Immunologic and intestinal permeability tests as predictors of relapse during gluten challenge in childhood coeliac disease

Small Bowel Permeability in Diagnosis of Celiac Disease and Monitoring of Compliance of a Gluten-Free Diet (Gut Permeability in Celiac Disease)

Background & Aim: Celiac disease is an autoimmune disease with the damage of the intestinal barrier. The aim of study was to measure gut permeability in patients with untreated celiac disease and during treatment with a gluten free diet. Methods: 30 patients with celiac disease before and during treatment with gluten-free diet were investigated, 30 patients without organic damage of the gastrointestinal tract served as control. Small bowel permeability was measured using lactulose/mannitol and lactulose/D-xylose ratios. The saccharides were examined in the 5 hours collected urine using capillary gas chromatography. Results: Small bowel permeability (indices lactulose/mannitol and/or lactulose/xylose) increased significantly in patients with untreated celiac disease. 23 patients were followed up before and during treatment with a gluten-free diet 2-6 months after beginning of this treatment and small bowel permeability (measured as indices lactulose/ mannitol and/or lactulose/xylose) significantly decreased. Conclusion: Small bowel permeability test is a non-invasive test suitable for the diagnosis of celiac disease and monitoring of compliance to a gluten-free diet in these patients.

The clinical response to gluten challenge: a review of the literature

The aim of this review was to identify, evaluate and summarize all relevant studies reporting on the clinical response to gluten challenge by adult or pediatric patients with suspected or diagnosed coeliac disease (CD) on a gluten-free diet. We evaluated the effect of gluten challenge on changes in symptoms, intestinal mucosa histology, and serum antibodies. A systematic electronic search was performed for studies published as of 1966 using PubMed and Scopus databases. In the reviewed studies, doses ranged from 0.2 to 30 g/day of wheat gluten or comprised a gluten-containing diet. The onset of symptoms upon gluten intake varied largely from days to months and did not parallel serum antibody or histological changes. Within 3 months of gluten challenge, 70%-100% of pediatric CD patients became positive for AGA-IgA and EMA-IgA antibodies and 50%-70% for AGA-IgG. A limited number of trials suggest that no more than half of adult patients developed positive AGA-IgA, EMA-IgA, tTG-IgA or DGP-IgA/IgG titers. Approximately 50%-100% of pediatric and adult patients experienced mucosal relapse of gluten provocation within 3 months, which was preceded by increased mucosal intra-epithelial lymphocytes within several days of challenge. A 3-month high-dose gluten challenge should be suitable to diagnose the majority of CD patients. In some cases prolonged challenge may be needed to verify diagnosis. Combination testing for antibodies and mucosal histology may fasten the diagnosis.

Nuclear fluorescence serum reactivity on monkey oesophagus: a new antibody for the follow-up of coeliac disease?

We have identified previously a nuclear fluorescence reactivity (NFR) pattern on monkey oesophagus sections exposed to coeliac disease (CD) patients' sera positive for anti-endomysium antibodies (EMA). The aim of the present work was to characterize the NFR, study the time-course of NFR-positive results in relation to gluten withdrawal and evaluate the potential role of NFR in the follow-up of CD. Twenty untreated, 87 treated CD patients and 15 healthy controls were recruited and followed for 12 months. Their sera were incubated on monkey oesophagus sections to evaluate the presence of NFR by indirect immunofluorescence analysis. Duodenal mucosa samples from treated CD patients were challenged with gliadin peptides, and thus the occurrence of NFR in culture supernatants was assessed. The NFR immunoglobulins (Igs) reactivity with the nuclear extract of a human intestinal cell line was investigated. Serum NFR was present in all untreated CD patients, persisted up to 151 ± 37 days from gluten withdrawal and reappeared in treated CD patients under dietary transgressions. Serum NFR was also detected in two healthy controls. In culture supernatants of coeliac intestinal mucosa challenged with gliadin peptides, NFR appeared before EMA. The Igs responsible for NFR were identified as belonging to the IgA2 subclass. The NFR resulted differently from EMA and anti-nuclear antibodies, but reacted with two nuclear antigens of 65 and 49 kDa. A new autoantibody, named NFR related to CD, was described. Furthermore, NFR detection might become a valuable tool in monitoring adherence to a gluten-free diet and identifying slight dietary transgressions.

Safety for patients with celiac disease of baked goods made of wheat flour hydrolyzed during food processing

BACKGROUND & AIMS

Celiac disease (CD) is characterized by an inflammatory response to wheat gluten, rye, and barley proteins. Fermentation of wheat flour with sourdough lactobacilli and fungal proteases decreases the concentration of gluten. We evaluated the safety of daily administration of baked goods made from this hydrolyzed form of wheat flour to patients with CD.

