effects demonstrating protective effect in inflammatory bowel disease.

Immunovirological parameters and cytokines in HIV infection

Although modern combined antiretroviral therapies (cART) result in lower morbidity and mortality and a visible improvement of clinical and laboratory parameters in HIV-infected, it is known that their long-term use contributes to appearance of the many events unrelated to AIDS such as cardiovascular diseases, cancer and osteoporosis, comorbidities which have been proposed as some of the most important that deprive the majority of infected to present an even better prognosis. This is because even with a decrease in inflammation and immune activation after drug intervention to the patient, these parameters remain higher than those shown by healthy individuals and the imbalance of cytokine profiles also persists. Therefore, evaluations of other biomarkers in clinical practice are needed to complement the exams already carried out routinely and allow more effective monitoring of HIV patients. This review aims to investigate the role of cytokines as potential markers showing studies on their behavior in various stages of HIV infection, with or without cART.

Common and specific signatures of gene expression and protein-protein interactions in autoimmune diseases

The aim of this study is to understand intracellular regulatory mechanisms in peripheral blood mononuclear cells (PBMCs), which are either common to many autoimmune diseases or specific to some of them. We incorporated large-scale data such as protein-protein interactions, gene expression and demographical information of hundreds of patients and healthy subjects, related to six autoimmune diseases with available large-scale gene expression measurements: multiple sclerosis (MS), systemic lupus erythematosus (SLE), juvenile rheumatoid arthritis (JRA), Crohn's disease (CD), ulcerative colitis (UC) and type 1 diabetes (T1D). These data were analyzed concurrently by statistical and systems biology approaches tailored for this purpose. We found that chemokines such as CXCL1-3, 5, 6 and the interleukin (IL) IL8 tend to be differentially expressed in PBMCs of patients with the analyzed autoimmune diseases. In addition, the anti-apoptotic gene BCL3, interferon-γ (IFNG), and the vitamin D receptor (VDR) gene physically interact with significantly many genes that tend to be differentially expressed in PBMCs of patients with the analyzed autoimmune diseases. In general, similar cellular processes tend to be differentially expressed in PBMC in the analyzed autoimmune diseases. Specifically, the cellular processes related to cell proliferation (for example, epidermal growth factor, platelet-derived growth factor, nuclear factor-κB, Wnt/β-catenin signaling, stress-activated protein kinase c-Jun NH2-terminal kinase), inflammatory response (for example, interleukins IL2 and IL6, the cytokine granulocyte-macrophage colony-stimulating factor and the B-cell receptor), general signaling cascades (for example, mitogen-activated protein kinase, extracellular signal-regulated kinase, p38 and TRK) and apoptosis are activated in most of the analyzed autoimmune diseases. However, our results suggest that in each of the analyzed diseases, apoptosis and chemotaxis are activated via different subsignaling pathways. Analyses of the expression levels of dozens of genes and the protein-protein interactions among them demonstrated that CD and UC have relatively similar gene expression signatures, whereas the gene expression signatures of T1D and JRA relatively differ from the signatures of the other autoimmune diseases. These diseases are the only ones activated via the Fcɛ pathway. The relevant genes and pathways reported in this study are discussed at length, and may be helpful in the diagnoses and understanding of autoimmunity and/or specific autoimmune diseases.

The therapeutic effect of chelidonic acid on ulcerative colitis

Chelidonic acid (CA), a constituent of Chelidonium majus L., has many pharmacological effects, including mild analgesic and antimicrobial effects. However, the effects of CA on intestinal inflammation and the molecular mechanisms responsible are poorly understood. The aim of this study was to investigate the protective effects of CA against dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Mice treated with DSS displayed obvious clinic signs, such as, body weight loss and a shortening of colon length, but the administration of CA attenuated both of these signs. Additionally, CA was found to regulate levels of interleukin-6 and tumor necrosis factor-α in serum. In colonic tissues, prostaglandin E(2) (PGE(2)) production levels and cyclooxygenase-2 (COX-2) and hypoxia induced factor-1α (HIF-1α) expression levels were increased by DSS, but CA attenuated increases in COX-2 and HIF-1α levels. These results provide novel insights into the pharmacological actions of CA and its potential use for the treatment of intestinal inflammation.

