Studies of intestinal lymphoid tissue. XIV--HLA status, mucosal morphology, permeability and epithelial lymphocyte populations in first degree relatives of patients with coeliac disease

No-biopsy diagnostic approach to coeliac disease

This brief review outlines contributions that Michael Marsh and others made to understanding the structure and function of the upper small bowel mucosa and the formation of abnormalities that occur in coeliac disease (CD). He introduced his classification of lesions 30 years ago that has been widely adopted. The development and use of serological tests to screen for and diagnose CD in children and adults without the need for a small bowel biopsy in a considerable proportion is also recognised and will gain traction.

Celiac Disease: Updates on Pathology and Differential Diagnosis

Celiac disease is a gluten-triggered immune-mediated disorder, characterized by inflammation of the enteric mucosa following lymphocytic infiltration and eventually resulting in villous blunting. There have been many developments in refining diagnostic laboratory tests for celiac disease in the last decade. Biopsy-sparing diagnostic guidelines have been proposed and validated in a few recent prospective studies. However, despite these developments, histologic evaluation of duodenal mucosa remains one of the most essential diagnostic tools as it helps in the diagnosis of celiac disease in individuals who do not fulfill the biopsy-sparing diagnostic criteria and in those not responding to a gluten-free diet. Histologic evaluation also allows for the assessment of mucosal recovery after treatment and in the identification of concurrent intestinal diseases. Therefore, pathologists should be familiar with the histologic spectrum of celiac disease and need to be aware of other disorders with similar symptoms and histopathology that may mimic celiac disease. This review aims to provide pathologists with updates on celiac laboratory testing, biopsy-sparing diagnostic criteria, histopathology, complications, and differential diagnoses of celiac disease.

Diagnosing celiac disease: A critical overview

The diagnosis of celiac disease (CD) no longer rests on a malabsorptive state or severe mucosal lesions. For the present, diagnosis will always require the gold-standard of a biopsy, interpreted through its progressive phases (Marsh classification). Marsh classification articulated the immunopathological spectrum of gluten-induced mucosal changes in association with the recognition of innate (Marsh I infiltration) and T cell-based adaptive (Marsh II, and the surface re-organisation typifying Marsh III lesions) responses. Through the Marsh classification the diagnostic goalposts were considerably widened thus, over its time-course, permitting countless patients to begin a gluten-free diet but who, on previous criteria, would have been denied such vital treatment. The revisions of this classification failed to provide additional insight in the interpretation of mucosal pathology. Morever, the subclassification of Marsh 3 imposed an enormous amount of extra work on pathologists with no aid in diagnosis, treatment, or prognosis. Therefore, it should now be apparent that if gastroenterologists ignore these sub-classifications in clinical decision-making, then on that basis alone, there is no need whatsoever for pathologists to persist in reporting them. Since new treatments are under critical assessment, we might have to consider use of some other higher level histological techniques sensitive enough to detect the changes sought. A promising alternative would be to hear more voices from imaginative histopathologists or morphologists together with some more insightful approaches, involving molecular-based techniques and stem cell research may be to evaluate mucosal pathology in CD.

Evolutionary Developments in Interpreting the Gluten-Induced Mucosal Celiac Lesion: An Archimedian Heuristic

The evolving history of the small intestinal biopsy and its interpretation—and misinterpretations—are described in this paper. Certain interpretative errors in the technical approaches to histological assessment are highlighted—even though we may never be rid of them. For example, mucosal “flattening” does not reduce individual villi to their cores, as still seems to be widely believed. Neither is the mucosa undergoing an atrophic process—since it can recover structurally. Rather, the intestinal mucosa manifests a vast hypertrophic response resulting in the formation of large plateaus formed from partially reduced villi and their amalgamation with the now increased height and width of the inter-villous ridges: this is associated with considerable increases in crypt volumes. Sections through mosaic plateaus gives an erroneous impression of the presence of stunted, flat-topped villi which continues to encourage both the continued use of irrelevant “atrophy” terminologies and a marked failure to perceive what random sections through mosaic plateaus actually look like. While reviewing the extensive 40+ year literature on mucosal analysis, we extracted data on intraepithelial lymphocytes (IEL) counts from 607 biopsies, and applied receiver-operating characteristic (ROC)-curve analysis. From that perspective, it appears that counting IEL/100 enterocyte nuclei in routine haematoxylin and eosin (H&E) sections provides the most useful discriminator of celiac mucosae at histological level, with an effective cut-off of 27 IEL, and offering a very high sensitivity with few false negatives. ROC-curve analysis also revealed the somewhat lesser accuracies of either CD3⁺ or γδ⁺ IEL counts. Current official guidelines seem to be somewhat inadequate in clearly defining the spectrum of gluten-induced mucosal pathologies and how they could be optimally interpreted, as well as in promoting the ideal manner for physicians and pathologists to interact in interpreting intestinal mucosae submitted for analysis. Future trends should incorporate 3-D printing and computerised modelling in order to exemplify the subtle micro-anatomical features associated with the crypt-villus interzone. The latter needs precise delineation with use of mRNA in-section assays for brush border enzymes such as alkaline phosphate and esterase. Other additional approaches are needed to facilitate recognition and interpretation of the features of this important inter-zone, such as wells, basins and hypertrophic alterations in the size of inter-villous ridges. The 3-D computerised models could considerably expand our understandings of the microvasculature and its changes—in relation both to crypt hypertrophy, in addition to the partial attrition and subsequent regrowth of villi from the inter-villous ridges during the flattening and recovery processes, respectively.