METHODS

Patients were randomly assigned to consumption of 200 g per day of natural flour baked goods (NFBG) (80,127 ppm gluten; n = 6), extensively hydrolyzed flour baked goods (S1BG) (2480 ppm residual gluten; n = 2), or fully hydrolyzed baked goods (S2BG) (8 ppm residual gluten; n = 5) for 60 days.

RESULTS

Two of the 6 patients who consumed NFBG discontinued the challenge because of symptoms; all had increased levels of anti-tissue transglutaminase (tTG) antibodies and small bowel deterioration. The 2 patients who ate the S1BG goods had no clinical complaints but developed subtotal atrophy. The 5 patients who ate the S2BG had no clinical complaints; their levels of anti-tTG antibodies did not increase, and their Marsh grades of small intestinal mucosa did not change.

CONCLUSIONS

A 60-day diet of baked goods made from hydrolyzed wheat flour, manufactured with sourdough lactobacilli and fungal proteases, was not toxic to patients with CD. A combined analysis of serologic, morphometric, and immunohistochemical parameters is the most accurate method to assess new therapies for this disorder.

Gluten-free sourdough wheat baked goods appear safe for young celiac patients: a pilot study

OBJECTIVES

This study was aimed at showing the safety, for young patients with celiac disease (CD), of sweet baked goods made of wheat flour, which was rendered gluten-free during sourdough fermentation.

METHODS AND RESULTS

As shown by R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay (ELISA), selected lactobacilli and fungal proteases, routinely used in bakeries, degraded gluten to <10 ppm during sourdough fermentation. The resulting flour was mainly a mixture of water-/salt-soluble low-size peptides and free amino acids. Gliadin and glutenin fractions extracted from the pepsin-trypsin (PT) digest of the fermented wheat flour induced the expression of interferon (IFN)-γ at the level comparable with the negative control. After fermentation, the wheat flour was spray dried and used for making sweet baked goods. Eight patients with CD in remission were enrolled for the clinical challenge, and they daily consumed 200 g of sweet baked goods equivalent to 10 g of native gluten. Hematology, serology (total serum IgA, IgG and IgA antigluten, endomysial and tissue transglutaminase IgA antibodies), and intestinal permeability analyses were carried out over time. One patient interrupted the trial after 15 days and another after 30 days only due to difficulties in the compliance of the daily consumption. All of the other patients showed normal values of hematology, serology, and intestinal permeability during 60 days of challenge.

CONCLUSIONS

This study showed that a wheat flour-fermented product, having gluten completely degraded, is not toxic for patients with CD. Nevertheless, these foods should not be recommended for patients with celiac disease until a formal trial has been done.

Alterations of the intestinal barrier in patients with autism spectrum disorders and in their first-degree relatives

OBJECTIVES

Intestinal permeability (IPT) was investigated in patients with autism as well as in their first-degree relatives to investigate leaky gut hypothesis. Faecal calprotectin (FC) was also measured in patients with autism, either with or without gastrointestinal symptoms, and in their first-degree relatives.

PATIENTS AND METHODS

IPT results, assessed by means of the lactulose/mannitol test, were compared with adult and child controls and with FC values.

RESULTS

A high percentage of abnormal IPT values were found among patients with autism (36.7%) and their relatives (21.2%) compared with normal subjects (4.8%). Patients with autism on a reported gluten-casein-free diet had significantly lower IPT values compared with those who were on an unrestricted diet and controls. Gastrointestinal symptoms were present in 46.7% of children with autism: constipation (45.5%), diarrhoea (34.1%), and others (alternating diarrhoea/constipation, abdominal pain, etc: 15.9%). FC was elevated in 24.4% of patients with autism and in 11.6% of their relatives; it was not, however, correlated with abnormal IPT values.

CONCLUSIONS

The results obtained support the leaky gut hypothesis and indicate that measuring IPT could help to identify a subgroup of patients with autism who could benefit from a gluten-free diet. The IPT alterations found in first-degree relatives suggest the presence of an intestinal (tight-junction linked) hereditary factor in the families of subjects with autism.

Mechanism of degradation of immunogenic gluten epitopes from Triticum turgidum L. var. durum by sourdough lactobacilli and fungal proteases

