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2.
ARS med. (Santiago, En línea) ; 45(3): 29-35, sept. 30, 2020.
Article in Spanish | LILACS | ID: biblio-1255300

ABSTRACT

Introducción: La enfermedad celíaca (EC) es una patología autoinmune, que se desarrolla a cualquier edad en personas genéticamentesusceptibles, y cuyo órgano diana principal es el intestino delgado. La diversidad en las formas de presentación actualmente conocidas implica un desafío permanente para el laboratorio, que debe ofrecer nuevas técnicas, cada vez más sensibles y específicas, para detectar de manera eficiente los autoanticuerpos específicos para el diagnóstico y seguimiento de estos pacientes. Nuestro objetivo fue evaluar la sensibilidad y especificidad de un nuevo antígeno para la detección de anticuerpos anti-transglutaminasa compuesto por transglutaminasa tisular unida covalentemente a péptidos deamidados de gliadina (neo-epítope) en pacientes con sospecha de EC, con biopsia duodenal como gold standard. Como objetivo secundario nos propusimos evaluar la sensibilidad y especificidad del antígeno convencional, transglutaminasa humana recombinante, para el mismo grupo de estudio. Metodología: Se realizó un estudio prospectivo, analizando muestras de pacientes con sospecha de EC o en seguimiento de dicha patología, en las que se estudiaron los anticuerpos anti-transglutaminasa con antígeno neo- epítope, y con antígeno transglutaminasa recombinante humana. Se determinó sensibilidad, especificidad, VPP, VPN y coeficiente de concordancia Kappa. Resultados: Se procesaron 56 muestras, incluidas en un período de 5 meses. La sensibilidad (100%) y especificidad (92,3%) obtenidas con la técnica de neo-epítope, en relación a la biopsia (gold standard), fue mayor que con la técnica transglutaminasa humana recombinante (88,3% y 78,9% respectivamente). La técnica con neo-epítope proporcionó un menor número de resultados en la "zona de indeterminación". Conclusiones: Nuestros resultados concuerdan con otros autores, ya que neo-epítope detecta con mayor sensibilidad y especificidad aquellos pacientes con diferente situación de presentación y transgresores de la dieta libre de gluten, quienes pueden presentar serología negativa o débilmente positiva con transglutamiasa humana recombinante. La nueva técnica neo-epítope constituiría una mejor herramienta para la pesquisa diagnóstica y de seguimiento en pacientes con EC.


Introduction: Celiac disease (CD) is an autoimmune disease, which develops at any age in genetically susceptible people, and whose main target organ is the small intestine. The diversity in the currently known forms of presentation implies a permanent challenge for the laboratory, which must offer new techniques, increasingly sensitive and specific, to efficiently detect the specific autoantibodies that collaborate in the diagnosis and follow-up of these patients. Our main objective was to evaluate the sensitivity and specificity of a new sensitizing antigen for the detection of anti-transglutaminase antibodies composed of tissue transglutaminase covalently linked to deamidated gliadin peptides (neo-epitope) in patients with suspected CD, with duodenal biopsy as the gold standard. As a secondary objective, we set out to evaluate the sensitivity and specificity of the conventional antigen, recombinant human transglutaminase, for the same study group. Methodology: A prospective study was carried out, including samples from patients with suspected CD or in follow-up of said pathology, in which anti-transglutaminase antibodies were studied with neo-epitope antigen, and with human re-combinant transglutaminase antigen. Sensitivity, specificity, PPV, NPV and Kappa coefficient of concordance were determined. Results: 56 samples were processed, included in a period of 5 months. The sensitivity and specificity obtained with the neo-epitope technique (S: 100% - E: 92.3%), in relation to the biopsy (gold standard), was higher than with the recombinant human transglutaminase technique (S: 88.3% - E: 78.9%). The neo-epitope technique provided fewer results in the "zone of indeterminacy". Conclusions: Our results agree with other authors, since the neo-epitope detects with greater sensitivity and specificity those patients with different presentation situations and transgressors of the gluten-free diet, who can present negative or weakly positive serology with recombinant human transglutaminase. The new neo-epitope technique would constitute a better tool for diagnostic and follow-up research in patients with CD


Subject(s)
Autoantibodies , Celiac Disease , Prospective Studies , Patients , Autoimmunity , Antibodies
3.
J Periodontal Implant Sci ; 46(6): 362-371, 2016 Dec.
Article in English | MEDLINE | ID: mdl-28050314

ABSTRACT

PURPOSE: The increasing demand for esthetically pleasing results has contributed to the use of ceramics for dental implant abutments. The aim of this study was to compare the biological response of epithelial tissue cultivated on lithium disilicate (LS2) and zirconium oxide (ZrO2) ceramics. Understanding the relevant physicochemical and mechanical properties of these ceramics will help identify the optimal material for facilitating gingival wound closure. METHODS: Both biomaterials were prepared with 2 different surface treatments: raw and polished. Their physicochemical characteristics were analyzed by contact angle measurements, scanning white-light interferometry, and scanning electron microscopy. An organotypic culture was then performed using a chicken epithelium model to simulate peri-implant soft tissue. We measured the contact angle, hydrophobicity, and roughness of the materials as well as the tissue behavior at their surfaces (cell migration and cell adhesion). RESULTS: The best cell migration was observed on ZrO2 ceramic. Cell adhesion was also drastically lower on the polished ZrO2 ceramic than on both the raw and polished LS2. Evaluating various surface topographies of LS2 showed that increasing surface roughness improved cell adhesion, leading to an increase of up to 13%. CONCLUSIONS: Our results demonstrate that a biomaterial, here LS2, can be modified using simple surface changes in order to finely modulate soft tissue adhesion. Strong adhesion at the abutment associated with weak migration assists in gingival wound healing. On the same material, polishing can reduce cell adhesion without drastically modifying cell migration. A comparison of LS2 and ZrO2 ceramic showed that LS2 was more conducive to creating varying tissue reactions. Our results can help dental surgeons to choose, especially for esthetic implant abutments, the most appropriate biomaterial as well as the most appropriate surface treatment to use in accordance with specific clinical dental applications.

