Within-patient emergence of the influenza A(H1N1)pdm09 HA1 222G variant and clear association with severe disease, Norway.

The association between a particular mutation in the HA1 subunit of the influenza virus haemagglutinin, D222G, and severe and fatal disease in cases of influenza A(H1N1)pdm09 in Norway during the 2009 pandemic was investigated using pyrosequencing. The prevalence of the variant among fatal cases was 8/26 and among severe non-fatal cases 5/52. No D222G mutations were found among the 381 mild cases. This difference could not be attributed to sampling differences, such as body location of sampling, or duration of illness. In cases with mutant virus where clinical specimens from different days of illness were available, transition from wild-type to mutant virus was commonly observed (4/5), indicating that the mutant virus emerged sporadically in individual patients. In patients with paired samples from both the upper and lower respiratory tract (n=8), the same viral genotypes were detected in both locations. In most of the D222G cases (11/13), the mutant virus was found as a quasispecies.

Age-dependent prevalence of antibodies cross-reactive to the influenza A(H3N2) variant virus in sera collected in Norway in 2011.

Antibody cross-reactivity to the influenza A(H3N2) variant virus recently reported in the United States, was investigated in Norwegian sera. Seroprevalence was 40% overall, and 71% in people born between 1977 and 1993. The most susceptible age groups were children and people aged around 50 years. The high immunity in young adults is likely to be due to strong priming infection with similar viruses in the 1990s. More research is needed to explain the poor immunity in 45­54 year-olds.

Observed association between the HA1 mutation D222G in the 2009 pandemic influenza A(H1N1) virus and severe clinical outcome, Norway 2009-2010.

Infection with the recently emerged pandemic influenza A(H1N1) virus causes mild disease in the vast majority of cases, but sporadically also very severe disease. A specific mutation in the viral haemagglutinin (D222G) was found with considerable frequency in fatal and severe cases in Norway, but was virtually absent among clinically mild cases. This difference was statistically significant and our data are consistent with a possible causal relationship between this mutation and the clinical outcome.

High prevalence of antibodies to the 2009 pandemic influenza A(H1N1) virus in the Norwegian population following a major epidemic and a large vaccination campaign in autumn 2009.

The prevalence of antibodies reactive to the 2009 pandemic influenza A(H1N1) was determined in sera collected before the start of the pandemic, during the early phase, and after the main epidemic wave and nationwide vaccination campaign in Norway. A substantial rise in prevalence of antibodies at protective titres, from 3.2% to 44.9%, was observed between August 2009 and January 2010. The highest prevalence, 65.3%, was seen in the age group of 10-19 year-olds.

Computer-aided detection (CAD) as a second reader using perspective filet view at CT colonography: effect on performance of inexperienced readers.

AIM: To evaluate whether computer-aided detection (CAD) as a second reader using perspective filet view [three-dimensional (3D) filet] improves the performance of inexperienced readers at computed tomography colonography (CTC) compared with unassisted 3D filet and unassisted two-dimensional (2D) CTC. MATERIAL AND METHODS: Fifty symptomatic patients underwent CTC and same-day colonoscopy with segmental unblinding. Two inexperienced readers read the CTC studies on 3D filet and 2D several weeks apart. Four months later, readers re-read the cases only evaluating CAD marks using 3D filet. Suspicious CAD marks not previously described on 3D filet were recorded. Jackknife free-response receiver operating characteristic (JAFROC-1) analysis was used to compare the observers' performances in detecting lesions with 3D filet, 2D and 3D filet with CAD. RESULTS: One hundred and three lesions > or =3mm were detected at colonoscopy with segmental unblinding. CAD alone had a sensitivity of 73% (75/103) at a mean false-positive rate per patient of 12.8 in supine and 11.4 in prone. For inexperienced readers sensitivities with 3D filet with CAD were 58% (60/103) and 48% (50/103) with an improvement of 14-16 percentage points (p<0.05) compared with 2D and of 10-11 percentage points (p<0.05) compared with 3D filet. For inexperienced readers, the false-positive rate was 25-41% and 71-200% higher with 3D filet with CAD compared with 3D filet and 2D, respectively. JAFROC-1 analysis showed no significant differences in per-lesion overall performance among reading modes (p=0.8). CONCLUSION: CAD applied as a second reader using 3D filet increased both sensitivity and the number of false positives by inexperienced readers compared with 3D filet and 2D, thus not improving overall performance, i.e., the ability to distinguish between lesions and non-lesions.

