Quantitation of intraepithelial lymphocytes in human duodenum: what is normal?

BACKGROUND

An increase in intraepithelial lymphocytes (IELs) is mandatory for the histological diagnosis of coeliac disease (CD). Currently, duodenal biopsies are used almost exclusively to establish the diagnosis, yet published work continues to cite an upper limit of 40 lymphocytes/100 epithelial cells, a figure derived from jejunal biopsies over 30 years ago.

AIM

To establish the normal range for IEL counts in distal duodenal biopsies.

MATERIALS/METHODS

Twenty subjects (seven men, 13 women; median age, 34 years; range, 20-65) with a normal sugar permeability test and concurrent distal duodenal biopsies were identified. The number of IELs and epithelial cell nuclei in an uninterrupted length of surface (villous) epithelium (> 500 cells) was counted. An image analysis system was used to assess villous architecture by calculating the villous height to crypt depth ratio.

RESULTS

The range of IEL counts in 20 subjects was 1.8-26/100 villous epithelial cells, with a mean value of 11 and SD of 6.8. The mean villous to crypt ratio was 1.82 (SD, 0.38; range, 1.22-2.46). There was no correlation between IEL counts and villous to crypt ratio (Spearman rank correlation, -0.066; p = 0.80).

CONCLUSIONS

These results suggest that 25 IELs/100 epithelial cells (mean +2 SD) should be taken as the upper limit of the normal range for duodenal mucosa.

Review article: management of patients with non-responsive coeliac disease

A substantial minority of patients with coeliac disease (estimated at anything between 7 and 30%) fail to respond to treatment with a gluten-free diet. Non-responsiveness may be primary, that is when the patient fails to respond to treatment following initial diagnosis, or secondary, when a patient who has previously had a documented response to gluten exclusion becomes non-responsive to therapy. The commonest cause of non-responsiveness is continued gluten ingestion, either voluntary or inadvertent. Other causes to be considered include intolerances to dietary constituents other than gluten (e.g. milk, soya), pancreatic insufficiency, enteropathy-associated T-cell lymphoma and ulcerative jejunitis. There is some evidence that ulcerative jejunitis is, in fact, a manifestation of lymphoma. The most important steps in the management of the non-responsive coeliac patient are (a) to determine whether the patient is indeed coeliac, (b) to exclude lymphoma and (c) to establish the cause of the non-responsiveness. In those coeliac patients with no demonstrable cause for non-responsiveness, a variety of therapeutic stratagems (mostly based on small, uncontrolled studies) have been described; these include elimination diets, dietary supplementation with zinc and copper, and pharmacological therapy in the form of steroids, azathioprine and cyclosporin. In a minority of non-responsive patients, the clinical course is characterized by a rapid decline, and total parenteral nutrition is required. None of the therapies described above has been subjected to rigorous controlled studies. The precise mechanisms of non-responsiveness in coeliac patients need to be unravelled before rational therapeutic approaches can be established.

Diagnostic yield and effect on clinical outcomes of push enteroscopy in suspected small-bowel bleeding

BACKGROUND AND STUDY AIMS

Endoscopic examination of the small bowel (enteroscopy) has become an important modality in the investigation of patients with obscure gastrointestinal bleeding/anaemia. The aim of this study was to look at our clinical experience and also to determine the clinical outcomes following push enteroscopy (PE) in patients with suspected small intestinal bleeding.

PATIENTS AND METHODS

The indications for PE were iron-deficiency anaemia/occult or obscure gastrointestinal bleeding (50 patients) and overt gastrointestinal bleeding (28 patients). Out of these 78 patients, a subgroup of 21 unselected patients with suspected small intestinal bleeding (six men, 15 women; mean age 59, range 26-85) was recruited to determine the clinical outcomes following PE. The principal outcome measures in this study were a) whether the procedure led to a change in the management of the patients referred for PE and b) whether it saved them from having further investigations.

RESULTS

In those patients with undiagnosed gastrointestinal bleeding/anaemia, small-bowel arteriovenous malformations (AVMs) were detected in 24/78 (31%). Heater probe ablation therapy was performed in 23 patients with small-bowel and gastric AVMs. In total, seven of these 23 patients (30%) re-bled or required transfusion; these seven had repeat enteroscopy and heater probe ablation therapy. Three of these seven re-bled and required further enteroscopy and therapy. PE resulted in a change in management and treatment plans in eight of 20 patients (40%). The certainty of diagnosis increased in seven of 20 patients (35%). It increased from a mean value of 1.35 before PE to 2.40 following PE ( P = 0.01). The test was assigned a median "usefulness score" of 3 by the requesting physicians on an integer scale from 1 (not helpful) to 5 (very helpful).

