Coeliac disease in Iraqi type 1 diabetic patients

Background and study aimsHigh prevalence rates of coeliac disease (CD) in patients with type 1 diabetes mellitus (T1DM) have been reported. The aim of this study was to evaluate the frequency of silent CD in a sample of Iraqi patients with T1DM.Patients and methodsThis is a cross-sectional study done in Baghdad Teaching Hospital, Baghdad Medical City, Baghdad, Iraq, on 62 patients with T1DM. For all patients, immunoglobulin A (IgA) anti-tissue transglutaminase antibodies (IgA tTG), IgG anti-tissue transglutaminase antibodies (IgG tTG), IgA endomysial antibody (IgA EMA), IgA antigliadin antibodies (IgA AGA) and IgG antigliadin antibodies (IgG AGA) tests were done, with duodenoscopy, and at least four biopsies were taken from the second part of the duodenum.ResultsA total of 27 patients (43.5%) had normal small-intestinal histopathology (Marsh 0), one of them had a positive result for all serological markers used in the study, and another patient was positive for IgA tTG only. Ten patients (16.1%) had Marsh grade I, one of them was positive for IgA tTG, IgG tTG and IgA EMA, another patient was IgA deficient and had positive IgG tTG only and another patient with Marsh I had positive IgA tTG and IgG tTG only. Two patients (3.2%) had Marsh IIIA; three patients (4.8%) had Marsh IIIB histopathology, two of them were positive for all tests and one had positive IgA tTG and IgA EMA only. Two patients (3.2%) had Marsh IIIC histopathological features; they were positive for all serological tests, hence, the frequency of CD was 11.2%.ConclusionThe frequency of silent CD in Iraqi patients with T1DM is not rare, reaching up to 11.2%. Both EMA and tTG antibodies are useful as screening tests.     

Population screening for coeliac disease in a low prevalence area in Italy

Objective. A screening program was proposed for the village of Carcare (population 5700), located in a region of Italy with an apparently low prevalence of coeliac disease (CD): only 1 patient diagnosed out of 2557 inhabitants. The study group comprised 1002 individuals (568?F, 434?M, age range 13–90 years) recruited from blood donors, secondary school pupils and people referred to the local outpatient facilities for routine blood chemistry. Material and methods. Total IgA, IgA anti-tissue transglutaminase (tTG) (ELISA, recombinant human antigen) and IgA antiendomysium (EMA) (IFI, umbilical cord substrate) antibodies were measured in the serum of all participants. All patients with IgA deficiency were investigated for IgG tTG antibodies, and in the case of disagreement between tTG and EMA, they were typed for HLA DQ2-DQ8 haplotypes. Results. Thirteen subjects were positive and 988 negative for autoantibodies (3/988 had IgA deficiency). One serum sample was positive for tTG antibodies but negative for EMA. Ten out of 13 positive subjects consented to undergo duodenal biopsy, which invariably produced evidence of CD despite the absence of clinical signs/symptoms. A post-diagnostic clinical investigation provided evidence showing mild iron deficiency (4 subjects) and osteoporosis (2 subjects). After counselling, all subjects accepted a gluten-free diet. Conclusions. The prevalence of CD in the study group was 1:100 (1.0%; 95% CI: 0.5–1.8%): this indicates that CD is largely underdiagnosed in Carcare. Our results suggest that the low prevalence of CD observed in some regions is likely to be due to underdiagnosis.     

Anti-transglutaminase IgA ELISA: Clinical Potential and Drawbacks in Celiac Disease Diagnosis

