Immune responses during COVID-19 breakthrough cases in vaccinated children and adolescents.

Background: Vaccine effectiveness against SARS-CoV-2 infection has been somewhat limited due to the widespread dissemination of the Omicron variant, its subvariants, and the immune response dynamics of the naturally infected with the virus. Methods: Twelve subjects between 3-17 years old (yo), vaccinated with two doses of CoronaVac®, were followed and diagnosed as breakthrough cases starting 14 days after receiving the second dose. Total IgGs against different SARS-CoV-2 proteins and the neutralizing capacity of these antibodies after infection were measured in plasma. The activation of CD4+ and CD8+ T cells was evaluated in peripheral blood mononuclear cells stimulated with peptides derived from the proteins from the wild-type (WT) virus and Omicron subvariants by flow cytometry, as well as different cytokines secretion by a Multiplex assay. Results: 2 to 8 weeks post-infection, compared to 4 weeks after 2nd dose of vaccine, there was a 146.5-fold increase in neutralizing antibody titers against Omicron and a 38.7-fold increase against WT SARS-CoV-2. Subjects showed an increase in total IgG levels against the S1, N, M, and NSP8 proteins of the WT virus. Activated CD4+ T cells showed a significant increase in response to the BA.2 subvariant (p<0.001). Finally, the secretion of IL-2 and IFN-γ cytokines showed a discreet decrease trend after infection in some subjects. Conclusion: SARS-CoV-2 infection in the pediatric population vaccinated with an inactivated SARS-CoV-2 vaccine produced an increase in neutralizing antibodies against Omicron and increased specific IgG antibodies for different SARS-CoV-2 proteins. CD4+ T cell activation was also increased, suggesting a conserved cellular response against the Omicron subvariants, whereas Th1-type cytokine secretion tended to decrease. Clinical Trial Registration: clinicaltrials.gov #NCT04992260.

Sobrepeso y obesidad en la enfermedad celiaca activa: posibles mecanismos fisiopatológicos / Overweight and obesity in active celiac disease: possible pathophysiological mechanisms

RESUMEN La enfermedad celiaca (EC) es una enteropatía crónica del intestino delgado, mediado por una respuesta inmune, gatillada por la exposición al gluten en individuos genéticamente susceptibles. La presentación clínica de la EC es variada y conduce a mala absorción. El estado nutricional en el momento del diagnóstico de la EC depende del tiempo en que la enfermedad ha estado activa, la extensión de la inflamación intestinal, grado de mala absorción e ingesta alimentaria. Sin embargo, en los últimos años se ha observado un cambio epidemiológico del estado nutricional en los pacientes celiacos al momento del diagnóstico. La presente revisión tuvo por objetivo realizar un análisis descriptivo de la presencia de obesidad en pacientes celiacos y de los posibles mecanismos fisiopatológicos que la explicarían.

ABSTRACT Celiac disease (CD) is a chronic enteropathy of the small intestinal, mediated by an immune response triggered by exposure to dietary gluten in genetically predisposed individuals. The clinical presentation of CD is varied and leads to malabsorption. Nutritional status at the time of diagnosis of CD depends on the time in which the disease has been active, the extent of intestinal inflammation, degree of malabsorption, and dietary intake. However, in recent years an epidemiological change of nutritional status has been observed in celiac patients at the time of diagnosis. The objective of this review was to perform a descriptive analysis of the presence of obesity in celiac patients and the possible physiopathological mechanisms that would explain it.

Caracterización de la enfermedad celiaca en niños atendidos en hospitales públicos chilenos / Characterization of celiac disease in chilean public hospitals