Oldenlandia diffusa Ameliorates Dextran Sulphate Sodium-Induced Colitis Through Inhibition of NF-κB Activation

Ulcerative colitis (UC) is an inflammatory bowel disease, which is a chronic gastrointestinal disorder. Oldenlandia diffusa (OD) has been used as a traditional oriental medicine for inflammation. However, the regulatory effect and molecular mechanism of OD in intestinal inflammation are not yet understood. This study investigated the protective effect of OD in dextran sulfate sodium (DSS)-induced colitis. Mice treated with DSS showed remarkable clinical signs, including weight loss, and reduced colon length. Administration of OD attenuated these signs and significantly suppressed levels of interleukin (IL)-6, IL-1β and expression of cyclooxygenase-2 in DSS-treated colon tissues. OD also reduced the activation of transcription nuclear factor-κB p65 in DSS-treated colon tissues. Hentriacontane, a constituent of OD, attenuated weight loss, colon shortening, and levels of IL-6 caused by DSS. Taken together, the results provide experimental evidence that OD might be a useful therapeutic medicine for patients with UC.

The protective effect of Cassia obtusifolia on DSS-induced colitis

Cassia obtusifolia (CO) has been traditionally used in Korea to treat eye inflammation, photophobia, and lacrimation. However, the regulatory effect and molecular mechanism of CO in intestinal inflammation has not been understood. In this study, we investigate the protective effect of CO in dextran sulfate sodium (DSS)-induced colitis. CO reduced clinical signs of DSS-induced colitis, including body weight loss, shortened colon length, and increased disease activity index. The results show that CO significantly suppressed the levels of interleukin (IL)-6 and expression of cyclooxygenase-2 in DSS-treated colon tissues. Additionally, we observed that CO reduced the activation of transcription nuclear factor-κB p65 in DSS-treated colon tissues. Taken together, these findings suggest that CO has improving effects on DSS-induced ulcerative colitis, which may explain its beneficial effect in the regulation of chronic intestinal inflammation.

Loss of IL-17-producing CD8 T cells during late chronic stage of pathogenic simian immunodeficiency virus infection

Progressive disease caused by pathogenic SIV/HIV infections is marked by systemic hyperimmune activation, immune dysregulation, and profound depletion of CD4(+) T cells in lymphoid and gastrointestinal mucosal tissues. IL-17 is important for protective immunity against extracellular bacterial infections at mucosa and for maintenance of mucosal barrier. Although IL-17-secreting CD4 (Th17) and CD8 (Tc17) T cells have been reported, very little is known about the latter subset for any infectious disease. In this study, we characterized the anatomical distribution, phenotype, and functional quality of Tc17 and Th17 cells in healthy (SIV-) and SIV+ rhesus macaques. In healthy macaques, Tc17 and Th17 cells were present in all lymphoid and gastrointestinal tissues studied with predominance in small intestine. About 50% of these cells coexpressed TNF-α and IL-2. Notably, ∼50% of Tc17 cells also expressed the co-inhibitory molecule CTLA-4, and only a minority (<20%) expressed granzyme B suggesting that these cells possess more of a regulatory than cytotoxic phenotype. After SIV infection, unlike Th17 cells, Tc17 cells were not depleted during the acute phase of infection. However, the frequency of Tc17 cells in SIV-infected macaques with AIDS was lower compared with that in healthy macaques demonstrating the loss of these cells during end-stage disease. Antiretroviral therapy partially restored the frequency of Tc17 and Th17 cells in the colorectal mucosa. Depletion of Tc17 cells was not observed in colorectal mucosa of chronically infected SIV+ sooty mangabeys. In conclusion, our results suggest a role for Tc17 cells in regulating disease progression during pathogenic SIV infection.

An unusual presentation of fistulating Crohn’s disease: Ascites

Whilst ascites is a common presenting complaint in patients with decompensated chronic liver disease and disseminated malignancy, in Crohn’s disease however, it is exceptionally rare. We describe a patient with no prior history of inflammatory bowel or liver disease, presenting with rapid onset gross ascites and scrotal swelling. Further investigations revealed severe hypoalbuminemia and transudative ascitic fluid with normal other liver function tests and a negative liver screen. Computed tomography revealed widespread ascites and pleural effusions with no features of malignancy or portal hypertension, and a small bowel barium series showed features of fistulating small bowel Crohn’s disease. An ileo-colonoscopy confirmed the presence of terminal ileal inflammatory stricture. The patient’s clinical condition and serum albumin improved with a combination of diuretics, elemental diet, antibiotics and oral 5-aminosalicylic acid therapy.