CONCLUSIONS

We conclude that (i) PE can establish a diagnosis in a high proportion of patients with undiagnosed gastrointestinal bleeding/anaemia; (ii) heater probe ablation therapy of vascular lesions can be performed routinely at the time of PE; (iii) a significant proportion of patients (42%) referred for enteroscopy have lesions in the stomach/proximal duodenum that are missed at diagnostic endoscopy; (iv) PE provides helpful information in routine clinical practice and is perceived as a helpful test by requesting physicians; (v) PE improves certainty of diagnosis as perceived by requesting physicians, and plays an important role in altering management plans.

Beta-amyloid(Phe(SO3H)24)25-35 in rat nucleus basalis induces behavioral dysfunctions, impairs learning and memory and disrupts cortical cholinergic innervation

Long-term behavioral effects, changes in learning and memory functions and aberrations of cholinergic fibers projecting to the parietal cortex were investigated after bilateral injections of beta-amyloid(Phe(SO3H)24)25-35 peptide in rat nucleus basalis magnocellularis (nbm). The beta-amyloid peptide used in these experiments contained the original beta-amyloid 25-35 sequence which was coupled to a phenylalanine-sulphonate group at position 24. This additional residue serves as a protective cap on the molecule without influencing its neurotoxic properties and results in water-solubility, stability and low rates of peptide metabolism. In this paper, home cage, locomotor and open-field activities, passive shock-avoidance and 'Morris' water maze learning abilities were assessed throughout a 35-day survival period. Subsequently, acetylcholinesterase (AChE) histochemistry was used to visualize alterations of parietal cortical cholinergic innervation. In response to the neurotoxic action of beta-amyloid(Phe(SO3H)24)25-35, a progressive hyperactivity developed in the rats in their home cages which were maintained throughout the 5-week post-injection period. This was accompanied by a significant hypoactivity in the novel environment of a locomotor arena. Beta-amyloid(Phe(SO3H)24)25-35-treated animals showed greatly impaired cortical memory functions in the step-through passive shock-avoidance paradigm, while spatial learning processes remained unaffected. Moreover, beta-amyloid(Phe(SO3H)24)25-35 injections in the nucleus basalis suppressed explorative behavior in rats and inhibited conditioned stress responses 28 days after surgery. Reductions of cortical cholinergic (AChE-positive) projections provided anatomical substrate for the behavioral changes. This indicated extensive, long-lasting neurodegenerative processes as a result of beta-amyloid(Phe(SO3H)24)25-35 infusion.

Immunosenescence and mucosal immunity: significant effects of old age on secretory IgA concentrations and intraepithelial lymphocyte counts

Concentrations of immunoglobulins (Ig) and levels of isotype specific antibodies to three dietary antigens in serum, pure parotid saliva, and in intestinal secretions obtained by whole gut lavage from groups of healthy elderly subjects (aged greater than 70 years) and of younger adult controls (aged 25-50 years) were measured. In addition, counts of lamina propria and intra-epithelial lymphoid cells were performed in histologically normal jejunal biopsy specimens from elderly and younger subjects. Elderly subjects had significantly higher concentrations of serum and salivary IgA and of salivary IgM (both, p less than 0.01), and of salivary IgA antibodies than did the younger subjects, but the amount of immunoglobulin and antibody in whole gut lavage fluid was similar in the two age groups. Jejunal biopsy specimen cell counts showed higher IgA plasma cell counts and lower intraepithelial lymphocyte counts in the elderly group (p less than 0.01), with similar counts of IgM and IgG plasma cells, eosinophils, and mast cells in the two groups. There is evidence of significant effects of old age on the mucosal immune system.