As shown by R5 antibody-based sandwich and competitive enzyme-linked immunosorbent assay (ELISA), selected sourdough lactobacilli, in combination with fungal proteases, hydrolyzed gluten (72 h at 37 degrees C) of various cultivars of Triticum turgidum L. var. durum to less than 20 ppm. Complementary electrophoretic, chromatography, and mass spectrometry techniques were used to characterize the gluten and epitope hydrolysis. Nine peptidases were partially purified from the pooled cytoplasmic extract of the sourdough lactobacilli and used to hydrolyze the 33-mer epitope, the most immunogenic peptide generated during digestion of Triticum species. At least three peptidases (general aminopeptidase type N [PepN], X-prolyl dipeptidyl aminopeptidase [PepX], and endopeptidase PepO) were necessary to detoxify the 33-mer without generation of related immunogenic epitopes. After 14 h of incubation, the combination of all or at least six different peptidases totally hydrolyzed the 33-mer (200 mM) into free amino acids. The same results were found for other immunogenic epitopes, such as fragments 57-68 of alpha 9-gliadin, 62-75 of A-gliadin, and 134-153 of gamma-gliadin. When peptidases were used for fermentation of durum wheat semolina, they caused the hydrolysis of gluten to ca. 2 ppm. The in vivo digestion was simulated, and proteins/peptides extracted from pepsin-trypsin (PT) digestion of durum wheat semolina fermented with selected sourdough lactobacilli induced the expression of gamma interferon and interleukin 2 at levels comparable to those of the negative control. Durum wheat semolina fermented with sourdough lactobacilli was freeze-dried and used for making Italian-type pasta. The scores for cooking and sensory properties for this pasta were higher that those of conventional gluten-free pasta.

Possible drug targets for celiac disease

Celiac disease (CD) is an intestinal disorder caused by an altered immune response against wheat gluten, a common dietary antigen, and related cereal proteins. Both CD4+ and CD8+ T cells have a role in inducing the intestinal damage, although recent studies have also pinpointed the involvement of the innate immune response in CD pathogenesis. So far, the only available treatment for CD is the strict avoidance of gluten in the diet, but the poor compliance and the associated complications demand alternative therapies. During the last decade, the knowledge of genetic, molecular and cellular mechanisms leading to CD pathogenesis made great progress. The improved understanding of gluten peptides activating either adaptive or innate immune response, of HLA restriction molecules, as well as of cytokines that mediate most of the inflammatory reactions, opens several new promising perspectives for therapeutic intervention. This review discusses both molecular and cellular strategies to treat CD, including the use of proteolytic enzymes active on gluten peptides, antibodies neutralising IL-15 and IFN-gamma, drugs targeting HLA, regulatory cytokines and T cells.

Primary sclerosing cholangitis and hepatitis C virus infection

Two cases of primary sclerosing cholangitis with hepatic C virus infection in a 62-year-old man and a 60-year-old woman are presented. The infection in the man was eradicated with interferon therapy in 1992. Seven years thereafter, endoscopic retrograde cholangiography revealed a diffuse 2.5-cm-long stenotic lesion in the common bile duct which was consequently resected. Histological examination of the resected specimen revealed proliferation of epithelial cells, plasma cell infiltration, and fibrosis in the submucosal layer of the common bile duct. The human leukocyte antigen DR loci were 2 and 9. In the woman, a 6-month course of interferon therapy in 1992 failed to eradicate the infection. Cholangiography in 1999 revealed multiple narrowings and dilatations of intra- and extrahepatic bile ducts. Ultrasound guided biopsy of the liver in 1992 had revealed onionskin lesions around the bile duct epithelium in the portal tract. The human leukocyte antigen DR locus was 2. From these findings, the 2 cases were diagnosed as primary sclerosing cholangitis. Further studies may provide insights into the relation between the pathogenesis of the disease and the infection.

Permeability, zonulin production, and enteropathy in dermatitis herpetiformis

BACKGROUND & AIMS

Dermatitis herpetiformis (DH) is characterized by variable degrees of enteropathy and increased intestinal permeability. Zonulin, a regulator of tight junctions, seems to play a key role in the altered intestinal permeability that characterizes the early phase of celiac disease. Our aim was to assess both intestinal permeability and serum zonulin levels in a group of patients with DH having variable grades of enteropathy.

METHODS

We studied 18 DH patients diagnosed on the basis of characteristic immunoglobulin (Ig)A granular deposits in the dermal papillae of noninvolved skin. Results were compared with those of classic celiac patients, patients with linear IgA dermatosis, and healthy controls.

RESULTS

According to Marsh's classification, 5 patients had no evidence of enteropathy (type 0), 4 patients had type II, 2 patients had type IIIb damage, and 7 patients had a more severe lesion (type IIIc). Intestinal permeability (lactulose/mannitol ratio [lac/man]) was abnormal in all patients with DH. Patients with more severe enteropathy had significantly greater permeability ( P < .05). The serum zonulin concentration (enzyme-linked immunosorbent assay) for patients with DH was 2.1 +/- .3 ng/mg with 14 of 16 (87.5%) patients having abnormally increased values. In contrast, patients with linear IgA dermatosis had normal histology, normal intestinal permeability, and negative celiac serology.