Primary three-dimensional analysis with perspective-filet view versus primary two-dimensional analysis: evaluation of lesion detection by inexperienced readers at computed tomographic colonography in symptomatic patients.

BACKGROUND: "Perspective-filet view" is a novel three-dimensional (3D) viewing technique for computed tomography colonography (CTC). Studies with experienced readers have shown a sensitivity for perspective-filet view similar to that of 2D or 3D endoluminal fly-through in detection of colorectal lesions. It is not known whether perspective-filet view, compared to axial images, improves lesion detection by inexperienced readers. PURPOSE: To compare primary 3D analysis using perspective-filet view (3D Filet) with primary 2D analysis, as used by inexperienced CTC readers. Secondary aims were to compare lesion detection by 3D Filet when used by experienced and inexperienced readers, and to evaluate the effect of combined 3D Filet + 2D analysis. MATERIAL AND METHODS: Fifty symptomatic patients were prospectively enrolled. An experienced reader performed 3D Filet analysis followed by complete 2D analysis (3D Filet + 2D), before colonoscopy with segmental unblinding. Two inexperienced readers (readers 2 and 3), blinded to CTC and colonoscopy findings, retrospectively performed 3D Filet analysis and, after 5 weeks, 2D analysis. True positives >or=6 mm detected by the inexperienced readers with 3D Filet and/or 2D were combined to obtain 3D Filet + 2D. RESULTS: Colonoscopy revealed 116 lesions: 16 lesions >or=10 mm, 19 lesions 6-9 mm, and 81 lesions or=6 mm with 3D Filet and 3D Filet + 2D were 77% and 83%, respectively. For the inexperienced readers, sensitivities for lesions >or=6 mm with 3D Filet and 2D were 51% and 57% (reader 2) and 40% and 43% (reader 3), respectively. There was no significant difference between 3D Filet and 2D regarding sensitivity and reading time. For lesions >or=6 mm, 3D Filet + 2D improved the sensitivity of reader 2 to 63% and of reader 3 to 51%. CONCLUSION: Lesion detection by inexperienced readers using perspective-filet view is comparable to that obtained by 2D. Lesion detection improves by combining 3D Filet + 2D, but not to the level of an experienced reader.

Intestinal immune responses in humans. Oral cholera vaccination induces strong intestinal antibody responses and interferon-gamma production and evokes local immunological memory.

We have examined secretory antibody and cell-mediated immune responses to oral cholera vaccine in the human gastrointestinal mucosa. Freshly isolated peripheral blood lymphocytes and intestinal lymphocytes obtained by enzymatic dispersion of duodenal biopsies were assayed for numbers of total and vaccine specific immunoglobulin-secreting cells by enzyme-linked immunospot assay (ELISPOT) techniques; the frequency of cells secreting interferon-gamma (IFN-gamma) was also examined by a new modification of the ELISPOT technique. After booster immunizations with oral cholera vaccine, large numbers of cholera toxin-specific antibody-secreting cells (ASC) appeared in the small intestine. The responses were dominated by IgA ASC. A single immunization, performed 5 mo after the initial vaccinations, gave rise to an ASC response similar to that seen after the first booster immunization, with respect to both magnitude and isotype distribution. Each of the immunizations also evoked an ASC response in blood which was of lower magnitude than that seen in the small intestine, and comprised similar proportions of IgA and IgG ASC. A booster immunization also resulted in increased frequencies of IFN-gamma-secreting cells, but this increase was confined to the duodenal mucosa. This study establishes the feasibility of studying, at the single-cell level, intestinal immune reactivity in humans. Furthermore, it indicates that the small intestinal mucosa is an enriched source of IFN-gamma. It also demonstrates marked differences between intestinal and peripheral blood immune responses after enteric immunization, and confirms the notion that the mucosal immune system in humans displays immunological memory.

Differential expression of tissue-specific adhesion molecules on human circulating antibody-forming cells after systemic, enteric, and nasal immunizations. A molecular basis for the compartmentalization of effector B cell responses.

