lipid-a and Crohn-Disease

Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction. Lipid A was isolated by preparative TLC, and its structure determined by MS and NMR to be similar to that of Bacteroides fragilis except for the number of fatty acids. The polysaccharide fraction was subjected to gel-filtration chromatography to give an OPS-rich fraction. The structure of OPS was determined by chemical analysis and NMR spectroscopy to be a polysaccharide composed of the following repeating unit: [-->4)alpha-L-Rhap(1-->3)beta-D-Manp(1-->].

Topics: Bacteroides; Carbohydrate Conformation; Crohn Disease; Humans; Lipid A; Lipopolysaccharides; Magnetic Resonance Spectroscopy; O Antigens; Spectrometry, Mass, Fast Atom Bombardment; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Virulence

This study looked at the intestinal permeability and the immune response to enteric bacterial antigens in patients with inflammatory bowel disease (IBD). They were evaluated by using a lactulose tolerance test and measuring blood anti-lipid A antibody concentrations, respectively. The lactulose tolerance tests were performed 22 times in 14 patients with Crohn's disease (CD), 19 times in 12 patients with ulcerative colitis (UC), and 12 times in 12 healthy controls. Blood lactulose concentrations were measured after oral administration every two hours for eight hours, also blood C reactive protein concentrations and anti-lipid A antibody concentrations were measured just before lactulose administration. Blood lactulose concentrations were significantly higher in patients with CD than in the controls from two to eight hours after administration, while in UC they were significantly higher than in the controls from six to eight hours. Maximum blood lactulose concentrations in each tolerance test in patients with the active phase significantly exceeded those in the inactive phase of either CD or UC. A significant correlation was also seen between the maximum blood lactulose concentrations and the C reactive protein concentrations. Blood anti-lipid A antibody concentrations in patients with CD were significantly higher than in the controls as well as in patients with UC in immunoglobulin (Ig) A class and IgG class. In UC they were significantly higher than in the controls in IgA class. But, they were not related to the severity of the disease of either CD or UC, and not correlated significantly with the maximum blood lactulose concentrations in either CD or UC. The intestinal permeability and the immune response to enteric bacterial antigens in patients with inactive CD were significantly increased over those in the controls as well as in patients with inactive UC. These findings suggest that an increase of the intestinal permeability and that of producing antibodies to enteric bacterial antigens are both important for the pathogenesis of IBD, and that the characteristics of CD and UC differ.

Topics: Adolescent; Adult; Antigens, Bacterial; C-Reactive Protein; Colitis, Ulcerative; Crohn Disease; Enterobacteriaceae; Female; Humans; Immunoglobulin A; Immunoglobulin G; Intestinal Mucosa; Lactulose; Lipid A; Male; Middle Aged; Permeability

Infection with a species of Mycobacterium has been implicated in the pathogenesis of Crohn's disease. Therefore, we attempted to determine whether a specific serum antibody response to mycobacteria occurs in patients with the disease. We tested sera of patients with active Crohn's disease and several control groups in an enzyme-linked immunosorbent assay for reactivity with two mycobacterial antigens: (a) lipoarabinomannan, a highly immunogenic somatic lipopolysaccharide present in the cell walls of all species of the Mycobacterium genus, and (b) a protoplasmic antigenic preparation from M. sp strain linda, the mycobacterium that has been specifically implicated in Crohn's disease. We found no significant elevation in immunoglobulin A, immunoglobulin G, or immunoglobulin M antibody levels to these two antigen preparations in the Crohn's disease patients. Moreover, no subset of patients (sex, age, Crohn's disease activity index, location of disease, duration of disease, operations, or response to treatment) had elevated antibody levels. As virtually all known chronic infectious diseases have an associated serologic response to the etiologic agent, our findings greatly diminish the likelihood that Crohn's disease is caused by an infection with a mycobacterium.

Topics: Adult; Aged; Antibodies, Bacterial; Antigens, Bacterial; Crohn Disease; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Humans; Immunoglobulins; Lipid A; Lipopolysaccharides; Male; Middle Aged; Mycobacterium

Topics: Antibody Formation; Colitis; Colitis, Ulcerative; Crohn Disease; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Intestinal Mucosa; Lipid A

Complement fixing antibodies against different Escherichia coli lipopolysaccharides were determined in patients with Crohn's disease and in healthy individuals and compared with antitetanus toxoid antibodies. All healthy individuals had antilipopolysaccharide antibodies, 10 of 27 patients with Crohn's disease had no antibodies and six had rapidly changing antibody titres. These abnormalities were found in patients with disease in the colon, with arthropathy and fistula. Antilipid A was found at lower titres in Crohn's disease. Neither antitetanus toxoid antibodies, nor immunoglobulin concentrations were different in patients with or without antilipopolysaccharide antibodies. There was no evidence for circulating immune complexes in patients lacking antilipopolysaccharide antibodies. Certain subgroups of patients with Crohn's disease have altered antibody levels to typical enteral antigens which most likely can be explained by local antibody binding to lipopolysaccharides at inflammatory sites, or by changes in immunoregulation in this disease.