Background: Since the identification of tissue transglutaminase (tTG) as the antigen for the antiendomysial antibodies (EMA), several antigen-specific immunoassays have been reported for celiac disease (CD) screening. A first objective was to evaluate the suitability for CD screening of three different IgA tTG ELISAs, two of them based on guinea pig liver tTG (gp-tTG) (an in-house ELISA with a partially purified extract and a commercial ELISA with purified gp-tTG antigen) and a third recombinant human tTG (rh-tTG) ELISA. The results are compared with EMA and with the final clinical diagnosis. A second objective was to analyze antibody reactivities in those patients with anti-tTG and EMA discrepancies. Methods: ELISA and EMA tests were used to measure IgA anti-tTG levels in sera from 259 patients (107 had CD and 72 had Type I diabetes mellitus). Results: The purified gp-tTG ELISA was highly sensitive (97.7%) and specific (98.8%) in the detection of CD, almost equaling EMA. Rh-tTG ELISA did not improved the sensitivity of EMA, but its specificity was slightly superior. Immunoblot analysis with partially purified gp-tTG extract, the antigen most frequently used for anti-tTG detection, showed that the majority of false positives were due to IgA reactivities to contaminant proteins present in the liver antigenic extract. This low specificity was particularly problematic in diabetics. Conclusion: Purified tTG ELISAs, either with purified guinea pig liver or recombinant human antigens, can be used as quantitative and observer-independent alternatives to the traditional and time-consuming EMA in the screening of CD.     

An algorithm for family screening for coeliac disease

INTRODUCTION Coeliac disease (CD) is a disorder in which geneticallypredisposed individuals develop a small intestinal enteropathy on exposure to dietary gluten. The small bowel abnormalities are reversed on withdrawal of gluten from the diet. Recent popu…     

Antibodies Against Human Tissue Transglutaminase and Endomysium in Diagnosing and Monitoring Coeliac Disease

Background: Coeliac disease (CD) patients often present a variety of uncharacteristic symptoms and therefore sensitive and specific screening tests are needed as an aid in making an accurate diagnosis. A recently developed ELISA, using human recombinant tissue transglutaminase (tTG) as antigen, was evaluated for its significance in the diagnosis of CD. The patient's compliance to a gluten-free diet and the serological reaction during gluten challenge were also monitored. The results were compared with IgA-endomysium antibody (EMA) results. Methods: Sera previously collected from 365 patients (0.4-76 years) with jejunal biopsy on a gluten-containing diet and from 41 patients on a gluten-free diet or challenge were tested for IgA anti-human tTG antibodies (IgA tTG ab) with Celikey ® (Pharmacia Diagnostics). The study population comprised 208 CD patients and 157 controls. The diagnostic performance and cut-off for the assay were estimated with ROC analysis. EMA was analysed by indirect immunofluorescence microscopy on cryostat sections of monkey oesophagus. Results: 200/208 patients with CD had positive IgA tTG ab (median >100 U/ml), while only 1/157 of the control patients were positive (median 1.67 U/ml). The area under the ROC curve was 98.3% and the sensitivity and specificity of the test were 96% and 99% for the study population. Only 4/365 patients (1%) presented discordant IgA tTG ab and EMA results, 2 of them had only IgA tTG ab and 2 only EMA. The IgA tTG ab levels and the EMA titres were closely correlated to the duration of gluten-free diet and gluten challenge, respectively. Conclusion: IgA tTG ab can be used as an accurate observer-independent alternative to EMA in diagnosing or monitoring CD.     

Anti-tissue transglutaminase antibodies in inflammatory and degenerative arthropathies

Recent studies identified tissue transglutaminase (tTG) as the antigen eliciting antiendomysial antibodies (EMA) in celiac disease (CD). Anti-tTG antibodies have therefore been proposed as a serological test for CD. Nevertheless, IgA anti-tTG but not EMA have also been found in inflammatory bowel disease patients, suggesting that these antibodies are linked to a tissue lesion rather than to an auto-immune component of CD. To confirm this hypothesis, we evaluated the presence of IgA anti-tTG in patients with inflammatory and degenerative diseases, in whom tissue lesions presented far away from the intestinal mucosa. The study was carried out on the serum and synovial fluid (SF) of 68 patients with rheumatoid arthritis (RA=33), psoriatic arthritis (PsA=26) and osteoarthritis (OA=9). In RA, PsA and OA sera, IgA anti-tTG were positive in 33%, 42% and 11% of patients, respectively. Serum anti-tTG levels were significantly higher in RA (p<0.0001), PsA (p<0.0001) and OA (p<0.02) with respect to healthy controls. SF anti-tTG levels were significantly higher in PsA (p<0.018) than in OA. A good correlation between serum and synovial fluid anti-tTG levels was found in all arthropathies This study suggests that tTG is not the only antigen of EMA and, furthermore, that IgA anti-tTG antibodies represent a general lesion-associated event. Moreover, the significant correlation between serum and synovial fluid anti-tTG levels allow us to hypothesise that these antibodies could be synthesized in the site of arthritic lesions.     