Expression of the adhesion molecules CD44, L-selectin (CD62L), and integrin alpha 4 beta 7 by antibody-secreting cells (ASC) was examined in human volunteers after oral, rectal, intranasal, or systemic immunization with cholera toxin B subunit. Almost all blood ASC, irrespective of immunization route, isotype (IgG and IgA), and immunogen, expressed CD44. On the other hand, marked differences were observed between systemically and intestinally induced ASC with respect to expression of integrin alpha 4 beta 7 and L-selectin, adhesion molecules conferring tissue specificity for mucosal tissues and peripheral lymph nodes, respectively. Thus, most ASC induced at systemic sites expressed L-selectin, whereas only a smaller proportion of ASC expressed alpha 4 beta 7. In contrast, virtually all IgA- and even IgG-ASC detected after peroral and rectal immunizations expressed alpha 4 beta 7, with only a minor fraction of these cells expressing L-selectin. Circulating ASC induced by intranasal immunization displayed a more promiscuous pattern of adhesion molecules, with a large majority of ASC coexpressing L-selectin and alpha 4 beta 7. These results demonstrate that circulating ASC induced by mucosal and systemic immunization express different sets of adhesion molecules. Furthermore, these findings provide for the first time evidence for differential expression of adhesion molecules on circulating ASC originating from different mucosal sites. Collectively, these results may explain the anatomical division of mucosal and systemic immune responses in humans as well as the compartmentalization of mucosal immune responses initiated in the upper vs. the lower aerodigestive tract.

Budesonide treatment is associated with increased bile acid absorption in collagenous colitis.

BACKGROUND: Bile acid malabsorption is frequent in collagenous colitis and harmful bile acids may play a pathophysiological role. Glucocorticoids increase ileal bile acid transport. Budesonide have its main effect in the terminal ileum. AIMS: To evaluate whether the symptomatic effect of budesonide is linked to increased uptake of bile acids. METHODS: Patients with collagenous colitis were treated with budesonide 9 mg daily for 12 weeks. Prior to and after 8 weeks of treatment, the (75)SeHCAT test, an indirect test for the active uptake of bile acid-s, measurements of serum 7alpha-hydroxy-4-cholesten-3-one, an indicator of hepatic bile acid synthesis, and registration of symptoms were performed. RESULTS: The median (75)SeHCAT retention increased from 18% to 35% (P < 0.001, n = 25) approaching the values of healthy controls (38%). The 7alpha-hydroxy-4-cholesten-3-one values decreased significantly among those with initially high synthesis (from 36 to 23 ng/mL, P = 0.04, n = 9); however, for the whole group the values were not altered (19 ng/mL vs. 13 ng/mL, P = 0.23, N.S., n = 19). CONCLUSION: The normalization of the (75)SeHCAT test and the reduction of bile acid synthesis in patients with initially high synthetic rate, suggests that the effect of budesonide in collagenous colitis may be in part due to decreased bile acid load on the colon.

Discontinuation of proton pump inhibitors in patients on long-term therapy: a double-blind, placebo-controlled trial.

BACKGROUND: The proportion of proton pump inhibitor users on long-term therapy who can discontinue proton pump inhibitor (PPI) medication without developing symptoms is unknown. AIM: To determine the proportion of patients on long-term PPI therapy who are able to discontinue PPIs without developing symptoms. METHODS: Patients on long-term PPIs, without a history of peptic ulcer or esophagitis underwent upper endoscopy. Patients were randomized double-blindly to taper down or continue a constant dosage of omeprazole for three weeks. Thereafter, all patients discontinued PPIs. RESULTS: Of the 97 patients enrolled, had used PPIs for 48 months, 78% had GERD. A total of 27% did not use PPIs during the year after discontinuation, 31% of the patients randomized to tapering discontinued PPIs and 22% of those who did not could discontinue therapy (NS). Gastro-oesophageal reflux disease (GERD) patients were more prone to continue PPIs than non-GERD patients. Only 16 (21%) of GERD patients were off PPIs vs. 48% of patients without GERD (p < 0.05). Serum gastrin was higher at baseline in GERD patients who resumed PPIs versus non-resumers (p < 0.05). GERD and serum gastrin were independent predictors of PPI requirement. CONCLUSIONS: Discontinuation of PPI was successful in 27% of long-term PPI users. GERD patients had more difficulty discontinuing PPIs than non-GERD patients.

Virus-specific antibody production and polyclonal B-cell activation in the intestinal mucosa of HIV-infected individuals.

