J. G. Gobert

Fecal Tumor Necrosis Factor alpha, Eosinophil Cationic Protein and IgE Levels in Infants with Cows Milk Allergy and Gastrointestinal Manifestations

Abstract Infants with atopic eczema exhibit a specific fecal protein pattern after oral challenge with cows milk, characterized by an increase in both eosinophil cationic protein (ECP) and tumor necrosis factor (TNF)α. The aim of our study was to determine the pattern of these proteins in allergic infants with intestinal manifestations. TNFα, ECP and immunoglobulin E (IgE) were measured in stools from 13 infants with intestinal symptoms and 10 healthy infants. The allergic infants underwent two stool collections, one before a cows milk challenge and the other after the challenge, either at the onset of clinical manifestations (n=6) or 15 days after the challenge if no clinical manifestations occurred (n=7). Baseline TNFα, ECP and IgE levels were low in all infants. The concentration of TNFα increased after the challenge in infants positive to challenge (p<0.05) but not in those negative to challenge. ECP and IgE levels remained low after the challenge in all the allergic infants. These data confirm that fecal TNFα and ECP levels indicate various reaction types of food allergy and that different immunologic disturbances lead to atopic eczema or intestinal symptoms during food allergy. Fecal protein pattern can thus be a useful tool in diagnosing food allergy in infants with intestinal manifestations.

Kinetics of mucosal ileal gamma-interferon response during cryptosporidiosis in immunocompetent neonatal mice

Abstract The kinetics of serum and ileal interferon-gamma (IFN-γ) content were determined during recovery from cryptosporidiosis in NMRI suckling mice. A total of 60 mice aged 4 days were inoculated by intragastric gavage with 104 cryptosporidia (n = 30) or phosphate-buffered saline (n = 30). Six animals per group were killed on days 0, 3, 6, 9 and 13 postinoculation. Blood samples and ileum were collected. Experimental infection was followed by a rise in parasite load in the ileum starting on day 3 postinfection, which peaked at day 6 postinoculation. Ileal IFN-γ levels increased rapidly in parasitized mice from day 3 to day 6, then fell rapidly. These levels were significantly higher than the control values (day 3 P<0.05, days 6 and 9 P<0.001). IFN-γ secretion began before parasite excretion, but the curves of these two parameters correlated positively. Recovery from cryptosporidiosis in immunocompetent neonatal mice is thus associated with an early and marked increase in ileal IFN-γ content.

Inefficacy of intestinal secretory immune response to Cryptosporidium in acquired immunodeficiency syndrome

BACKGROUND/AIMS An alteration of the secretory immune response has been forwarded to explain frequent and chronic mucosal infections in patients with acquired immunodeficiency syndrome (AIDS). The aim of this study was to explore the intestinal immunoglobulin (Ig) secretions in patients with AIDS and their relationships to cryptosporidiosis. METHODS Patients with AIDS and enteric cryptosporidiosis (n = 12), other enteric infections (n = 10), and no identifiable enteric pathogen (n = 10) and human immunodeficiency virus-seronegative controls (n = 18) were studied. The number of intestinal IgA and IgM plasma cells of the duodenal lamina propria mucosa and total and anti-Cryptosporidium IgA, IgM, and IgG were measured in serum and feces. RESULTS Although not significantly increased, the number of IgA and IgM plasma cells was greater in patients with AIDS (n = 20) than in controls (n = 5). In feces, total IgA outputs and specific anti-Cryptosporidium IgA levels were significantly higher in patients with AIDS and cryptosporidiosis than in the two other groups of patients with AIDS (P < 0.05 and P < 0.01, respectively) and controls (P < 0.001 and P < 0.01, respectively). Total fecal IgM output and specific anti-Cryptosporidium IgM coproantibodies were increased only in the Cryptosporidium-infected patients relative to the controls (P < 0.05). CONCLUSIONS Despite the development of pathogen-specific mucosal antibody responses, patients with AIDS and cryptosporidiosis fail to clear the parasite.