Assessing of Celiac Disease and Nonceliac Gluten Sensitivity

The publication of papers on the topic of gluten related disorders has substantially increased over the last few years. This has motivated healthcare professionals to pay attention not only to celiac disease and wheat allergy but also to a condition termed nonceliac gluten sensitivity (NCGS). Until now this condition has been diagnosed clinically on the basis of exclusion criteria and clinical response to gluten withdrawal. In addition, recent research in this field has shown that other food components distinct from gluten are implicated in NCGS cases, thereby changing our general understanding of NCGS diagnosis in either individuals on gluten containing diets or those already following a gluten-free diet with no proper diagnostic work-up of celiac disease. With this in mind, the assessment of NCGS will require extensive knowledge of celiac disease manifestations and the laboratory tests commonly performed during diagnosis of celiac disease.

Duodenal intraepithelial lymphocytosis with normal villous architecture in pediatric patients: Mayo Clinic experience, 2000-2009

OBJECTIVES

Small bowel intraepithelial lymphocytosis (IELs) with normal villous architecture is a relatively common finding, often of uncertain significance. The aims of our study were to determine the prevalence of this finding, its clinical associations, its specificity for celiac disease (CD), and whether histologic clues exist that increase the specificity for CD in this setting, all in the pediatric population.

METHODS

The Mayo Clinic electronic pathology database was searched between January 1, 2000 and December 31, 2009 for patients younger than 18 years who had the terms "normal villi" and "increased intraepithelial lymphocytes" in their small bowel biopsy reports. All of the slides were reviewed to confirm the histologic findings. Demographic, serologic, pathologic, and clinical informations were obtained.

RESULTS

Among 1290 duodenal biopsies obtained from children during the years 2000 and 2009, 56 (4.3%) were noted to have "normal villous architecture with increased intraepithelial lymphocytes." In the 54 patients not known to have CD before biopsy, 48 (89%) had serologic testing for CD. Of these 48 patients, 9 were labeled with CD, although only 5 of 9 met the definite criteria for the diagnosis, based on a combination of serologic markers, human leukocyte antigen haplotyping, and response to gluten-free diet. No clinical features pointed to a diagnosis of CD. There was no correlation between CD and number of IELs, but patients with newly diagnosed CD were more likely to have a tip-heavy lymphocyte distribution. Other diagnoses made during the study period and in follow-up were inflammatory bowel disease (5), Helicobacter pylori infection (3), medication-related injury (10), and systemic autoimmune disorders (2).

CONCLUSIONS

Increased IELs with normal villous architecture in small bowel biopsies are clinically important in children, and are associated with a new definite diagnosis of CD in 9% of pediatric patients. Even at this low sensitivity, clinical work-up for CD is mandated in all of the patients with this finding.

Familial prevalence of celiac disease

BACKGROUND AND OBJECTIVE

Serological screening enables us to detect patients of celiac disease (CD) before they develop serious complications. This study was planned to assess the prevalence of CD in the family members of index cases by serological screening.

PATIENTS AND METHODS

A prospective study was conducted on 50 children diagnosed to be having CD. Serological screening of the family members of index cases was done and those showing positivity for the screening tests were further subjected to endoscopic duodenal biopsy for histopathological examination.

RESULTS

A total of 164 members of 50 celiac families were initially screened for antibodies. Antibody picked up 32.9% by IgG anti-gliadin (AGA), 20.7% by endomysial antibody, 19.5% by tissue transglutaminase and 14.6% IgA AGA as seropositive for CD. Endoscopic findings characteristics for CD were present in only eight family members.

CONCLUSION

Family members of CD cases represent potential cases of CD.

Antibodies to human tissue transglutaminase and alterations of vitamin D metabolism in ankylosing spondylitis and psoriatic arthritis

Both in ankylosing spondylitis (ASP) and psoriatic arthritis (PsA), osteopenia is present in one-third of women and men, whereas osteoporosis mainly affects men, even in their 30 s. Subclinical gut inflammation has been described in patients with AS or PsA. Joint involvement also occurs with other gastrointestinal diseases such as celiac disease. We tested the hypothesis, whether elevated serum levels of human anti-tissue-transglutaminase-IgA (htTG) are associated with changes in disease activity, vitamin D metabolism and bone mineral density (BMD) in patients with ASP and PsA. In a cross-sectional study, we evaluated both biochemical markers of bone turnover, BMD and htTG in 76 patients with ASP and 120 patients with PsA. A reduction of BMD in lumbar spine was determined both in ASP (42.7%) and in PsA (57.3%). Furthermore, a significantly higher prevalence of htTG was detected only in ASP (14/76). ASP patients with negative htTG status have significant higher 25-vitamin D3 levels. ASP patients with positive htTG status are younger. A positive htTG status entails the risk of a bad vitamin D supply, which should be considered in young patients since this constellation favors a reduction in bone density. The coincidence of ASP along with detection of htTG and clinically asymptomatic celiac disease as an accessory source of inflammation with a negative influence on the bone metabolism is also conceivable. Clinicians need to be aware of patients younger than 45 years with ASP, which have important implications for the correct treatment and vitamin D supplementation.

Duodenal intraepithelial lymphocytosis during Helicobacter pylori infection is reduced by antibiotic treatment

AIM

To evaluate clinical, biological and immunological features of patients with increased duodenal intraepithelial lymphocytes (IELs), and its relation to Helicobacter pylori (HP) and coeliac disease (CD).

METHODS

We have studied all patients accrued over a 4-year period with increased duodenal IELs. Those patients were recalled for biological and immunological evaluation and a second endoscopy.

RESULTS

Twenty-three from a total of 639 patients were identified and 17 of them were included in the study. The median duodenal IEL count was 59 per 100 epithelial cells. Twelve (71%) patients were HP+; eight of them received HP eradication. At the second endoscopy the duodenal IEL count was significantly lower 2 months after HP eradication (73 versus 28), while the IEL count was unchanged in those patients seronegative for HP (n = 5) or those in whom it was not eradicated (n = 4) (55 versus 55). No patient had coeliac antibodies, four expressed HLA-DQ2, lower than in the general population, and the prevalence of CD was 2% (12/639 patients).

CONCLUSION

In some cases an increased duodenal IEL count may be due to an inappropriate host response to HP. HP screening and eradication should be considered before recommending a gluten-free diet.