OBJECTIVE: To examine possible changes in mucosal B-cell activation status. DESIGN: To examine the frequency and isotype distribution of total and HIV-specific antibody-secreting cells (ASC) in the intestinal mucosa of HIV-infected individuals. METHODS: Mucosal lymphocytes were obtained by enzymatic treatment of duodenal pinch biopsies and the numbers of ASC were assayed with the enzyme-linked immunospot technique. RESULTS: High numbers of HIV-specific ASC were found in the intestine of all HIV-infected individuals despite low levels of HIV-specific blood ASC. All HIV-infected individuals had large numbers of intestinal immunoglobulin (Ig) A-ASC against the HIV envelope glycoprotein gp160. Eight out of nine patients also had HIV gp160-specific intestinal IgG-ASC. These HIV-specific ASC were detected irrespective of disease stage, route of infection, or levels of circulating CD4+ T cells. HIV-specific ASC were found in peripheral blood from patients with CD4+ T cells > or = 100 x 10(6)/l blood, but in none of three patients with low CD4+ T-cell counts. The frequencies of virus-specific ASC in the blood were on average 100-fold lower than that observed within the intestinal mucosa. Mucosal polyclonal B-cell activation was evident in HIV-infected individuals, as documented by significantly elevated numbers of Ig-secreting cells (ISC) in all three major Ig classes; on average, seven-, five- and 20-fold numbers of IgA, IgG and IgM-ISC compared with healthy controls. Furthermore, substantial numbers of ASC reacting with unrelated antigens such as dog albumin and keyhole limpet haemocyanin were detected in HIV-infected patients. Interestingly, patients with CD4+ T cells < 100 x 10(6)/l blood displayed large numbers of HIV-specific intestinal ASC even though total numbers of ISC, including ASC reactive to unrelated antigens, were decreased. CONCLUSIONS: The large numbers of virus-specific ASC found in the intestine of HIV-infected individuals may be a consequence of local replication of HIV-1 resulting in a continuous antigen stimulation. The persistence of strong intestinal anti-HIV responses even at late stages of disease suggest that the mucosal B-cell responses are functionally intact throughout the disease. Furthermore, these results suggest that there is no correlation between HIV-specific ASC numbers and polyclonal B-cell activation. These observations indicate that intestinal B-cell activation is profoundly disregulated in HIV-infected individuals.

Intestinal antibody responses to oral vaccination in HIV-infected individuals.

OBJECTIVE: To examine whether and at what stage mucosal immune responsiveness is impaired during HIV-1 infection. DESIGN: Intestinal and systemic antibody-secreting cell (ASC) responses were examined in eight HIV-1-infected volunteers and 10 seronegative control subjects after oral cholera and parenteral tetanus vaccinations. METHODS: ASC numbers were determined before and after booster vaccinations by the enzyme-linked immunospot (ELISPOT) technique. This technique was performed on cell suspensions obtained from enzymatically dispersed duodenal biopsies and from peripheral blood. RESULTS: Oral cholera vaccination evoked ASC responses in the intestinal mucosa of six out of eight HIV-1-infected volunteers, including patients with advanced disease and very low levels of circulating CD4+ T cells. The intestinal cholera ASC responses in HIV-infected volunteers were comparable to those in uninfected controls with regard to both magnitude and distribution of antibody classes. Most HIV-infected volunteers with only moderately reduced CD4+ T-cell counts also responded with vaccine-specific ASC in the blood, whereas none of the patients with < 200 x 10(6)/l CD4+ T cells per litre blood had detectable circulating ASC. CONCLUSION: These findings indicate that mucosal humoral immune responsiveness to a T-cell dependent antigen is maintained in HIV-infected individuals, despite concomitant systemic humoral hyporesponsiveness.

Allopurinol in addition to 5-aminosalicylic acid based drugs for the maintenance treatment of ulcerative colitis.

