Blockade of the integrin alphaLbeta2 but not of integrins alpha4 and/or beta7 significantly prolongs intestinal allograft survival in mice

BACKGROUND—Small bowel transplantation remains a difficult therapeutic option endangered by a high rate of rejection and infectious complications. To improve these clinical results, it is mandatory to set up animal models to test alternative immunosuppressive regimens which may lead to immunotolerance.
AIMS—To determine the value of blockade of αLβ2 (LFA-1) and α4 and β7 integrins (α4β1, α4β7, and αEβ7) in the prevention of rejection of fetal small bowel grafts in mice and the effect of the association of calcineurin dependent drugs in anti-LFA-1 treated mice.
METHODS—Adult recipient mice engrafted with allogeneic fetal small bowel received a short course of anti-α4 and/or anti-LFA-1 monoclonal antibodies (mAb) with or without FK506 or cyclosporin A. In addition, in a set of experiment, β7−/− mice were used as recipients. Graft biopsies were performed and processed for standard histology.
RESULTS—Blockade of the pathways of the integrins α4 and β7 had a modest or no effect on intestinal graft survival. In contrast, transitory, short administration of anti-LFA-1 monoclonal antibody alone, when started before engraftment (day −1), allowed long term survival of intestinal grafts, even when associated with calcineurin dependent drugs. However, early withdrawal of FK506 reversed the immunosuppressive effect of anti-LFA-1 treatment.
CONCLUSION—These results suggest that firstly, anti-LFA-1, but not anti-α4 mAb treatment, may be useful in improving the results of intestinal transplantation, and secondly, that this treatment is not incompatible with long term administration of tacrolimus currently used in the prevention of small bowel graft rejection in humans.


Keywords: small bowel transplantation; integrins; calcineurin; tolerance; mouse     

Increased secretion of pro-inflammatory cytokines by circulating polymorphonuclear neutrophils and regulation by interleukin 10 during intestinal inflammation

Background—Concentrations of pro-inflammatorycytokines are increased in the intestinal mucosa of patients withactive inflammatory bowel disease (IBD). Polymorphonuclear neutrophilgranulocytes (PMN) are the most abundant cell type in intestinallesions in IBD. Interleukin 10 (IL-10) is an importantcontra-inflammatory cytokine which induces downregulation ofpro-inflammatory cytokines.
Aims—To investigate whether PMN from patients withIBD or infectious colitis, respectively, secrete increased amounts ofpro-inflammatory cytokines and can be regulated by IL-10.
Methods—Secretion (ELISA) as well as correspondingmRNA levels (semiquantitative RT-PCR) of pro-inflammatory cytokines(IL-1β, TNF-α) and of IL-1 receptor antagonist were assessed inperipheral PMN.
Results—PMN from patients with IBD are primed tosecrete enhanced amounts of pro-inflammatory cytokines accompanied bydetection of corresponding mRNAs in comparison with normal controls.This finding is not specific for IBD but rather reflects intestinal inflammation in general. IL-10 markedly inhibited pro-inflammatory cytokine secretion as well as corresponding mRNA concentrations.
Conclusions—PMN are an important source ofpro-inflammatory cytokines in patients with intestinal inflammation andcan be downregulated by IL-10.

Keywords:granulocytes; interleukin 1β; interleukin 10; inflammatory bowel disease; intestinal immunity; inflammation; neutrophils; tumour necrosis factor α

     

Decreased expression of the interleukin 2 receptor on CD8 recipient lymphocytes in intestinal grafts rendered tolerant by liver transplantation in rats

Background—In a previous study, it was shown thata spontaneously tolerated DA (RT1a) liver allograft in a PVG (RT1c)recipient was able to induce tolerance of a DA small bowel graftperformed 17 days later in spite of infiltration of the intestinalgrafts by mononuclear cells.
Aims—To compare the phenotype of graftinfiltrating cells in rejecting and tolerated small bowel grafts inorder to elucidate the mechanism(s) which block the graft infiltratingcells from mediating rejection.
Methods—Multiparameter immunofluorescence wasused to compare the phenotype and state of activation of donor andrecipient cells isolated from intestinal grafts rejected or toleratedafter liver transplantation.
Results—Three differences were found. Firstly,there was a more rapid replacement of lamina propria (LP) cells byrecipient lymphocytes in tolerated than in rejected grafts. Secondly,the proportion of LP recipient CD8αβ+ lymphocytes bearing the high affinity receptor for interleukin 2 was significantly less in toleratedgrafts (1.1%, range 0-2%) than in rejected grafts (21.3%, range9-26%). Finally, tolerated grafts contained significantly less NKlymphocytes (NKR-P1+) and macrophages than rejected intestinal allografts.
Conclusions—These observations make it possibleto delineate clear cut differences in the phenotype of cellsinfiltrating rejecting versus tolerated grafts. Furthermore, the datasuggest that liver transplantation induces tolerance of intestinalgrafts by hampering the activation of recipient TcRαβ+ CD8αβ+ Tcells and subsequently the recruitment of non-specific effector cells.