Modulating effect of Hesperidin on experimental murine colitis induced by dextran sulfate sodium

Hesperidin, a flavanone-type flavonoid, is abundant in citrus fruit and has a wide range of pharmacological effects. Here we investigated the effect of Hesperidin on dextran sulphate sodium (DSS)-induced experimental ulcerative colitis in mice. Sulfasalazine (positive control) and Hesperidin in doses of 10, 40 and 80 mg/kg were administered orally once a day for 7 days, beginning concurrently with exposure to DSS. The symptom of ulcerative colitis was evaluated by disease activity index (DAI) and the wet weight of colon. Myeloperoxidase (MPO) activity, malondialdehyde (MDA) content and the levels of interleukin-4 (IL-4) and interleukin-6 (IL-6) in serum were measured to observe the possible mechanisms. Oral administration of Hesperidin significantly decreased DAI, MPO activity, MDA content and the level of IL-6 in serum (p<0.01), while there was no significantly effect on the level of IL-4 in serum. These results demonstrate that Hesperidin can ameliorate DSS-induced experimental colitis, and may be useful in the prevention and treatment of colitis.

An experimental study on ulcerative colitis as a potential target for probiotic therapy by Lactobacillus acidophilus with or without "olsalazine"

Traditional medical treatments for ulcerative colitis (UC) are still compromised by its adverse effects and not potent enough to keep in remission for long-term periods. So, new therapies that are targeted at specific disease mechanisms have the potential to provide more effective and safe treatments for ulcerative colitis. Probiotics is recently introduced as a therapy for ulcerative colitis. In the present study, Lactobacillus acidophilus was selected as a probiotic therapy to investigate its effects in oxazolone-induced colitis model in rats that mimics the picture in human. The rats were grouped (8 rats each) as normal control group (Group I), Group II served as untreated oxazolone-induced colitis, Group III oxazolone-induced colitis treated with probiotic L. acidophilus (1×10(7) colony-forming units (CFU)/mL/day oral for 14 days), Group IV oxazolone-induced colitis treated with olsalazine (60 mg/kg/day oral for 14 days), Group V oxazolone-induced colitis treated with probiotic L. acidophilus and olsalazine in the same doses and duration. Disease activity index (DAI) was recorded, serum levels of C-reactive protein (CRP), tumor necrosis factor-α (TNF-α) and intrleukin-6 (IL-6) was assessed as inflammatory markers and the histopathological picture of the colon of each rat was studied. Disease activity index (DAI) showed significant positive correlation with the elevated serum levels of CRP (r=0.741, p<0.05), TNF-α (r=0.802, p<0.05) and IL-6 (r=0.801, p<0.05). Treatment with either L. acidophilus (group III) or olsalazine (group IV) resulted in significant reduction in serum levels of CRP, TNF-α and IL-6, as well as disease activity index (DAI). Treatment with combination of L. acidophilus and olsalazine (group V) offered more significant reduction in serum levels of CRP, TNF-α, IL-6 and disease activity index (DAI) when compared to either group II (untreated group), group III (treated with L. acidophilus) or group IV (treated with olsalazine). So, it was concluded that L. acidophilus probiotic could be recommended as adjuvant therapy in combination with olsalazine to achieve more effective treatment for ulcerative colitis. For application in human, this needs to be verified in further clinical studies.

Alternative drug delivery approaches for the therapy of inflammatory bowel disease

This article shall give an overview on drug delivery systems for new therapeutic strategies in the treatment of inflammatory bowel disease. The various features of the different approaches allowing locally restricted drug delivery to the inflamed colon are discussed including the main physiological and pathophysiological limitations for the different systems. Conventional drug delivery systems are tightly adapted from developments for colonic delivery by oral administration triggered by release mechanisms owing to the physiological environment that these systems encounter in the colonic region. The newer developments in this context aim for an increased selectivity of drug delivery by targeting mechanisms which have a closer relation to pathophysiological particularities of the disease. Therefore, we were focused especially on new strategies for such treatment including liposomal formulations, cyclodextrins, micro- or nanoparticles, viral gene therapy approaches, and others. Effective and selective delivery even of an otherwise nonspecifically acting drug could provide new therapeutic pathways in the treatment of inflammatory bowel disease.