Elevation of IgG antibodies against tissue transglutaminase as a diagnostic tool for coeliac disease in selective IgA deficiency

BACKGROUND: IgA serum autoantibodies against tissue transglutaminase (tTG) have an established diagnostic value in coeliac disease, and high efficacy tests are widely available for their detection. However, serological evaluation of IgA deficient subjects is still difficult. AIMS: To evaluate the diagnostic potential of IgG class anti-tTG autoantibodies measured quantitatively using an enzyme linked immunosorbent assay (ELISA) compared with immunofluorescent detection of coeliac autoantibodies. PATIENTS: We tested serum samples from 325 IgA deficient subjects, including 78 patients with coeliac disease, 73 disease controls, and 174 blood donors. METHODS: IgG antibodies against human recombinant tTG were measured with an ELISA. IgG antiendomysium antibodies (EMA) were assayed by indirect immunofluorescence on human jejunum and appendix sections. RESULTS: The IgG anti-tTG ELISA had a sensitivity of 98.7% and a specificity of 98.6%, and the correlation with IgG EMA titres was high (r(s)=0.91). One coeliac patient, initially negative in all autoantibody tests, displayed both IgG anti-tTG antibodies and IgG EMA during later gluten exposure. IgG anti-tTG antibodies and EMA titres showed significant decreases (p<0.001) in treated patients. The frequency of IgG anti-tTG autoantibody positivity was 9.8% among IgA deficient blood donors and 11 of the 12 positive subjects with known HLA-DQ haplotypes carried DQ2 or DQ8 alleles. CONCLUSIONS: IgG anti-tTG and IgG EMA autoantibody tests are highly efficient in detecting coeliac disease in IgA deficient patients. The high prevalence of coeliac antibodies among symptom free IgA deficient blood donors who also carry coeliac-type HLA-DQ genes indicates that all IgA deficient persons should be evaluated for coeliac disease.     

Population screening for coeliac disease in a low prevalence area in Italy

OBJECTIVE: A screening program was proposed for the village of Carcare (population 5700), located in a region of Italy with an apparently low prevalence of coeliac disease (CD): only 1 patient diagnosed out of 2557 inhabitants. The study group comprised 1002 individuals (568 F, 434 M, age range 13-90 years) recruited from blood donors, secondary school pupils and people referred to the local outpatient facilities for routine blood chemistry. MATERIAL AND METHODS: Total IgA, IgA anti-tissue transglutaminase (tTG) (ELISA, recombinant human antigen) and IgA antiendomysium (EMA) (IFI, umbilical cord substrate) antibodies were measured in the serum of all participants. All patients with IgA deficiency were investigated for IgG tTG antibodies, and in the case of disagreement between tTG and EMA, they were typed for HLA DQ2-DQ8 haplotypes. RESULTS: Thirteen subjects were positive and 988 negative for autoantibodies (3/988 had IgA deficiency). One serum sample was positive for tTG antibodies but negative for EMA. Ten out of 13 positive subjects consented to undergo duodenal biopsy, which invariably produced evidence of CD despite the absence of clinical signs/symptoms. A post-diagnostic clinical investigation provided evidence showing mild iron deficiency (4 subjects) and osteoporosis (2 subjects). After counselling, all subjects accepted a gluten-free diet. CONCLUSIONS: The prevalence of CD in the study group was 1:100 (1.0%; 95% CI: 0.5-1.8%): this indicates that CD is largely underdiagnosed in Carcare. Our results suggest that the low prevalence of CD observed in some regions is likely to be due to underdiagnosis.     