Dissociation between systemic and mucosal humoral immune responses in coeliac disease

We examined humoral immunity in coeliac disease as expressed in serum (systemic immunity), and in saliva, jejunal aspirate, and whole gut lavage fluid (mucosal immunity). The aims were to define features of the secretory immune response (IgA and IgM concentrations and antibody values to gliadin and other food proteins measured by enzyme linked immunosorbent assay (ELISA)) in active disease and remission, and to establish whether secretions obtained by relatively non-invasive techniques (saliva and gut lavage fluid) can be used for indirect measurements of events in the jejunum. Serum, saliva, and jejunal aspirate from 26 adults with untreated coeliac disease, 22 treated patients, and 28 immunologically normal control subjects were studied, together with intestinal secretions obtained by gut lavage from 15 untreated and 19 treated patients with coeliac disease and 25 control subjects. Jejunal aspirate IgA and IgM and gut lavage fluid IgM concentrations were significantly raised in patients with untreated coeliac disease; the lavage fluid IgM concentration remained higher in patients with treated coeliac disease than in controls. Serum and salivary immunoglobulin concentrations were similar in the three groups. Patients with untreated coeliac disease had higher values of antibodies to gliadin compared with treated patients and control subjects in all body fluids tested; these were predominantly of IgA and IgG classes in serum, and of IgA and IgM classes in jejunal aspirate and gut lavage fluid. Values of salivary IgA antibodies to gliadin were significantly higher in untreated coeliacs, though antibody values were generally low, with a large overlap between coeliac disease patients and control subjects. In treated patients, with proved histological recovery on gluten free diet, serum IgA antigliadin antibody values fell to control values, though serum IgG antigliadin antibody values remained moderately raised. In contrast, there was persistence of secretory antigliadin antibodies in treated patients (particularly IgM antibody) in both jejunal aspirate and gut lavage fluid. Antibody responses to betalactoglobulin and ovalbumin were similar to those for gliadin, including persistence of high intestinal antibody values in patients with treated coeliac disease. There was a positive correlation between antibody values in jejunal aspirate and gut lavage fluid, but not between saliva and jejunal aspirate; thus salivary antibodies do not reflect intestinal humoral immunity.

The pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence of duodenal pathology

AIM

To determine whether the pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence or absence of duodenal pathology.

METHODS

50 cases (M:F, 26:24; median age 57 years) diagnosed as lymphocytic gastritis between 1986 and 1998 with concurrent duodenal (D2) biopsies were identified from a computer search of the pathology records and validated by counting gastric intraepithelial lymphocytes. Gastric and duodenal intraepithelial lymphocyte counts were performed on haematoxylin and eosin (H&E) and anti-CD3 stained sections. D2 biopsies were assessed for villous atrophy and chronic inflammatory cell infiltration by subjective grading, and gastritis was classified and graded according to the updated Sydney system. A case was designated corpus predominant when the corpus chronic inflammation grade exceeded that of the antrum. If it was less, then the case was antrum predominant, and if they were equal it was diffuse (pan-) gastritis. The ratio between the corpus and antral intraepithelial lymphocyte count in individual patients was calculated.

RESULTS

Of 50 cases of lymphocytic gastritis, 21 were classified as corpus predominant. With one exception (a case of mild villous atrophy), all were accompanied by normal duodenal morphology. Cases with a corpus predominant gastritis had median duodenal intraepithelial lymphocyte counts of 19 (H&E) and 14.1 (CD3), whereas 29 subjects with an antrum predominant or diffuse gastritis had median counts of 39.9 (H&E) and 37.9 (CD3). Fifteen of these 29 cases (52%) showed villous atrophy; all were graded as moderate or severe. Patients with any degree of villous atrophy had a mean corpus/antrum intraepithelial lymphocyte ratio (H&E) of 0.59 (representing antral predominance), while those with normal duodenal morphology had a ratio of 2.39 (p < 0.0001).

CONCLUSIONS

The pattern of involvement of gastric mucosa in lymphocytic gastritis is closely related to the associated duodenal pathology. Those with the corpus predominant form are unlikely to have duodenal pathology, while those with an antral predominant or diffuse form should have distal duodenal biopsies taken to exclude villous atrophy.

