Aetiological Theories of Inflammatory Bowel Disease

Fullerene nanoparticles for the treatment of ulcerative colitis

Ulcerative colitis (UC) is a long-term, recurrent inflammatory bowel disease for which no effective cure is yet available in the clinical setting. Repairing the barrier dysfunction of the colon and reducing intestinal inflammation are considered key objectives to cure UC. Here we demonstrate a novel therapeutic strategy based on a C₆₀ fullerene suspension (C₆₀FS) to treat dinitrobenzene sulfonic acid-induced UC in an animal model. C₆₀FS can repair the barrier dysfunction of UC and effectively promote the healing of ulcers; it also manifests better treatment effects compared with mesalazine enema. C₆₀FS can reduce the numbers of basophils in the blood of UC rats and mast cells in the colorectal tissue, thereby effectively alleviating inflammation. The expression of H1R, H4R, and VEGFR2 receptors in colorectal tissues is inhibited by C₆₀FS, and the levels of histamine and prostaglandin in the rat blood are reduced. This work presents a reliable strategy based on fullerene to cure UC and provides a novel guide for UC treatment.

Evaluation of B and T lymphocytes and plasma cells in colonic mucosa from healthy dogs and from dogs with inflammatory bowel disease

The aim of this study was to investigate the subpopulations of lymphocytes in the colonic mucosa of healthy dogs and dogs with inflammatory bowel disease (IBD). Fourteen normal dogs and 13 dogs with IBD were examined. Endoscopic biopsy specimens of colonic mucosa from each dog were stained specifically for pan T lymphocytes (CD3) and pan B lymphocytes (CD79a), and for plasma cells with methyl green pyronin (MGP) stain. Cells were counted by means of a grid and statistical analysis was performed on the data collected. B and T lymphocytes were also counted in the glandular epithelium of normal dogs and dogs with IBD and the normal and abnormal groups compared statistically. Healthy dogs had significantly lower numbers of T cells in the lamina propria and glandular epithelium and significantly lower numbers of B cells in the lamina propria. Significant group differences for plasma cells were not evident. Our results indicate that in IBD a chronic cellular immune reaction is present in the diseased gut involving increased numbers of B and T lymphocytes.

Disturbed autonomic nerve function in patients with Crohn's disease

Autonomic nerve function was evaluated in 33 patients with Crohn's disease (age range, 19-66 years; mean, 36 years) by three established non-invasive tests based on the heart reactions to deep breathing (E/I ratio) and to tilt (acceleration and brake indices). Peripheral nerve function was evaluated neurographically and by measuring thresholds to vibration and temperature changes. None of the patients were diabetic, and all had normal thyroid function. In spite of normal peripheral nerve function, almost half of the patients, 48% (16/33), showed signs of autonomic neuropathy (AN). The occurrence of AN was not related to duration or severity of Crohn's disease or to biochemical evidence of inflammation or malabsorption of vitamins and trace elements. We conclude that autonomic nerve dysfunction is a feature of Crohn's disease which may be relevant with regard to the frequent disturbance in bowel function in patients with this disorder.

Effect of diets low and high in refined sugars on gut transit, bile acid metabolism, and bacterial fermentation

Increasing consumption of refined sugar has been implicated in many gastrointestinal disorders on epidemiological grounds. Nine volunteers agreed to participate in a study comparing the effects of a diet containing 165 g refined sugar/day with a diet of only 60 g/day on gut transit, bile acid metabolism, and fermentative activity of the intestinal flora. The wet and dry weight, pH, and water content of the stools were similar on the two diets. On the high sugar diet mouth-to-anus transit time was significantly prolonged, despite a shortened mouth-to-caecum transit time. The faecal concentration of total bile acids and the faecal concentration of secondary bile acids increased significantly. Diet affected neither the serum bile acid pattern nor the concentration. Breath hydrogen tests showed significantly enhanced H2 production on the high sugar diet. We conclude that the quantity of refined sugar in the diet can significantly influence gut function and the composition of bowel contents.

Chronic inflammatory bowel disease in glycogen storage disease type 1B

Two children with glycogen storage disease type 1B developed chronic inflammatory bowel disease. The first, a 7-year-old boy, had ileitis and later developed perianal disease. The second developed colitis by the age of 9 years; in both the features were consistent with Crohn disease. The children had neutropenia and neutrophil mobility defects characteristic of GSD-1B. It is suggested that these neutrophil abnormalities are important in the pathogenesis of the bowel inflammation.

