Peripheral gamma delta T cell receptor-bearing lymphocytes are increased in children with celiac disease

The percentages of gamma delta T cell receptor-bearing (TCR+) cells in the peripheral blood and jejunal mucosa of patients with celiac disease were measured before treatment, during a gluten free-diet, and after a gluten challenge. The percentages of the different cell types were evaluated by flow cytometry, and immunohistochemical staining of the jejunal specimen was used to identify lymphocyte surface markers. Nineteen blood samples and intestinal specimens from 13 children with celiac disease (eight samples taken before treatment, six during gluten-free diet, and five after gluten challenge) and samples from nine controls were studied. The proportion of gamma delta TCR+ lymphocytes was significantly higher both in the peripheral blood and the jejunal mucosa of the patients with celiac disease. A significant correlation was found between the percentage of peripheral gamma delta TCR+ cells and the density of gamma delta TCR+ cells in the lamina propria.

Comparison of endotoxin release by different antimicrobial agents and the effect on inflammation in experimental Escherichia coli meningitis

In a rabbit Escherichia coli meningitis model, endotoxin liberation and concentrations of leukocytes, tumor necrosis factor (TNF), and lactate were compared after a single intravenous dose of cefotaxime, cefpirome, meropenem, chloramphenicol, or gentamicin. These antibiotics caused a 2- to 10-fold increase in cerebrospinal fluid concentrations of free (filterable) endotoxin within 2 h of starting treatment. By contrast, free endotoxin concentrations increased almost 100-fold in untreated animals 4 h later as bacteria continued to multiply. An initial enhancement of inflammation in the central nervous system occurred in all treatment groups compared with untreated controls. No significant differences were observed between treatment groups except for lower TNF concentrations in chloramphenicol-treated animals. Antibiotic therapy in E. coli meningitis, irrespective of the agent used, may result in an increase in free endotoxin and enhancement of inflammation, but the amount of endotoxin liberated is considerably smaller than that shed by untreated bacteria.

Detection of enterobacterial lipopolysaccharides and experimental endotoxemia by means of an immunolimulus assay using both serotype-specific and cross-reactive antibodies

The immunolimulus (IML) assay system uses solid-phase endotoxin antibodies to capture lipopolysaccharide (LPS), which is then quantified by a modification of the chromogenic limulus amebocyte lysate (CLAL) method. Monoclonal antibodies (MAbs) reactive with selected O antigen serotypes of Escherichia coli (O18) and Salmonella typhimurium (O9, 12), when used in the IML, were shown to be highly specific in detecting their respective endotoxins in purified form and in plasma samples from experimentally infected animals. A murine MAb that was broadly cross-reactive with E. coli, Salmonella, and Shigella endotoxins also proved to be highly effective in the IML assay for capturing LPS molecules from both E. coli and S. typhimurium strains. These results indicate that IML assays can detect smooth-type enterobacterial endotoxins in plasma and suggest that such assays have potential for use in the rapid diagnosis of sepsis and endotoxemia caused by different enterobacterial species.

Surgical treatment of intractable cholestasis associated with total parenteral nutrition in premature infants

We report surgical reversal of intractable total parenteral nutrition (TPN)-associated cholestasis refractory to conservative treatment in 9 premature infants. Indications for TPN were poorly tolerated enteral feedings in all patients. Five patients had undergone gastrointestinal operations; in addition, 7 of the 9 patients had had bacterial sepsis. The median duration of TPN was 28 days (range, 20 to 50 days). The median duration of preoperative full enteral nutrition after weaning from TPN was 34 days (range, 16 to 95 days). All patients had progressive conjugated hyperbilirubinemia, no excretion of Tc-labeled HIDA to the biliary tree and duodenum, and markedly elevated liver enzyme values. Intraoperative cholangiography showed normal biliary anatomy in all cases; in addition, 2 patients had gallbladder stones. Bile was hyperviscous in all patients and contained biliary sludge in 4. The biliary tree was irrigated and the liver biopsied in all patients. The gallbladder was removed from 2 patients who had stones in the gallbladder. Liver histology was consistent with TPN-associated cholestasis in all cases, and in addition, 4 cases showed significant destruction of intrahepatic bile ducts. One patient died 2 weeks postoperatively from intracerebral hemorrhage. Jaundice completely resolved in other patients within 2 weeks. HIDA-biligraphy performed 1 to 2 months postoperatively showed normal excretion of the radioactive marker to the biliary tree and duodenum in all cases. The functional abnormality in bile excretion and bile duct motility in TPN-associated cholestasis may be reversed by irrigation of the biliary tree. Surgical intervention should be considered when cholestasis is progressive and refractory to medical management.

The protective capacity of immune sera in experimental mouse salmonellosis is mainly due to IgM antibodies

Passive immunization was used to protect mice against a general infection caused by Salmonella typhimurium and our purpose was to compare the protective capacity of different immunoglobulin isotypes (classes and subclasses). Three antisera were studied, one pool of mouse serum against the envelope of rough bacteria, and two rabbit sera against smooth bacteria. Three different methods were used to separate isotypes. The consistent finding was that only IgM antibodies protected efficiently. A unit of IgG antibodies had an effect that was 1/50th of the IgM effect or less. This effect could have been due to a contamination by IgM. IgA appears to be non-protective like IgG. In two of the antisera a considerable proportion of protective antibodies were against a defined antigenic determinant (anti-0-4,5 or anti-0-9). IgG antibodies of these sera measured by the solid phase assay were also predominantly anti-0-4,5 or anti-0-9, respectively. This argues that the failure of IgG antibodies to protect cannot be explained by assuming that unlike IgM antibodies they are directed against "non-protective" determinants. We conclude that the observed difference between the protective capacities of IgM and IgG antibodies is due to C-region differences between the mu- and gamma-chains.

Immunization with major outer membrane proteins in experimental salmonellosis of mice

Porin (outer membrane protein) preparations extracted from a rough (Rb2) mutant of Salmonella typhimurium proved to be good immunogens in mice and rabbits. The antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques. High titers of both antiporin and antilipopolysaccharide were detected in both species. The rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal Salmonella infection of mice. Absorption of the rabbit antiporin serum with lipopolysaccharide immunosorbent did not change its protective capacity in a passive immunization experiment, suggesting that the antiporin antibody preparations were the active components.