Keywords:liver transplantation; small bowel transplantation; tolerance; intestinal T lymphocytes; interleukin 2 receptor; rat

     

Prevalence and clinical features of selective immunoglobulin A deficiency in coeliac disease: an Italian multicentre study

Background—Selective immunoglobulin A (IgA)deficiency (SIgAD) is associated with coeliac disease (CD).
Aim—To make a retrospective study of theassociation of SIgAD with CD in Italy.
Methods—Hospital medical records of 2098 patientsconsecutively diagnosed as having CD were reviewed.
Results—Of 2098 patients with CD, 54 (2.6%) hadSIgAD, representing a 10-16-fold increase over that in the populationin general. This increase was not influenced by age or geographicalfactors. Patients with SIgAD had a higher incidence of silent forms(7/54, 13%), recurrent infections (16/54, 29.6%), and atopic diseases (7/54, 13%) than those without. The association with autoimmune andmalignant diseases and the outcome after eating a gluten free diet weresimilar in patients with or without SIgAD. In all patients with SIgAD,antibodies for IgA gliadin and endomysium were absent, but serum levelsof IgG anti-gliadin antibodies were high in almost all of them (51/54).
Conclusions—Serum IgA should be measured in orderto be able to interpret negative results for IgA anti-gliadinantibodies and anti-endomysial antibodies in patients being screenedfor CD. Since some patients with CD and SIgAD may be negative for IgGanti-gliadin antibodies, an intestinal biopsy should be performed inall suspected cases.

Keywords:coeliac disease; IgA deficiency

     

Original research: Diagnosis of coeliac disease by flow cytometry of intraepithelial lymphocytes: a new ‘gold’ standard?

ObjectiveThe analysis of intraepithelial lymphocytes (IELs) by flow cytometry of duodenal biopsies—the ‘IEL’ lymphogram—has been proposed as a diagnostic test for coeliac disease. However, its clinical applicability has been limited due to variability in methods and definitions. This study set out to define useful parameters for the application of the IEL lymphogram to the diagnosis of coeliac disease.DesignFlow cytometry was performed on 117 sets of duodenal biopsies in 107 adult patients with active coeliac disease, long-term coeliac disease on a gluten free diet and a control group. The initial 95 samples were used for hypothesis generation for the subsequent samples comprising 12 patients with coeliac disease and 10 controls.ResultsRather than using single linear cut-offs for CD3 and T-cell receptor γδ (TCRγδ)+ve IELs, a discriminant function was identified as %CD3+ve IELs+2x(%TCRγδ+IELs)>100. This differentiated coeliac disease from control biopsies in the hypothesis generating group. These results were replicated in the validation group and found to be independent of histology in patients on long-term gluten free diet up to 12 years (combined sensitivity, 98.5%; specificity, 97.7%).ConclusionsFlow cytometric analysis of IELs is a highly sensitive and specific adjunct to serology and histological examination for the diagnosis of coeliac disease, even in individuals with coeliac disease following a gluten free diet who exhibit normal duodenal histology.     

Wheat starch-containing gluten-free flour products in the treatment of coeliac disease and dermatitis herpetiformis. A long-term follow-up study