Evaluation of intestinal clearance and faecal excretion of α1-antiproteinase and immunoglobulins during Crohn's disease and ulcerative colitis

The intestinal clearance of alpha 1-antiproteinase, monomeric IgA and IgG, and the daily fecal output of polymeric IgA and IgM were investigated in patients with inflammatory bowel diseases (inactive and active Crohns disease, ulcerative colitis) and in a control group. The intestinal clearance of alpha 1-antiproteinase was significantly increased in all patients with inflammatory bowel diseases (p less than 0.01), irrespective of the grade of the disease. In contrast, increases in intestinal clearances of monomeric IgA and IgG were more closely related to the severity of the intestinal lesions. The associate determination of these three quantities should therefore be of interest for monitoring the degree of intestinal bowel inflammation. Faecal output of polymeric IgA was significantly increased in active intestinal disease (p less than 0.01), whereas faecal IgM levels were not. The determination of the faecal output of polymeric IgA should contribute to the assessment of the activity of inflammatory bowel diseases, and may provide insight into the activation of the mucosal immune system.

Cryptosporidiosis-Induced Impairment of Ion Transport and Na/-Glucose Absorption in Adult Immunocompromised Mice

Electrolyte transport was investigated during chronic cryptosporidiosis in adult anti-interferon-gamma-treated SCID mice by means of Ussing chamber techniques. In basal conditions, infection of immunocompromised mice with Cryptosporidium parvum resulted in a 30% reduction (P < .05) in the ileal short-circuit (Isc) current related to a 28% reduction (P < .05) in tissue conductance compared with controls. The rises in Isc and transepithelial potential difference induced by glucose (10 mM) were significantly reduced by Cryptosporidium infection (P < .01) compared with controls. In contrast, responses to mucosal glutamine were marginally affected. Electrical parameters of the ileum were not affected by the addition of indomethacin or furosemide, in either control or Cryptosporidium-infected mice. Thus, long-term cryptosporidiosis in immunocompromised animals leads to a reduction in net ion exchanges, decreased paracellular shunting, and impaired Na+-glucose cotransport in the ileum, without prostanoid- or enterotoxin-mediated electrogenic Cl- secretion.

Impairment of amino-acid absorption in suckling rats infected with Cryptosporidium parvum

Abstract. In the present study, we explored the nutritional consequences of cryptosporidiosis. In order to ascertain the direct responsibility of C. parvum for impairment of staturoponderal development observed during the infection in neonatal animals, we investigated the absorption of two major components of the total amino acids in dams milk (leucine and glutamate) across the ileal mucosa. The infection resulted in significant (47% and 34%, respectively) reductions in leucine and glutamate fluxes (P<0.01). Moreover, the leucine aminopeptidase and alkaline phosphatase activities were reduced in the infected ileal mucosa. Interestingly, the reduction in weight gain, which began at day 6 post-infection (PI), persisted until day 20 PI, although no cryptosporidia were detected in the ileal mucosa after day 12 PI. We thus provide evidence that the malabsorption of amino acids during cryptosporidiosis contributes to impairing the development of neonatal animals, with consequences that persist beyond eradication of the parasite.

Intestinal lipid metabolism in suckling rats infected with Giardia duodenalis

We carried out a quantitative and qualitative analysis of intestinal digestion of neutral lipids in suckling rats infected withGiardia duodenalis. Total lipids were measured after extraction from the contents of the stomach, proximal and distal small bowel, caecum and colon. Amounts gradually fell from the stomach to the colon and were identical in infected animals and controls, although high values were occasionally found in the caecum of infected rats. Relative glyceride quantities were determined by means of high-performance thin-layer chromatography. Triglycerides were absent from the distal small bowel, and only free fatty acids and cholesterol were present in the caecum, reflecting normal digestion of neutral lipids in infected suckling rats. Our results suggest thatG. duodenalis does not impair intestinal fat digestion in suckling rats.