4.
Rev Med Chil ; 132(8): 979-84, 2004 Aug.
Article in Spanish | MEDLINE | ID: mdl-15478300

ABSTRACT

BACKGROUND: Celiac patients are at high risk of developing insulin-dependent diabetes mellitus, a condition that has a long pre-diabetic period. During this lapse, anti-islet cell antibodies serve as markers for future disease. This may be related with the duration of the exposure to gluten. AIM: To test the hypothesis that long term adherence to a gluten free diet decreases the frequency of risk markers for insulin dependent diabetes mellitus during adolescence and early adulthood. PATIENTS AND METHODS: 158 celiac patients were classified as: G1, (n=30 patients) studied at the time of diagnosis; G2 (n=97 patients) exposed to gluten as a result of non compliance with the gluten free diet and, G3 (n=31 patients) who had maintained a long term, strict gluten free diet. Isotype IgG anti-islet cell antibodies were detected by indirect immunofluorescence using monkey pancreas, results were reported in Juvenile Diabetes Foundation (JDF) units. RESULTS: Celiac patients exposed to a gluten containing diet had a significantly higher prevalence of anti-islet cell antibodies than those who had been exposed only briefly (p < 0.017). In addition, a significantly higher prevalence of anti-islet cell antibodies was observed in those patients whose exposure to gluten was longer than 5 years than in those whose exposure was shorter (p < 0.02). CONCLUSIONS: Celiac patients long exposed to gluten have a significantly higher prevalence of anti-islet cell antibodies than those exposed for a short period. This fact supports the hypothesis that the development of these antibodies is associated with the length of the exposure to gluten.


Subject(s)
Celiac Disease/immunology , Diabetes Mellitus, Type 1/immunology , Glutens/administration & dosage , Islets of Langerhans/immunology , Adolescent , Adult , Autoantibodies/isolation & purification , Biomarkers/blood , Child , Child, Preschool , Diet , Female , Glutens/adverse effects , Humans , Infant , Infant, Newborn , Male , Middle Aged , Risk Factors , Time Factors
5.
Rev Med Chil ; 131(1): 25-9, 2003 Jan.
Article in Spanish | MEDLINE | ID: mdl-12643215

ABSTRACT

BACKGROUND: Endomysium antibodies (EMA) do not detect minor dietary transgressions in patients with celiac disease. AIM: To compare the sensitivity and specificity of tissue transglutaminase antibodies (tTGA) and endomysium antibodies (EMA) in biopsy proven celiac patients at the time of diagnosis and during gluten free diet (GFD). PATIENTS AND METHODS: One hundred fifty three subjects were studied: a) 30 healthy controls; b) 9 cases with cow's milk allergy; c) 24 celiac patients at time of diagnosis; d) 25 celiac patients adhering to the GFD; e) 65 celiac patients with poor/no adhesion to GFD. EMA and tTGA IgA were measured by immunofluorescence and ELISA, respectively. RESULTS: Sensitivity and specificity were 100% and 97.4% for tTGA, respectively. All patients with cow's milk allergy were EMA (-) and 8 of 9 (88.9%) were tTGA (-). In celiac patients not adhering to the GFD, EMA and tTGA positivity were similar (80% and 81.5%, respectively); 95.4% of the subjects tested positive for at least one of them. All patients adhering to GFD were EMA (-) but tTGA were (+) in 28% of them. CONCLUSIONS: EMA and tTGA have similar sensitivity and specificity at the time of diagnosis of celiac disease. Positive tTGA in 28% of patients that adhered strictly to the GFD and whose EMA were negative suggest that tTGA may be helpful in detecting minor dietary transgressions and should be further evaluated.


Subject(s)
Celiac Disease/diet therapy , Diet , GTP-Binding Proteins/immunology , Immunoglobulin A/immunology , Transglutaminases/immunology , Adolescent , Adult , Antibody Specificity , Celiac Disease/diagnosis , Celiac Disease/enzymology , Child , Child, Preschool , Female , Glutens , Humans , Infant , Male , Milk Hypersensitivity/enzymology , Milk Hypersensitivity/immunology , Protein Glutamine gamma Glutamyltransferase 2 , Sensitivity and Specificity
6.
Rev Med Chil ; 130(8): 901-6, 2002 Aug.
Article in Spanish | MEDLINE | ID: mdl-12360800

ABSTRACT

We report a 10 years old boy, admitted with a history of asthenia, anorexia and weight loss of 4 kg. Initial laboratory work up showed metabolic acidosis and hyponatremia. The patient had no circadian rhythm of serum cortisol and an adrenal stimulation test confirmed the presence of adrenal insufficiency. Anti-adrenal antibodies were positive. Treatment with cortisol and fluorocortisone resulted in a complete remission of symptoms.


Subject(s)
Adrenal Cortex Diseases/complications , Adrenal Insufficiency/etiology , Autoimmune Diseases/complications , Adrenal Insufficiency/diagnosis , Autoantibodies/blood , Child , Fatty Acids/analysis , Humans , Male , Pituitary-Adrenal Function Tests
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