BACKGROUND: We investigated whether wheat starch-based gluten-free products are safe in the treatment of gluten intolerance. METHODS: The study involved 41 children and adults with coeliac disease and 11 adults with dermatitis herpetiformis adhering to a gluten-free diet for 8 years on average. Thirty-five newly diagnosed coeliac patients at diagnosis and 6 to 24 months after the start of a gluten-free diet and 27 non-coeliac patients with dyspepsia were investigated for comparison. Daily dietary gluten and wheat starch intake were calculated. Small-bowel mucosal villous architecture, CD3+, alphabeta+, and gammadelta+ intraepithelial lymphocytes, mucosal HLA-DR expression, and serum endomysial, reticulin, and gliadin antibodies were investigated. RESULTS: Forty of 52 long-term-treated patients adhered to a strict wheat starch-based diet and 6 to a strict naturally gluten-free diet; 6 patients had dietary lapses. In the 46 patients on a strict diet the villous architecture, enterocyte height, and density of alphabeta+ intraepithelial lymphocytes were similar to those in non-coeliac subjects and better than in short-term-treated coeliac patients. The density of gammadelta(+)cells was higher, but they seemed to decrease over time with the gluten-free diet. Wheat starch-based gluten-free flour products did not cause aberrant upregulation of mucosal HLA-DR. The mucosal integrity was not dependent on the daily intake of wheat starch in all patients on a strict diet, whereas two of the six patients with dietary lapses had villous atrophy and positive serology. CONCLUSION: Wheat starch-based gluten-free flour products were not harmful in the treatment of coeliac disease and dermatitis herpetiformis.     

Dermatogenic enteropathy

Steatorrhoea has been found in a large proportion of patients with inflammatory dermatoses, especially eczema and psoriasis. It is due to the rash itself and disappears rapidly after topical treatment of the skin. This particular enteropathy, unlike that associated with dermatitis herpetiformis, is not accompanied by an alteration in the stereomicroscopic appearance of the small bowel mucosa. The mechanism is not known. It is important to differentiate dermatogenic enteropathy from gluten sensitivity which has produced a rash, as in the former condition a gluten-free diet is not indicated.     

Beta human chorionic gonadotropin concentrations in serum of patients with pancreatic adenocarcinoma

Background—Human chorionic gonadotropin (hCG) isnormally produced and secreted by trophoblastic cells during pregnancyand from gestational trophoblastic neoplasms. It is also detected in ovarian, stomach, and colon adenocarcinomas, as well as in squamouscell carcinoma of the oesophagus. Recently, interest in its role in thepathogenesis of tumours has been enlivened after the presence of βhCGin the cell membrane of several malignant cells was shown in vitro.
Aims—To investigate the circulatingconcentrations of βhCG in patients with exocrine pancreaticadenocarcinoma and to examine its potential prognostic value.
Patients—Thirty six patients with exocrinepancreatic adenocarcinoma, 12 patients with chronic pancreatitis, and21 healthy volunteers were studied.
Methods—βhCG serum concentrations were detectedby the application of a radioimmunoassay technique.
Results—Fifteen of 36 patients with pancreaticadenocarcinoma and only one patient with chronic pancreatitis haddetectable plasma concentrations of βhCG (p<0.01). The patients withcirculating serum titres of βhCG had a worse outcome compared withthe group of βhCG negative patients: the difference was statisticallysignificant (p=0.01).
Conclusion—More than 40% of pancreatic exocrinetumours produce βhCG and its production is correlated with an adverseeffect on outcome.

Keywords:β-human chorionic gonadotropin; chorionicgonadotropin; pancreatic cancer; tumour marker; paraneoplasticsyndrome

     

Five genetic markers in the interleukin 1 family in relation to inflammatory bowel disease

Background—An imbalance between theproinflammatory cytokine interleukin 1β (IL-1β) and theanti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra) has beenpostulated as a pathogenic factor in inflammatory bowel disease (IBD).
Aims—To study allelic frequenciesof novel polymorphisms in the genes for IL-1β and IL-1ra in patientswith IBD and to assess the relation between ex vivo cytokine productionand allelic variants of the IL-1β and IL-1ra genes.
Subjects—Two hundred and seventyhealthy controls, 74 patients with ulcerative colitis (UC), 72 withCrohn's disease (CD), 40 with primary sclerosing cholangitis for theallelic frequencies, and 60 healthy individuals for the ex vivostimulation test.
Methods—Genotyping was performed bypolymerase chain reaction and subsequent cleavage with specificendonucleases (Mwo1, MspAI1, Alu1, Taq1, BsoF1) for five novelrestriction fragment length polymorphisms (RFLPs) in the genes forIL-1ra and IL-1β.
Results—No significant differences were found inthe allelic frequencies or allele carriage rates of the markers in theIL-1β and IL-1ra genes between CD, UC, and healthy controls. Noassociation between the genetic markers and cytokine production levelswas observed. Patients with UC carried the combination of both the infrequent allele of the Taq1 RFLP and the Mwo1 RFLP significantly morefrequently (35.2% in UC versus 71.1% in controls).
Conclusions—UC is associatedwith carriage of both infrequent alleles of the Taq1 and Mwo1 RFLPs.However, it could not be confirmed whether the association reflects apathogenic mechanism underlying UC.

