Coeliac disease in the COVID-19 pandemic: does HLA have a protective effect?

BACKGROUND: The coronavirus disease 2019 (COVID-19), an acute respiratory disease caused by a novel coronavirus (SARS-CoV-2), is emerging as a worldwide public health emergency. Several scientific contributions reported the potential relevance of human leukocyte antigen (HLA) polymorphism and susceptibility to viruses, such as SARS-CoV. In our study, we examined a population of coeliac subjects presenting the HLA haplotype DQ2 and/or DQ8. Our aim was to evaluate whether HLA DQ2 and/or DQ8 haplotype play a role in SARS-CoV-2-infection. The aim was also to evaluate the difficulty in following the gluten-free diet due to all the adversities produced by the pandemic, such as the food supply disruption, and the difficulties in managing the clinical follow-up. METHODS: 191 consecutive coeliac patients completed a questionnaire on their current clinical status, psychological effects, and management of the gluten-free diet experienced during the COVID-19 pandemic and questions regarding possible SARS-CoV-2 infection. RESULTS: Out of the 191 patients who participated in the study, 42 were full-blown coeliac and 149 were in remission. From the answers provided, 84.8% of patients declared that they no longer consider themselves vulnerable to COVID-19 as they suffer from coeliac disease; 94.2% of patients did not encounter any difficulties in managing the gluten-free diet or in acquiring specific foods and 64.9% of patients in our study underwent diagnostic testing for SARS-CoV-2. Out of this number, 31.5% did so due to contacts with subjects affected by COVID-19, 26.6% for work related reasons, 11.3% due to flu-like symptoms and 30.6% for other reasons. Only 5.8% of the enrolled patients received a diagnosis of COVID-19. Out of all the patients in our population who were diagnosed with COVID-19, 94.8% developed no symptoms and none of them needed hospitalization or intensive care. CONCLUSION: The hypothesis that the HLADQ2 and/or DQ8 haplotype plays a protective role against SARS-CoV-2 infection, as against other viral infections, is intriguingly suggestive.KEY MESSAGESCOVID-19 as a public health emergency;SARS-CoV-2 and possible complications in coeliac disease;Role of HLA DQ2 and/or DQ8 in SARS-CoV-2 infection.

Visceral and subcutaneous adipose tissue as markers of local and systemic inflammation: a comparison between celiac and obese patients using MRI.

BACKGROUND: Celiac disease (CD) is a systemic inflammatory disease, which primarily affects the gastrointestinal tract. It has been recently demonstrated that adipose-tissue infiltration by proinflammatory immune cells causes a chronic low-grade inflammation in obese patients. Magnetic resonance imaging (MRI) has already proved to be useful in evaluation of inflammatory states. The aim of the present study was to determine whether alterations of visceral and subcutaneous adipose tissue, identified with MRI, could serve as markers of local and systemic inflammation in patients with CD. METHODS: A pilot study was conducted comparing alterations in visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) in CD patients vs obese patients and healthy controls. Fifty patients were enrolled and assigned to one of the following groups: Group A: 11 active CD patients; Group B: 11 CD patients in remission; Group C: 16 obese patients; Group D: 12 healthy controls. A 3-T MRI unit was used and T2-weighted TSE images of VAT and SAT were obtained in specific regions of interest. Serum cytokine concentrations (TNF-α, IL-6, adiponectin, leptin, IL-2, IFN-γ) were determined. RESULTS: There was a significant difference in VAT T2 relaxation time between Group A and B (p < 0.001), A and D (p < 0.01), B and C (p < 0.001). There was a statistically significant difference in SAT T2 relaxation time between Group A and B (p < 0.001), A and C (p < 0.05), A and D (p < 0.001), B and C (p < 0.01). In addition, VAT/SAT T2 relaxation time ratio showed a statistically significant difference between Group A and C (p < 0.05) and between Group B and C (p < 0.01). Only TNF-α and IL-6 significantly correlated with both VAT and VAT/SAT ratio in active CD. CONCLUSIONS: MRI showed similar increased visceral inflammatory signals in patients with active CD and obese patients. However, subcutaneous inflammatory signals were higher in active CD than in all the other groups. These data show that there is a systemic inflammatory state in active CD, whereas chronic inflammation appears confined to VAT in obesity. These data were only partially confirmed by serological cytokine profiles, which showed less specificity than MRI.