Proximal small-bowel mucosal villous intraepithelial lymphocytes

Small-bowel biopsies are routinely obtained from adult patients as a screening tool to evaluate the possibility of gluten sensitivity (GS). Previous morphological criteria of GS including completely flattened villi are usually absent. In the context of screening for GS, an altered distribution density pattern of villous intraepithelial lymphocytes (IELs) is probably the most sensitive morphological feature to suggest the possibility of GS and prompt the initiation of further medical evaluation. Altered villous IEL density distribution is a more sensitive screening feature than villous IEL counts. With increased small-bowel GS screening biopsies, occasional adults without GS with complete villous flattening and numerous villous IELs are encountered. These patients are usually incorrectly diagnosed with GS. However, they do not respond to a gluten-free diet and slowly improve over months.

Significance of intraepithelial lymphocytosis in small bowel biopsy samples with normal mucosal architecture

OBJECTIVES

The aim of this study was to determine the specificity of increase in intraepithelial lymphocytes (IELs) with normal villous architecture in small bowel biopsy samples for diagnosis of gluten sensitivity (GS) and its significance in the absence of GS.

METHODS

Small bowel biopsy samples from 43 patients with increased IELs and no other pathology were reviewed. Patients with prior diagnosis of GS were excluded. A group of 46 patients with normal duodenal biopsy during the same period served as controls. The clinical records of patients and controls were examined for presenting symptoms, laboratory tests, and final clinicopathological diagnosis. Immunohistochemical characterization of IELs was performed in 13 cases.

RESULTS

Four (9.3%) patients had GS based on positive IgA antiendomysial antibodies (n = 3) and favorable response to gluten-free diet (n = 4). One patient (2.2%) had partially treated tropical sprue; six patients (14%) had disorders of immune regulation including Hashimoto's thyroiditis (n = 2) and one case each of Graves' disease, rheumatoid arthritis, psoriasis, and multiple sclerosis; and six patients (14%) were on nonsteroidal anti-inflammatory drugs (NSAIDs). In contrast, none of the control subjects had GS (p = 0.05), tropical sprue, or immunoregulatory disorders (p = 0.011), and one (2.2%) was on NSAIDs (p = 0.04). Increased IELs were also observed in Crohn's disease, lymphocytic/collagenous colitis, and bacterial overgrowth, but the association did not reach statistical significance. Histological features (number and distribution of IELs, crypt mitoses) and immunophenotypic analysis of IELs did not reliably distinguish GS-related from non-GS-related causes of increased IELs.

CONCLUSIONS

Intraepithelial lymphocytosis in an otherwise normal small bowel biopsy is somewhat nonspecific, but in nearly 10% of cases can be the initial presentation of GS. Therefore all patients with this finding should be investigated for GS. Increased IELs may also be associated with autoimmune disorders and NSAIDs.

Screening for celiac disease in non-Hodgkin's lymphoma patients: a serum anti-transglutaminase-based approach

Several studies have shown the existence of an association between celiac disease (CD) and non-Hodgkin's lymphoma (NHL). Our aim was to evaluate the usefulness of the serum anti-tissue transglutaminase (anti-tTG) antibody assay in screening for CD in consecutive NHL patients. In all, 80 consecutive patients (median age 61 years) with a new diagnosis of NHL were included. To compare the frequency of CD and of positive results for the anti-tTG assay, we enrolled 500 blood donors. In all patients serum anti-tTG was determined with two different ELISA: one based on tTG from guinea pig (gp-tTG) and the other based on human recombinant t-TG (h-tTG) as the antigens. Serum anti-endomysial antibodies (EmA) were also assayed. Subjects with positive serum EmA and/or anti-tTG underwent intestinal biopsy for histology study, HLA-DQ phenotype determination, and serum anti-gliadin (AGA) assay. Eight of 80 (10%) NHL patients were positive for anti-tTG ELISA--two of these exclusively for anti-gp-tTG and six for anti-h-tTG (7.5%). None of the 80 NHL patients were positive for serum EmA. The frequency of anti-tTG positivity in the blood donor controls was 2/500 (0.4%), significantly lower than that observed in the NHL patients (P < 0.0001). Both these blood donors were found to have CD. Only in one anti-h-tTG-positive NHL patient was there intestinal mucosa atrophy, and follow-up confirmed a CD diagnosis (CD frequency in NHL patients is 1.2%; versus blood donors: P = 0.4). In all the other seven anti-tTG-positive NHL patients a normal intestinal architecture was found, although, inflammatory infiltration of the lamina propria was observed in four patients. No anti-tTG-positive NHL patients, including the subject diagnosed as having CD, had a family history of CD, and all had normal weight and no signs of malabsorption. Anti-tTG false positive results were associated with a higher frequency of serum autoantibody positivity and T-cell type NHL. In conclusion, NHL patients the anti-tTG assay often gives discordant data with the EmA assay, with a high frequency of anti-tTG false positive results for CD diagnosis.

Is a raised intraepithelial lymphocyte count with normal duodenal villous architecture clinically relevant?

BACKGROUND

A raised intraepithelial lymphocyte (IEL) count with normal villous architecture is a recognised finding in latent coeliac disease. Little information is available in cases without gluten sensitive enteropathy in adults.

AIMS

To assess the frequency of such a finding in routine practice and to determine whether it is clinically relevant.

METHODS

Patients with subjectively increased IELs as the only abnormality were identified prospectively from a routine duodenal biopsy series over a 12 month period. The biopsy specimens in these index cases were re-examined together with two controls with normal histology for each case, and three counts of IEL/100 epithelial cells were made in all samples. The index cases were then contacted and interviewed to obtain clinical information, approximately 12 months from the initial biopsy. Further data were obtained from their clinical records.