Enhanced peripheral blood T-cell cytotoxicity in inflammatory bowel disease

Monoclonal antibodies to the CD3 component of the T-cell antigen receptor can trigger antigen-specific cytotoxic T cells to elicit nonantigen-specific cytotoxicity, possibly by mimicking or bypassing the requirement for antigen triggering. We have used this technique to investigate the possible presence of in vivo primed cytotoxic T cells, of unknown antigen specificity, in peripheral blood of patients with inflammatory bowel disease. Peripheral blood lymphocytes, which were depleted of background natural killer (NK) activity (CD16-), from patients with Crohn's disease exhibited significantly enhanced levels of anti-CD3-triggered T-cell cytotoxicity compared with lymphocytes from normal subjects. Enhanced lytic activity was also found in some patients with ulcerative colitis and in patients with ulcerative colitis postcolectomy. These results were not influenced by treatment or disease activity. There was no correlation between the anti-CD3-triggered T lytic activity and the NK activity in normal subjects or in patients with inflammatory bowel disease. The surface antigen phenotype of the anti-CD3-triggered T killer cell was CD3+, CD8+, CD16-, and Leu 7+. The results provide indirect evidence for increased activity of a subpopulation of cytotoxic T cells, of unknown antigen specificity, in inflammatory bowel disease. Increased activity in patients with ulcerative colitis postcolectomy suggests that this might reflect a fundamental immunological disturbance.

Inflammatory bowel disease and leukemia. A report of seven cases of leukemia in ulcerative colitis and Crohn's disease and review of the literature

In a review of a large number of patients with inflammatory bowel disease, leukemia was observed in five patients with chronic ulcerative colitis and in two patients with Crohn's disease. In ulcerative colitis patients, there were three cases of acute myelocytic leukemia and one case each of acute lymphoblastic leukemia and chronic granulocytic leukemia. In Crohn's disease patients, there was one case each of chronic granulocytic leukemia and chronic lymphocytic leukemia associated with thrombocythemia. Sixteen other cases of leukemia have been reported to date in inflammatory bowel disease. All types of leukemia, but particularly acute myelocytic leukemia, have been described. There has been no single common feature as to type (whether ulcerative colitis or Crohn's disease), extent and course, or medical and surgical treatment of the bowel disease. The relative risk of leukemia in patients with ulcerative colitis was 5.3 [95% confidence interval 1.7 to 12.3 (P less than 0.01)] and of acute myelocytic leukemia 11.4 [95% confidence interval 2.3 to 24.9 (P less than 0.01)]. Our data on patients with Crohn's disease were not sufficient to assess the statistical significance of leukemia in this disease. This study suggests that there may be an increased risk of leukemia, particularly acute myelocytic leukemia, in ulcerative colitis. The causal relationship, if any, remains undetermined.

[Effect of intestinal resection on the behavior of mononuclear subpopulations in Crohn disease]

The literature data about the distribution of mononuclear cells in Crohn's disease are still contradictory. In 50 surgical C.D. patients, clinically classified corresponding to the Crohn's Disease Activity Index (CDAI), the T-lymphocytes and their subsets helper-T- and suppressor-T-lymphocytes (TH/TS) were therefore determined by use of monoclonal antisera, the B-lymphocytes by F(a b)-anti human Ig and the macrophages by uptake of latex microparticles. 37 C.D. patients underwent diseased bowel removal. Blood was drawn from the Crohn-draining mesenteric vein for analysis. Further investigations were performed at the 10th p. op. day as well as after an average period of 7 months (2-18). In comparison the mononuclear cell distribution was examined in 14 patients suffering from chronic osteitis and in 14 patients without any inflammatory disease as controls. C.D. patients showed preoperatively a significantly decreased TH/TS-ratio as well as a significantly increased proportion of macrophages. There was a lymphocytopenia in the peripheral differential blood count. Whereas the distribution of mononuclear subpopulations in the mesenteric blood was identical to the peripheral blood, significant lymphocytosis in the differential blood count of mesenteric blood was found. On the 10th p. op. day the TH/TS-ratio rose almost up to normal, which continued during the follow-up period. The macrophages remained constantly increased in all stages of investigation although during the follow-up none of the patients had signs of disease recurrence. Osteitis patients showed a similar distribution as C.D. patients, even if the changes compared to controls were not as distinct. The proportion of B-lymphocytes was the same in all groups examined. The individual TH/TS-ratios and proportions of macrophages of C.D. patients did not correlate to their clinical data. The changes within the T-cell-subpopulations seem to reflect less M. Crohn's disease itself than its inflammatory complications. Further studies have to be undertaken concerning the impact of the constant increase in macrophages, even after resection of the Crohn bearing bowel segment.