Appraisal of gut lavage in the study of intestinal humoral immunity

Direct investigation of intestinal humoral immunity requires collection of intestinal secretions or mucosal biopsy specimens, or both. A non-invasive technique of gut lavage, with a polyethyleneglycol electrolyte lavage solution as a means of collecting intestinal secretions for immunoglobulin and antibody studies, was evaluated. Fifty patients were studied--25 immunologically normal patients or volunteers, 15 patients with untreated coeliac disease, and 10 patients with active Crohn's disease. Protease inhibitors were added promptly to samples to prevent proteolysis of immunoglobulin content. Treated lavage samples were assayed by enzyme linked immunosorbent assay for immunoglobulin and antibody content. Studies of serial lavage specimens showed that early, faecally contaminated specimens contained negligible quantities of immunoglobulin, but once the specimens became clear a steady state was reached, with little variation in immunoglobulin content between serial specimens and with a uniform dilution (around 20%) of the ingested polyethyleneglycol. Gut lavage fluid IgA was predominantly secretory, comprising 92%, 81.6%, and 76.7% respectively of the total IgA gut lavage fluid content in the control, coeliac, and Crohn's groups. High values of total IgM and IgA and IgM antigliadin antibodies were detected in the coeliac group, and high values of IgG in the Crohn's disease group. This method of gut lavage is not only an effective bowel cleanser, but also a noninvasive means of obtaining intestinal secretions for the study of humoral immunity in gastrointestinal disease.

Gut lavage fluid protein concentrations: objective measures of disease activity in inflammatory bowel disease

BACKGROUND

Fluid obtained by whole gut lavage normally contains traces of immunoglobulin (Ig) G, albumin, and alpha-1-antitrypsin; higher concentrations have been found in patients with inflammatory bowel disease (IBD).

METHODS

In a prospective study, 53 lavages were performed in 45 IBD patients (27 Crohn's disease, 18 ulcerative colitis), in whom disease activity was simultaneously assessed by Crohn's Disease Activity Index or Powell Tuck index. Concentration of IgG in lavage fluid was measured by enzyme-linked immunosorbent assay, and of albumin and alpha-1-antitrypsin by immunoturbidimetry.

RESULTS

For IgG, concentrations in lavage fluid correlated closely with activity indices: in Crohn's disease, r = 0.723 (P < 0.0001), in ulcerative colitis, r = 0.714 (P < 0.0001). Results for albumin and alpha-1-antitrypsin concentrations were similar to those for IgG, but they were less sensitive in detecting active disease. However, this method cannot be used as a diagnostic test for IBD; normal results were obtained for IgG in 6 (all inactive) of 42 lavages in patients who had unequivocal radiological or endoscopic abnormalities.

CONCLUSIONS

Assay of protein concentrations in gut lavage fluid is a simple, objective means of grading disease activity in patients with IBD; its potential uses are likely to be in the evaluation of complex cases and in clinical trials.

Similarities in intestinal humoral immunity in dermatitis herpetiformis without enteropathy and in coeliac disease

Intestinal humoral immunity was examined in eight patients with dermatitis herpetiformis and normal jejunal histology (as determined by quantitative morphometry) on a gluten-containing diet. Jejunal aspirate was taken at the time of jejunal biopsy, and levels of total immunoglobulins (IgA, IgM, IgG) and specific antibody to gliadin and two other dietary proteins, betalactoglobulin and ovalbumin, were measured. The pattern of secretory immune responses in the dermatitis herpetiformis patients was similar to that in twenty-six patients with untreated coeliac disease--ie, higher than normal concentrations of IgA, IgM, and IgG and high levels of specific antibodies (IgA and IgM) to the three dietary proteins. Serum levels of IgA antigliadin were similar in the dermatitis herpetiformis and control (twenty-eight patients who underwent jejunal biopsy to exclude coeliac disease) groups, and serum levels of IgG antigliadin were intermediate between those of the control and coeliac disease groups. These findings suggest that investigation of gut humoral immunity may provide a diagnostic index of latent coeliac disease. The definition of coeliac disease as a permanent gluten-sensitive enteropathy may have to be revised if the proposed two-stage model is confirmed.

