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1.
Cells ; 10(7)2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34360011

RESUMO

Transglutaminase 2 (TG2) is a ubiquitously expressed enzyme catalyzing the crosslinking between Gln and Lys residues and involved in various pathophysiological events. Besides this crosslinking activity, TG2 functions as a deamidase, GTPase, isopeptidase, adapter/scaffold, protein disulfide isomerase, and kinase. It also plays a role in the regulation of hypusination and serotonylation. Through these activities, TG2 is involved in cell growth, differentiation, cell death, inflammation, tissue repair, and fibrosis. Depending on the cell type and stimulus, TG2 changes its subcellular localization and biological activity, leading to cell death or survival. In normal unstressed cells, intracellular TG2 exhibits a GTP-bound closed conformation, exerting prosurvival functions. However, upon cell stimulation with Ca2+ or other factors, TG2 adopts a Ca2+-bound open conformation, demonstrating a transamidase activity involved in cell death or survival. These functional discrepancies of TG2 open form might be caused by its multifunctional nature, the existence of splicing variants, the cell type and stimulus, and the genetic backgrounds and variations of the mouse models used. TG2 is also involved in the phagocytosis of dead cells by macrophages and in fibrosis during tissue repair. Here, we summarize and discuss the multifunctional and controversial roles of TG2, focusing on cell death/survival and fibrosis.


Assuntos
Aminoaciltransferases/genética , Carbono-Nitrogênio Liases/genética , Fibrose/enzimologia , Proteínas de Ligação ao GTP/genética , Inflamação/enzimologia , Isomerases de Dissulfetos de Proteínas/genética , Transglutaminases/genética , Processamento Alternativo , Aminoaciltransferases/imunologia , Animais , Cálcio/imunologia , Cálcio/metabolismo , Carbono-Nitrogênio Liases/imunologia , Morte Celular , Sobrevivência Celular , Fibrose/genética , Fibrose/imunologia , Fibrose/patologia , Proteínas de Ligação ao GTP/imunologia , Expressão Gênica , Guanosina Trifosfato/imunologia , Guanosina Trifosfato/metabolismo , Humanos , Inflamação/genética , Inflamação/imunologia , Inflamação/patologia , Isoenzimas/genética , Isoenzimas/imunologia , Macrófagos/enzimologia , Macrófagos/imunologia , Fagocitose/genética , Isomerases de Dissulfetos de Proteínas/imunologia , Transglutaminases/imunologia
2.
J Autoimmun ; 122: 102682, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34214763

RESUMO

The variability in resolution of SARS-CoV-2-infections between individuals neither is comprehended, nor are the long-term immunological consequences. To assess the long-term impact of a SARS-CoV-2-infection on the immune system, we conducted a prospective study of 80 acute and former SARS-CoV-2 infected individuals and 39 unexposed donors to evaluate autoantibody responses and immune composition. Autoantibody levels against cyclic citrullinated peptide (CCP), a specific predictor for rheumatoid arthritis (RA), were significantly (p = 0.035) elevated in convalescents only, whereas both acute COVID-19 patients and long-term convalescents showed critically increased levels of anti-tissue transglutaminase (TG), a specific predictor of celiac disease (CD) (p = 0.002). Both, anti-CCP and anti-TG antibody levels were still detectable after 4-8 months post infection. Anti-TG antibodies occurred predominantly in aged patients in a context of a post-SARS-CoV-2-specific immune composition (R2 = 0.31; p = 0.044). This study shows that increased anti-CCP and anti-TG autoantibody levels can remain long-term after recovering even from mildly experienced COVID-19. The inter-relationship of the lung as viral entry side and RA- and CD-associated autoimmunity indicates that a SARS-CoV-2-infection could be a relevant environmental factor in their pathogenesis.


Assuntos
Autoanticorpos/sangue , COVID-19/imunologia , Peptídeos Cíclicos/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Anti-Proteína Citrulinada/sangue , Anticorpos Anti-Proteína Citrulinada/imunologia , Artrite Reumatoide/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Doença Celíaca/imunologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , SARS-CoV-2 , Transglutaminases/imunologia , Adulto Jovem
3.
Front Immunol ; 12: 674313, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34149709

RESUMO

Several environmental, genetic, and immune factors create a "perfect storm" for the development of coeliac disease: the antigen gluten, the strong association of coeliac disease with HLA, the deamidation of gluten peptides by the enzyme transglutaminase 2 (TG2) generating peptides that bind strongly to the predisposing HLA-DQ2 or HLA-DQ8 molecules, and the ensuing unrestrained T cell response. T cell immunity is at the center of the disease contributing to the inflammatory process through the loss of tolerance to gluten and the differentiation of HLA-DQ2 or HLA-DQ8-restricted anti-gluten inflammatory CD4+ T cells secreting pro-inflammatory cytokines and to the killing of intestinal epithelial cells by cytotoxic intraepithelial CD8+ lymphocytes. However, recent studies emphasize that the individual contribution of each of these cell subsets is not sufficient and that interactions between these different populations of T cells and the simultaneous activation of innate and adaptive immune pathways in distinct gut compartments are required to promote disease immunopathology. In this review, we will discuss how tissue destruction in the context of coeliac disease results from the complex interactions between gluten, HLA molecules, TG2, and multiple innate and adaptive immune components.