Extraintestinal cancers in inflammatory bowel disease

The case histories of 1961 patients with inflammatory bowel disease (IBD), 1227 with Crohn's disease (CD) and 734 with ulcerative colitis (UC), have been studied for the incidence of extraintestinal malignant neoplasms. There were 54 extraintestinal cancers in 51 patients: 28 patients with CD and 23 with UC; 25 men and 26 women. There were 9 breast, 7 skin, 15 reticuloendothelial, 11 genitourinary, 3 lung, 3 perianal, 2 pancreatic islet cell, and several miscellaneous cancers. The number of patient-years from the onset of disease to the last date of follow-up was calculated for men and women with each form of IBD. The observed number (O) of neoplasms was recorded. The expected number (E) of neoplasms was derived from the Department of Health, Education, and Welfare (DHEW) incidence figures for the same neoplasms that occurred in a standard age- and sex-matched population. The O/E ratio was then calculated for each type of cancer as well as for the entire series. There were no statistically significant increases in overall O/E ratios of extraintestinal cancers for either CD (0.76) or UC (1.32). On the other hand, several specific types of cancer did appear to occur with a frequency that was significantly greater than expected. These cancers were classified into two groups. The first group included reticuloendothelial neoplasms. There was an excess of leukemias in UC (P less than 0.005) and an excess of lymphomas in both UC and CD (P less than 0.005). The second group included three squamous cell cancers of the perianal region, an incidence 30 times greater than expected, and two squamous cell cancers of the vagina, also in excess of the expected number. Lymphoma, leukemia, and squamous cell cancers have been reported to occur in excess in immunosuppressed or irradiated patients. It may therefore be speculated that the apparently increased incidence of these neoplasms in the patients with ileitis and colitis might be related to immunologic deficiencies associated with IBD, to the long-term administration of steroids or other immunosuppressive medications that were given to most of the patients or, possibly, to increased exposure to ionizing radiation. The apparently increased incidence of perianal and vaginal cancers of the squamous variety might be a consequence of the combined effects of chronic inflammatory disease involving these areas and primary immune suppression.

Crohn's disease: maintenance of remission by diet

20 patients with Crohn's disease took part in a controlled trial in which remission was maintained by either an unrefined carbohydrate fibre rich diet or a diet which excluded specific foods to which a patient was intolerant. 7 out of the 10 patients on the exclusion diet remained in remission for 6 months compared with none out of the 10 on an unrefined carbohydrate fibre rich diet (p less than 0.05, Fisher's exact test). In an uncontrolled study an exclusion diet allowed 51 out of 77 patients to remain well on the diet alone for periods of up to 51 months, and with an average annual relapse rate of less than 10%.

Nutritional management of inflammatory bowel disease

Malnutrition and growth failure are frequent complications of inflammatory bowel disease in childhood owing to inadequate dietary nutrient intakes, excessive intestinal losses, malabsorption, and increased nutrient requirements. Aggressive nutritional therapy is indicated for primary and supportive management of disease activity, drug nutrient interactives, individual nutrient abnormalities, and the overall complications of inflammatory bowel disease, malnutrition, and growth failure. The prevention of nutritional disorders in inflammatory bowel disease is accomplished by monitoring anthropometric and biochemical indices and by instituting appropriate enteral or parenteral nutritional therapy when indicated.