Evidence of an enhanced central 5HT response in irritable bowel syndrome and in the rat maternal separation model

Efforts to define either a biomarker for irritable bowel syndrome (IBS) or a valid animal model have proven disappointing. The aims of this study were to determine if buspirone stimulates prolactin release through the 5-hydroxytryptamine (5HT)1a receptor and whether this response is altered in patients with IBS and in the rat maternal separation model. Buspirone (30 mg) was used to stimulate prolactin release in 40 patients with IBS and in 40 healthy controls. In study 1, 10 IBS patients and 10 controls underwent pretreatment with pindolol (5HT1a antagonist) or placebo followed by buspirone. In study 2, 30 patients with IBS and 30 healthy controls had prolactin release stimulated by buspirone. Maternally separated and nonseparated rats were also treated with buspirone and prolactin monitored. Serotonin metabolites were measured together with the expression of the 5HT1a and serotonin transporter (SERT) gene. Pindolol produced a dose-dependent decrease in the buspirone prolactin response. Patients with IBS and maternally separated rats showed an exaggerated release of prolactin in response to buspirone. In the animal model, an increased turnover of 5HT was found in the brainstem together with a trend toward increased activity of the SERT gene. In conclusion altered central serotonin responses are found in both IBS and in an animal model.

Smoking, humoral immunity, and ulcerative colitis

Since ulcerative colitis predominantly affects non-smokers and ex-smokers we have examined the possibility that smoking modifies the humoral immune response to an antigenic challenge from the gut lumen. Gut lavage was used in healthy subjects and patients with ulcerative colitis, including both smokers and non-smokers. Antibodies in the intestinal fluid to Escherichia coli (five pooled serotypes), Candida albicans, gliadin, ovalbumin, and beta lactoglobulin were measured by ELISA to determine specific antibody concentrations of IgG, IgA, and IgM classes. Total IgG, IgA, and IgM were also measured in intestinal secretions and serum. In addition, circulating antibody concentrations of IgG, IgA, and IgM to three gut commensals - E coli (five pooled serotypes) C albicans, and Poroteus mirabilis were measured. There was a significant reduction in the IgA concentration in intestinal fluid of smokers with ulcerative colitis compared with healthy non-smoking controls. No other significant differences were found between the groups. Overall, these data are not consistent with the idea that smoking suppresses immune responses in the gut and suggest that the effect of smoking in colitis is mediated by another mechanism.

Effects of Helicobacter pylori eradication on the natural history of lymphocytic gastritis

BACKGROUND

Lymphocytic gastritis is characterised by an accumulation of lymphocytes in the surface epithelium of the stomach. Lymphocytic gastritis has been linked to coeliac disease and Helicobacter pylori infection.

AIMS

To determine whether H pylori eradication leads to resolution of the lymphocytic infiltrate and clinical improvement in patients with lymphocytic gastritis, and to determine their HLA status.

METHODS

The Leeds Dyspepsia Questionnaire (LDQ) was administered to 13 patients with lymphocytic gastritis. H pylori serology, (13)C urea breath test (UBT), and upper gastrointestinal endoscopy with sampling of the duodenum, antrum, and corpus were done in all cases and the HLA status was determined. Eleven patients had at least one positive test for H pylori. Patients with lymphocytic gastritis and H pylori infection were treated with a one week course of omeprazole, clarithromycin, and metronidazole. Gastric and duodenal intraepithelial lymphocyte (IEL) counts were performed, along with histological assessment of gastric and duodenal biopsies before and after H pylori eradication.

RESULTS

Two months after treatment there was a significant reduction in gastric IEL counts in both antrum and corpus. There was no significant change in duodenal IEL counts before and after eradication. According to the Sydney grading there was significant improvement in corpus inflammation after eradication. The patients histologically H pylori positive before treatment became H pylori negative. Dyspepsia scores also improved significantly after treatment.

CONCLUSIONS

H pylori eradication treatment in patients with lymphocytic gastritis causes significant improvement in the gastric IEL infiltrate, corpus inflammation, and dyspeptic symptoms. H pylori serology is frequently positive when histology and UBT are negative. Lymphocytic gastritis may represent a specific immune response to H pylori infection.

Beta-amyloid-induced cholinergic denervation correlates with enhanced nitric oxide synthase activity in rat cerebral cortex: reversal by NMDA receptor blockade