RESULTS

Fourteen of 626 (2.2%) patients who had duodenal biopsies over the 12 month period had a subjective increase in IELs with normal villous architecture. Fifteen patients with newly diagnosed gluten sensitive enteropathy were also identified during the study period. Formal counting of the index cases and controls revealed a significant difference in IELs/100 epithelial cell counts between the two (mean, 38 (SD, 6.2) v 12.4 (4.6); p < 0.0001). Three of the 14 index cases tested had a positive coeliac antibody test compared with 12 of 15 newly diagnosed patients with coeliac disease and 10 of 93 patients with normal histology. The major clinical diagnostic categories in raised IEL cases were those with positive coeliac serology (n = 3), unexplained anaemia (n = 3), and chronic liver disease (n = 3). Six of 10 patients who were interviewed had ongoing gastrointestinal symptoms one year later. Three patients had had follow up duodenal biopsies, at the discretion of their responsible clinicians, with no change in IEL counts despite the commencement of a gluten free diet in two patients.

CONCLUSION

A raised IEL count with normal villous architecture is not uncommon. Six of the 14 patients may have had latent coeliac disease. The cause in at least half of cases is not obvious at present. The finding of a raised IEL count with normal villous architecture is of sufficient clinical importance to be highlighted in routine duodenal biopsy reports.

Intestinal permeation and gastrointestinal disease

The gastrointestinal tract constitutes one of the largest sites of exposure to the outside environment. The function of the gastrointestinal tract in monitoring and sealing the host interior from intruders is called the gut barrier. A variety of specific and nonspecific mechanisms are in operation to establish the host barrier; these include luminal mechanisms and digestive enzymes, the epithelial cells together with tight junctions in between them, and the gut immune system. Disruptions in the gut barrier follow injury from various causes including nonsteroidal anti-inflammatory drugs and oxidant stress, and involve mechanisms such as adenosine triphosphate depletion and damage to epithelial cell cytoskeletons that regulate tight junctions. Ample evidence links gut barrier dysfunction to multiorgan system failure in sepsis and immune dysregulation. Additionally, contribution of gut barrier dysfunction to gastrointestinal disease is an evolving concept and is the focus of this review. An overview of the evidence for the role of gut barrier dysfunction in disorders such as Crohn's disease, celiac disease, food allergy, acute pancreatitis, non-alcoholic fatty liver disease, and alcoholic liver disease is provided, together with critical insight into the implications of this evidence as a primary disease mechanism.

Cigarette smoking and celiac sprue: a case-control study

OBJECTIVE

Environmental factors other than gliadin exposure and certain HLA haplotypes may play a role in the pathogenesis of celiac disease. Previous studies have suggested a strong inverse relationship between cigarette smoking and celiac disease. We sought to determine the relationship between celiac disease and cigarette smoking in our patient population.

METHODS

All newly diagnosed adults with biopsy-proven celiac disease evaluated at Mayo Clinic Rochester between January 1, 1993, and June 30, 1998, were identified. Three clinic patients who were matched to each case on geographical area of residence, age, gender, and calendar year of visit served as controls. Smoking information was obtained from a standard medical questionnaire that was completed by all clinic patients at the time of registration. The adjusted odds ratio for celiac disease in current and former smokers relative to nonsmokers was estimated with a matched three-to-one conditional logistic regression model.

RESULTS

A total of 82 adults with biopsy-proven celiac disease were identified. At the time of diagnosis, the proportion of current smokers was 10% in cases and 10% in controls, yielding an adjusted odds ratio of 1.5 (95% CI = 0.5-4.3). In all, 34% of cases were former smokers versus 28% of controls, yielding an odds ratio of 1.6 (95% CI = 0.8-3.2).

CONCLUSION

This case-control study was unable to detect an association between cigarette smoking and celiac disease.

Morphologic features suggestive of gluten sensitivity in architecturally normal duodenal biopsy specimens

We studied small bowel biopsy specimens with architecturally normal villi from 78 adult patients with potential gluten sensitivity (GS) and correlated them with outcome to characterize morphologic features that would allow a pathologist to suggest GS. No patient had a previous GS diagnosis. Twelve study patients had GS. The mean number of intraepithelial lymphocytes (IELs) per 20 enterocytes from the tips of 5 random villi was significantly greater in GS than non-GS biopsy samples, but the groups overlapped significantly, making the number diagnostically useful only when markedly increased. Crypt mitoses counts had similar relationships. Twelve patients had an even distribution of IELs along villus sides and over tips (3/66 [5%] non-GS patients, 9/12 [75%] GS patients). Non-GS patients had a decrescendo pattern of IELs along the sides of villi. Architecturally normal small bowel biopsy specimens with an appreciable, continuous, even distribution of IELs along the sides and tips of villi and a mean of 12 or more IELs in the tips of several villi are suggestive of GS. Pathologists should be watchful for these morphologic features in small bowel biopsy specimens to suggest GS.

Antiendomysium antibodies in Brazilian patients with celiac disease and their first-degree relatives

BACKGROUND

Literature data have shown high specificity of antiendomysial antibodies (EmA IgA) in celiac disease. The scarcity of Brazilian reports concerning this subject motivated the present study.

OBJECTIVES

To determine the sensitivity and specificity of antiendomysial IgA antibodies in Brazilian celiac patients at diagnosis and after treatment, to confirm patient adherence to a gluten-free diet and to screen first-degree relatives.

METHODS

An extensive clinical and serological study was performed by investigating the presence of these antibodies in 392 individuals from Southern Brazil. Indirect immunofluorescence using human umbilical cord as substrate was employed and the total levels of IgA were determined by turbidimetry in all groups. The study was conducted on 57 celiac patients (18 at diagnosis, 24 who adhered to a gluten-free diet and 15 with marked or slight transgression of the diet), 115 relatives of celiac patients (39 families), 94 patients with other gastrointestinal diseases, and 126 healthy individuals from the general population.