     

Transition of care between paediatric and adult gastroenterology. Coeliac disease

Coeliac disease is a condition in which there is an abnormal mucosa in the small intestine. It improves with a gluten free diet, with avoidance of wheat, rye, barley and possibly oats. The history and epidemiology of this condition are discussed. Diagnosis is based on demonstrating that the characteristic histological abnormalities in the small intestine are dependent on gluten ingestion. Diagnostic pitfalls are discussed. The anti-endomysium and anti-tissue transglutaminase antibodies are specific and sensitive diagnostic tools. The wide variety of clinical symptoms and presentations are discussed including the associated condition of dermatitis herpetiformis. Failure to respond to a gluten-free diet can represent simple dietary problems, an alternative diagnosis or, occasionally, the development of a serious complication of coeliac disease such as ulcerative jejunitis or enteropathy-associated T cell lymphoma. Progress towards the characterization of the toxic epitopes within gluten that exacerbate coeliac disease and our current understanding of the genetics of the disorder are presented.     

Imbalance of the interleukin 1 system in colonic mucosa—association with intestinal inflammation and interleukin 1 receptor agonist genotype 2

Background—Interleukin 1 (IL-1) α and β arepotent cytokines which play key roles in inflammation. They arecontrolled by IL-1 receptor antagonist (IL-1ra).
Aims—To investigate the influence of mucosalinflammation and IL-1ra genotype on the IL-1ra:IL-1 balance.
Patients and methods—IL-1α, IL-1β, and IL-1rawere measured by enzyme linked immunosorbent assay (ELISA) in biopsyspecimens taken from inflamed and non-inflamed colon of 60 patientswith Crohn's disease (CD), 34 with ulcerative colitis (UC), 15 inflammatory controls, and 103 non-inflamed controls. IL-1ra genotypewas determined by polymerase chain reaction and gel electrophoresis.
Results—IL-1α and IL-1β were significantlyincreased in inflamed mucosa in inflammatory bowel disease (IBD) (CD:53.5 (22.4) and 409.9 (118.7) pg/mg protein, respectively; UC: 18.9 (6.8) and 214.5 (78.2) pg/mg, respectively) and non-IBD patients (19.2(7.4) and 281.4 (121.0) pg/mg, respectively; p<0.0001) compared withnormal controls (2.8 (0.6) and 30.6 (5.6) pg/mg, respectively). In CDIL-1α and β were also significantly increased in non-inflamed mucosa (6.1 (1.3) pg/mg and 88.7 (17.4) pg/mg, respectively;p<0.0012). IL-1ra:(IL-1α+β) ratios were significantly decreased ininflamed mucosa of patients with CD (182 (45); p<0.0001), UC (425 (136); p=0.0018) and without IBD (221 (76); p<0.0001), and innon-inflamed mucosa in CD (369 (149); p<0.0001) compared with normalcontrols (1307 (245); p<0.0001). Patients with IL-1ra genotype 2 hadslightly but significantly reduced mucosal IL-1ra concentrations(p=0.003). The greatest difference was seen in colonic biopsy specimensfrom patients with inflamed Crohn's disease.
Conclusion—Mucosal inflammation can modulate thebalance of the IL-1:IL-1ra system in colonic mucosa.

Keywords:interleukin 1; interleukin 1 receptor antagonist; inflammatory bowel disease; Crohn's disease; mucosal inflammation; genotype

     

Guidelines of the Italian societies of gastroenterology on the diagnosis and management of coeliac disease and dermatitis herpetiformis

IntroductionCoeliac disease and dermatitis herpetiformis are immune-mediated diseases triggered by the consumption of gluten in genetically predisposed individuals. These guidelines were developed to provide general practitioners, paediatricians, gastroenterologists, and other clinicians with an overview on the diagnosis, management and follow-up of coeliac patients and those with dermatitis herpetiformis.MethodsGuidelines were developed by the Italian Societies of Gastroenterology. Following a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of the evidence. Statements and recommendations were developed by working groups consisting of gastroenterologists and a paediatrician with expertise in this field.ResultsThese guidelines provide a practical guidance for the diagnosis, management and follow-up of coeliac patients and dermatitis herpetiformis in children and adults, both in primary care and in specialist settings. We developed four sections on diagnosis, gluten-free diet, follow-up and risk of complications in adults, one section focused on diagnosis and follow-up in children and one on the diagnosis and management of dermatitis herpetiformis.ConclusionsThese guidelines may support clinicians to improve the diagnosis and management of patients with coeliac disease.     