Ample experimental evidence indicates that acute beta-amyloid infusion into the nucleus basalis of rats elicits abrupt degeneration of the magnocellular cholinergic neurons projecting to the cerebral cortex. In fact, involvement of a permanent Ca2+ overload, partially via N-methyl-D-aspartate (NMDA) receptors, was proposed as a pivotal mechanism in beta-amyloid-induced neurodegeneration. A definite measure of NMDA receptor-mediated processes and subsequent Ca2+ entry is the induction of Ca2+/calmodulin-activated neuronal nitric oxide synthase (nNOS) in nerve cells. In the present account we therefore assessed activation of nNOS in correlation with cholinergic decline after beta-amyloid(1-42) or beta-amyloid(25-35) infusion into the rat nucleus basalis. The results demonstrate the beta-amyloid conformation-dependent enhancement of cortical nitric oxide synthase (NOS) activity. Furthermore, chronic application of the polyamine site NMDA receptor blocker ifenprodil effectively attenuated beta-amyloid neurotoxicity. We propose that nNOS activation reflects the degree of beta-amyloid-induced excitotoxic injury in a proportional manner. Moreover, Ca2+-mediated processes via NMDA receptors, or direct binding of beta-amyloid to this receptor may be a critical step in the neurotoxic mechanisms in vivo.

Systemic and mucosal antibodies to Klebsiella in patients with ankylosing spondylitis and Crohn's disease

Whole gut lavage fluid is a useful source of material for the study of intestinal immunity and inflammation in humans. Systemic and mucosal antibodies to Klebsiella pneumoniae were measured by enzyme linked immunosorbent assay (ELISA) in serum samples and whole gut lavage fluid from 14 patients with ankylosing spondylitis, 14 with Crohn's disease, and 16 immunologically normal controls. As the concentration of IgG in whole gut lavage fluid reflects disease activity in Crohn's disease, this approach was used to detect intestinal inflammation in patients with ankylosing spondylitis who also had disease activity and use of non-steroidal anti-inflammatory drugs (NSAIDs) recorded. Small intestinal permeability to cellobiose and mannitol was also studied. In serum samples, levels of IgA antibody to klebsiella were high in patients with Crohn's disease and in patients with active ankylosing spondylitis, and were significantly correlated with the erythrocyte sedimentation rate in patients with ankylosing spondylitis. Levels of IgG antibody to klebsiella were also high in patients with Crohn's disease. Studies of whole gut lavage fluid showed similar levels of IgA antibody to klebsiella in the three study groups, but levels of whole gut lavage fluid IgM and IgG antibodies to klebsiella were high in patients with Crohn's disease. Levels of IgG in whole gut lavage fluid were high in patients with Crohn's disease but in only one patient with ankylosing spondylitis, though the cellobiose/mannitol permeability ratio was abnormal in eight of 13 patients with ankylosing spondylitis. It is concluded that high levels of serum IgA antibody to klebsiella are not specific to ankylosing spondylitis, and that there is no evidence of an abnormal intestinal IgA antibody response to klebsiella in patients with ankylosing spondylitis.

Coagulation factor XIII and markers of thrombin generation and fibrinolysis in patients with inflammatory bowel disease

OBJECTIVE

To relate factor XIII levels and other prothrombotic markers to inflammatory bowel disease and investigate the frequency of valine34leucine and its effect on factor XIII cross-linking activity in patients with inflammatory bowel disease.

DESIGN

Fifty patients with active inflammatory bowel disease but no venous thromboembolism (32 with ulcerative colitis, 18 with Crohn's disease), 50 patients with inactive inflammatory bowel disease but no venous thromboembolism (32 with ulcerative colitis, 18 with Crohn's disease), two age- and gender-matched healthy control groups of 100 subjects each were recruited. To further explore the relationship between valine34leucine and inflammatory bowel disease, 21 patients with the disease (13 with ulcerative colitis and eight with Crohn's disease) and venous thromoembolism (male to female ratio = 7 : 14, median age 59.5 years (range, 19-80 years)) were recruited. Two hundred and fifteen control subjects (M : F = 121 : 94, median age 62 years (28-74 years)), with venous thromboembolism (119 with deep venous thrombosis, and 96 with pulmonary embolism) were drawn from the same geographical area as the patients.

METHODS

Factor XIII A, B-subunit antigen and A2B2 tetramer levels were measured using an in-house sandwich enzyme-linked immunoassay method.