Topics: Adolescent; Adult; Antibodies, Bacterial; Antigen-Antibody Complex; Complement System Proteins; Crohn Disease; Escherichia coli; Female; Humans; Immunoglobulins; Lipid A; Lipopolysaccharides; Male; Middle Aged; Tetanus Toxoid

Endotoxins have been suggested to be a factor in the pathophysiology of Crohn's disease (CD). We determined circulating antibodies against lipid A, a component common to endotoxins of gram-negative bacteria. Lipid A antibody titers in 91 patients with CD were significantly higher than in 56 patients with ulcerative colitis and 68 healthy subjects. In active CD lipid A antibodies were higher than in quiescent CD and markedly elevated titers of lipid A antibodies were associated with a severe course of CD. Duration, extent and localisation of CD showed no relationship to antibody titers against lipid A. Patients with prior bowel resection had a tendency towards lower antibody titers in comparison with non-operated patients. After total removal of inflamed bowel tissue, lipid A antibodies frequently disappeared. Medical therapy had different effects: prednisone and sulfasalazine did not influence antibody formation against lipid A, whereas antibody titers dropped significantly after therapy with ampicillin. These results confirm elevated circulating lipid A antibodies in patients with CD. Although it remains unclear whether lipid A antibodies are only an epiphenomenon in CD, on the basis of this clinical study further evidence is provided for the involvement of lipid A in the pathophysiology of CD.

Topics: Adolescent; Adult; Aged; Antibodies, Bacterial; Colitis, Ulcerative; Crohn Disease; Female; Humans; Lipid A; Male; Middle Aged; Prognosis

To find out whether the increased immunoglobulin A (IgA) levels commonly reported in patients with alcoholic liver disease (ALD) are part of the immune response to gut-derived endotoxin antigen, an enzyme-linked immunoabsorbent assay was used to measure serum levels of antibodies to lipid A (the shared core of various lipopolysaccharides and the biologically active component of endotoxins) in patients with various diseases and in controls. Of 41 patients with ALD, 35 had significantly raised titres of IgA anti-lipid A. Rises of antilipid A were found in the secretory fraction of IgA as well, and titres of IgG antibody were also consistently increased. IgM titres were high in only 7 of 35 ALD patients tested. Patients with other diseases did not show significantly high titres of IgA antibodies to lipid A even though many had rises in total concentration of their serum IgA.

Topics: Antibodies; Crohn Disease; Enzyme-Linked Immunosorbent Assay; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Lipid A; Liver Cirrhosis, Alcoholic; Liver Cirrhosis, Biliary; Liver Diseases, Alcoholic; Nephelometry and Turbidimetry

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.

Topics: Adolescent; Adult; Aged; Antibodies, Bacterial; Colitis, Ulcerative; Crohn Disease; Drug Therapy, Combination; Endotoxins; Female; Humans; Limulus Test; Lipid A; Male; Middle Aged; Prednisone; Sulfasalazine

Sera from patients with inflammatory bowel disease, ulcerative colitis (UC), or Crohn's disease (MC) were analysed for antibodies to lipid A and Tamm-Horsfall protein (TH), Escherichia coli O antigens, and food antigens, using enzyme-linked immunosorbent assay, indirect haemagglutination, and thin-layer immunoassay, respectively. C-reactive protein (CRP), an indicator of acute inflammation, was also studied. The MC and UC groups were not separated by any of the factors tested. The extent of the disease, however, seemed to influence the IgG antibody response to lipid A and TH. Patients with extended inflammatory areas in the intestine had decreased anti-lipid-A levels during the active phase of the disease compared with patients with less inflammation. In contrast, the IgG anti-TH levels were increased in these patients during both the active and inactive phases compared with less affected patients. Compared with healthy individuals, MC or UC patients showed decreased IgG anti-lipid-A levels. Both IgG and IgA anti-TH and total anti-O levels were increased compared with controls. Antibodies to cow's milk were lower in patients with inflammatory bowel disease than in the control group. CRP was increased in patients with active inflammatory bowel disease compared with inactive.

Topics: Adolescent; Adult; Aged; Antibodies; Antigens; Antigens, Bacterial; C-Reactive Protein; Colitis, Ulcerative; Crohn Disease; Escherichia coli; Female; Food; Humans; Lipid A; Male; Middle Aged; Mucoproteins; Uromodulin

The results of previously published studies on serum immunoglobulin concentrations in patients with Crohn's disease are controversial. Therefore a long term study of serum immunoglobulin concentrations comparing 31 patients with Crohn's disease was carried out. The serum IgM concentrations of patients with active disease was significantly lower than the serum IgM concentration in patients with inactive disease. 7/25 patients who were all treated with steroids had an elevated serum IgE concentrations. It could not be demonstrated that serum immunoglobulin concentrations are influenced by steroids, by bowel resection or by the activity of the disease. As no characteristic change of serum immunoglobulin concentration in patients with Crohn's disease could be found the determination of serum immunoglobulins seems to be of no clinical value. Furthermore a possible connection between serum immunoglobulin concentrations and antibody titers against the lipid A component of endotoxins was investigated: Serum IgM concentrations were significantly higher in patients with elevated lipid-A-antibody titers than in patients with normal lipid-A-antibody titers. Thus indicates a specific antibody formation to endotoxins and lipid A, respectively.

Topics: Adrenal Cortex Hormones; Adult; Ampicillin; Antibodies, Bacterial; Crohn Disease; Female; Humans; Immunoglobulins; Lipid A; Lipopolysaccharides; Male; Middle Aged

Lipid A antibody titers and O antibody titers against E. coli were determined in 18 patients with Crohn's disease, 28 patients with ulcerative colitis, 24 patients with acute enteritis and in 68 healthy adults. The patients with Crohn's disease showed a statistically significant elevation of the lipid A antibody titers and of the O antibody titers against E. coli compared with each of the three other groups investigated. The results could be indicative of bacterial involvement in the pathogenesis of Crohn's disease. The determination of lipid A antibody titers may be useful for the differential diagnosis between Crohn's disease and ulcerative colitis.

Topics: Adult; Antibodies, Bacterial; Antibody Specificity; Colitis, Ulcerative; Crohn Disease; Diagnosis, Differential; Humans; Lipid A; Lipopolysaccharides