Impairment of intestinal glutathione synthesis in patients with inflammatory bowel disease

Background—Reactive oxygen species contribute totissue injury in inflammatory bowel disease (IBD). The tripeptideglutathione (GSH) is the most important intracellular antioxidant.
Aims—To investigate constituent amino acid plasmalevels and the GSH redox status in different compartments in IBD withemphasis on intestinal GSH synthesis in Crohn's disease.
Methods—Precursor amino acid levels were analysedin plasma and intestinal mucosa. Reduced (rGSH) and oxidisedglutathione (GSSG) were determined enzymatically in peripheral bloodmononuclear cells (PBMC), red blood cells (RBC), muscle, and innon-inflamed and inflamed ileum mucosa. Mucosal enzyme activity ofγ-glutamylcysteine synthetase (γGCS) and γ-glutamyl transferase(γGT) was analysed. Blood of healthy subjects and normal mucosa froma bowel segment resected for tumour growth were used as controls.
Results—Abnormally low plasma cysteine and cystinelevels were associated with inflammation in IBD (p<10^-4).Decreased rGSH levels were demonstrated in non-inflamed mucosa (p<0.01) and inflamed mucosa (p=10^-6) in patients withIBD, while GSSG increased with inflammation (p=0.007) compared withcontrols. Enzyme activity of γGCS was reduced in non-inflamed mucosa(p<0.01) and, along with γGT, in inflamed mucosa(p<10^-4). The GSH content was unchanged in PBMC, RBC, and muscle.
Conclusions—Decreased activity of key enzymesinvolved in GSH synthesis accompanied by a decreased availability ofcyst(e)ine for GSH synthesis contribute to mucosal GSH deficiency inIBD. As the impaired mucosal antioxidative capacity may further promote oxidative damage, GSH deficiency might be a target for therapeutic intervention in IBD.

Keywords:Crohn's disease; ulcerative colitis; glutathione; amino acids; γ-glutamylcysteine synthetase; mucosa

     

Identification of common epitopes on gliadin, enterocytes, and calreticulin recognised by antigliadin antibodies of patients with coeliac disease

Background—Sera of patients withcoeliac disease, containing IgA and IgG antigliadin antibodies (AGA)and various IgA autoantibodies, react with isolated enterocytes. AGAcross react with enterocyte antigens, one of which has been identifiedas calreticulin.
Aims—To characterise the antigenicstructures of gliadin, enterocytes, and calreticulin recognised by AGAfrom patients with active coeliac disease.
Methods—AGA were isolated from seraof nine patients by affinity chromatography and tested by competitiveELISA using 40 α-gliadin synthetic dodecapeptides (A1-F6).
Results—Reactivity of gliadin withall purified AGA tested was inhibited by peptide A4 at the N-terminalregion; by C2, C3, and D4 at the central region; and by F3 and F4 atthe C-terminal region of the gliadin molecule. AGA cross reactivity with enterocytes was inhibited by peptides A4, D1-D4, and F6 and withcalreticulin by peptides A4, D3, and D4. As dominant epitopes AGA ofcoeliac patients recognise similar structures corresponding to peptidesA4, D3, D4, and F6 present on gliadin, enterocytes, and calreticulin.Substitution of glutamine in the A4 peptide by glutamic acid causedloss of inhibitory capacity. Shortening of peptide A4 on the N-terminalby three amino acids increased its inhibitoryeffect.
Conclusions—AGA of patients withcoeliac disease react with similar structures on gliadin and potentialautoantigens on enterocytes.