Assuntos
Imunidade Adaptativa/imunologia , Doença Celíaca/imunologia , Glutens/imunologia , Antígenos HLA/imunologia , Imunidade Inata/imunologia , Animais , Doença Celíaca/patologia , Proteínas de Ligação ao GTP/imunologia , Humanos , Transglutaminases/imunologia
4.
Nutrients ; 13(5)2021 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-34064541

RESUMO

An association between celiac disease and IgA nephropathy (IgAN) has been suggested. In celiac disease, in addition to circulating in serum, IgA-class tissue transglutaminase (tTG) autoantibodies are deposited in the small bowel mucosa and extraintestinal organs. In this case series of IgAN patients with or without celiac disease, we studied whether celiac disease-type IgA-tTG deposits occur in kidney biopsies. The study included nine IgAN patients, four of them with celiac disease. At the time of the diagnostic kidney biopsy serum tTG autoantibodies were measured and colocalization of IgA and tTG was investigated in the frozen kidney biopsies. Three IgAN patients with celiac disease had IgA-tTG deposits in the kidney even though in two of these the celiac disease diagnosis had been set years later. These deposits were not found in a patient with already diagnosed celiac disease following a gluten-free diet. Of the five non-celiac IgAN patients, three had IgA-tTG deposits in the kidney. We conclude that tTG-targeted IgA deposits can be found in the kidney biopsies of gluten-consuming IgAN patients but their specificity to celiac disease seems limited.


Assuntos
Autoanticorpos/sangue , Biópsia , Doença Celíaca/diagnóstico , Doença Celíaca/patologia , Proteínas de Ligação ao GTP/imunologia , Glomerulonefrite por IGA/patologia , Rim/patologia , Transglutaminases/imunologia , Adulto , Dieta Livre de Glúten , Feminino , Glutens , Humanos , Imunoglobulina A/sangue , Mucosa Intestinal/patologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
5.
Sci Rep ; 11(1): 11946, 2021 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34099759

RESUMO

The detailed pathogenesis of eosinophilic bronchitis (EB) remains unclear. Transglutaminase 2 (TG2) has been implicated in many respiratory diseases including asthma. Herein, we aim to assess preliminarily the relationship of TG2 with EB in the context of the development of an appropriate EB model through ovalbumin (OVA) sensitization and challenge in the C57BL/6 mouse strain. Our data lead us to propose a 50 µg dose of OVA challenge as appropriate to establish an EB model in C57BL/6 mice, whereas a challenge with a 400 µg dose of OVA significantly induced asthma. Compared to controls, TG2 is up-regulated in the airway epithelium of EB mice and EB patients. When TG2 activity was inhibited by cystamine treatment, there were no effects on airway responsiveness; in contrast, the lung pathology score and eosinophil counts in bronchoalveolar lavage fluid were significantly increased whereas the cough frequency was significantly decreased. The expression levels of interleukin (IL)-4, IL-13, IL-6, mast cell protease7 and the transient receptor potential (TRP) ankyrin 1 (TRPA1), TRP vanilloid 1 (TRPV1) were significantly decreased. These data open the possibility of an involvement of TG2 in mediating the increased cough frequency in EB through the regulation of TRPA1 and TRPV1 expression. The establishment of an EB model in C57BL/6 mice opens the way for a genetic investigation of the involvement of TG2 and other molecules in this disease using KO mice, which are often generated in the C57BL/6 genetic background.