Loss of suppressor T-cells in active inflammatory bowel disease

The proportions and absolute numbers of helper and suppressor T-cells in 40 patients with inflammatory bowel disease and 22 control subjects were determined, using the monoclonal antibodies OKT 4 and OKT 8. There were no significant differences in helper or suppressor cell proportions among 15 steroid treated patients with active inflammatory bowel disease, 10 patients with inactive inflammatory bowel disease, 10 patients with other gastrointestinal diseases, or 12 normal control subjects. In contrast, 15 patients with active inflammatory bowel disease not treated with corticosteroids manifested increased proportions of helper cells and decreased proportions of suppressor cells (p less than 0.001), compared with all other patient groups and to normal controls. When absolute numbers of helper and suppressor subsets were measured, these alterations in proportions of helper and suppressor cells were primarily attributable to decreased counts of suppressor T-cells both in patients with active Crohn's disease and in those with ulcerative colitis (p less than 0.01). In four patients undergoing serial study, the helper/suppressor ratios appeared to rise and fall respectively with clinical exacerbations and remissions of disease. These data provide additional evidence for the involvement of cellular immune systems in these disease processes.

Circulating lipid A antibodies despite absence of systemic endotoxemia in patients with Crohn's disease

Lipid A is a component common to endotoxins of gram-negative bacteria. It has been suggested that the gut wall of patients with inflammatory bowel disease is more permeable to luminal bacterial macromolecules which may stimulate the gut-associated lymphoid tissue. We therefore investigated 40 patients with Crohn's disease (CD) and 23 patients with ulcerative colitis (UC) with respect to their lipid A antibody titers and presence of endotoxins (Limulus test). Both tests were performed simultaneously using peripheral venous blood. Systemic endotoxin was demonstrated in only two of the patients. The lipid A antibody titers in the CD patients were significantly higher than either in patients with UC or in 42 healthy controls. Lipid A titers of patients with UC did not differ from those of controls. Titers of lipid A were significantly higher in patients with active Crohn's disease than in patients with inactive disease. It is concluded that systemic endotoxemia occurs rarely in patients with inflammatory bowel disease; however, despite this virtual absence of endotoxins in their peripheral blood, patients with CD show an increase in antibody formation against lipid A. This is suggestive of an altered immunologic reactivity against endotoxins in patients with CD and may be relevant to the pathogenesis of this disease.

Serum antibodies to Bacteroides species in chronic inflammatory bowel disease

It has been proposed that the presence of elevated serum titres against various Bacteroides species among patients with chronic inflammatory bowel disease (CIBD) may yield aetiological, pathogenic, or prognostic information. Using a crossed immunoelectrophoretic method, we investigated circulating antibodies against four Bacteroides species in 122 patients with CIBD (80 with ulcerative colitis (UC) and 42 with Crohn's disease (CD)) and in 32 patients with the irritable colon syndrome. In this cross-sectional study we found raised titre scores (greater than 0) among 26% of the patients with CD, among 46% of the patients with UC, and among 34% of the patients with the irritable colon syndrome. These differences are not significant. There were no correlations between the antibody titres and the duration of the disease, the clinical disease activity, or the site of the disease. Furthermore, the antibody titres yielded no prognostic information as to the necessity of surgery--that is, colectomy and/or small-bowel resection.

Gastritis, peptic ulcer disease, inflammatory bowel disease, and stomach and colon cancers- are they all caused by viral infections?

It is hypothesized that chronic gastritis and ulcerative colitis both are induced by viral infection, and that such chronic infection of the mucosa may lead to ulceration and occasionally cancer. Duodenal ulcer disease and Crohn's disease may on the other hand, be due to activation of latent viral infection of the corresponding neural ganglions, with subsequent migration of virus along the nerves to the gut wall. The gastric acid hypersecretion often occurring in patients with duodenal ulcer disease might be a consequence of viral interference with the efferent nerve function of vagal ganglions. Correspondingly, non-ulcer dyspepsia as well as irritable colon may reflect viral infection of afferent nerve function leading to pain and discomfort.

Crohn's disease and the enterohepatic circulation

Crohn's disease is a chronic inflammatory process which may affect any part of the alimentary tract. This cause is unknown. Overall the distribution of the lesions coincides with that of the enterohepatic circulation. A possible causative agent is a metabolic or ingested substance excreted into the bile in the form of a polar and inactive conjugates. The agent would have to have a prolonged half life in the enterohepatic circulation. In the ileocaecal region and elsewhere when bacterial colonisation occurs the inactive conjugates may be hydrolysed to release the active substance. This would act locally on the intestinal tissues either as a result of altering the physicochemistry of mucus or during passage through the gut wall.