Keywords:coeliac disease; antigliadin antibodies; enterocyteautoantigens; cross reactivity

     

Interferon γ induces differential upregulation of α and β chemokine secretion in colonic epithelial cell lines

Background—Production of chemoattractant factorsby the intestinal epithelium may contribute to mucosal infiltration byinflammatory cells in inflammatory bowel disease. Secretion of the α chemokine interleukin 8 (IL-8), a neutrophil chemoattractant, has beenwidely studied, but little is known about epithelial secretion of β chemokines, which are preferentially involved in recruiting monocytes.
Aims—To investigate the profiles of α and β chemokine secretion in colonic cell lines and their differentialmodulation by interferon γ (IFN-γ), a product of activated Tlymphocytes and natural killer cells.
Methods and results—HT29-19A, a model of theCl secretory crypt cell, exhibited a parallel secretionof the α chemokines IL-8 and GROα, which could be markedlyupregulated by tumour necrosis factor α (TNF-α) and IL-1β. Thesecells showed no significant expression of the β chemokines RANTES(regulated upon activation T cell expressed and secreted), MIP-1α(macrophage inflammatory protein 1α), and MCP-1 (monocyte chemotacticprotein 1) under these conditions, but IFN-γ in combination withTNF-α caused a dose dependent induction of RANTES and MCP-1secretion. This was accompanied by a marked increase of RANTES mRNA. Incontrast, IFN-γ had no significant effect on TNF-α stimulated IL-8secretion. Caco-2 cells, with features more typical of villusabsorptive cells, were relatively poor secretors of α chemokines butsecreted high levels of MCP-1 in response to IL-1β. IFN-γ did notinfluence α or β chemokine secretion in these cells.
Conclusions—These studies suggest that intestinalepithelial cells may produce chemokines capable of attracting bothneutrophils and monocytes. The ability of IFN-γ to activate theexpression of β chemokines preferentially could facilitate thedevelopment of chronic inflammatory infiltrates.

Keywords:inflammatory bowel disease; RANTES; interferongamma; chemokine

     

Reduced susceptibility of mice overexpressing transforming growth factor α to dextran sodium sulphate induced colitis

Background—Transforminggrowth factor α (TGF-α) knockout mice have increased susceptibilityto dextran sodium sulphate (DSS) induced colitis.
Aim—To substantiatethe findings that TGF-α is a key mediator of colonic mucosalprotection and/or repair mechanisms by evaluating the susceptibility ofmice overexpressing TGF-α to DSS induced colitis.
Methods—TGF-αoverexpression was induced in transgenic mice by ZnSO₄administration in drinking water (TG+). Three groups were used ascontrols: one transgenic group without ZnSO₄ administration (TG−), and two non-transgenic littermate groups receivingZnSO₄ (Non-TG+) or only water (Non-TG−). Acute colitiswas induced in all groups by administration of DSS (5%, w/v) indrinking water for six days ad libitum.
Results—About 35-39%of the entire colonic mucosa was destroyed in Non-TG−, Non-TG+, andTG− animals compared with 9% in TG+ mice. The crypt damage score was18.7 (0.9), 18.2 (1.0), 18.9(0.8), and 6.8 (1.5) (means (SEM)) inNon-TG−, Non-TG+, TG−, and TG+ mice respectively. Mucin andbromodeoxyuridine staining were markedly enhanced in colons of TG+ micecompared with controls, indicating increased mucosal protection and regeneration.
Conclusions—Thesignificantly reduced susceptibility of mice overexpressing TGF-α toDSS further substantiates that endogenous TGF-α is a pivotal mediatorof protection and/or healing mechanisms in the colon.

Keywords:transforming growth factor α; epidermal growthfactor; dextran sodium sulphate; colitis; inflammatory bowel disease; transgenic mice

     

The association between primary biliary cirrhosis and coeliac disease: a study of relative prevalences

Background—Coexistent primary biliary cirrhosis(PBC) and coeliac disease has been recorded but the association has notbeen systematically studied.
Aims—To determine relative prevalences of PBC andcoeliac disease in a defined population over a 12 year period.
Patients and methods—All patients with PBCor coeliac disease in a stable population of 250 000 in South Waleswere identified from a clinical register and laboratory records.
Results—Sixty seven patients with PBC and 143 patients with coeliac disease have been diagnosed and followed over amedian of 86 (4-135) months; point prevalences in 1996 were 20 per100 000 for PBC and 54 per 100 000 for coeliac disease. PBC inpatients with coeliac disease was sought by investigating abnormalliver function tests. Ten (7%) had persistent abnormalities and three had PBC. Coeliac disease in patients with PBC was sought byinvestigating malabsorption, haematinic deficiency, positiveantigliadin antibody, or coeliac disease family history. Elevenpatients underwent duodenal biopsy revealing one further coeliacdisease case. Four patients (three women) have both conditions giving apoint prevalence for patients with both conditions of 1.6 per 100 000(95% confidence limits 0.44 to 4.1 per 100 000). Prevalence of PBC inpatients with coeliac disease was 3% and of coeliac disease inpatients with PBC was 6%.
Conclusion—A 12 year study of a stable 250 000population revealed a relative prevalence of PBC in 3% of 143 patientswith coeliac disease and of coeliac disease in 6% of 67 patients with PBC. PBC and coeliac disease are therefore associated. Screening forPBC in patients with coeliac disease using antimitochondrial antibodytesting and screening for coeliac disease in patients with PBC withantigliadin antibody testing or duodenal biopsy are recommended.