Assuntos
Bronquite/imunologia , Modelos Animais de Doenças , Eosinófilos/imunologia , Proteínas de Ligação ao GTP/imunologia , Transglutaminases/imunologia , Animais , Asma/induzido quimicamente , Asma/imunologia , Bronquite/induzido quimicamente , Bronquite/metabolismo , Cistamina/farmacologia , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Eosinófilos/efeitos dos fármacos , Eosinófilos/metabolismo , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/genética , Inflamação/imunologia , Inflamação/metabolismo , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/patologia , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Ovalbumina , Canal de Cátion TRPA1/genética , Canal de Cátion TRPA1/imunologia , Canal de Cátion TRPA1/metabolismo , Transglutaminases/genética , Transglutaminases/metabolismo
6.
Front Immunol ; 12: 645143, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33959126

RESUMO

The reason why only few coeliac patients develop the cutaneous manifestation of the disease, named dermatitis herpetiformis (DH), is still unknown. Epidermal transglutaminase (TG3) has been described as the main autoantigen of humoral immunity in DH but the mechanisms leading to this autoimmune response remain obscure. Here we characterized T cells from skin, gut and peripheral blood of DH and coeliac disease (CD) patients, evaluated the impact of the gluten-free diet on circulating T lymphocytes' phenotype and investigated antigen specific T cell response toward epidermal and tissue transglutaminase (TG2). DH patients showed an increased frequency of skin-derived T cells producing TNFα when compared to CD patients. Moreover, circulating T cells producing TNFα and IL-17A positively correlated with clinical score of skin disease activity and decreased after gluten-free diet. Finally, TG2 and TG3-specific T cells resulted more reactive to antigens stimulation in DH patients and showed cross reactivity toward the two autoantigens in both the group of patients. Our data suggest a role of TNFα and IL-17A producing cells in the development of DH and, for the first time, show the existence of a crossed T cell response toward the two transglutaminases isoforms, thus suggesting new insights on T cells role in skin damage.


Assuntos
Doença Celíaca/imunologia , Dermatite Herpetiforme/imunologia , Proteínas de Ligação ao GTP/imunologia , Linfócitos T/imunologia , Transglutaminases/imunologia , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Interleucina-17/imunologia , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/imunologia
7.
J Immunol ; 206(10): 2420-2429, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33941660

RESUMO

We have recently shown that type 2 transglutaminase (TG2) plays a key role in the host's inflammatory response during bacterial infections. In this study, we investigated whether the enzyme is involved in the regulation of the STING pathway, which is the main signaling activated in the presence of both self- and pathogen DNA in the cytoplasm, leading to type I IFN (IFN I) production. In this study, we demonstrated that TG2 negatively regulates STING signaling by impairing IRF3 phosphorylation in bone marrow-derived macrophages, isolated from wild-type and TG2 knockout mice. In the absence of TG2, we found an increase in the IFN-ß production and in the downstream JAK/STAT pathway activation. Interestingly, proteomic analysis revealed that TG2 interacts with TBK1, affecting its interactome composition. Indeed, TG2 ablation facilitates the TBK1-IRF3 interaction, thus indicating that the enzyme plays a negative regulatory effect on IRF3 recruitment in the STING/TBK1 complex. In keeping with these findings, we observed an increase in the IFNß production in bronchoalveolar lavage fluids from COVID-19-positive dead patients paralleled by a dramatic decrease of the TG2 expression in the lung pneumocytes. Taken together, these results suggest that TG2 plays a negative regulation on the IFN-ß production associated with the innate immunity response to the cytosolic presence of both self- and pathogen DNA.


Assuntos
COVID-19/imunologia , Proteínas de Ligação ao GTP/imunologia , Imunidade Inata , Fator Regulador 3 de Interferon/imunologia , Proteínas de Membrana/imunologia , Proteínas Serina-Treonina Quinases/imunologia , SARS-CoV-2/imunologia , Transdução de Sinais/imunologia , Transglutaminases/imunologia , Animais , COVID-19/genética , COVID-19/patologia , Proteínas de Ligação ao GTP/genética , Humanos , Fator Regulador 3 de Interferon/genética , Interferon beta/genética , Interferon beta/imunologia , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Proteínas Serina-Treonina Quinases/genética , Transdução de Sinais/genética , Transglutaminases/genética
8.
Am J Gastroenterol ; 116(7): 1545-1549, 2021 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-33852450

RESUMO

INTRODUCTION: To evaluate the diagnostic performance of celiac serologic tests in asymptomatic patients with type 1 diabetes (T1D). METHODS: Patients with T1D asymptomatic for celiac disease were prospectively screened with immunoglobulin A anti-tissue transglutaminase. Test characteristics were calculated and optimal cutoffs for a positive screen determined. RESULTS: Two thousand three hundred fifty-three patients were screened and 101 proceeded to biopsy. The positive predictive value of immunoglobulin A anti-tissue transglutaminase at the assay referenced upper limit of normal (30CU) was 85.9%, and the sensitivity and specificity were 100% and 38%, respectively. DISCUSSION: Thresholds extrapolated from the general population for the diagnostic evaluation of celiac disease are not suitable for use in asymptomatic T1D patients. Population-specific screening cutoffs are required.


