Superoxide production by Crohn's disease neutrophils

Article Abstract:

Crohn's disease is an inflammatory bowel condition affecting the ileum (the lower portion of the small intestine), characterized by abdominal pain, anemia, loss of weight, and other gastrointestinal complaints. One cellular abnormality manifested by Crohn's disease patients is a defect in the ability of neutrophils (a type of white blood cell involved in the body's natural defense system) to destroy foreign substances. In normal individuals, a characteristic burst in metabolic rate is seen during activation of neutrophils; this corresponds to the increased energy requirement of the neutrophils while they kill invading microorganisms, and reflects activation by the neutrophils of an enzyme system (NADPH oxidase system) necessary for their action. To determine whether activation of this pathway is defective in patients with Crohn's disease, 15 healthy volunteers and 25 patients with Crohn's disease were studied. Three different chemical stimuli were used to activate neutrophil NADPH oxidase (as determined by production of superoxide anions, a metabolic product of this pathway). Neutrophils isolated from healthy patients produced significantly more superoxide anion in response to two of the three stimuli than did neutrophils from Crohn's disease patients. The suppression was seen in all patients with Crohn's disease, but the degree of suppression was independent of the severity of the disease (making it unlikely that neutrophil dysfunction is a secondary effect of the disease). Hence, NADPH oxidase activation is impaired in neutrophils from patients with Crohn's disease. Whether or not this defect can be linked to the intestinal symptoms seen in these patients remains to be determined. (Consumer Summary produced by Reliance Medical Information, Inc.)

Active oxygen

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Candidacidal activity of Crohn's disease neutrophils

Article Abstract:

Crohn's disease is a gastrointestinal disorder in which part of the gastrointestinal tract, usually the ileum (a segment of the small intestine), becomes inflamed. The cause of Crohn's disease is not understood, but it has been postulated that an impaired response to certain forms of bacterial infection may be one causal factor. Neutrophils are a type of white blood cell that form one of the body's defenses against invading microorganisms. Candida albicans is a common bacterium which is present in the gastrointestinal tract of between 14 and 47 percent of the normal population. When unchecked, C. albicans can cause a variety of inflammatory diseases, possibly including Crohn's disease. To investigate whether there is an impairment of neutrophil function in Crohn's disease patients, the ability of neutrophils isolated from normal subjects and those with Crohn's disease to kill C. albicans was determined. After 30 and 60 minutes of incubation with C. albicans, neutrophils from Crohn's disease patients had killed significantly less C. albicans than neutrophils from normal patients. There was no evidence for inhibitory factors from other blood components, and there was no evidence for impairment of the mechanism of phagocytosis (ingestion and digestion of the bacteria by the neutrophil). A cellular defect in the neutrophil is most likely responsible for the diminution in candidacidal activity (ability to kill C. albicans) of these neutrophils. (Consumer Summary produced by Reliance Medical Information, Inc.)

Causes of, Candida albicans

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Antibody to selected strains of Saccharomyces cerevisiae (baker's and brewer's yeast) and Candida albicans in Crohn's disease

Article Abstract:

Crohn's disease, or regional ileitis, is an inflammatory condition of the intestine characterized by diarrhea, abdominal pain, anemia, weight loss, and symptoms of intestinal obstruction. The cause of Crohn's disease is not known, but it has been suggested that hypersensitivity to dietary antigens (substances which mobilize a response by the immune system) may be an important factor. It has been reported that in Crohn's disease patients (but not in patients with the similar inflammatory condition ulcerative colitis), blood levels of antibodies against a strain of baker's yeast (Saccharomyces cerevisiae) are increased. To determine whether this increased antibody level would generalize to other strains of yeast commonly used in industrial applications, a study was carried out with 15 Crohn's disease patients, 15 ulcerative colitis patients, and 15 healthy controls. Levels of antibodies to 11 of the 12 strains of yeast tested were increased in the Crohn's disease patients, but not in either the ulcerative colitis or control group. The antibody response to the 11 strains was not homogeneous, suggesting that the various strains have different effects on activation of the immune system, and that the increased antibody levels are not simply the result of increased intestinal permeability to antigens. Levels of antibodies to the infective yeast microorganism Candida albicans did not differ between the patients and control subjects. (Consumer Summary produced by Reliance Medical Information, Inc.)

Saccharomyces, Inflammation, Intestine, Small, Small intestine

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