Antibodies against human tissue transglutaminase and endomysium in diagnosing and monitoring coeliac disease

BACKGROUND: Coeliac disease (CD) patients often present a variety of uncharacteristic symptoms and therefore sensitive and specific screening tests are needed as an aid in making an accurate diagnosis. A recently developed ELISA, using human recombinant tissue transglutaminase (tTG) as antigen, was evaluated for its significance in the diagnosis of CD. The patient's compliance to a gluten-free diet and the serological reaction during gluten challenge were also monitored. The results were compared with IgA-endomysium antibody (EMA) results. METHODS: Sera previously collected from 365 patients (0.4-76 years) with jejunal biopsy on a gluten-containing diet and from 41 patients on a gluten-free diet or challenge were tested for IgA anti-human tTG antibodies (IgA tTG ab) with Celikey (Pharmacia Diagnostics). The study population comprised 208 CD patients and 157 controls. The diagnostic performance and cut-off for the assay were estimated with ROC analysis. EMA was analysed by indirect immunofluorescence microscopy on cryostat sections of monkey oesophagus. RESULTS: 200/208 patients with CD had positive IgA tTG ab (median >100 U/ml), while only 1/157 of the control patients were positive (median 1.67 U/ml). The area under the ROC curve was 98.3% and the sensitivity and specificity of the test were 96% and 99% for the study population. Only 4/365 patients (1%) presented discordant IgA tTG ab and EMA results, 2 of them had only IgA tTG ab and 2 only EMA. The IgA tTG ab levels and the EMA titres were closely correlated to the duration of gluten-free diet and gluten challenge, respectively. CONCLUSION: IgA tTG ab can be used as an accurate observer-independent alternative to EMA in diagnosing or monitoring CD.     

The frequency of the celiac disease among children with familial Mediterranean fever

We aimed to assess the frequency of celiac disease (CD) in patients with Familial Mediterranean Fever (FMF). This prospective study was carried out from October 2015 to March 2016 and included 303 patients with FMF. We used 98 sex- and age-matched healthy subjects as a control group. Levels of total IgA and tissue transglutaminase (tTG) IgA antibody were measured in all groups. Those with increased level of tTG IgA were tested for anti-endomysium IgA antibodies (EMA). Patients with positive EMA underwent gastro-duodenoscopy and intestinal biopsy for a definite diagnosis of CD. Only 9 of 303 patients (2.9%) were positive for tTG IgA. Patients positive for tTG IgA were then tested for EMA and only one of them (0.3%) had a positive result. This patient underwent gastro-duodenoscopy. The pathological report was compatible with Marsh 0 classification score for the diagnosis of CD. Two subjects from the control group were positive for tTG IgA but none of them had positive EMA antibodies. We did not find CD in the large cohort of childhood FMF patients. The prevalence of CD did not show association with presence of childhood FMF in this study and CD would not be a considerable complication of childhood FMF.     

Antibody testing in Indian children with celiac disease.

BACKGROUND: We prospectively evaluated the usefulness of IgA tissue transglutaminase antibodies (IgA tTG) in the initial diagnosis of celiac disease (CD) and compared its diagnostic potential with that of IgA anti-endomysial antibodies (IgA EMA) and anti-IgA and IgG gliadin antibodies (AGA and AGG, respectively). METHODS: Sera of 23 untreated children fulfilling the revised ESPGHAN criteria for diagnosis of CD (Group I; mean age 10.8 y); 19 disease controls (Group II; mean age 8.5 y) presenting with chronic diarrhea, short stature or both; and 22 healthy children (Group III; mean age 8.8 y) were studied. These were tested in a blinded manner for AGA, AGG, IgA tTG (guinea pig as antigen) and IgA EMA. RESULTS: In Group I, IgA EMA was positive in 19, IgA tTG in 17, AGA in 14 and AGG in 17 patients. In Group II, these tests were positive in 1, 0, 2 and 14 patients, respectively and in Group III, in 0, 0, 0 and 1 child, respectively. Analyzing data from Group I and II, IgA EMA, IgA tTG, AGA and AGG had sensitivity rates of 83%, 74%, 61% and 74%, respectively; the specificity rates were 95%, 100%, 89% and 26%; positive predictive values were 95%, 100%, 88% and 55% and negative predictive values were 82%, 74%, 65% and 45%, respectively. CONCLUSION: IgA tTG is useful for the diagnosis of CD, with sensitivity and specificity rates comparable to those of EMA and this test is well suited for use in tropical countries like India.     