Assuntos
Doenças Assintomáticas , Doença Celíaca/diagnóstico , Diabetes Mellitus Tipo 1/complicações , Adolescente , Adulto , Biópsia , Doença Celíaca/imunologia , Doença Celíaca/patologia , Criança , Duodeno/patologia , Feminino , Proteínas de Ligação ao GTP/imunologia , Humanos , Imunoglobulina A/imunologia , Masculino , Programas de Rastreamento , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Testes Sorológicos , Transglutaminases/imunologia , Adulto Jovem
9.
Eur J Dermatol ; 31(2): 155-160, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33871374

RESUMO

BACKGROUND: Although specific IgE antibodies reactive to exogenous antigens are found in patients with atopic dermatitis (AD), some patients do not have such antibodies. Autoimmunity has been proposed as a possible mechanism in these patients. OBJECTIVES: To identify specific IgE antibodies reactive to human transglutaminase 3 (TG3) and tropomysin (TMP) and determine whether auto-reactive T cells are induced by these proteins in patients with AD. MATERIALS & METHODS: Forty-two patients with AD and 27 healthy controls were included in this study. IgE antibodies against recombinant human TG3 and TMP were measured by ELISA. Cross-reactivity between allergens was determined by EdU of peripheral blood mononuclear cells (PBMCs) proliferation assays. T-cell lines were generated from PBMCs in the presence of house dust mites (HDM), TG3 and TMP. TG3/TP-specific T-cell clones were generated from T-cell lines, and were characterized by antigen specificity and cytokine pattern. RESULTS: In 12 patients with anti-HDM IgE antibodies, six (50%) had anti-TG3 IgE antibody and four (33.3%) had both anti-TG3 and anti-TMP IgE antibodies. Lymphocyte proliferation was induced in 12 patients by TG3 or TMP. T-cell lines and T-cell clones from PBMCs of patients with AD who had IgE antibody reactive to HDM were fully cross-reactive with TG3 and TMP. These cell clones included both Th1 cell (producing IFN-γ) and Th2 cell (inducing IL-4) responses. TG3-and TMP-specific T-cell clones were not generated from healthy controls. CONCLUSION: Specific IgE antibody and T cell clones reactive to human TG3 and TMP were found in patients with AD, indicating that an autoimmune mechanism might contribute to AD.


Assuntos
Dermatite Atópica/imunologia , Imunoglobulina E/sangue , Pyroglyphidae/imunologia , Transglutaminases/imunologia , Tropomiosina/imunologia , Animais , Autoimunidade/imunologia , Estudos de Casos e Controles , Proliferação de Células , Células Cultivadas , Reações Cruzadas/imunologia , Dermatite Atópica/sangue , Humanos , Interferon gama/metabolismo , Interleucina-4/metabolismo , Células Th1/imunologia , Células Th2/imunologia
10.
Pediatr Dev Pathol ; 24(3): 206-212, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33538229

RESUMO

OBJECTIVES: The goal of our study was to determine whether visual assessment of the esophagus and stomach could predict abnormal histology and determine the frequency of interventions based on biopsies in patients undergoing endoscopy for elevated tissue transglutaminase immunoglobulin A antibody (TTG). METHODS: Pathology records were searched for patients with biopsy performed for elevated TTG. Pathology report, endoscopy report, and follow-up were obtained and slides from the duodenum reviewed. Pathology was considered gold standard for sensitivity and specificity calculations. RESULTS: 240 patients were included. 215 patients had esophageal biopsies performed. Esophageal endoscopic visual assessment had sensitivity of 47% and specificity of 93% for abnormal histology. 16(7%) patients had therapy or referral related to results and, of these, 6(38%) had visually normal endoscopy. 237 biopsies were performed of stomach. Gastric endoscopic visual assessment had a sensitivity and specificity of 20% and 87%. 24(10%) patients had therapy based on findings and, of these, 12 (50%) had visually normal endoscopy. CONCLUSIONS: Endoscopic assessment of esophagus and stomach has low sensitivity and high specificity for pathologic abnormalities when indication for endoscopy is elevated TTG. When endoscopy is visually normal clinical interventions based on biopsy are rare, and foregoing biopsy may be considered.