Five cases of de novo inflammatory bowel disease after orthotopic liver transplantation

Immunosuppression is currently the treatment of choice for severe inflammatory bowel disease (IBD). Thus, it was anticipated that the course of preexisting IBD should improve after orthotopic liver transplantation (OLT). Despite sufficient allograft immunosuppressive therapy, however, exacerbation of IBD or the development of de novo IBD after OLT were described in some cases, primarily in patients transplanted for end-stage primary sclerosing cholangitis (PSC). In addition, the development of de novo IBD in patients undergoing OLT for indications other than PSC was described. Evaluating our collective of 314 liver transplanted patients we found five patients transplanted for various indications other than PSC (autoimmune hepatitis [AIH], acute-on-chronic hepatitis B, Wilson's disease, and cryptogenic cirrhosis) who developed de novo IBD after OLT despite sufficient immunosuppressive therapy with tacrolimus or cyclosporine. PSC was widely excluded in these patients by clinical and histological examinations and there was no sign of an enteric infection. It was remarkable that all patients were suspected to have an autoimmune background. Four of our patients were women and almost all patients showed histologically typical signs of an ulcerative colitis (UC). To prevent allograft rejection, three of five patients were treated with cyclosporine and the other two with tacrolimus. After diagnosis, treatment with aminosalicylates and corticosteroids led to complete clinical and histological remission. However, relapses occurred frequently after termination of specific therapy. In combination with previous reports, our cases indicate an immune dysregulation leading to the development of de novo IBD after OLT under immunosuppressive therapy. Reviewing the literature, it should be considered that apart from the autoimmune background, immunosuppressive therapy may itself play a major role in the development of de novo IBD. From the clinical point of view, it is of critical importance to detect this phenomenon, since diarrhea is an important cause of morbidity and mortality in transplanted patients and therapy for this disorder completely differs from the treatment for other causes of diarrhea. Aminosalicylates and courses of corticosteroids offer an effective treatment.

Novel approaches to inflammatory bowel disease

Ulcerative colitis and Crohn's disease, collectively known as inflammatory bowel disease (IBD), are chronic, spontaneously relapsing disorders of unknown cause. These diseases appear to be immunologically mediated and have genetic and environmental influences. Although the cause of these diseases remains obscure, the pathogenesis of chronic intestinal inflammation is becoming clearer, due to improved animal models of enterocolitis and important advances in immunological techniques. Traditional therapy for IBD, although helping to induce and maintain disease remission, does little to alter the underlying fundamental disease process. New IBD therapy has not developed significantly over the past twenty years and includes 5-aminosalicylic acid preparations, corticosteroids and immunomodulatory agents, such as azathioprine, 6-mercaptopurine and methotrexate. There is, therefore, a need for new, specific disease-modifying therapy and the development of such therapy has been hastened by a greater understanding of the pathophysiology of IBD. This review examines the most recent novel therapies for IBD, with specific emphasis on immunomodulatory and novel anti-inflammatory therapies. Recent clinical trials are reviewed, and the potential advances and clinical impact that these novel agents may provide are discussed.

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention.

AIM

To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls.

METHODS

A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies.

RESULTS

A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes.

CONCLUSIONS

IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Treatment of distal colitis with local anaesthetic agents

The results of clinical and experimental studies on topical treatment of distal colitis with local anaesthetic agents are summarized. The original observation was an adrenergic hyperinnervation of the inflamed mucosa (hyperinnervation hypothesis). In order to silence local nervous reflexes, the mucosa was treated topically with 2% lidocaine gel. The clinical results are promising and no side effects have been observed. The relapse rate is relatively high and related to the duration of treatment. In studies of experimental colitis a potential antagonism between harmful adrenergic nerves (vasoconstrictor substances and proinflammatory cytokines) and mucosa-protective visceral afferents (antiinflammatory cytokines) in the pathogenesis of colitis is intriguing. Other studies have emphasized the importance of neutrophils for causing damage to the colon epithelium (neutrophil hypothesis) and local anaesthetics have potent effects on several steps of the inflammatory response in addition to the nervous blockade.

Characterization of antigens from the human exocrine pancreatic tissue (Pag) relevant as target antigens for autoantibodies in Crohn's disease

BACKGROUND

The present study was performed to analyse the immunological properties of the autoantigens recognized by autoantibodies against exocrine pancreas (PAb), which have been described in Crohn's disease.