Autoantibodies to tissue transglutaminase as predictors of celiac disease

Background & Aims: Immunoglobulin A (IgA) autoantibodies to endomysium (EMA) are highly specific and sensitive markers for celiac disease. Recently, we identified tissue transglutaminase (tTG) as the major if not sole endomysial autoantigen. Methods: An enzyme-linked immunosorbent assay (ELISA) was established to measure IgA anti-tTG titers in serum samples from 106 celiac patients with partial or subtotal villous atrophy, 43 celiac patients on a gluten-free diet, and 114 diseased and healthy controls. Results were correlated with clinical and histological data and with EMA titers. Results: In patients with biopsy-proven celiac disease consuming a normal, gluten-containing diet, 98.1% of the serum samples had elevated IgA titers against tTG, whereas 94.7% of the control sera were negative. IgA anti-tTG correlated positively with semiquantitative IgA EMA titers (r = 0.862; P < 0.0001). Conclusions: An ELISA based on tTG allows diagnosis of celiac disease with a high sensitivity and specificity. IgA anti-tTG and IgA EMA show an excellent correlation, further confirming the enzyme as the celiac disease autoantigen. Because the assay is quantitative, not subjected to interobserver variation, and easy to perform, it will be a useful tool for population screening of a hitherto underdiagnosed disease.GASTROENTEROLOGY 1998;115:1317-1321     

Anti-transglutaminase IgA ELISA: clinical potential and drawbacks in celiac disease diagnosis

BACKGROUND: Since the identification of tissue transglutaminase (tTG) as the antigen for the anti-endomysial antibodies (EMA), several antigen-specific immunoassays have been reported for celiac disease (CD) screening. A first objective was to evaluate the suitability for CD screening of three different IgA tTG ELISAs, two of them based on guinea pig liver tTG (gp-tTG) (an in-house ELISA with a partially purified extract and a commercial ELISA with purified gp-tTG antigen) and a third recombinant human tTG (rh-tTG) ELISA. The results are compared with EMA and with the final clinical diagnosis. A second objective was to analyze antibody reactivities in those patients with anti-tTG and EMA discrepancies. METHODS: ELISA and EMA tests were used to measure IgA anti-tTG levels in sera from 259 patients (107 had CD and 72 had Type I diabetes mellitus). RESULTS: The purified gp-tTG ELISA was highly sensitive (97.7%) and specific (98.8%) in the detection of CD, almost equaling EMA. Rh-tTG ELISA did not improved the sensitivity of EMA, but its specificity was slightly superior. Immunoblot analysis with partially purified gp-tTG extract, the antigen most frequently used for anti-tTG detection, showed that the majority of false positives were due to IgA reactivities to contaminant proteins present in the liver antigenic extract. This low specificity was particularly problematic in diabetics. CONCLUSION: Purified tTG ELISAs, either with purified guinea pig liver or recombinant human antigens, can be used as quantitative and observer-independent alternatives to the traditional and time-consuming EMA in the screening of CD.     

Autoantibodies to tissue transglutaminase in Sjögren's syndrome and related rheumatic diseases