Assuntos
Autoanticorpos , Doença Celíaca/diagnóstico , Esofagoscopia/métodos , Gastroscopia/métodos , Autoantígenos/imunologia , Biópsia , Doença Celíaca/imunologia , Doença Celíaca/patologia , Criança , Feminino , Proteínas de Ligação ao GTP/imunologia , Humanos , Imunoglobulina A , Masculino , Sensibilidade e Especificidade , Transglutaminases/imunologia
12.
Am J Gastroenterol ; 116(1): 180-187, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32701732

RESUMO

INTRODUCTION: The Autoimmunity Screening for Kids (ASK) study is a large scale pediatric screening study in Colorado for celiac disease (CD) and type 1 diabetes. This is a report of the CD outcomes for the first 9,973 children screened through ASK. METHODS: ASK screens children aged 1-17 years for CD using 2 highly sensitive assays for tissue transglutaminase autoantibodies (TGA): a radiobinding (RBA) assay for IgA TGA and an electrochemiluminescence (ECL) assay that detects all TGA isotypes. Children who test positive on either assay are asked to return for confirmatory testing. Those with a confirmed RBA TGA level ≥ 0.1 (twice the upper limit of normal) are referred to the Colorado Center for Celiac Disease for further evaluation; all others are referred to primary care. RESULTS: Of the initial 9,973 children screened, 242 children were TGA+ by any assay. Of those initially positive, 185 children (76.4%) have completed a confirmation blood draw with 149 children (80.5%) confirming positive by RBA TGA. Confirmed RBA TGA+ was associated with a family history of CD (odds ratio [OR] = 1.83; 95% confidence interval 1.06-3.16), non-Hispanic white ethnicity (OR = 3.34; 2.32-4.79), and female sex (OR = 1.43; 1.03-1.98). Gastrointestinal symptoms of CD, assessed at the initial screening, were reported equally often among the RBA TGA+ vs TGA- children (32.1% vs 30.5%, P = 0.65). DISCUSSION: The initial results of this ongoing mass-screening program confirm a high prevalence of undiagnosed CD autoimmunity in a screened US population. Symptoms at initial screening were not associated with TGA status (see Visual abstract, Supplementary Digital Content 5, http://links.lww.com/AJG/B587).


Assuntos
Autoanticorpos/imunologia , Doença Celíaca/diagnóstico , Proteínas de Ligação ao GTP/imunologia , Transglutaminases/imunologia , Adolescente , Doenças Assintomáticas , Doença Celíaca/imunologia , Criança , Pré-Escolar , Técnicas de Diagnóstico por Radioisótopos , Técnicas Eletroquímicas , Feminino , Humanos , Imunoglobulina A/imunologia , Imunoglobulina D/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Lactente , Masculino , Programas de Rastreamento , Testes Sorológicos
13.
J Gastroenterol Hepatol ; 36(1): 44-54, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32621396

RESUMO

BACKGROUND AND AIM: Short stature is a common extraintestinal manifestation of celiac disease (CeD). We conducted a systematic review and meta-analysis to assess the global prevalence of CeD in patients presenting with short stature. METHODS: We searched Medline and EMBASE databases for the keywords "celiac disease, coeliac disease, anti-gliadin, tissue transglutaminase antibody, anti-endomysial antibody, short stature and growth retardation." All the studies published from January 1991 to May 2020 were included. Patients without any prior evaluation for short stature were classified as all-cause short stature, while prior evaluated patients, where no cause was found for short stature, were classified as idiopathic short stature. The diagnosis of CeD was based on the European Society for Paediatric Gastroenterology, Hepatology and Nutrition guidelines. A random-effects model was used to pool the data. RESULTS: Seventeen studies screening 3759 patients (1582 with all-cause short stature and 2177 with idiopathic short stature) were included. The pooled seroprevalence of CeD based on positive anti-tissue transglutaminase antibody and anti-endomysial antibody was 11.2% (95% CI 4.0-21.2%; I2  = 86%) and 9.7% (95% CI 2.7-20.2%; I2  = 95%) for all-cause and idiopathic short stature, respectively. Similarly, pooled prevalence of biopsy-confirmed CeD was 7.4% (95% CI 4.7-10.6%; I2  = 76%) and 11.6% (95% CI 4.1-22.2%; I2  = 97%), for all-cause and idiopathic short stature, respectively. There was an overall severe risk of selection bias and significant heterogeneity in the pooled results. CONCLUSIONS: Approximately one in 14 patients with all-cause short stature and one in nine patients with idiopathic short stature had biopsy-confirmed CeD. Therefore, evaluation for CeD may be prudent in all patients with short stature.