RESULTS

Factor XIII A2B2 tetramer and the A-subunit were significantly decreased in patients with active inflammatory bowel disease compared with controls (59% vs 95%, P < 0.0001 and 75% vs 102%, P < 0.0001, respectively), but not between the inactive inflammatory bowel disease group and controls. The D-dimer and prothrombin 1+2 fragment levels in patients with active inflammatory bowel disease were raised compared with controls (178 (152) vs 109 (84), P = 0.0007 and 82 (43) vs 55 (28), P = 0.0001, respectively). The factor XIII B-subunit and factor XIII cross-linking activity were not significantly different between patients with active or inactive inflammatory bowel disease and controls. There was no significant difference in genotype distribution in inflammatory bowel disease patients with or without venous thromboembolism and respective control subjects. Levels of tissue plasminogen activator antigen were significantly increased in patients with active inflammatory bowel disease when compared to inactive inflammatory bowel disease and controls (8.9 (3.7) vs 6.7 (3.4) vs 6.9 (3.4), P < 0.001).

CONCLUSIONS

Active inflammatory bowel disease is associated with activation of coagulation. Factor XIII A and A2B2 tetramer levels were markedly decreased in active inflammatory bowel disease. Variations in the level of factor XIII in patients with inflammatory bowel disease could be multifactorial and in part may result from the increased formation of microthrombi and accelerated turnover of the factor XIII. We found no evidence of association of factor XIII valine34leucine polymorphism and inflammatory bowel disease.

Beta-amyloid(1-42)-induced cholinergic lesions in rat nucleus basalis bidirectionally modulate serotonergic innervation of the basal forebrain and cerebral cortex

Ample experimental evidence suggests that beta-amyloid (A beta), when injected into the rat magnocellular nucleus basalis (MBN), impels excitotoxic injury of cholinergic projection neurons. Whereas learning and memory dysfunction is a hallmark of A beta-induced cholinergic deficits, anxiety, or hypoactivity under novel conditions cannot be attributed to the loss of cholinergic MBN neurons. As mood-related behavioral parameters are primarily influenced by the central serotonergic system, in the present study we investigated whether A beta(1-42) toxicity in the rat MBN leads to an altered serotonergic innervation pattern in the rat basal forebrain and cerebral cortex 7 days postsurgery. A beta infusion into the MBN elicited significant anxiety in the elevated plus maze. A beta toxicity on cholinergic MBN neurons, expressed as the loss of acetylcholinesterase-positive cortical projections, was accompanied by sprouting of serotonergic projection fibers in the MBN. In contrast, the loss of serotonin-positive fiber projections, decreased concentrations of both serotonin and 5-hydroxyindoleacetic acid, and decline of cortical 5-HT(1A) receptor binding sites indicated reduced serotonergic activity in the somatosensory cortex. In conclusion, the A beta-induced primary cholinergic deficit in the MBN and subsequent cortical cholinergic denervation bidirectionally modulate serotonergic parameters in the rat basal forebrain and cerebral cortex. We assume that enhanced serotonin immunoreactivity in the damaged MBN indicates intrinsic processes facilitating neuronal recovery and cellular repair mechanisms, while diminished cortical serotonergic activity correlates with the loss of the subcortical cholinergic input, thereby maintaining the balance of neurotransmitter concentrations in the cerebral cortex.

Medicine and the McNamara fallacy

The 'McNamara fallacy' (also known as quantitative fallacy) is named after the US Secretary of Defense during the Vietnam War. The fallacy consists of over-reliance on metrics, and may be summarised as: 'if it cannot be measured, it is not important'. This paper describes the McNamara fallacy as it applies to medicine and healthcare, taking as examples hospital mortality data, NHS targets and quality assurance.

Push enteroscopy in the investigation of small-intestinal disease

We report our experience with small-bowel push enteroscopy in 50 patients. The indications for push enteroscopy were: anaemia/occult gastrointestinal bleeding (22 patients); overt gastrointestinal bleeding (17 patients); abnormal small-bowel radiology (8 patients) and miscellaneous (3 patients). In those with undiagnosed gastrointestinal bleeding/anaemia, abnormalities were detected in 24/39 patients (62%): small bowel arteriovenous malformations (AVMs) were detected in 19 (49%), and five (13%) had lesions in the upper gastrointestinal tract. Seventeen patients had heater-probe ablation therapy of vascular lesions: nine patients had small-intestinal lesions, four patients gastric lesions, and four patients combined gastric and small-intestinal lesions. In those with abnormal small-bowel radiology, abnormalities were detected in 6/8 patients. We conclude that (i) push enteroscopy can establish a diagnosis in a high proportion of patients with gastrointestinal bleeding; (ii) heater-probe ablation therapy of vascular lesions can be performed routinely at the time of enteroscopy; (iii) a significant proportion of patients (9/50) referred for enteroscopy with undiagnosed gastrointestinal bleeding have lesions in the stomach/proximal duodenum missed at diagnostic endoscopy. Push enteroscopy is a valuable diagnostic and therapeutic endoscopic procedure.