Sporadic pedunculated duodenal adenomas. Clinical presentations and endoscopic management: a case series.

The prevalence of sporadic duodenal polyps is estimated to be 0.3%-4.6% in patients referred for an upper endoscopy. Most of patients are asymptomatic (66-80%) at the time of diagnosis though bleeding, anemia and abdominal pain are the most commonly reported symptoms. These are related to the polyp's size, location and histological characteristics. We describe three cases of big, pedunculated nonampullary sporadic duodenal polyps (tubulovillous low-grade dysplasia adenomas) located in the second part of the duodenum and characterized by different clinical presentations, managed in our Endoscopic Unit within one year (between 2016 and 2017). Polypectomies were performed, either piece-meal or en-bloc using various endoscopic instruments. In one of our patients (case 1), a delayed bleeding (36 hours after the procedure) occurred eventually managed conservatively with two units of blood transfusion. In the same patient, in the following months after polypectomy, the pre-procedural state of anemia misclassified as Mediterranean anemia has improved with a significant rise of hemoglobin value (14.1g/dl). In a patient who previously underwent a renal transplant (case 2), endoscopy was indicated, based on the positive fecal occult blood test. In another patient (case 3), a big polyp induced pancreatitis since it exerted a strong traction on the duodenal wall during peristaltic movements. The removal of the polyp has led to the resolution of pancreatitis and associated symptoms.

Impact of gluten-free diet on quality of life in celiac patients.

BACKGROUND AND AIM: Celiac disease (CD) is a common gluten-related disorder, whose only treatment is a gluten-free diet (GFD). Since a unique view on psychological consequences of a GFD still lacks, our aim was to assess the quality of life (QoL) and the depression state in symptomatic CD patients after GFD. Socio-demographic features were considered. PATIENTS AND METHODS: 210 adult CD patients were recruited and divided into 3 groups : 70 newly diagnosed patients (​Group A​),70 patients who have been on GFD for 6-12 months (​Group B​), and 70 patients who have been on GFD for more than 12 months (​Group C​). We recruited 210 healthy controls (​Group D). Psychological General Well-Being Index (PGWBI) and Beck Depression Inventory (BDI) questionnaires were administered. Each group was evaluated according to age, gender and school ranking. RESULTS: Groups A ​and B showed lower PGWBI scores compared with both Group C ​and D (p <0.001 for each comparison). Moreover, Groups A and B showed higher BDI scores compared with both ​Group C ​and D (p <0.001 for each comparison).Women, the elderly and the poorly educated seemed to suffer more psychological stress. CONCLUSION: GFD induces an improvement of well-being and a decrease of depression state after 12 months of strict GFD. Negative psychological implications were observed only in specific risk categories. (Acta gastroenterol. belg., 2016, 79, 447-453).

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.

Antitissue transglutaminase antibodies in acute coronary syndrome: an alert signal of myocardial tissue lesion?