Assuntos
Estatura , Doença Celíaca/complicações , Doença Celíaca/epidemiologia , Transtornos do Crescimento/etiologia , Autoanticorpos/sangue , Biomarcadores/sangue , Biópsia , Doença Celíaca/diagnóstico , Doença Celíaca/imunologia , Feminino , Gliadina/imunologia , Transtornos do Crescimento/epidemiologia , Transtornos do Crescimento/patologia , Humanos , Masculino , Prevalência , Estudos Soroepidemiológicos , Transglutaminases/imunologia
14.
Front Immunol ; 11: 575805, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072118

RESUMO

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of coeliac disease (CD). Patients with DH have an elevated risk of development of another autoimmune blistering skin disease, bullous pemphigoid (BP). In this study we investigated whether patients with DH and CD (mean age for both 49 years) have circulating autoantibodies against BP180, the major BP autoantigen. ELISA tests showed that only a few DH (3/46) and CD (2/43) patients had BP180-NC16A IgG autoantibodies. Immunoblotting found that more than half of the DH samples contained IgG autoantibodies against full-length BP180. Epitope mapping with 13 fusion proteins covering the BP180 polypeptide revealed that in DH and CD patients, IgG autoantibodies did not target the NC16A or other epitopes typical of BP but recognized other intracellular and mid-extracellular regions of BP180. None of the analyzed DH and CD patients with either ELISA or immunoblotting positivity had IgG or IgA reactivity against the cutaneous basement membrane in indirect immunofluorescence analysis or skin symptoms characteristic of BP. Although only a minority of middle-aged DH patients had IgG autoantibodies against the immunodominant epitopes of BP180, our results do not exclude the possibility that intermolecular epitope spreading could explain the switch from DH to BP in elderly patients.


Assuntos
Autoanticorpos/sangue , Autoantígenos/imunologia , Autoimunidade , Doença Celíaca/imunologia , Dermatite Herpetiforme/imunologia , Epitopos Imunodominantes , Imunoglobulina G/sangue , Colágenos não Fibrilares/imunologia , Penfigoide Bolhoso/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Doença Celíaca/sangue , Doença Celíaca/diagnóstico , Dermatite Herpetiforme/sangue , Dermatite Herpetiforme/diagnóstico , Ensaio de Imunoadsorção Enzimática , Mapeamento de Epitopos , Feminino , Proteínas de Ligação ao GTP/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Penfigoide Bolhoso/sangue , Penfigoide Bolhoso/diagnóstico , Transglutaminases/imunologia
15.
Nutrients ; 12(9)2020 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-32911716

RESUMO

Non-biopsy diagnosis of celiac disease is possible in children with anti-transglutaminase 2 antibodies (TGA) > 10× the upper limit of normal (ULN) and positive anti-endomysial antibodies (EMA). Similar criteria have been suggested for adults, but evidence with different TGA assays is scarce. We compared the performance of four TGA tests in the diagnosis of celiac disease in cohorts with diverse pre-test probabilities. Serum samples from 836 adults with either clinical suspicion or family risk of celiac disease were tested with four commercial TGA assays, EmA and celiac disease-associated genetics. The diagnosis was set based on duodenal lesion or, in some cases, using special methods. 137 (57%) patients with clinical suspicion and 85 (14%) of those with family risk had celiac disease. Positive predictive value (PPV) for 10×ULN was 100% in each TGA test. The first non-diagnostic investigations were encountered with ULN 1.0×-5.1× in the clinical cohort and 1.3×-4.9× in the family cohort, respectively. Using the assays' own cut-offs (1×ULN) the PPVs ranged 84-100%. Serology-based diagnosis of celiac disease was accurate in adults using different commercial kits and pre-test probabilities using 10×ULN. The results also suggest that the ULN threshold for biopsy-omitting approach could be lower.


Assuntos
Biópsia/métodos , Doença Celíaca/diagnóstico , Probabilidade , Testes Sorológicos/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Autoanticorpos/sangue , Doença Celíaca/patologia , Estudos de Coortes , Duodeno/patologia , Feminino , Proteínas de Ligação ao GTP/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Transglutaminases/imunologia , Adulto Jovem
16.
Eur J Gastroenterol Hepatol ; 32(12): 1523-1526, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32956181

RESUMO

OBJECTIVES: Recent guidelines for celiac disease have allowed a biopsy-free approach in endomysial antibodies (EMAs) positive children with high antitransglutaminase (TGA-IgA) titer [>10 time upper limit of normal (ULN)]. Esophagogastroduodenoscopy is still necessary for diagnosis in children with lower title. Because elective pediatric endoscopy has been substantially shouted down during coronavirus disease (COVID-19) pandemic, many children remained undiagnosed - and therefore untreated - for a long time. We aimed to analyze the feasibility and accuracy of a biopsy-free approach in suspected celiac disease children with TGA-IgA values <10 ULN to facilitate the diagnostic process by avoiding endoscopy. METHODS: In this study cohort, we retrospectively analyzed all biopsy-confirmed diagnosis of celiac disease in our center (between 2014 and 2019). The positive predictive value (PPV) of TGA-IgA titers between 5 and 10 ULN and positive EMA in diagnosing celiac disease were determined. Mucosal atrophy and resolution of symptoms after gluten-free diet (GFD) were considered to confirm initial diagnosis. RESULTS: Of 430 celiac disease patients (F: 274; mean age 7.54 years) diagnosed by endoscopy, 84 (F: 46; mean age 8 years) with TGA-IgA between 5 and 10 ULN and positive EMA were identified. The PPV of TGA-IgA between 5 and 10 ULN and positive EMA was 0.93 (95% confidence interval 0.90-0.96). All these children had a symptom resolution and antibodies normalization after GFD. CONCLUSION: During the COVID-19 outbreak, a temporarily reduction of the TGA-IgA threshold for biopsy-sparing approach seems feasible in EMA positive children with TGA-IgA between 5 and 10 ULN.