Helicobacter pylori serology in patients with coeliac disease and dermatitis herpetiformis

AIMS

To investigate whether Helicobacter pylori infection or autoimmune gastritis is responsible for the reported increase in gastric pathology and abnormalities of gastric function in patients with coeliac disease and dermatitis herpetiformis (DH).

METHODS

Serum H pylori IgG antibodies were assayed by enzyme linked immunosorbent assay and intrinsic factor antibodies by radioimmunoassay in 99 patients with coeliac disease and 58 patients with dermatitis herpetiformis from two geographic areas.

RESULTS

H pylori positivity in patients with coeliac disease and dermatitis herpetiformis increased with age, reaching 50% and 70%, respectively, in patients over 50 years. The percentage H pylori seropositivity in coeliac disease did not differ from the percentage positivity observed in 250 similarly aged blood donors from the same geographic area (Leeds). Seropositivity in patients with dermatitis herpetiformis was not significantly different from the level of positivity observed in 98 age matched patients without dermatitis herpetiformis attending the same Edinburgh dermatology clinic. Only one patient with coeliac disease had positive intrinsic factor antibodies. H pylori seropositivity in Edinburgh control subjects under 30 years of age (41.9%) was significantly higher (p less than 0.03) than in Leeds controls (18%) of corresponding age. An increasing prevalence of H pylori seropositivity with age in coeliac disease and dermatitis herpetiformis paralleled that of the control groups.

CONCLUSIONS

Gastritis in coeliac disease and dermatitis herpetiformis is largely caused by H pylori infection at a level that is no different from that of the general population. Any increase in the prevalence of gastritis in these two diseases might be caused by lymphocytic gastritis rather than pernicious anaemia.

Coeliac disease and collagenous colitis

We describe a case of collagenous colitis in a young man with coeliac disease who had responded clinically and histologically to a gluten-free diet three years previously. The collagenous colitis responded initially to oral corticosteroid therapy and he is now asymptomatic (and with normal rectal mucosa) on oral mesalazine. Collagenous colitis should be considered in the coeliac patient with diarrhoea despite adherence to a gluten-free diet.

Role of paroxetine in interferon-alpha-induced immune and behavioural changes in male Wistar rats

Treatment with pro-inflammatory cytokine, IFNalpha was documented to result in neuropsychiatric complications including depression and treatment with antidepressant, paroxetine could improve the depressive symptoms. Therefore, the effects of IFNalpha on behaviour and cytokine changes in the whole blood culture and in the prefrontal cortex, hypothalamus and hippocampus areas of the brain in wistar rats were investigated with emphasis on the role of paroxetine in the prevention of depressive behaviour induced by pro-inflammatory cytokines. The group of rats treated with IFNalpha (s.c. 50,000 IU/kg for 3 days/week for 5 weeks) was compared with three other groups; 1) saline control group (s.c. normal saline 0.2 ml/kg/day for 7 weeks), 2) paroxetine control group (paroxetine suspension orally 10 mg/kg/day for 7 weeks) and 3) group treated with paroxetine for 2 weeks followed by IFNalpha for 5 weeks. In open filed, the IFNalpha treated rats showed anxiety behaviour compared to the rats from the other groups. There was no significant difference in home cage emergence test, Morris water maze and object recognition test. There is no significant difference in plasma corticosterone between groups. The pro-inflammatory cytokines (TNFalpha, IL1beta and IFNgamma), were significantly higher whereas the anti-inflammatory cytokine, IL10 was lower in the stimulated whole blood culture of IFNalpha treated rats. In the brain, both pro-inflammatory cytokine IL1beta and anti-inflammatory cytokine IL10 were higher in hypothalamus of the IFNalpha treated rats; by contrast the concentration of IL10 was lowest in hippocampus region of this group compared to the other groups. The paroxetine pretreated rats did not show these cytokine changes following IFNalpha treatment. Thus it appears that paroxetine pretreatment prevents the pro-inflammatory changes in blood and brain following IFNalpha treatment in turn prevents the anxiety behaviour.