CONCLUSIONS

Increased intestinal permeability and zonulin up-regulation are common and concomitant findings among patients with DH, likely involved in pathogenesis. Increased permeability can be observed even in patients with no evidence of histologic damage in biopsy specimens. Patients with linear IgA dermatosis appear to be a distinct population with no evidence of gluten sensitivity.

Ultrastructural mucosal alterations and increased intestinal permeability in non-celiac, type I diabetic patients

BACKGROUND

Increased intestinal permeability was described in several intestinal auto-immune conditions. There are very few and contradictory reports about type I diabetes mellitus, an auto-immune condition sometimes associated with celiac disease.

AIMS

To investigate intestinal permeability in type I diabetes mellitus patients with no concomitant celiac disease, with a comparison to ultra-structural aspects of duodenal mucosa.

PATIENTS

46 insulin dependent diabetes mellitus, non-celiac, patients (18 females and 28 males, mean age 15.8 +/- 5.3 [S.D.] years) were enrolled. The mean duration of the disease was 5.7 years.

METHODS

The morphological aspect of the small bowel mucosa, at standard light microscopy and electron transmission microscopy, along with intestinal permeability (by lactulose/mannitol test) were studied. Lactulose and mannitol urinary excretion were determined by means of high performance anion exchange chromatography-pulsed amperometric detection.

RESULTS

The lactulose/mannitol ratio was 0.038 [0.005-0.176] (median and range) in 46 patients compared to 0.014 [0.004-0.027] in 23 controls: insulin dependent diabetes mellitus group values being significantly higher than those of the controls (P < 0.0001, Mann-Whitney test). Eight insulin dependent diabetes mellitus patients underwent endoscopy and biopsies were analysed by means of light microscopy and transmission electron microscopy. At the light microscopy level, none of the biopsy samples showed any sign of atrophy nor inflammation, whereas transmission electron microscopy analysis showed remarkable ultra-structural changes in six out of the eight patients. Four parameters were evaluated: height and thickness of microvilli, space between microvilli and thickness of tight junctions.

CONCLUSIONS

This alteration of intestinal barrier function in non-celiac type I diabetes mellitus, frequently associated with mucosal ultra-structural alterations, could suggest that a loss of intestinal barrier function can be a pathogenetic factor in a subset of insulin dependent diabetes mellitus patients.

Fasting plasma nitric oxide products in coeliac disease

OBJECTIVES

In coeliac disease, inducible nitric oxide synthase activity in the duodenal mucosa is greatly increased, resulting in increased production of nitric oxide. We investigated whether this resulted in increased plasma concentrations of its stable end products (nitrate/nitrite: NOx).

METHODS

Fasting plasma NOx was determined in 66 patients attending for upper gastrointestinal endoscopy. Of these, 21 had coeliac disease (nine were on a gluten-free diet). The remainder had a variety of other gastrointestinal disorders. NOx was determined using the Griess reaction. Distal duodenal biopsies for coeliac patients were graded according to the Marsh score.

RESULTS

Patients with untreated coeliac disease had a higher fasting NOx concentration (mean 117.5 microM) than either those with coeliac disease taking a gluten-free diet (mean 71.2 microM) or those with other diseases (mean 33.5 microM; one-way analysis of variance, P < 0.001). Coeliac patients with higher fasting NOx concentrations had more marked histological changes (P < 0.05).

CONCLUSION

Fasting plasma NOx is significantly elevated in untreated coeliac disease and correlates with histological grade. The potential clinical utility of serial NOx measurements to monitor improvement on a gluten-free diet requires further study.

Reliability of antitransglutaminase antibodies as predictors of gluten-free diet compliance in adult celiac disease

OBJECTIVE

Strict lifelong compliance to a gluten-free diet (GFD) minimizes the long-term risk of mortality, especially from lymphoma, in adult celiac disease (CD). Although serum IgA antitransglutaminase (IgA-tTG-ab), like antiendomysium (IgA-EMA) antibodies, are sensitive and specific screening tests for untreated CD, their reliability as predictors of strict compliance to and dietary transgressions from a GFD is not precisely known. We aimed to address this question in consecutively treated adult celiacs.

METHODS

In a cross-sectional study, 95 non-IgA deficient adult (median age: 41 yr) celiacs on a GFD for at least 1 yr (median: 6 yr) were subjected to 1) a dietician-administered inquiry to pinpoint and quantify the number and levels of transgressions (classified as moderate or large, using as a cutoff value the median gluten amount ingested in the overall noncompliant patients of the series) over the previous 2 months, 2) a search for IgA-tTG-ab and -EMA, and 3) perendoscopic duodenal biopsies. The ability of both antibodies to discriminate celiacs with and without detected transgressions was described using receiver operating characteristic curves and quantified as to sensitivity and specificity, according to the level of transgressions.