Assuntos
Autoanticorpos/sangue , Betacoronavirus , Doença Celíaca/diagnóstico , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Guias de Prática Clínica como Assunto , Transglutaminases/imunologia , Autoanticorpos/imunologia , Biópsia , COVID-19 , Doença Celíaca/epidemiologia , Doença Celíaca/imunologia , Criança , Comorbidade , Infecções por Coronavirus/enzimologia , Infecções por Coronavirus/imunologia , Endoscopia do Sistema Digestório , Feminino , Humanos , Masculino , Pandemias , Pneumonia Viral/enzimologia , Pneumonia Viral/imunologia , Estudos Retrospectivos , SARS-CoV-2 , Transglutaminases/sangue
17.
Int J Biol Macromol ; 164: 4516-4531, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32941911

RESUMO

Recombinant antibodies fragments in several new formats are routinely investigated and used in diagnostic and therapeutic applications as anti-cancers molecules. New antibody formats are generated to compensate the need for multispecificity and site-specific introduction of fluorescent dyes, cytotoxic payloads or for generating semisynthetic multimeric molecules. Fabs of trastuzumab bearing transglutaminase (MTG) reactive sites were generated by periplasmic expression in E. coli and purified. Multimeric Fabs were generated by either disulfide bridge formation or by using MTG-sensitive peptide linkers. Binding to receptor was assessed by ELISA and SPR methods. Internalization and growth inhibition assays were performed on BT-474 and SKBR3 Her2+ cells. Fabs were successfully produced and dimerized or trimerized using MTG and suitably designed peptide linkers. Site-specific derivatizations with fluorophores were similarly achieved. The monomeric, dimeric and trimeric variants bind the receptor with affinities similar or superior to the full antibody. Fab and Fab2 are rapidly internalized in Her2+ cells and exhibit growth inhibition abilities similar to the full antibody. Altogether, the data show that the recombinant Fabs can be produced in E. coli and converted into multimeric variants by MTG-based bioconjugation. Similar approaches are extendable to the introduction of cytotoxic payloads for the generation of novel Antibody Drug Conjugates.


Assuntos
Imunoconjugados/química , Fragmentos Fab das Imunoglobulinas/química , Transglutaminases/imunologia , Trastuzumab/química , Sequência de Aminoácidos , Neoplasias da Mama/patologia , Carcinoma/patologia , Linhagem Celular Tumoral , Cistina/química , DNA Complementar/genética , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Escherichia coli , Feminino , Corantes Fluorescentes , Humanos , Imunoconjugados/imunologia , Fragmentos Fab das Imunoglobulinas/genética , Fragmentos Fab das Imunoglobulinas/imunologia , Modelos Moleculares , Fragmentos de Peptídeos/síntese química , Conformação Proteica , Engenharia de Proteínas , Multimerização Proteica , Receptor ErbB-2/imunologia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Ressonância de Plasmônio de Superfície , Trastuzumab/imunologia
18.
Nutrients ; 12(9)2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32967363

RESUMO

Dermatitis herpetiformis (DH) is an extraintestinal manifestation of gluten sensitivity, in which an autoimmune response is directed against transglutaminase 3 (TG3), an epidermal transglutaminase. TG2 is the autoantigen in celiac disease (CD), defined by the presence of enteropathy, and TG6 is the autoantigen in neurological manifestations of gluten sensitivity. The interplay between B cell responses to these 3 transglutaminases in developing the clinical spectrum of disease manifestations is not completely understood. Also, the individual or combined diagnostic and predictive value of the respective autoantibodies is not fully explored. We examined the prevalence of TG6 antibodies in a cohort of patients with DH. TG6 positivity was found in 13/33 (39%), with IgA detected in 11 patients, IgG in 3, and both in 1. This was significantly higher compared to what is seen in the classic CD cases (14%) in a Finnish population. TG6 positive baseline samples constituted 60% of DH patients with no enteropathy (n = 10), as opposed to 17% positivity in those with overt enteropathy (n = 12; Marsh IIIB). Repeat testing after adherence to a gluten-free diet for 1 year showed reduced titers for TG6 antibodies in 11/13 (85%), whereby 7 patients were now TG6 antibody-negative. Four patients seroconverted and tested positive for TG6 antibodies at one year, due to the ongoing exposure to gluten. We report another patient who presented with neurological manifestations (encephalopathy) leading to the diagnosis of CD, who was intermittently adhering to a gluten-free diet. Serological testing at baseline showed him to be positive for antibodies to all 3 transglutaminases. Eleven years later, he developed DH. He also subsequently developed ataxia and peripheral neuropathy. Although TG3 and TG6 autoantibodies are linked to certain disease manifestations, TG2, TG3, and TG6 autoantibodies can be present across the spectrum of GRD patients and might develop years before onset of symptoms of extraintestinal manifestations. This is consistent with gluten-dependent adaptive immunity being a necessary but not sufficient pretext to organ-specific damage. TG6 antibodies appear to develop more frequently in patients where tolerance to gluten was broken but, either there was no development of the molecular state driving the tissue destruction at the level of the gut, or perhaps more likely, there was more resistance to developing this phenotype.