BACKGROUND AND AIM: Antitransglutaminase, previously considered identical to antiendomysial in coeliac sprue (CS), have been reported in end-stage heart failure. To clarify the above-mentioned data, we evaluated these antibodies in a cohort of cardiological patients with respect to troponin I, creatine kinase (CK), MB fraction creatine kinase (CK-MB mass) and myoglobin. METHODS: Forty-one patients with acute coronary syndrome (ACS), 39 with dilated cardiomyopathy (DCM), 45 with CS and 58 blood donors (BDs) were evaluated. Antitransglutaminase and antiendomysial antibodies were tested in serum of the patients being studied. RESULTS: High-positive antitransglutaminase values were found in CS, whilst low-positive values were also found in ACS and DCM. In patients at the second ACS, antibody levels were higher than in those at the first cardiac event. In patients with infarct Q, antitransglutaminase were higher than those in infarct non-Q, in which antibody levels were higher than those in unstable angina. A correlation between antitransglutaminase and troponin I, CK, CK-MB mass and myoglobin was found. Finally, antibody levels rose to reach a peak at 30 days from the cardiac event, whereas after further 150 days, approached the values of BDs. Antiendomysial were detectable only in CS. CONCLUSIONS: Data highlight that antitransglutaminase can occur in cardiological patients, and that these antibodies are related to the severity/extent of the myocardial tissue lesion. This feature suggests a loss of specificity for antitransglutaminase in CS. Furthermore, the possibility of employing these antibodies in the long-term follow-up of ACS, could become an object of interesting discussion.

Prevalence of celiac disease in patients with autoimmune thyroiditis.

AIM: Many autoimmune disorders are associated to celiac disease (CD) but the association with autoimmune thyroiditis has been more frequently documented; this is in part explained by a shared immunogenetic make-up, and in part caused to time gluten-exposition, as suggested by the significant correlation observed in celiac patients between the increase occurrence of autoimmune diseases and the length of exposure to gluten. The aim of this study was to establish the prevalence of celiac disease in a group of subjects with autoimmune thyroiditis newly diagnosed on the basis of antibodies anti-peroxidase (TPO). METHODS: A total of 113 untreated patients with TPO >70 IU/mL were enrolled. CD was screened by measuring anti-endomysial antibodies (EMA) both IgA and IgG; an high prevalence of positive serology was resulting in this group, justified, in part, from EMA IgG investigation. RESULTS: In fact 31/113 patients showed IgA and/or IgG positivity and were diagnosed as celiacs with jejunal biopsy. CONCLUSION: On the basis of this paper, such as in according to current research-setting studies, the greater frequency of CD in association to autoimmune thyroid disease suggests that all subjects with TPO should be routinely screened for CD, through EMA IgA and IgG. However, the performance of this screening has never been evaluated until now, even if it could, in fact, be valid in order to increment diagnosis of CD, today still undiagnosed.

Detection of anti-endomysial and anti-tissue transglutaminase autoantibodies in media following culture of oral biopsies from patients with untreated coeliac disease.

BACKGROUND AND AIMS: Coeliac disease is an autoimmune disorder characterised by high levels of anti-endomysial and anti-tissue transglutaminase autoantibodies in sera and media of cultured intestinal mucosa biopsies from affected patients. In this study, we wished to investigate whether anti-endomysial and anti-tissue transglutaminase antibodies can also be detected in culture media of oral mucosa specimens, and whether the mouth can be used as an area of immunological testing for coeliac disease. METHODS: Small intestine and cheek biopsy samples taken from 16 patients with active coeliac disease and from 11 controls were cultured in vitro for 48 h at 37 degrees C in presence of medium alone. Anti-endomysial and anti-tissue transglutaminase were detected in sera and in supernatants of these cultured biopsy samples by indirect immunofluorescence and enzyme immunoassay (EIA), respectively. RESULTS: Anti-endomysial and anti-tissue transglutaminase were positive in sera of 15/16 coeliac disease patients. Culture media of intestinal mucosa samples from 14/16 coeliac disease patients were anti-endomysial positive, while the same antibodies were positive in supernatants of cultured oral mucosa samples from 15/16 coeliac disease patients. Anti-tissue transglutaminase were positive in both intestinal and oral culture media of 15/16 coeliac disease patients. Neither anti-endomysial nor anti-tissue transglutaminase were found in sera or in culture supernatants of both intestinal and oral biopsy samples from 11 controls. CONCLUSIONS: Our study suggests a new immunological site to detect the pathognomonic autoantibodies of coeliac disease and confirms that the mouth is involved in this illness.