RESULTS

Forty (42%) patients strictly adhered to a GFD, 55 (58%) had committed transgressions, classified as moderate (< or = 18 g of gluten/2 months; median number 6) in 27 and large (>18 g; median number 69) in 28. IgA-tTG-ab and -EMA specificity (proportion of correct recognition of strictly compliant celiacs) was 0.97 and 0.98, respectively, and sensitivity (proportion of correct recognition of overall, moderate, and large levels of transgressions) was 0.52, 0.31, and 0.77, and 0.62, 0.37, and 0.86, respectively. IgA-tTG-ab and -EMA titers were correlated (p < 0.001) to transgression levels (r = 0.560 and R = 0.631, respectively) and one to another (p < 0.001) in the whole patient population (r = 0.834, N = 84) as in the noncompliant (r = 0.915, N = 48) group. Specificity and sensitivity of IgA-tTG-ab and IgA-EMA for recognition of total villous atrophy in patients under a GFD were 0.90 and 0.91, and 0.60 and 0.73, respectively.

CONCLUSIONS

In adult CD patients on a GFD, IgA-tTG-ab are poor predictors of dietary transgressions. Their negativity is a falsely secure marker of strict diet compliance.

Gluten sensitivity in a subset of children with insulin dependent diabetes mellitus

OBJECTIVES

The association between celiac disease and insulin dependent diabetes mellitus (IDDM) is well established. Rectal gluten challenge has been used in patients with celiac disease and in first degree relatives as a tool to assess the mucosal immune response to gluten. The aim of this study was to assess the mucosal immune response to gluten in IDDM children by rectal gluten challenge.

METHODS

Rectal biopsy specimens were obtained from 19 children with IDDM before and 6 h after rectal challenge with 2 g of a peptic tryptic digest of gliadin. A total of 16 treated celiac patients and 10 control subjects were also investigated. Epithelium and lamina propria CD3(+) and gamma delta(+) lymphocytes were counted with reference to a standard reference area of muscularis mucosae (10(4) microm(2)).

RESULTS

After a local instillation of gliadin, a significant (>mean + 1 SD) percentage increment of lamina propria and epithelium CD3(+) and of lamina propria and epithelium gamma delta(+) lymphocytes was observed in five IDDM children, as compared to 11 and 13 celiac patients and one and two controls, respectively. A discriminant analysis allowed correct classification of 100% of patients with celiac disease and controls. The same analysis classified four of 19 IDDM children in the group of celiac patients. The positivity was associated with normal serology (antigliadin antibody, antiendomysial antibody, and antitissue transglutaminase antibodies) and a morphologically normal jejunal mucosa. All four patients had HLA-DQ alleles associated with celiac disease.

CONCLUSIONS

Approximately 20% of IDDM children react to rectal instillation of gliadin. Long term follow-up is necessary to establish whether these subjects are at increased risk for developing celiac disease.

Even small amounts of gluten cause relapse in children with celiac disease

BACKGROUND

Previously, a gluten challenge was customary to establish the diagnosis of celiac disease in children. There are no clear recommendations on how to perform this challenge or what markers to rely on for timing the biopsy after the challenge. The authors' aim was to monitor gluten intake, clinical symptoms, and antibody kinetics to evaluate the influence of gluten exposure during the challenge.

METHODS

Twenty-five children under investigation for suspected celiac disease were challenged. One child was excluded because blood samples, food records, or biopsy was lacking. Median age at the postchallenge biopsy was 3.8 (2.7-8.8) years. The families kept daily records of the children's gluten intake and of symptoms that occurred. Blood samples were taken monthly for analysis of antigliadin and endomysium antibodies and total immunoglobulin A (IgA). A third biopsy was performed when clinical symptoms suggested a relapse.

RESULTS

All 24 children showed deterioration of the mucosa or elevated antibodies during gluten challenge. Median duration of the challenge was 13 (5-51) weeks, and mean gluten intake was 1.7 (0.2-4.3) g/d and 0.1 (0.02-0.26) g/kg daily.

CONCLUSIONS

Gluten intake during the challenge varied widely, and the parents were unable to give their children the recommended amount. Despite the small amounts given, all children showed signs of relapse at a clinical, laboratory, or histologic level. Much smaller amounts of gluten than previously suggested seem sufficient to cause relapse during gluten challenge in children.

Intestinal permeability in Crohn's disease patients and their first degree relatives

BACKGROUND

Family studies suggested that an altered intestinal permeability plays a role in the genesis of Crohn's disease.

AIM

Aim of the present study was to investigate a possible genetic alteration of the mucosal barrier in Crohn's disease.

SUBJECTS

16 Crohn's disease patients and 26 of their cohabiting first degree relatives were studied.

METHODS

To investigate intestinal permeability, Cellobiose/Mannitol test was administered to both groups.