BACKGROUND: To investigate the value of combined treatment with allopurinol and 5-aminosalicylic (5-ASA) based drugs as maintenance treatment for ulcerative colitis (UC). METHODS: 199 patients with UC in remission but with active disease during the preceding 3 years were included. Allopurinol 100 mg twice daily or placebo was added to the 5-ASA based maintenance treatment. Clinical and endoscopic follow up was performed after 1, 6 and 12 months. RESULTS: Intention-to-treat analysis after 6 and 12 months showed similar results in both groups. A log-rank test showed that 77% in the allopurinol compared to 59% in the placebo group were still in remission after 6 months (P=0.0083) and 62% and 53% after 12 months, respectively (P=0.0936). This was mainly due to a higher than expected number of relapses during the first 3 months in the placebo group. After the first 3 months, the rate of relapse in each group was similar. CONCLUSIONS: It appears possible that allopurinol in combination with 5-ASA is better than 5-ASA alone for a 6-month, but not a 12-month period. This has to be verified in further dose-ranging studies.

Impact of bile acid malabsorption on steatorrhoea and symptoms in patients with chronic diarrhoea.

OBJECTIVE: Bile acids are important for fat absorption. The relationship between bile acid malabsorption and steatorrhoea and gastrointestinal symptoms in patients with chronic diarrhoea has only been studied on a limited scale. DESIGN: Ninety-four patients referred for chronic diarrhoea were prospectively investigated with the 75SeHCAT test, a faecal fat excretion test and registration of symptoms in addition to the standard clinical work-up. METHODS: The correlation between the 75SeHCAT value and the faecal fat excretion was calculated for different groups of patients. Symptoms were registered in a questionnaire over a period of seven consecutive days. RESULTS: Forty-two patients had a 75SeHCAT value < 10%. Mild steatorrhoea was common in patients with non-organic bile acid malabsorption (50%) and in patients with functional diarrhoea (38%). There was no correlation between low 75SeHCAT values and steatorrhoea, although some patients with severe organic disease had a concomitant malabsorption of fat and of bile acids. In coeliac disease, severe steatorrhoea was common even in patients with high 75SeHCAT values. Patients with bile acid malabsorption had more frequent (P < 0.008) and looser (P= 0.0021) stools compared with patients with functional diarrhoea. There was no difference in abdominal pain, distension or flatulence. CONCLUSION: Mild steatorrhoea is common in both non-organic bile acid malabsorption and functional diarrhoea. The 75SeHCAT value cannot predict the risk of steatorrhoea. The high prevalence of bile acid malabsorption in patients with chronic diarrhoea and the absence of specific symptoms, except frequent and more liquid stools, indicates that the 75SeHCAT test should be performed early in the investigation of these patients.

Serum antibodies to H+,K+-ATPase, serum pepsinogen A and Helicobacter pylori in relation to gastric mucosa morphology in patients with low or low-normal concentrations of serum cobalamins.

OBJECTIVES: To compare the diagnostic performance of serum antibodies to H+,K+-ATPase (EC 3.6.1.36), serum pepsinogen A (EC 3.4.23.1) and the Schilling test in diagnosing chronic atrophic body gastritis; to study the interrelationships between H+,K+-ATPase antibodies, serology for Helicobacter pylori, and gastric morphology. DESIGN: Patients with suspected cobalamin deficiency and serum cobalamin < 200 micromol/l were investigated using upper gastrointestinal endoscopy, the Schilling test and serum tests for H+,K+-ATPase antibodies, pepsinogen A, and H. pylori. SETTING: The Department of Internal Medicine, Sahlgrenska University Hospital, Göteborg, Sweden. PATIENTS: Ninety seven consecutively referred patients. MAIN OUTCOME MEASURES: Sensitivity and specificity of assays for serum H+,K+-ATPase antibodies, serum pepsinogen A, and the Schilling test. RESULTS: Assays of serum antibodies to H+,K+-ATPase and of serum pepsinogen A displayed equal diagnostic sensitivity for atrophic gastritis (around 0.90 for the severe forms) and higher than that for the Schilling test (0.65). The diagnostic specificity for pepsinogen A (1.0) was higher than for H+,K+-ATPase antibodies (about 0.80). The prevalence of antral gastritis and positivity for H. pylori antibodies declined with the transition of body gastritis into severe atrophy, while the prevalence of H+,K+-ATPase antibodies increased. CONCLUSION: Pepsinogen A is preferable to serum H+,K+-ATPase antibodies in the diagnosis of gastric body mucosal atrophy. The formation of H+,K+-ATPase antibodies does not seem to be a primary event in the development of gastric body muscosal atrophy.

Early predictors of glucocorticosteroid treatment failure in severe and moderately severe attacks of ulcerative colitis.