OBJECTIVE: Sj?gren's syndrome (SS) has been reported in up to 15% of patients with biopsy proven celiac disease (CD). The diagnosis of CD in the setting of SS and other systemic rheumatic diseases can be difficult because they are often associated with a number of gastrointestinal symptoms and diseases. Although the diagnosis of CD is often confirmed by a small bowel biopsy, marker autoantibodies directed against the endomysium of transitional epithelium (EMA) and tissue transglutaminase (tTG) are highly correlated with biopsy-proven disease and serve as a valuable screening test. We used an IgA-anti-tissue transglutaminase antibody (anti-tTG) ELISA to assess the prevalence of anti-tTG in an unselected cohort of patients with SS and other systemic rheumatic diseases. METHODS: Sera from 50 patients with SS, 50 with systemic lupus erythematosus (SLE), 50 with rheumatoid arthritis (RA), 30 with systemic sclerosis (SSc), and 50 healthy controls were tested for autoantibodies to tTG. A comparison group of 40 sera from patients with biopsy-confirmed CD was also included. IgA anti-tTG was measured by a commercially available ELISA kit (Inova, San Diego, CA) that employs purified tTG. RESULTS: Six of the 50 (12%) IgA sufficient SS patients had anti-tTG compared to 2 (4%) normal sera, 3 (6%) SLE, 2 (7%) SSc, and 1 (2%) RA. By comparison, in the CD cohort, 33 (83%) had anti-tTG. Five of 6 SS patients with anti-tTG had symptoms, signs, or small bowel biopsy findings consistent with a diagnosis of CD. IgA anti-tTG and EMA were accompanied by other IgA autoantibodies in SS sera. CONCLUSION: Anti-tTG ELISA is a reliable method to indicate a coexisting diagnosis of CD in patients with SS. Interestingly, the frequency of false positive tTG tests in any of the systemic rheumatic diseases is not significantly greater than in controls. Further, our study shows that anti-tTG is more prevalent in SS than in other systemic rheumatic diseases. The tTG ELISA may be used as a screening test to identify patients with SS who are at risk and require further evaluation for the presence of CD.     

IgA antibodies to human tissue transglutaminase: audit of routine practice confirms high diagnostic accuracy

Background: The diagnostic accuracy of IgA tissue transglutaminase antibodies (TGA) for coeliac disease (CD) has been assessed following the introduction of the test into routine practice in 2002. Methods: Specificity was assessed in serum samples received from 1554 adults for routine coeliac serology. The population for assessing sensitivity was 75 consecutive new adult diagnoses of CD. TGA was measured by enzyme-linked immunoassay using human tissue transglutaminase as antigen. Concordance between TGA and endomysial antibody (EMA) was also assessed. Results: The prevalence of new diagnoses of CD in the population tested was 2.8% with similar proportions of new diagnoses in males and females. The positive predictive values at a cut-off of 3 units/mL were 0.77 for samples from Primary Care and 0.92 for samples from Hospital sources, with a sensitivity of 92%. At TGA &lt;3 units/mL, EMA was usually negative; when TGA was &gt;4.9 units/mL, EMA was rarely negative. Conclusions: We have assessed the role of TGA in routine clinical practice and confirmed high diagnostic accuracy. Sensitivity (92%) is identical to the sensitivity for EMA. IgA deficiency should be excluded in samples showing low absorbance readings in the TGA assay and interference from monoclonal and polyclonal IgA should be excluded in samples with slightly raised TGA levels and negative EMA. TGA is recommended as the first-line serological test for coeliac disease.     

IgA and IgG tissue transglutaminase antibodies in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) and coeliac disease (CD) are diseases of an autoimmune origin that share the human leukocyte HLA-B8 and HLA-DR3 histocompatibility antigens, yet the co-association of CD with SLE is mainly based on case reports. Thus, the real prevalence of CD in SLE is unclear. The aim of this study was to determine the prevalence of antitissue transglutaminase (anti-tTG) in SLE and the relation between SLE and CD. In this case-control study, 100 patients with SLE, and 120 healthy subjects were studied. Sera from all participants were analysed for the presence of IgA and IgG anti-tTG antibodies using a human recombinant tissue transglutaminase (tTG) immuno-enzymatic assay. Anti-tTG positive patients and controls were further tested for antiendomysial (EMA) antibodies by an indirect immunofluorescence and HLA typing (DQalpha1*0501-DQbeta1*0201 allele determination). Subjects who had EMA or the mentioned allele, underwent duodenal biopsy to confirm a possible diagnosis of CD. Anti-tTG antibodies (IgA or IgG isotypes) were found in three of the 100 SLE patients (overall prevalence of 3%): one had the IgA and two the IgG isotypes. Only 1 of 120 healthy subjects (0.8%) had a low positive reaction for IgA anti-tTG. Only the IgA anti-tTG positive SLE patient was diagnosed as having CD based on a positive IgA-EMA and small bowel biopsy findings. The two IgG anti-tTG positive SLE patients and the IgA anti-tTG positive healthy subject were classified as false positives (EMA negative and HLA DQalpha1*0501-DQbeta1*0201 allele negative). In conclusion, anti-tTG antibodies were found at a low rate in SLE patients and mostly did not indicate the presence of CD. Thus, serological screening for CD is not recommended in SLE, unless a clinical suspicion of CD is present.     