Keywords:primary biliary cirrhosis; coeliac disease; prevalence

     

Persistent systemic inflammatory response after stent insertion in patients with malignant bile duct obstruction

Background—Surgery in patients with malignantbile duct obstruction is associated with high postoperative morbidityand mortality. Tumour necrosis factor α (TNF-α) plays a key role inthe pathogenesis of these complications.
Aims—To determine the effect of biliary drainageon plasma concentrations of TNF-α, its soluble circulating receptors(sTNFr), and other proinflammatory cytokines.
Methods—Plasma concentrations of TNF-α,sTNFr-P75, interleukin 6 (IL-6), and IL-1α were measured in 25 patients with malignant bile duct obstruction before and afterendoscopic stent insertion.
Results—Mean serum bilirubin was 157 µmol/lbefore stent insertion and 35.2 µmol/l one week post stent insertion.There was complete relief of jaundice in 77% of patients by fourweeks. Plasma concentrations of TNF-α and IL-1α were below thedetection limit of the assays in all samples. Median plasma sTNFr-P75in the cancer patients was 960 ng/l (range 400-6600) before stent insertion and remained unchanged at one and four weeks after stenting. Plasma sTNFr-P75 in cancer patients was significantly higher(p<0.01) than in healthy controls (250 (200-650) ng/l).Before stent insertion, plasma IL-6 concentrations were detectable(above 5 ng/l) in 17(68%) patients. After relief of biliaryobstruction IL-6 levels fell from a prestent median of 13.2 to lessthan 5 ng/l at one week after stent insertion. Plasma concentrations ofIL-6 were undetectable in 76% of patients at this time.
Conclusion—Activation of the TNF/sTNFr complex isunchanged after biliary drainage in patients with malignant bile ductobstruction. This may explain why preoperative drainage does notinfluence the high morbidity and mortality associated with surgery inthese patients.

Keywords:jaundice; tumour necrosis factor α; biliarydrainage; pancreatic cancer

     

Spontaneous secretion of interferon γ and interleukin 4 by human intraepithelial and lamina propria gut lymphocytes

Background—Cytokines secreted by intestinal Tlymphocytes probably play a critical role in regulation of the gutassociated immune responses.
Aims—To quantify interferon γ (IFN-γ) andinterleukin 4 (IL-4) secreting cells (SC) among human intraepithelial(IEL) and lamina propria (LPL) lymphocytes from the duodenum and rightcolon in non-pathological situations and in the absence of in vitro stimulation.
Patients—Duodenal and right colonic biopsyspecimens were obtained from patients with no inflammation of theintestinal mucosa.
Methods—Intraepithelial and lamina propria cellsuspensions were assayed for numbers of cells spontaneously secretingIFN-γ and IL-4 by a two site reverse enzyme linked immunospottechnique (ELISPOT).
Results—The relatively high proportion ofduodenal lymphocytes spontaneously secreting IFN-γ (IEL 3.6%; LPL1.9%) and IL-4 (IEL 1.3%; LPL 0.7%) contrasted with the very lownumbers of spontaneously IFN-γ SC and the absence of spontaneouslyIL-4 SC among peripheral blood mononuclear cells. In the basal state,both IFN-γ and IL-4 were mainly produced by CD4⁺ cells.Within the colon, only 0.2% of IEL and LPL secreted IFN-γ in thebasal state, and 0.1% secreted IL-4.
Conclusions—Compared with peripheral lymphocytessubstantial proportions of intestinal epithelial and lamina proprialymphocytes spontaneously secrete IFN-γ and/or IL-4. These cytokinesare probably involved in the normal homoeostasis of the humanintestinal mucosa. Disturbances in their secretion could play a role inthe pathogenesis of gastrointestinal diseases.