OBJECTIVE: To analyse the ability of simple clinical and biochemical parameters to predict glucocorticosteroid (GCS) treatment failure in patients with acute attacks of ulcerative colitis. DESIGN/METHODS: Retrospective analysis of clinical and biochemical data. SETTING: Four Swedish university hospitals. PATIENTS: Ninety seven patients with acute attacks of ulcerative colitis severe enough to warrant treatment with intravenous GCS, hospitalized during the years 1988-93. MAIN OUTCOME MEASURE: Colectomy within the first 30 days after hospitalization, defined as 'clinical steroid resistance'. RESULTS: Thirty days after admission, 39 patients (40%) were in complete clinical and endoscopic remission while 33 (34%) had undergone colectomy. During follow-up for 24 months, four patients among the 39 initially in remission underwent colectomy. Among the 25 patients (26%) not attaining remission after 30 days, an additional nine patients subsequently required colectomy. Steroid resistance was associated with duration of disease (2.7 vs 8.1 years, P=0.0037) and steroid treatment before hospitalization (70 vs 42%, P=0.010). In particular, elevation of body temperature (37.4 vs 36.9 degrees C, P=0.012), persistence of diarrhoea (6.8 vs 3.6 bowel movements/day, P<0.0001) and passage of blood (83 vs 42%, P=0.0003) as well as CRP elevation (36.3 vs 18.0 mg/l, P=0.007) on day 3 after treatment initiation were identified as predictors of a poor response. CRP > or = 25 mg/l and > 4 bowel movements/day on day 3 of hospitalization independently predicted a high risk for colectomy within 30 days. CONCLUSIONS: Sustained elevation of body temperature, persistent bloody diarrhoea and continued CRP elevation on day 3 of intravenous GCS treatment strongly predict clinical steroid resistance in acute attacks of ulcerative colitis. In the group of poor or non-responders, colectomy or more aggressive medical treatment should be considered at an early stage.

Adult coeliac patients do tolerate large amounts of oats.

OBJECTIVE: The aim of the present study was to investigate whether adult patients with coeliac disease in remission could include large amounts of oats in their daily gluten-free diet for an extended period of time without adverse effects. DESIGN, SUBJECTS AND METHODS: Twenty adult coeliac patients in remission included large amounts of uncontaminated rolled oats in their daily diet for a prolonged period. The examinations, performed four times during the study period, included small bowel endoscopy with biopsies, blood samples (nutritional status, serological analysis), height and body weight, gastrointestinal symptoms and dietary records. Gastrointestinal symptoms and diet were also investigated through unannounced telephone interviews once a month during the study period. RESULTS: No adverse effects of a large intake of oats were seen in small bowel histology, serology nor in nutritional status in the 15 subjects who completed the whole study period. Two of the subjects dropped out because of gastrointestinal symptoms and three for non-medical reasons. The median intake of oats was 93 g/day and the compliance to the oat diet was found to be good. Examinations of the patients after drop-out did not show any deterioration in small bowel histology or nutritional status nor raised levels of antibodies. CONCLUSION: Results from this study indicate that adult patients with coeliac disease in remission can include large amounts of controlled wheat-free rolled oats for an extended period of time without adverse effects.

Induction of specific immunity at mucosal surfaces: prospects for vaccine development.

We have demonstrated the feasibility of studying antigen-specific immune responses in a variety of mucosal tissues in humans after vaccination and during infection. In this respect, we have documented the usefulness of both oral cholera and ETEC vaccines for assessing in functional terms specific subpopulations of B- and T-cell immunocytes during an immune response initiated and/or expressed in human mucosal tissues. Circulating specific IgA antibody-secreting cells in blood appear to reflect recent or ongoing antigen exposure of mucosal surfaces. This implies that the detection of such cells in blood, the most accessible lymphoid compartment in humans, represents the simplest way to assess the immunogenicity of mucosal vaccines and to supplement the diagnostic and monitoring of active mucosal infections. Our studies indicate that while the concept of an integrated mucosal immune network is clearly operational in humans (at least in regards to induction of secretory antibody responses), its generalization appears somewhat simplistic as illustrated by the compartmentalization of immune responses initiated in certain mucosal organs such as the small intestine and the tonsils. Finally, the potential of the cholera toxin B subunit as a carrier for delivery of chemically or genetically linked foreign epitopes for induction of disseminated mucosal immune responses raises hope for the development of broadly applicable vaccines to control mucosal infections.