Identification of a new coeliac disease subgroup: antiendomysial and anti-transglutaminase antibodies of IgG class in the absence of selective IgA deficiency

OBJECTIVE: The aim of the present study was to increase the sensitivity of the antiendomysial antibody (EMA) test by evaluating also EMAs of IgG1 isotype. DESIGN AND SUBJECTS: Over the last 2 years, serum EMAs IgA and IgG1 were determined in 1399 patients, referred to our gastrointestinal unit due to clinical suspicion of malabsorption. Serum anti-tissue transglutaminase (tTG) antibodies IgA and IgG, as well as total IgA levels, were also investigated. Furthermore, EMAs IgA and IgG1 were evaluated in biopsy culture supernatants. Biopsy specimens were also admitted to histological and immunohistochemical evaluation. Twenty-six patients with gastroenterological disease other than coeliac disease (CD) were used as a disease control group. Ninety-nine blood donors were used as a healthy control group. RESULTS: Diagnosis of CD was based on histological findings in the 110/1399 patients showing EMA IgA positivity, and in a further 56/1399 patients presenting both EMA IgA and IgG1 positivity in sera as well as in culture supernatants. Of the remaining 1233 EMA IgA-negative patients, 60 showed only EMA IgG1 positivity both in sera and in culture supernatants. It is noteworthy that anti-tissue transglutaminase antibodies IgG (anti-tTG) were positive in all 60 EMA IgG1-positive patients as well. By contrast, a selective IgA deficiency was found in only 11 out of the 60 EMA IgG1-positive patients. Villous height/crypt depth ratio was < 3:1 in 38 of the 60 EMA IgG1-positive patients (63.3%), whilst overexpression of ICAM-1 and CD25 was observed in all these patients. CONCLUSIONS: In this study, we observed a group of CD patients who were EMA IgG1-positive even in the absence of EMA IgA positivity and IgA deficiency. The diagnosis was based on the finding of the gluten-dependent clinical and histological features typical of CD. Data emerging from the present investigation thus suggest that the prevalence of CD should be reassessed and that the determination of EMA IgG1 could offer a new tool in the diagnostic armamentarium of CD.     

Screening for celiac disease in Down＇s syndrome patients revealed cases of subtotal villous atrophy without typical for celiac disease HLA-DQ and tissue transglutaminase antibodies

AIM: To investigate the prevalence of celiac disease (CD) as well as CD marker antibodies and susceptibility HLA-DQ haplotypes in 134 karyotyped Down's syndrome (DS) patients. METHODS: Immunoglobulin A (IgA) and G (IgG) type anti-gliadin antibodies (AGA), IgA type anti-tissue transglutaminase (tTG) antibodies (anti-tTG) with antigen of guinea pig and human source were determined by enzyme-linked immunosorbent assay and endomysium antibodies (EMA) by indirect immunofluoresence test. HLA-DQA1*0501/DQB1*0201 (DQ2) was revealed by polymerase chain reaction. Celiac disease was diagnosed by revised ESPGHAN criteria. RESULTS: 41% of DS patients had AGA, 6.0% IgA anti-tTG with guinea pig antigen, and 3.0 % IgA EMA (all positive for anti-tTG with human tTG). Subtotal villous atrophy was found in 5 out of 9 DS patients who had agreed to small bowel biopsy. One of them had DQA1*0501/DQB1*0201 and anti-tTG and EMA i.e. typical for CD markers (this case also fulfilled the ESPGHAN diagnostic criteria), but other four lacked these markers. Three non-biopsied DS patients had also most probably CD because DQA1*0501/DQB1*0201 and IgA anti-tTG (EMA) were detected. Thus, the prevalence of CD among our DS patients population is 3.0 % (95 % of confidence interval [CI]: 0.1-5.9 %). CONCLUSION: We confirm the increased frequency of CD among DS patients. In addition, we have revealed a subgroup of patients with subtotal villous atrophy but without characteristic for CD immunological and genetic markers. Whether these cases represent CD (with atypical immunopathogenesis) or some other immune enteropathy, requires further investigations.     