RESULTS

The results demonstrated 100% positivity for the recently diagnosed patients and for those consuming gluten, in contrast to the patients who complied with the diet (0%). In the control group one individual was positive, but refused to undergo a biopsy. In the group of other gastrointestinal diseases, one positive patient presented ulcerative colitis, Down's syndrome and epilepsy, and the intestinal biopsy was diagnostic for celiac disease. These data showed 99.3% specificity for the test. Eighteen relatives were positive for antiendomysial antibodies IgA (15.65%), and comparison with the healthy population revealed a significant difference. An intestinal biopsy was obtained from seven subjects (one with total villous atrophy and six without alterations in the mucosal architecture, but all with a high number of intra-epithelial lymphocytes).

CONCLUSIONS

The method revealed 100% sensitivity and 99.3% specificity. Because it is not an invasive method it can be used for the screening of atypical and latent forms of celiac disease to avoid serial biopsies and to control adherence to a gluten-free diet with implications in the prevention of malignancy in celiac disease.

Human leukocyte antigen class II alleles in white Brazilian patients with celiac disease

BACKGROUND

Celiac disease (CD) is a permanent gluten intolerance disorder characterized by malabsorption, intestinal mucosa villus atrophy, and crypt hyperplasia. Clinical and histologic features improve in persons consuming a gluten free diet. The pathogenesis of CD involves environmental, genetic, and immunologic factors.

METHODS

The frequencies of human leukocyte antigen (HLA) class II alleles were evaluated in white Brazilian patients who had CD and compared with those observed in healthy individuals from the same geographical area (Ribeirão Preto, São Paulo) and of similar ethnic background. Twenty-five patients with CD, 11 females and 14 males, and 91 control individuals were studied. The HLA class II alleles were typed using amplified DNA hybridized with sequence-specific primers. Statistical analysis was performed using the two-tailed Fisher exact test. The relative risk (RR), etiologic fraction (EF), and preventive fraction (PF) were also estimated. The EF represents the attributable risk for the development of CD at the population level, whereas PF represents the protective risk.

RESULTS

The frequency of the HLA-DRB1*03, HLA-DRB1*07, and HLA-DQB1*02 alleles was significantly increased in patients. The RR conferred by these alleles was 5.35, 7.15, and 10.6, respectively, and the EF was 48.7%, 44.7%, and 76%, respectively. The frequency of HLA-DQB1*06 alleles was significantly decreased in CD patients, conferring an RR of 0.08 and a PF of 48%.

CONCLUSIONS

The results show that HLA-DRB1*03, HLA-DRB1*07, and HLA-DQB1*02 alleles conferred susceptibility to CD in Brazilian patients. In contrast, HLADQB1*06 alleles conferred protection against development of the disease.

Histopathology of celiac disease

The diagnosis of celiac disease (CD) is based upon histologic findings in duodenal or jejunal biopsies. In the past few years it has turned out that the development of CD lesion in the small bowel is a dynamic process which may present in various histologic forms. At one end of the spectrum is a mucosa with normal architecture and an increase in intraepithelial lymphocytes (IEL), at the other end is the classical flat mucosa. Histologic features supporting the diagnosis of CD are architectural changes of the villi and/or crypts, an increase in lamina propria cell density and an increase in IEL counts. For diagnostic purposes and for monitoring CD patients an exact histologic classification of the histologic findings has to be given. This has become possible by using a modified Marsh classification. In the present paper the histologic presentation of CD is presented as well as the modified Marsh classification.

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.

Review article: coeliac disease and its management

Coeliac disease (CD) is a disorder of the small intestine, characterized by villous atrophy, due to an intolerance to dietary gluten in genetically susceptible individuals, which responds to gluten withdrawal. The underlying immunological mechanisms causing the disorder are still being worked out. In recent years a wide range of clinical presentations has become increasingly apparent, as has a lengthening list of associated conditions. Severe malabsorption with steatorrhoea and profound weight loss is seen infrequently, perhaps as a result of earlier diagnosis and the recognition of 'silent' and 'latent' disease. The prevalence of CD as judged by population screening with, in particular, anti-endomysial antibodies, appears to be much higher than that found with clinically apparent cases. There are a variety of well recognized complications, the commonest probably being osteopenia and osteoporosis. The marked increased risk of lymphoma can be avoided by a strict gluten-free diet. Follow-up of patients needs to be lifelong with prompt investigation of new symptoms and blood test abnormalities.

New clinical issues in celiac disease

Celiac disease is a chronic disorder of gluten sensitivity associated with a spectrum of mucosal lesions termed preinfiltrative, infiltrative, hyperplastic, destructive, and atrophic. The symptoms are not related to the degree of mucosal pathology but to the extent of the mucosal lesion. Neoplasms constitute the major complication of celiac disease, and EATCL is the most common neoplasm in this category. There is evidence that a strict gluten-free diet is protective against the complications of celiac disease; hence it is important that even the subclinical forms be diagnosed early. Small bowel biopsy remains the gold standard for diagnosis of celiac disease; however, antibody tests are a useful adjunct in deciding whom to biopsy and for screening groups at high risk before initiating a lifelong gluten-free diet.

Evidence that intestinal intraepithelial lymphocytes are activated cytotoxic T cells in celiac disease but not in giardiasis