Chronic abdominal pain associated with intermittent compression of the celiac artery.

Recurrent abdominal pain (RAP), surely one of the most frequent causes of medical intervention, is frequently present in many gastrointestinal disease. Usually no structural and/or biochemical alterations can be demonstrated. This condition is, therefore, considered to be due to functional disorders such as irritable bowel syndrome (IBS) or functional dyspepsia. Previous observations suggest the presence of a rare alteration of celiac vessels among the possible causes of RAP. This pathological condition was known as Dunbar syndrome. We report 2 cases of chronic abdominal pain. The former reported weight loss and the latter anemia with iron deficiency. It is remarkable that patients with initial diagnosis of IBS can be affected by celiac disease (CD), which is the cause of their abdominal pain. Our patients were tested for CD; the former was negative and IBS was diagnosed, the latter was positive and a gluten free diet was prescribed. The presence of an epigastric bruit, accentuated during expiration, suggested a possible vascular alteration known as tripod celiac artery compression syndrome. Duplex Doppler sonography suggests the diagnosis of celiac arterial constriction due the diaphragmatic ligament. These cases show that tripod celiac artery compression syndrome might be a cause of RAP and that it may be evaluated and investigated when the clinical examination discloses an abdominal systolic bruit.

Gloves and socks syndrome caused by parvovirus B19 infection.

The papular purpuric gloves and socks syndrome (PPGSS) is an uncommon dermatosis with a typical purpuric exanthem limited to hands and feet; it occurs mainly in young adults. We report a case of a 19-year-old man with an acute febrile illness accompanied by purpuric and papular lesions located mostly on the dorsal areas of his hands and feet. Serologic analysis for parvovirus B19 yielded positive results. The diagnosis of PPGSS was made. The eruption cleared without therapy in 12 days with plantar and palmar desquamation. Parvovirus B19 and some other viral infections have been proven to be causative agents of this syndrome.

Evidence of a selective epitope loss of anti-transglutaminase immunoreactivity in gluten-free diet celiac sera: a new tool to distinguish disease-specific immunoreactivities.

The aim of the present study was to evaluate the epitope specific humoral human tissue transglutaminase (tTG) immunoreactivity against 3 different human recombinant tTG constructs [(full-length tTG (a.a. 1-687), tTG (a.a. 227-687); tTG (a.a. 473-687)] before and after the introduction of a gluten-free diet (GFD). To this end, sera from 64 celiac disease (CD) subjects on a gluten-containing diet (44 f, 20 m) and after 0.6 +/- 0.3 years and 2.1 +/- 1.3 years of GFD were studied using a quantitative radioimmunoprecipitation assay. All 64 CD patients at diagnosis were full-length anti-tTG (a.a. 1-687)Ab positive. These Abs significantly decreased in frequency and titer after 6 months and 2 years of GFD. However, at low titers, 64.1% (41/64) of CD patients were still fl-tTG (a.a. 1-687)Ab positive after 2 years of GFD. At disease diagnosis, 70.3% (45/64) of the CD patients had Abs directed against fragments (227-687) and/or (473-687) of the tTG protein. This percentage, after 2 years of GFD, significantly decreased to 18.7%, whereas almost 50% of GFD patients had no tTG (227-687) and tTG (473-687) fragment reactivity, but only persistent, low-titer full-length tTG (1-687)Abs. We suggest that the selective loss of immunoreactivity against tTG (227-687) and tTG (473-687) fragments in CD patients with a GFD, could be due to quantitative decrease of autoreactivity driven by tTG-gliadin interaction underlying celiac disease pathogenesis.

Anti-endomysial antibody of IgG1 isotype detection strongly increases the prevalence of coeliac disease in patients affected by type I diabetes mellitus.