METHODS

Autoantibodies were detected by indirect immunofluorescence. Inhibition studies were performed by preincubating tissue sections with various glycoproteins and the different fractions obtained in fractioned salt precipitation of pancreas homogenate with ammonium sulphate. Immunoblotting of human pancreas homogenate was conducted using PAb-positive sera.

RESULTS

In size exclusion chromatography, the molecular weight of the pancreas autoantigen (PAg) was determined as > 800 kD. In the fractionated salt precipitation, the autoantigen could be detected in fractions I (0-25% ammonium sulphate) and III (50-90% ammonium sulphate). In immunoblotting, a number of protein bands were observed (at 16, 18, 19, 24, 27, 29, 31 and 34 kD), and the binding pattern showed little variation between individual patients.

CONCLUSIONS

The protein that is recognized by PAb appears to be a large protein complex consisting of several subunits which exhibit reactivity to PAb.

Network of inflammatory cytokines and correlation with disease activity in ulcerative colitis

OBJECTIVE

The inflammatory component of most human inflammatory chronic diseases implicates the production of proinflammatory cytokines. Tumor necrosis factor alpha (TNFalpha) and interleukin 1beta (IL1beta) seem to play an important role in ulcerative colitis (UC) in relevant experimental models. Moreover, antiTNF therapy seems promising experimentally and clinically. However, these cytokines, and TNFalpha more particularly, are hardly seen in vivo in such patients. The mediators of choice, correlated with disease activities or drug efficacy, remain unclear. To characterize in vivo the network of colonic cytokines in patients with UC, and the contribution of the various cytokines to disease activity we performed this study, using the colonic perfusion method.

METHODS

A 20-cm colon length was perfused. Perfusate samples were collected for cytokine determination by enzyme-linked immnoassays. Nineteen perfusions were performed in mild to moderate UC, including two successive perfusions in four patients. Six healthy control patients and four having Crohn's disease (CD) with rectal involvement were studied. Endoscopic score, leukocyte scintigraphy, and systemic markers of inflammation were simultaneously quantified.

RESULTS

Large amounts of IL1beta, TNFalpha, IL6, and IL8 were produced in UC patients with a highly significant correlation between TNFalpha, IL1beta and IL8 two by two. Multivariate factorial analysis indicated that IL1beta showed the best correlation with disease activity. Locally produced IL6 was strongly associated with circulating platelet counts. Moreover, production of inflammatory cytokines was associated with similar variations of disease activity in the four patients with two successive perfusions performed. The level of inflammatory cytokines in CD was lower than in UC; TNFalpha, IL1beta, and IL6 were not found in any control patients.

CONCLUSION

UC appears to be a chronic inflammatory disease characterized by high production of all four proinflammatory cytokines (IL1beta, TNFalpha, IL6, and IL8). These results suggest that colonic perfusion may be a suitable method to evaluate the local anticytokine properties of new drugs, in correlation with disease activity and systemic markers of inflammation.

Nutrition in inflammatory bowel disease

Nutrition is clearly disturbed by active intestinal inflammation. Appetite is reduced, yet energy substrates are diverted into the inflammatory process, and thus weight loss is characteristic. The nutritional disturbance represents part of a profound defect of somatic function. Linear growth and pubertal development in children are notably retarded, body composition is altered, and there may be significant psychosocial disturbance. Macrophage products such as tumour necrosis factor-alpha and interleukins-1 and 6 may be the central molecules that link the inflammatory process to this derangement of homeostasis. Intriguingly, there is also increasing evidence that an aggressive nutritional programme may in itself be sufficient to reduce the mucosal inflammatory response. Recent evidence suggests that enteral nutrition alone may reduce many pro-inflammatory cytokines to normal and allow mucosal healing. In addition, specific nutritional components, such as n-3 polyunsaturated fatty acids, may have an anti-inflammatory effect as they may alter the pattern of leukotrienes generated during the immune response. The recent discovery of the specific molecular mediators of appetite and body composition, such as leptin and myostatin, may allow increased therapeutic specificity and further improvement in the nutritional treatment of the inflammatory bowel diseases.

Helicobacter pylori-positive gastritis in pediatric patients with chronic inflammatory bowel disease

BACKGROUND

Gastritis is a common finding in patients with inflammatory bowel disease. However, the association of gastritis with Helicobacter pylori is unclear in these patients.