To further define intraepithelial lymphocytes (IELs) in celiac disease (CD) and giardiasis, IELs were probed for the presence of cytolytic granules containing granzyme B (GrB) and T-cell-restricted intracellular antigen (TIA)-1. The expression of TIA-1, GrB, CD3 (T-cell-receptor-associated complex), and Leu-7 (subset of natural killer cells) was studied by a sensitive three-step immunoperoxidase technique. Stained IELs were determined quantitatively, and results were expressed as number of stained IELs per 100 epithelial cells (ECs). The relative content in labeled lamina propria lymphocytes was determined and expressed as the percentage of all lamina propria cells counted. When compared with controls, CD3+ and GrB+ IELs were significantly increased (P < 0.0004) in CD paralleled by an increase in TIA-1+ IELs (P < 0.0004). In CD, the highest numbers of IELs containing GrB were found in subjects with a flat mucosa (median, 38 IELs/100 ECs, P < 0.0004), followed by cases with shortened and blunted villi (median, 8 IELs/100 ECs, P < 0.0004) and, finally, CD patients with an intact villous architecture (median, 0.5 IELs/100 ECs, P < 0.02). Except for cases with giardiasis, Leu-7+ IELs were virtually absent in all groups as were GrB+ IELs in the controls and in subjects with giardiasis. In the lamina propria of CD subjects, GrB+ lymphocytes were also significantly increased (P < 0.001), whereas controls and cases with giardiasis were essentially free of GrB+ cytotoxic T lymphocytes. The percentage of CD3+ lamina propria lymphocytes was nearly equal in all groups. In humans and mice, extensive studies revealed a GrB expression to be absolutely restricted to activated cytotoxic T lymphocytes and natural killer cells. TIA-1, on the other hand, is considered a marker of resting T lymphocytes possessing cytolytic potential. We therefore conclude that IELs are cytotoxic T cells that are in a resting state in the normal small bowel and in giardiasis. In CD, they become activated as suggested by the GrB positivity of their granules.

Lymphocytic gastritis and associated small bowel disease: a diffuse lymphocytic gastroenteropathy?

AIM

To investigate the natural history of lymphocytic gastritis (LG) and its relation to Helicobacter pylori infection and to coeliac disease using serology, duodenal biopsy and a small intestinal permeability test.

METHOD

Twenty two patients diagnosed as having LG between 1984 and 1994 were investigated by upper gastrointestinal endoscopy at which gastric and duodenal biopsy specimens were taken for histological assessment and immunohistology. Serum was collected for measurement of anti-H pylori, anti-gliadin and anti-endomysial antibodies. A lactulose/mannitol absorption test was performed within one week of endoscopy. Control groups were studied by histology, serology and permeability tests.

RESULTS

Three patients had been recently diagnosed as having LG while 15 still had the condition after a mean of 13.9 (range two to 38) months. LG involved the antrum alone in three patients, antrum and body in seven, body alone in six, and gastric remnant in two. Gastroduodenal intraepithelial lymphocytes (IELs) were T cells and predominantly of T suppressor (CD8) type. Duodenal IELs were increased compared to age/sex matched controls with chronic gastritis. Four patients had duodenal villous atrophy. Four patients no longer had LG after a mean of 29.3 (10-70) months but had increased gastroduodenal IELs. H pylori was present in four (22%) of 18 patients with LG but H pylori serology was positive in 11 (61%) of 18. There was no difference in seropositivity when compared with age/sex matched controls with dyspepsia. Eleven of 20 patients with LG tested had abnormal lactulose/mannitol absorption (v none of 22 controls with chronic gastritis). Four patients with LG, all with villous atrophy, were seropositive for IgA endomysial antibody.

CONCLUSIONS

The persistence of LG with time, the association with increased duodenal IELs and abnormal small intestinal permeability suggests LG may be a manifestation of a diffuse lymphocytic gastroenteropathy related to sensitivity to gluten or some other agent.

T-cell responses and cellular immunity in coeliac disease

Increasing evidence points to a direct role for T cells in the mediation of the coeliac intestinal lesion. There is good evidence for increased local T-cell reactivity, manifest as increased in T-cell activation in the lamina propria and T-cell proliferation in the epithelial compartment. A likely scenario is that gluten elicits antigen-specific responses by lamina propria T helper cells, probably of the Th1 (inflammatory-mediator) subtype, leading to secretion of pro-inflammatory cytokines. Such cytokines may have direct effects on intestinal enterocytes, as well as mediating indirect effects by upregulation of MHC antigens and by enhancing the activity of cytolytic T cells. Although gluten-specific IEL responses have not been demonstrated by intraepithelial T lymphocytes (IELs), increasing evidence suggests that IELs can act as cytolytic effector cells and hence are likely to exert enteropathic effects under the influence of pro-inflammatory cytokines.

Morphology of the mucosal lesion in gluten sensitivity

Gluten sensitivity is associated with a spectrum of mucosal lesions, arbitrarily termed pre-infiltrative, infiltrative-hyperplastic, flat-destructive and atrophic-hypoplastic. Histologically and immunohistologically these lesions are all compatible with T-cell-driven events operative at a local mucosal level. They are classifiable either in terms of antibody titres (pre-infiltrative) (see Chapter 10) or by the characteristic disposition of IELs throughout the surface and crypt epithelium. From in-vivo challenges, it has been demonstrated: (i) that all these lesions comprise a dynamically interrelated series of events, culminating in the severe flat-destructive lesion; and (ii) that gluten evokes a dose-responsive infiltration of IELs (CD3+ CD8+ and TCR alpha beta + or gamma delta +) into the epithelium. Apart from that, little is known of the functions of IELs; it is possible they may have little to do with the evolving mucosal pathology of gluten sensitivity. Increasing work seems to support a view, proposed from this laboratory over 10 years ago, that the immune-mediated responses in jejunal tissue in gluten sensitivity arise in the lamina propria, in association with DR+ macrophages and an abundance of CD4(+)-activated lymphocytes. Many other inflammatory consequences flow from these interactions, involving activation of mast cells, eosinophils and neutrophils, elaboration of cytokines and other products of inflammation, and increased hyperpermeability of the microvasculature with upregulation of adhesion molecules. The result is a doubling of lamina propria volumes in the severe flat lesion. Evidence is also given to show that measurable changes in lamina propria inflammation occur with the infiltrative-hyperplastic lesion. Symptomatology is not related to the degree of proximal mucosal pathology, but to the extent of the mucosal lesion. Data, although scanty, suggests that lesional pathology involves only 30-50% of the entire small bowel mucosa. Thus, most patients, irrespective of proximal mucosal damage, have latent (or asymptomatic) gluten sensitivity. Symptom development requires additional environmental triggers, of which infection is a major contributor. It should also be noted that, while these various environmental triggers may precipitate symptomatology, they do not advance the severity of the mucosal lesion.