RESULTS

In the two groups, we found that the median intestinal permeability values were higher and statistically different from those obtained in 32 healthy control subjects as well as in five healthy control families. Six (37.5%) Crohn's disease patients and three (11.5%) of their first degree relatives showed increased individual intestinal permeability values. Intestinal permeability alteration in Crohn's disease patients was unrelated to sex, age, disease activity, localisation, duration, treatment schedule, as well as to serum anti-Saccharomyces cervisiae antibody positivity in a pilot study conducted in 7 Crohn's disease patients; anti-Saccharomyces cervisiae antibody values were negative in all 10 first degree relatives investigated.

CONCLUSIONS

These findings demonstrate the increase in IP in 37% of the patients and in 11% of their relatives. More extensive investigation of the correlation between ASCA alterations and IP will be needed in both patients with Crohn's disease and their relatives.

Is lactobacillus GG helpful in children with Crohn's disease? Results of a preliminary, open-label study

BACKGROUND

Lactobacillus GG is a safe probiotic bacterium known to transiently colonize the human intestine. It has been found to be useful in treatment of several gastrointestinal conditions characterized by increased gut permeability. In the current study, the efficacy of Lactobacillus GG was investigated in children with Crohn's disease.

METHODS

In this open-label pilot evaluation viewed as a necessary preliminary step for a possible subsequent randomized placebo-controlled trial, four children with mildly to moderately active Crohn's disease were given Lactobacillus GG (10(10) colony-forming units [CFU]) in enterocoated tablets twice a day for 6 months. Changes in intestinal permeability were measured by a double sugar permeability test. Clinical activity was determined by measuring the pediatric Crohn's disease activity index.

RESULTS

There was a significant improvement in clinical activity 1 week after starting Lactobacillus GG, which was sustained throughout the study period. Median pediatric Crohn's disease activity index scores at 4 weeks were 73% lower than baseline. Intestinal permeability improved in an almost parallel fashion.

CONCLUSIONS

Findings in this pilot study show that Lactobacillus GG may improve gut barrier function and clinical status in children with mildly to moderately active, stable Crohn's disease. Randomized, double-blind, placebo-controlled trials are warranted for a final assessment of the efficacy of Lactobacillus GG in Crohn's disease.

Celiac disease and human leukocyte antigen genotype: accuracy of diagnosis in self-diagnosed individuals, dosage effect, and sibling risk

BACKGROUND

Celiac disease is an autoimmune disorder of the small intestine characterized by intolerance to gluten. Traditionally, diagnosis is made by intestinal biopsy. Testing for immunoglobulin (Ig) A endomysial antibodies in the serum also is used for diagnosis. Biopsy and serology revert to normal with adherence to a gluten-free diet. Often, after an index case is diagnosed, siblings with symptoms adhere to a gluten-free diet without biopsy or serologic confirmation. More than 90% of patients with celiac disease have the human leukocyte antigen (HLA) DQA1*0501-DQB1*0201 genotype. Non-HLA genes also have been implicated.

METHODS

One hundred ninety-five individuals with confirmed or suspected celiac disease were identified in 73 families affected by the disease. IgA endomysial antibody testing was performed for all symptomatic family members who did not have biopsy-confirmed diagnoses. DNA samples were genotyped at D6S276 and the HLA class II loci DQA and DQB.

RESULTS

At the time sampling was begun in families, 88 of 177 (49.7%) individuals were self-diagnosed and adhering to a gluten-free diet. Ninety percent (91/101) of confirmed cases (biopsy or serology) had at least 1 copy of the DQA1*0501-DQB1*0201 genotype, whereas only 67% (46/69) of cases self-diagnosed (adherence to gluten-free diet without confirmation) had at least 1 copy. Of confirmed cases, 61% carried two copies of DQB*0201. It is estimated that the HLA association and other unlinked genes contribute approximately equally to the sibling risk of celiac disease.

CONCLUSIONS

A dosage effect of DQB1*0201 may be associated with an increased risk of celiac disease. Self-diagnosis of celiac disease is as common as confirmed diagnosis in families in the United States. Diagnosis of celiac disease on the basis of clinical response to gluten restriction is inaccurate. With long-term adherence to a gluten-free diet, serologic test results are likely to be negative. Based on HLA genotype, approximately one third of self-diagnosed individuals are unlikely to have celiac disease. However, it is not possible to determine which individuals consuming a gluten-free diet have the disease. Therefore, before starting a gluten-free diet, serologic screening and biopsy confirmation are necessary.