METHODS

The prevalence of antibodies for H. pylori in serum was determined in 47 pediatric patients with inflammatory bowel disease (19 with Crohn's disease, 21 with ulcerative colitis, and 7 with unclassified disease). H. pylori antibodies of the IgG and IgA classes were measured by enzyme immunoassay in 24 patients at the time of diagnosis of inflammatory bowel disease and in 23 more patients during the follow-up of inflammatory bowel disease (mean follow-up, 3.5 years; range 1-10 years). Esophagogastroduodenoscopy was performed on 40 patients during the examination for inflammatory bowel disease.

RESULTS

In contrast to earlier findings, no patient was determined to be positive for H. pylori, either in serologic or histologic examination. This negative finding was unexpected, because it is known that approximately 10% of asymptomatic Finnish children have antibodies for H. pylori in serum and approximately 10% of analyses of specimens obtained in gastric antral biopsies obtained at the Hospital for Children and Adolescents, Helsinki, Finland, are positive for H. pylori.

CONCLUSIONS

Permanent colonization of the stomach with H. pylori is unusual in children with inflammatory bowel disease.

Urinary 8-hydroxydeoxyguanosine excretion as a non-invasive marker of neutrophil activation in animal models of inflammatory bowel disease

BACKGROUND

Because free radicals contribute to ulcerative colitis and Crohn's disease, assessing oxidative load in vivo could provide a surrogate marker of inflammation and disease status.

METHODS

Electrochemical high-performance liquid chromatography was used to study urinary excretion of 8-hydroxydeoxyguanosine (8-OH-dGUA), formed by reaction of hydroxyl radicals with native DNA, in 2,4,6-trinitrobenzene-sulfonic acid (TNBS) and dextran sulfate (DSS) rat models of bowel inflammation. Bowel myeloperoxidase (MPO) and histopathology were also assessed.

RESULTS

TNBS enema (75 mg/kg in 50% ethanol) and oral DSS (6% via drinking water) both yielded an inflammatory response reflected by increases in bowel MPO that were significantly correlated with tissue injury. In both models urinary 8-OH-dGUA excretion was significantly correlated with bowel MPO activity and epithelial injury and remained at control levels when neutrophils (PMN) were eliminated, whereas epithelial injury and crypt erosion persisted despite neutropenia.

CONCLUSIONS

Urinary 8-OH-dGUA excretion directly reflects PMN activation in vivo, thereby providing a non-invasive surrogate marker for inflammation in these models which is more indicative of PMN activation than either MPO activity, which does not distinguish inactive from active MPO, or epithelial status, which is independent of PMN activation in both models.

Review article: Homing of mucosal immune cells--a possible connection between intestinal and articular inflammation

An adaptive immune system has developed to protect mucosa, mainly by performing immune exclusion with secretory antibodies (SIgA and SIgM) but also by downregulating pro-inflammatory antibody responses and delayed type hypersensitivity against harmless soluble proteins and the indigenous bacterial flora. In general, mucosal immunopathology appears to represent abrogation of such mucosal tolerance mechanisms. An important consequence is disturbance of the 'gatekeeper' function normally performed by the microvasculature through complementary sets of tightly regulated adhesion molecules on mucosal endothelium and circulating leukocytes. The B cells responsible for local polymeric immunoglobulin (Ig) production (mainly dimeric IgA) are stimulated initially in organized lymphoepithelial structures, particularly the Peyer's patches in the distal small intestine, from which they migrate as memory cells to secretory tissues all over the body. Mucous membranes are thus furnished with primed B cells in an integrated way, ensuring a variety of secretory antibody specificities at every exocrine site. There is currently great interest in exploiting this integrated or 'common' mucosal immune system for topical vaccination against pathogenic infectious agents and also to induce therapeutic peripheral tolerance to ameliorate T-cell-mediated autoimmune diseases. Moreover, homing of immune cells from the gut to the inflamed synovium may represent a modifiable link between intestinal immunity and chronic arthropathies.

Oral immunoglobulin treatment in Crohn's disease

Two patients with severe Crohn's disease who failed to respond to traditional medical treatment were given immunoglobulin orally. We used the 6-h urinary recovery of mixture of polyethyleneglycols PEG 400 and 1000 (molecular weight range 282-1250 Da) to test the intestinal permeability. Both patients showed a similar permeability pattern with an increased leakage of large-sized PEGs before treatment and a lower urinary recovery of probes after treatment with immunoglobulin. This might indicate that the inflammatory process in Crohn's disease can be affected from the luminal side of the mucosa.