A strong association between type 1 insulin-dependent diabetes mellitus (IDDM1) and coeliac disease (CD) is well documented, but it is known that prevalence values are underestimated. Serum anti-endomysial antibodies (EMA), considered diagnostic for CD because of their high sensitivity and specificity, belong to the IgA class, but the existence of EMA of IgG1 isotype in the presence or absence of IgA deficiency was reported. In order to re-evaluate the occurrence of CD in IDDM1 patients we performed a screening in IDDM1 patients using EMA of both isotypes. Ninety-four adults affected by IDDM1 (unaffected by CD before enrolling) were enrolled and 83 blood donors as controls. All subjects were on a gluten-containing diet. Histology and biopsy culture were performed. EMA IgA and IgG1 in sera and culture supernatants were detected. Serum EMA were positive in 13 of 94 IDDM1 patients (13.8%). Six of 13 presented IgA-EMA, seven of 13 presented IgG1-EMA. No EMA were found in the control population. Total intestinal atrophy was found in all six patients with serum IgA-EMA and in five of seven with serum IgG1-EMA. Diagnosis of CD was confirmed by histology and organ culture in all 13 patients with serum EMA. The prevalence of CD in the patients affected by IDDM1 was 6.4% for IgA-EMA-positive and 7.4% for IgG1-EMA-positive patients. We confirmed the prevalence of CD in the IDDM1 population obtained with IgA-EMA screening only (6.4%). This prevalence value increases dramatically to 13.8% when IgG1-EMA are also used in the screening. We conclude that IgG1-EMA should also be sought whenever an IDDM1 patient undergoes screening for CD.

Abdominal CT findings may suggest coeliac disease.

BACKGROUND: Coeliac disease is the most common gastrointestinal immunological disorder in the western countries. Many adult patients present non-specific symptoms and signs of malabsorption such as chronic diarrhoea, anaemia, weight loss and abdominal distention. In non-specific and doubtful conditions, computed tomography is often the first medical examination performed. In a clinical practice, a critical review of computed tomography signs is therefore mandatory. AIMS: To evaluate the abdominal computed tomography findings, which are useful to suggest the presence of coeliac disease in adult patients. PATIENTS AND METHODS: The computed tomography studies of 28 coeliac patients were reviewed, looking for any intestinal and extraintestinal abnormality. The computed tomography findings evaluated were: abnormalities of intestinal fold pattern, bowel dilatation, fluid and air excess, duodenal abnormalities, intestinal intussusception, bowel wall thickening, lymphadenopathy, ascites, intestinal stenosis, mesenteric vascular changes. The abdominal computed tomography of a group of 30 normal subjects was also analysed. RESULTS: Intestinal fold pattern abnormalities were seen in 23/28 patients. Intestinal dilatation was seen in 21/28. Fluid excess in 18/28 and lymphadenopathy was seen in 12/28 patients; engorgement of mesenteric vessels in 7/28. Bowel wall thickening was observed in 6/28 patients and transient intussusception was observed in 6/28 patients. Increased air content within the bowel in 4/28 and ascites in 2/28 patients. Bowel dilatation together with fluid excess was observed in 18/28 patients. None of the above mentioned abnormalities abnormalities were seen in normal subjects. CONCLUSIONS: Data of the present study show that several abdominal computed tomography findings may be seen in coeliac adult patients; these findings should be taken into consideration with a high in level of suspicion by radiologists, to avoid diagnostic delay and unnecessary diagnostic and therapeutic procedures.

Celiac disease-associated transglutaminase autoantibody target domains at diagnosis are age and sex dependent.