Intestinal permeability: an overview

The noninvasive assessment of intestinal permeability in humans has a 20-year history. Because the tests are increasingly used in clinical practice and research and because there is much controversy, we reviewed the literature and outlined the potential and possible shortcomings of these procedures. Data was obtained from personal files and from a systemic search through MEDLINE and EMBASE. The principle of the differential urinary excretion of orally administered test markers is explained with reference to the desired physicochemical properties of the markers and how the principle can be exploited to allow assessment of various other gastrointestinal functions. The use of intestinal permeability tests for diagnostic screen for small bowel disease and assessment of responses to treatment, the pathogenesis of disease, normal intestinal physiology, and the effect of drugs and toxins on the intestine is described and reviewed. The controversy surrounding the anatomic location of the permeation pathways that the markers use is highlighted. Noninvasive tests of intestinal permeability have fulfilled early promises of usefulness in clinical practice and research. There is now a need for integrated research into the basic mechanisms of regulatory control of the intestinal barrier function.

Changing clinical features of coeliac disease

The classical clinical picture of coeliac disease includes prolonged diarrhoea with failure to thrive. During the past two decades this type of active presentation of coeliac disease has decreased in many European countries, giving the impression that coeliac disease is a disappearing disease. However, this is not true. The disease can be found in older children with a more or less silent presentation. Silent coeliac disease can be detected by active screening with serological tests. Coeliac disease can be suspected in children suffering from mild gastrointestinal symptoms, such as abdominal pain, and in those with signs of nutritional deficiencies, as well as in children of first-degree relatives of already diagnosed coeliacs, patients with IgA-deficiency, patients suffering from dental enamel hypoplasia or dermatitis herpetiformis, and patients with some other disease known to be associated with coeliac disease, such as diabetes mellitus. According to the fundamental criteria of coeliac disease, the intestinal mucosa is flat when the individual is eating gluten-containing foods. However, this is not strictly true. Intolerance to gluten is obviously variable and the intestinal mucosa may be normal. This type of latent coeliac disease can be detected by analysing genetic markers, measuring antibodies in intestinal fluid or counting the density of intra-epithelial gamma/delta T cells which are increased greatly even in the latent phase of coeliac disease. Thus the general concept of the natural history of coeliac disease is changing.

Immunohistochemical changes in the jejunum in first degree relatives of patients with coeliac disease and the coeliac disease marker DQ genes. HLA class II antigen expression, interleukin-2 receptor positive cells and dividing crypt cells

The staining of HLA class II antigens, the presence of cells positive for interleukin-2 receptors, the proportion of crypt cells in mitosis in the jejunal biopsy specimens, and the dose of coeliac disease marker HLA-DQ genes were studied in 75 healthy family members of coeliac disease patients. Eleven had silent coeliac disease; in the rest the morphology of the jejunum was normal. In the specimens from family members, staining of epithelial cells with HLA-DP and -DR antibodies was more widely distributed and stronger than in those from 19 controls. Interleukin-2 receptor+ cells were seen in the epithelium of all eight specimens from subjects with silent coeliac disease, and also in 24 morphologically normal specimens from family members, but not in the 19 control specimens. The proportion of crypt cells in mitosis was increased only in the specimens from the subjects with silent coeliac disease. The staining intensity of the epithelial cells with HLA-DP and -DR antibodies, the presence of interleukin-2 receptor+ cells and the percentage of crypt cells in mitosis were significantly associated with the number of coeliac disease marker DQB genes. Many family members of patients with coeliac disease have signs of inflammation even in morphologically normal jejunum; these inflammatory changes together with coeliac disease marker DQ genes may point to latent disease in these subjects.

The interactive role of mucosal T lymphocytes in intestinal growth, development and enteropathy

Over the past 15-20 years, research has progressively focused on the mucosal T cell as the central factor in the initiation of physiological or pathological changes, first in the growth and maturation of the early (postnatal) intestine, and second in adult-type enteropathies resulting from sensitivity to either food or pathogen-derived antigens. T cell-mediated events may be measured, for example, in terms of specific immunopathologic patterns of change and injury, such as type 1 (lymphocyte infiltration), type 2 (crypt hyperplasia) and type 3 (flat-destructive), which can be recognized and quantitated microscopically; by determination of lymphocyte reactivity through secretion of interleukin-2 receptors (IL-2R) into plasma or expression by mucosal lymphocytes; by quantitation of lymphocyte subsets emigrating into inflamed tissues by immunoperoxidase-labelled monoclonal antibodies; or by the determination of T cell receptor polymorphisms. Alterations in intestinal growth, structure and function at weaning are likely to be T cell-mediated as they are analogous to the same type 1/2 lesions that reflect modulation of adult mucosal architecture in food and parasite-induced hypersensitivity reactions. Enteropathies associated with HIV infection and T cell deficiency display a milder degree of villous flattening and impaired crypt hyperplasia than that typical of gluten-sensitivity, suggesting a reversion to lesser degrees of mucosal pathology (type 1/2). Clearly more information will accrue; meanwhile the remarks in this brief survey should provide a firm basis whereby clinician and scientist can meet, and together recognize and further dissect the modulatory effect of T lymphocytes on mucosal structure and function.

Activation of mucosal V beta 3+ T cells and tissue damage in human small intestine by the bacterial superantigen, Staphylococcus aureus enterotoxin B

Staphylococcus aureus enterotoxin B (SEB) was added to explants of fetal human intestine in organ culture or administered into the lumen of fetal small intestine prior to culture. Both routes produced a massive increase in lamina propria T cells expressing V beta 3, and to a lesser extent, those expressing V beta 5 and V beta 12. SEB-activated lamina propria T cells produced interleukin-2 and interferon-gamma and T cell activation was accompanied by tissue damage, which was inhibited by FK506.