Serologic testing for celiac disease in the United States: results of a multilaboratory comparison study

The aim of this study was to compare the efficiencies of six reference laboratories for serologic testing for celiac disease. Serum from 20 patients with untreated celiac disease and from 20 controls was thawed, divided, and distributed to each participating laboratory, which performed endomysial antibody tests. Five laboratories also performed antigliadin antibody tests. Sensitivity for endomysial antibody immunoglobulin A (IgA) varied from 57 to 90%. In all laboratories, the specificity for celiac disease was 100%. The sensitivity and specificity for both IgA and IgG antigliadin antibody varied significantly. When results from all three tests were combined in each laboratory, sensitivity was 90 to 100%. The specificity for endomysial antibody was 100% in the laboratories. Sensitivity was less than reported previously. Standardization of these tests is needed in the United States.

Sensitivity of a hyperosmolar or "low"-osmolar test solution for sugar absorption in recognizing small intestinal mucosal damage in coeliac disease

Reliability of differential sugar absorption tests is hampered by a lack of standardization of the content and osmolarity of the test solutions. We evaluated the effect of osmolarity of the test solution of the sugar absorption test on the 5 hour urine excretion of orally administered lactulose and mannitol. A group of 28 controls and 14 coeliacs, with villous atrophy grade II to IV, ingested a hyperosmolar sugar absorption test solution and a "low"-osmolar solution, respectively. After an overnight fast, each subject ingested hyperosmolar sugar absorption test solution (2 g mannitol, 5 g lactulose and 40 g sucrose/100 ml (around 1,560 mmol/l)). After two days, this procedure was repeated with low-osmolar solution (2 g mannitol and 5 g lactulose/100 ml (around 375 mmol/l). The influence of the sequence of the tests on the results had previously been excluded. All urine from the 5 h-period following ingestion of the test solution was collected. To calculate the low-osmolar solution ratio, samples were analysed for lactulose and mannitol concentrations by gas chromatography The sensitivity of hyperosmolar SAT solution and low-osmolar solution for the detection of mucosal abnormalities in coeliacs was 64% and 43%, respectively. In conclusion, a hyperosmolar solution discriminates better between normal and damaged mucosa of the small bowel such as villous atrophy due to a relative increase in permeability for lactulose.

Sensitivity of antiendomysium and antigliadin antibodies in untreated celiac disease: disappointing in clinical practice

OBJECTIVE

We have undertaken a study to assess the efficiency of serological tests in the diagnosis of celiac disease (CD) during the period January 1, 1994 to January 7, 1997. Our aim was to evaluate the sensitivity of IgA antiendomysium (EMA) and IgA antigliadin (AGA) with regard to the degree of histological abnormality in biopsy specimens of small intestine in untreated celiac disease patients and first-degree relatives.

METHODS

The study population comprised 101 cases: 85 untreated celiac patients and 16 first-degree relatives with a mean age of 42 yr (range, 2-76 yrs). Sixteen of 85 were excluded from study because they did not satisfy the study or diagnostic criteria of CD. EMA and AGA have been compared with the degree of villous atrophy (VA) in 69 celiac patients and 16 relatives according to the Marsh criteria of 1992. We divided the Marsh III histology into three subgroups as follows: Marsh IIIa (partial VA), Marsh IIIb (subtotal VA), and Marsh IIIc (total villous atrophy).

RESULTS

The specificity and positive predictive value of EMA for CD was excellent, because all EMA-positive patients (n = 42) were diagnosed with CD. The sensitivity of EMA, however, differed between CD subgroups; in patients with total VA, the sensitivity of EMA was 100% (17/17). However, in patients with partial VA (Marsh IIIa), the sensitivity of EMA was disappointing, only 9/29 (31%). Three of 72 celiacs with Marsh IIIb and Marsh IIIc had IgA deficiency and were excluded from the study. Elevated AGA has been detected in the sera of 39 of 69 (62%) patients. A combination of EMA and AGA tests showed a sensitivity of 76% (53/69). None of 16 first-degree relatives with Marsh I-II had positive EMA.

CONCLUSIONS

Interpretation of negative serology needs great awareness. Although EMA sensitivity in total villous atrophy is excellent, in partial villous atrophy the sensitivity of EMA appears to be disappointing. Our experience shows that EMA and AGA have only limited value in screening programs for CD.

Altered intestinal permeability to mannitol in diabetes mellitus type I

BACKGROUND

Intestinal permeability has seldom been investigated in diabetes mellitus, even though patients frequently report gastrointestinal symptoms, and it has recently been shown that the prevalence of celiac disease associated with diabetes mellitus is higher than expected.

METHODS

Intestinal permeability to cellobiose and mannitol was investigated in 31 patients affected by type I uncomplicated diabetes mellitus. Values were compared with those obtained in 32 normal subjects.

RESULTS

The percentage of mannitol recovery was far higher than normal in two thirds of the investigated patients and correlated with the length of disease, even though the probes' ratio (cellobiose/mannitol) was in the normal range.