Diagnosis of small intestinal bacterial overgrowth in clinical praxis: a comparison of the culture of small bowel aspirate, duodenal biopsies and gastric aspirate.

BACKGROUND/AIMS: This study was undertaken to validate the usefulness of the culture of duodenal biopsy specimens and gastric aspirate compared to the culture of small bowel aspirate for diagnosing small intestinal bacterial overgrowth. We also investigated the occurrence of predisposing conditions in these patients. METHODOLOGY: Seventy five consecutive patients, admitted because of symptoms which caused us to suspect small intestinal bacterial overgrowth, were studied. For all patients, specimens for the culture of small bowel aspirate, duodenal biopsies and gastric aspirate were obtained during upper endoscopy. RESULTS: Eighteen patients showed growth of gram negative bacteria, 22 growth of gram positive bacteria and 35 showed no significant growth in cultures of small bowel aspirate. Cultures of duodenal biopsies revealed gram negative bacteria in 11 patients, gram positive bacteria in 9 and no growth in 55. Cultures of gastric aspirate revealed gram negative bacteria in 7 patients, gram positive bacteria in 12 and no growth in 51. Ten of the 18 patients with gram negative overgrowth and 13 of the 22 patients with gram positive overgrowth had a predisposing condition. In contrast, only 4 of the 35 without overgrowth had a predisposing condition. CONCLUSIONS: The culture of duodenal biopsy specimens or gastric aspirate is a less sensitive method than the culture of small bowel aspirate. Most patients with culture-proven small intestinal bacterial overgrowth had at least one predisposing condition.

Bile duct bacterial isolates in primary sclerosing cholangitis and certain other forms of cholestasis--a study of bile cultures from ERCP.

BACKGROUND/AIMS: The pathogenesis of the inflammatory lesion in primary sclerosing cholangitis is unknown. We have recently demonstrated a high positivity rate of bacterial cultures in bile and bile ducts of explanted livers from primary sclerosing cholangitis patients compared with patients with primary biliary cirrhosis. In particular, alpha-hemolytic Streptococci was a frequent finding, suggesting an etiopathogenic role of that particular bacteria in primary sclerosing cholangitis. We therefore wanted to study naive primary sclerosing cholangitis patients and compare them with primary sclerosing cholangitis patients that have previously undergone endoscopic retrograde cholangiopancreatography, in order to evaluate the potential role of these bacteria in the etiopathogenesis in primary sclerosing cholangitis. METHODOLOGY: Samples for bacterial cultures were obtained during a diagnostic endoscopic retrograde cholangiopancreatography. PARTICIPANTS: 12 naive primary sclerosing cholangitis patients, 10 patients with primary sclerosing cholangitis, previously investigated using endoscopic retrograde cholangiopancreatography, 47 patients with choledocholithiasis, 19 patients with cancer obstructing the common bile duct, and 29 patients with other forms of biliary disorders. RESULTS: Positive cultures were obtained from 3 of the naive primary sclerosing cholangitis patients and from 6 of the primary sclerosing cholangitis patients with previous endoscopic retrograde cholangiopancreatography (NS). The most frequent finding in all the primary sclerosing cholangitis patients was alpha-hemolytic Streptococci. Bacteria were cultured from the bile in 64% of the patients with choledocholithiasis, higher than the 25% in the naive primary sclerosing cholangitis patients (P < 0.03), and in 56% of patients with obstructing cancer (NS) but in only 24% of patients with other forms of biliary disorders, all of whom, except 4, had normal cholangiograms. In the 22 patients with primary sclerosing cholangitis, 75% of the positive bacterial cultures consisted of Gram-positive isolates and 25% were enteric bacteria, which differed statistically from the 74% enteric bacteria and 26% Gram-positive bacteria in the patients with common duct stone (P < 0.01). CONCLUSIONS: Alpha-hemolytic Streptococci do not seem to play a primary role in the etiopathogenesis of primary sclerosing cholangitis since most naive primary sclerosing cholangitis patients were found to have negative bacterial cultures. This does not exclude the possibility that they play a role in the progression of primary sclerosing cholangitis following infection in conjunction with the first endoscopic retrograde cholangiopancreatography.