The immune response to hepatitis B vaccine in humans: inheritance patterns in families

We have recently shown that the human antibody response to the hepatitis B virus surface antigen (HBsAg) vaccine is major histocompatibility complex (MHC) associated. In studies of nonresponders to the vaccine, we found an increased incidence of individuals homozygous for human histocompatibility leukocyte antigen (HLA) proteins associated with the extended (conserved) haplotype [HLA-B8,SC01,DR3]. In later prospective vaccination trials, we showed that none of five individuals homozygous for this haplotype developed more than 1,300 radioimmunoassay (RIA) units of antibody (mean, 467 RIA units), while all heterozygotes made at least 2,500 RIA units (mean antibody level, 15,608 units). Our results suggested that [HLA-B8,SC01,DR3] lacks an immune response gene for HBsAg, and that response is inherited in a dominant fashion. To provide further evidence for this hypothesis, we have now analyzed the results of HBsAg immunization in families. 43 members of 10 families were immunized with the hepatitis B vaccine, including seven families where at least one member bore the haplotype [HLA-B8,SC01,DR3], and three families where one member had already received, but failed to respond to, the vaccine. In two of these three families, the presence of [HLA-B8,SC01,DR3] was subsequently found. Of nine MHC-identical sibling pairs in the study, both members of eight pairs had similar antibody responses (five nonresponder and three responder pairs). In all families with such sibling pairs, including the discordant pair, rank-ordering members by antibody level demonstrated that no relative's value came between the sibling pair values. Furthermore, of nine [HLA-B8,SC01,DR3]-haplotype-homozygous individuals, six were nonresponders, and two others had only low-normal responses. [HLA-B8,SC01,DR3]-heterozygous family members always had higher levels of antibody than their homozygous relatives. Linkage analysis of nonresponse to HLA haplotypes revealed a maximum likelihood LOD (logarithm of the odds) score of 6.3 at a recombination fraction of 0.1. The MHC association with lack of antibody response to HBsAg was not seen with tetanus immunization, where 1 of 20 HBsAg responders and 1 of 21 poor or nonresponders had tetanus titers of less than 1:512; both tetanus nonresponders were [HLA-B8,SC01,DR3] heterozygotes. Our results indicate that: (a) response to the HBsAg vaccine is MHC linked, and inherited in a dominant fashion; (b) an abnormal or missing immune response (Ir) gene for HBsAg is a characteristic of most examples of the extended haplotype [HLA-B8,SC01,DR3]; and (c) other haplotypes also have abnormal or missing Ir genes for HBsAg.

Increase in gamma/delta T cell receptor bearing lymphocytes in normal small bowel mucosa in latent coeliac disease

A jejunal biopsy specimen from an asymptomatic 35 year old man was studied because of a low serum titre of reticulin antibody and the finding of coeliac disease in his son. In this specimen villous structure was quite normal as was the total number of intraepithelial lymphocytes, but the number of gamma/delta T cell receptor bearing lymphocytes was 10 times higher than the mean in control subjects. Two years later a further biopsy specimen was obtained because of clinical symptoms and an increased titre of reticulin antibody. This specimen showed villous atrophy with crypt hyperplasia and increased infiltration of intraepithelial lymphocytes compatible with coeliac disease. A control biopsy specimen taken during gluten free diet showed normalisation of the villous architecture. Latent coeliac disease may be characterised by an increase in gamma/delta positive cells similar to that seen in established coeliac disease.

Abnormal permeability precedes the development of a gluten sensitive enteropathy in Irish setter dogs

Intestinal permeability to 51Cr-EDTA was examined during the development of gluten sensitive enteropathy in dogs bred from affected Irish setters and reared on a normal wheat containing diet. Comparisons were made with litter mates reared on a gluten free diet and with a control group of age matched, clinically healthy Irish setters reared on the normal diet. Studies at 4, 6, 8, and 12 months of age were correlated with morphometric and biochemical examinations of peroral jejunal biopsy specimens. Permeability was increased at all ages in the group fed gluten free diet compared with control dogs, although there were no differences in villus height, intraepithelial lymphocyte density, and alkaline phosphatase activity. At four months, permeability in the normal diet group was greater than in controls, although comparable with that in the gluten free diet group. Permeability in the normal diet group increased further in conjunction with the development of partial villus atrophy and reduced alkaline phosphatase activity, and by 12 months permeability was significantly greater than in their gluten free diet litter mates and the control dogs. The findings suggest that an underlying permeability abnormality may be involved in the pathogenesis of gluten sensitive enteropathy in Irish setter dogs.

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.

Grains of truth: evolutionary changes in small intestinal mucosa in response to environmental antigen challenge

Images

Studies of intestinal lymphoid tissue. XV. Histopathologic features suggestive of cell-mediated reactivity in jejunal mucosae of patients with dermatitis herpetiformis

Peroral jejunal mucosae from 32 patients with untreated DH were quantitated by computerized image-analysis in terms of surface (villous) and crypt epithelial volumes and their corresponding lymphoid infiltrates, together with lamina propria volumes, neutrophils, mast cells and basophils. Three distinctive patterns of mucosal abnormality were identified: (a) the "infiltrative" lesion in which normal villus epithelium was infiltrated by small, non-mitotic lymphocytes: (b) the "hyperplastic" type, in which crypt hyperplasia and hypertrophy together with lymphoid infiltration of crypt epithelium was additional to the "infiltrative" lesion, and in which lamina propria was swollen and contained modest neutrophilic and basophilic infiltration: and (c) the "destructive" lesion, identical to the classic celiac sprue appearances with effacement of villi, crypt hypertrophy and more intensive polymorph infiltration of lamina propria. These progressive lesions parallel those seen in experimental graft-versus-host reactions, so that the entire spectrum of changes described here in DH appear consistent with a cell-mediated mucosal response to gluten. The extent of mucosal abnormality was unrelated to individual HLA status.