The contribution of age and/or sex to the transglutaminase (tTG) autoantibody response in celiac disease (CD) is not known. To gain insights into transglutaminase humoral autoimmunity at CD diagnosis, our aim was to characterize the autoimmune response against three tTG constructs [(full-length tTG(a.a.1-687), tTG(a.a.227-687), and tTG(a.a.473-687)] and to investigate into its relationship with CD patients' age and sex. One hundred seventy-five newly diagnosed CD patients (115 females and 60 males), subdivided into different groups according to age and sex, were studied using a serum 35S-radioimmunoassay. We found that among full-length tTG autoantibody-positive CD subjects (175/175), 50.9% (89/175) and 83.4% (146/175) had autoantibodies against tTG(227-687) and tTG(473-687) domains, respectively. Female patients of less than 4 years expressed tTG(227-687)Abs in significantly higher percentage and mean autoantibody titers vs. all other groups investigated, and tTG(473-687)Abs in significantly higher titers with respect to adult female patients. Our data identify a subset of CD patients showing a strong humoral tTG immunoreactivity at diagnosis, thus suggesting that age and sex influence the anti-tTG autoantibody response.

123I-Interleukin-2: biochemical characterization and in vivo use for imaging autoimmune diseases.

We describe in detail the labelling of interleukin-2 with I ( I-IL2), its biochemical characterization, the binding assay and its use for the detection of tissues infiltrated with mononuclear cells. Human recombinant IL2 was labelled using an enzymatic method and its biochemical characterization was performed using high performance liquid chromatography (HPLC) analysis of cyanogen bromide-cleaved protein. biological and binding assays were performed on CTLL-2 cell line and on activated peripheral blood lymphocytes. studies were performed 1 h after administration of 2-3 mCi of I-IL2 in 10 newly diagnosed type 1 diabetes patients, five pre-diabetic patients, 10 Hashimoto's thyroiditis patients, 10 coeliac disease patients and 10 normal volunteers. I-IL2 scintigraphy allowed the detection and quantification of activated mononuclear cells in several affected tissues. In detail, I-IL2 accumulation was detected in the thyroid of all patients affected by Hashimoto's thyroiditis, in the bowel of all coeliac disease patients and in the pancreas of all pre-type 1 diabetic patients. By contrast, in newly diagnosed type 1 diabetics, I-IL2 scan was positive in five of the 10 studied patients. I-IL2 scintigraphy may be useful for studying autoimmune phenomena and in diagnostic protocols to evaluate the presence of other tissue involvement in patients with an organ-specific autoimmune disease.

Antibodies to bovine beta-casein in diabetes and other autoimmune diseases.

Cow's milk is thought to be an environmental trigger for autoimmune response in Type 1 diabetes. In the present study, our aim was to investigate the antibody response to bovine beta-casein in different immune- and non-immune-mediated diseases and to establish whether such an antibody response is specific to Type 1 diabetes. We measured antibodies to bovine beta-casein using an enzyme-linked immunosorbent assay in a total of 519 sera from subjects as follows: 71 patients with Type 1 diabetes, 33 patients with coeliac disease, 100 patients with latent autoimmune diabetes in adults (LADA), 50 patients with autoimmune thyroid disease (ATD), 50 patients with Type 2 diabetes, 24 patients with multiple sclerosis (MS), and 3 different groups of controls (n = 191). Significantly increased levels of antibodies to beta-casein were found in patients with Type 1 diabetes, coeliac disease and in LADA compared to age-matched controls (p = 0.01, p = 0.02 and p = 0.01, respectively). No differences were observed in beta-casein antibody titres between patients with other disease conditions (MS, and ATD) and age-matched controls. The highest antibody response to beta-casein in Type 1 diabetic patients and in patients with coeliac disease could reflect the gut mucosal immune disorders common to Type 1 diabetes and coeliac disease. Furthermore, the elevated beta-casein antibody levels found in LADA patients suggest that the antibody response to this protein may be relevant in autoimmune diabetes.

[Anti-tissue transglutaminase antibodies in inflammatory and degenerative arthropathies]. / Anticorpi anti-transglutaminasi tissutale nelle artropatie a carattere infiammatorio e degenerativo.

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.