CONCLUSIONS

A not previously reported increase of intestinal permeability to mannitol, clear-cut and not associated with that of the larger probe, is found in type I uncomplicated diabetes mellitus. These results may describe a primary feature of type I diabetes mellitus and the initial steps of evolution to celiac disease.

IgA antibodies to tissue transglutaminase: An effective diagnostic test for celiac disease

OBJECTIVE

Tissue transglutaminase (tTG) is the main autoantigen recognized by endomysial antibodies. The aim of this study was to assess sensitivity, specificity, and predictive value of IgA and IgG antibodies to tTG in the diagnosis of celiac disease compared with endomysial antibodies.

STUDY DESIGN

We established enzyme-linked immunosorbent assay procedures to measure IgA and IgG antibodies to tTG in sera from 48 untreated and 33 treated patients with celiac disease and from 63 patients with gastrointestinal disease who were in a control group. Sera from 10 patients with celiac disease were examined at various times after gluten was reintroduced into the patients' diet.

RESULTS

Both IgA and IgG to tTG were significantly (P <.001) higher in serum of untreated patients with celiac disease versus those in the control group; IgA but not IgG was significantly (P <.001) higher in untreated versus treated patients with celiac disease. IgA and IgG antitissue tTG had a diagnostic sensitivity, specificity, and positive predictive value of 92% and 21%, 98% and 97%, and 98% and 83%, respectively. The concordance rate of IgA anti-tTG with IgA antiendomysial antibodies was 95%. In 5 of the 10 patients undergoing gluten challenge, IgA antiendomysium antibodies were detected earlier than IgA anti-tTG antibodies.

CONCLUSIONS

tTG-based enzyme-linked immunosorbent assay is an effective diagnostic test, although immunofluorescent-based assays are more sensitive, particularly during gluten challenge.

Superior mesenteric artery blood flow in children with celiac disease

BACKGROUND

Knowledge of splanchinic hemodynamics in celiac disease is scarce. The hemodynamic parameters of the superior mesenteric artery were evaluated by duplex Doppler ultrasonography in children with celiac disease to show whether histomorphologic changes in small bowel mucosa led to any alteration in splanchinic blood flow.

METHODS

The hemodynamic parameters of the superior mesenteric artery were evaluated by Doppler ultrasonography in 23 children with celiac disease. Ten patients were studied at the time of diagnosis. The remaining 13 children were studied after complete clinical and histologic recovery induced by gluten-free diet. Additionally, 9 patients out of 13 who were on a gluten-free diet for about 2 years were given gluten challenge, and superior mesenteric artery blood flow was measured after the challenge. The results were compared with those of healthy children.

RESULTS

Peak systolic velocity of the superior mesenteric artery was higher in untreated celiac patients than in healthy controls and treated celiac patients. Peak systolic velocity of the superior mesenteric artery in the treated group of children was close to that of control subjects, implying that successful treatment with gluten-free diet improves hemodynamic changes. The comparison of Doppler ultrasonographic measurements of the challenge group before and after the gluten challenge revealed that the peak systolic velocity, resistive index, and blood flow of the superior mesenteric artery were changed significantly.

CONCLUSIONS

The pathophysiologic events in small bowel mucosa during the active phase of celiac disease induce some hemodynamic changes that can be detected noninvasively by duplex Doppler ultrasonography.

Gluten-sensitive enteropathy

Gluten-sensitive enteropathy is induced by dietary wheat gliadin and related proteins in genetically susceptible individuals. Most evidence suggests that the mucosal lesion represents an immunologically mediated injury triggered by gluten in the context of a particular assortment of major histocompatibility complex genes. The amino acid residues of gliadin and related proteins responsible for toxicity have not been identified; in vitro systems are available, but definitive conclusions must rely on in vivo jejunal challenges. At a conservative estimate, symptomatic gluten-sensitive enteropathy affects approximately 1 in 1000 individuals in Europe; however, it is now becoming clear that a greater proportion of individuals has clinically silent disease, and probably many others have a minor form of the the enteropathy. In most countries, the clinical presentation has changed over the past few years coming closer to the adult type of the disease, and the age of onset of symptoms is shifting upward. Liver, joint, hematologic, dental, and neurologic symptoms are increasingly being recognized. Several diseases are associated the gluten-sensitive enteropathy, such as IgA deficiency, insulin-dependent diabetes mellitus, and a range of other autoimmune diseases. Tests based on the measurement of antigliadin and antiendomysium antibodies have gained success as noninvasive screening tests; however, the ultimate diagnosis still is based on the finding of a severe histologic lesion of the jejunum while the patient is on a gluten-containing diet and on its disappearance once the gluten is excluded from the diet. A lifelong, strict GFD is mandatory for celiac children. Among other long-term problems, an increased risk of intestinal lymphoma has been reported in patients on a normal gluten-containing diet.