Assuntos
Autoanticorpos/imunologia , Dermatite Herpetiforme/imunologia , Transglutaminases/imunologia , Adulto , Dermatite Herpetiforme/diagnóstico , Ensaio de Imunoadsorção Enzimática , Humanos , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Masculino
19.
Nutrients ; 12(8)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32751809

RESUMO

Adherence to a gluten-free diet (GFD) is currently the mainstay of treatment strategy for celiac disease (CD). The aim of our study was measuring a GFD adherence in CD patients using two newly validated methods of dietary assessment-Standardized Dietician Evaluation (SDE) and the Celiac Dietary Adherence Test (CDAT). Ninety-two adults with CD were evaluated by a registered dietitian with extensive experience with the use of SDE and CDAT. Duodenal biopsy was performed and blood was drawn for serum anti-endomysial, anti-deamidated gliadin peptide and anti-tissue transglutaminase antibodies in forty four of those patients. The results of CDAT and SDE were very convergent, but SDE scores better correlated with serologic and histologic findings. As many as 24-52% of study participants did not adhere well enough to a GFD. Insufficient adherence to a GFD in CD patients is still a significant problem. The knowledge about gluten content in food ingredients and additives is very low among adults with CD. SDE is the most accurate method in assessing compliance with a GFD and is especially helpful in determining hidden sources of gluten. The CDAT may be a fast tool for screening for a GFD adherence in CD patients.


Assuntos
Doença Celíaca/dietoterapia , Inquéritos sobre Dietas/estatística & dados numéricos , Dieta Livre de Glúten/estatística & dados numéricos , Cooperação do Paciente/estatística & dados numéricos , Adolescente , Adulto , Idoso , Autoanticorpos/sangue , Autoanticorpos/imunologia , Biópsia , Doença Celíaca/sangue , Doença Celíaca/patologia , Inquéritos sobre Dietas/métodos , Inquéritos sobre Dietas/normas , Duodeno/patologia , Feminino , Proteínas de Ligação ao GTP/imunologia , Gliadina/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Transglutaminases/imunologia , Adulto Jovem
20.
Scand J Clin Lab Invest ; 80(7): 552-555, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32844702

RESUMO

In coeliac disease, the diagnostic work-up is based on a combination of clinical, histopathological and serological evaluation. Among the serological tests, the presence of tissue transglutaminase (tTG) IgA antibodies is the cornerstone owed to a high sensitivity and specificity. Recently, Immunodiagnostic Systems Ltd (IDS) introduced the fully automated chemiluminescent autoimmune assays for use on the IDS-iSYS Multi-Discipline Automated System. In this study, we aimed to compare the performance of the IDS-iSYS assay to the Thermo Fisher Phadia assay and to establish the upper reference limit of tTG IgA in a healthy population from Denmark based on the IDS-iSYS assay. We discovered a total imprecision of CV = 12.2% (2.87 AU/mL) and CV = 10.6% (47.55 AU/mL). Moreover, we compared the performance of IDS-iSYS assay to Thermo Fisher Phadia assay in 236 samples from unselected patients submit for tTG IgA testing and found a concordance of 97% (p < .0001). Furthermore, in 150 healthy blood donors, we established the upper reference limit of 3.26 AU/mL (95% CI: 3.10 - 3.90) was identified. Our study validates the performance of the IDS-iSYS tTG IgA assay and demonstrates results in concordance with the established Thermo Fisher Phadia. Furthermore, it provides estimates for the upper reference interval limit of the tTG-IgA.


Assuntos
Doença Celíaca/sangue , Imunoglobulina A/sangue , Transglutaminases/imunologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Adulto Jovem
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