Elevated tissue transglutaminase antibodies in juvenile idiopathic arthritis children: Relation to neutrophil-to-lymphocyte ratio and disease activity

Background: Subclinical gut inflammation is described in juvenile idiopathic arthritis (JIA), so has joint involvement been related to celiac disease (CD). The well-known involvement of tissue transglutaminase (tTG) in the pathogenesis of CD stimulated progress in the field of autoimmune diseases. Aim of the work: To screen JIA children for tTG antibodies and to detect its relation to the neutrophil-lymphocyte ratio (NLR) and disease activity. Patients and methods: The study included 44 JIA children with 44 matched controls. All subjects had no GIT symptoms suggestive of CD. Disease activity was assessed using the juvenile arthritis disease activity score in 27 joints (JADAS-27). The tTG antibodies (IgA and IgG) were assessed. Results: The patients mean age was 12.5 ± 2.8 years and disease duration 5.01 ± 2.9 years; Female:Male 3.4:1. The mean JADAS-27 score was 12.6 ± 2.04. tTG antibodies were positive in 43.2% of the patients compared to 18.2% control (p = 0.01). Antibodies positivity was comparable according to gender and subtypes. The NLR in JIA children (1.62 ± 0.58) was significantly higher than in control (1.3 ± 0.5) (p = 0.006). Those with positive tTG antibodies had a significantly reduced body mass index (p = 0.02) and increased NLR (p = 0.02) compared to those with negative tTG. Only NLR and JADAS-27 would significantly predict antibodies positivity (p = 0.037 and p = 0.04, respectively). Conclusion: Increased tTG antibodies are frequent in JIA children raising the possibility of an associated subclinical CD. Markedly reduced BMI and increased NLR could forecast the presence of these antibodies. In addition to the JADAS-27, the NLR is a simple test that could predict this association and could be a useful biomarker.     

Endomysial and Tissue Transglutaminase Antibodies in Coeliac Sera: a Comparison not Influenced by Previous Serological Testing

Background: Since transglutaminase was shown to be the antigen of endomysial antibodies (EMA), it has become possible to screen for coeliac disease (CD) with an enzyme-linked immunosorbent assay (ELISA) for transglutaminase antibodies (TTA). However, it is possible that sera used to show that TTA are found in CD were obtained from patients diagnosed because they were positive for EMA. So, a comparison between EMA and TTA has not been possible so far. Methods: EMA and TTA were tested in sera from 52 controls and 56 untreated CD patients, who had not undergone serological testing. Samples were tested for TTA with an ELISA kit. Based on the ROC analysis of a pilot study, results were considered as either positive, borderline, or negative. EMA were analysed by indirect immunofluorescence on monkey oesophagus. Results: Forty-nine CD patients were positive for TTA, six borderline, one negative. Forty-four controls were negative, seven borderline, one positive. If we consider borderline results to be positive, sensitivity is 98.2% and specificity 84.6%. EMA were positive in 53 CD patients; the controls were all negative. Performing TTA in all cases and EMA only in the few TTA borderline cases (12.0%) would have a sensitivity of 94.6% and a specificity of 98.1%. Conclusions: This study is the first to compare TTA with EMA. Due to 100% specificity and high sensitivity, EMA seems to be the most accurate coeliac antibody. Conversely, TTA offer advantages in terms of sensitivity and simplicity. A satisfactory strategy is to use TTA first and then EMA to confirm the borderline results.