Resumen: Introducción: La prevalencia global de enfermedad celíaca (EC) es ~1% de la población. En Chile, la Encuesta Nacional de Salud 2009-2010 mostró una prevalencia serológica en mayores de 15 años de 0,76% (IgA-TTG2), que en Concepción correspondió a 0,6%. Objetivo: Determinar las caracte rísticas clínicas, de búsqueda, diagnóstico, tratamiento y seguimiento de la EC en los dos hospitales públicos de Concepción con servicio de Gastroenterología. Pacientes y Método: Estudio descriptivo, se recogieron datos de las fichas electrónicas (código CIE10) y clínicas de menores de 18 años estu diados por EC entre 2010 - 2016 provenientes de dos hospitales públicos de la ciudad de Concepción, Chile. Se identificaron los casos cuyo protocolo diagnóstico cumplía con los criterios ESPGHAN 2012 (confirmación con biopsia intestinal), 207 de 216 pacientes identificados cumplían los criterios de inclusión. El estado nutricional se clasificó según grupo etario (menores de 5 años OMS 2006; en los niños entre 5 y 18 años OMS 2007). Se calculó el Z-score (Z), a través del software WHO Anthro (en menores de 5 años) y WHO Anthro Plus (entre 5-18 años). Los anticuerpos antiendomisio se evaluaron mediante inmuno fluorescencia en cortes de esófago de mono; los anticuerpos antitrans- glutaminasa IgA e IgG a través ELISA; e IgA en sangre mediante ELISA. Resultados: Se confirmó EC por biopsias duodenales en 33,8%. IgA-TTG estuvo registrada en 70% e IgG-TTG en 52,9%, aunque solo dos pacientes tenían deficiencia de IgA. Los motivos de consulta preponderantes fueron gas trointestinales (80%) y/o derivación por un endocrinólogo (45,7%). La principal presentación clínica fue gastrointestinal, con diarrea (71,4%). El 17,1% presentaba Síndrome de Down (SD), 11,4% talla baja y 5,7% diabetes mellitus 1. Al diagnóstico, la relación obesidad: desnutrición (Z-score IMC) fue 2:1 y 6,8% de los pacientes eran obesos. Al año post-diagnóstico, en 26 pacientes celíacos sin SD la frecuencia de estado nutricional eutrófico disminuyó de 65,4% a 42,3%, aumentando el sobrepeso de 23,1 a 34,6% y la obesidad de 0 a 7,7%. Conclusiones: En Concepción, la especialidad de endo crinología efectúa una significativa y exitosa búsqueda activa, siendo responsable de 47,3% de los diagnósticos. La alta proporción de pacientes con sobrepeso/obesidad concuerda con el fenómeno descrito actualmente en Chile y otros países.

Abstract: Introduction: The worldwide prevalence of celiac disease (CD) is ~1% of the population. In Chile, the National Health Survey 2009-2010 showed a serological prevalence in individuals older than 15 years of 0.76% (IgA-tTG2), which corresponded in Concepción to 0.6%. Objective: Determine cli nical characteristics, search, diagnosis, treatment and follow-up of CD in the two public hospitals in Concepción that have a Gastroenterology Department. Patients and Method: Descriptive study. Data were collected from electronic medical records (CIE10 code) and medical records of patients youn ger than 18 years of age, assessed for CD during 2010 - 2016 from two public hospitals in the city of Concepción, Chile. Cases whose diagnostic protocol met the ESPGHAN 2012 criteria (confirmation with intestinal biopsy), 207 out of 216 identified patients met the inclusion criteria. The nutritional status was classified according to age group (in children under five years old by WHO 2006 and in children between five and 18 years old by WHO 2007). The Z-score (Z) was calculated using the WHO Anthro software (in children under five years old) and WHO Anthro Plus software (in those between five and 18 years old). Antiendomysial antibodies were assessed by immunofluorescence test in cuts of the esophagus of mono, IgA and IgG anti-transglutaminase antibodies via ELISA, as well as serum IgA. Results: CD was confirmed by duodenal biopsies in 33.8% of the patients. IgA-tTG was identified in 70% and IgG-tTG in 52.9%, although only two patients had IgA deficiency. The main reasons for consultation were gastrointestinal (80%) and/or referral by an endocrinologist (45.7%). The main clinical presentation was gastrointestinal, with diarrhea (71.4%). 17.1% of the patients had Down syndrome (DS), 11.4% short stature, and 5.7% had type 1 diabetes mellitus. At diagnosis, the obesitymalnutrition ratio (Z-score BMI) was 2:1 and 6.8% of the patients were obese. One year after diagnosis, in 26 patients without DS, the frequency of eutrophic patients decreased from 65.4% to 42.3%, increasing overweight from 23.1% to 34.6% and obesity from 0 to 7.7%. Conclusions: In Con cepción, endocrinologists conduct a significant and successful active search of CD, being responsible for 47.3% of the diagnoses. The high proportion of overweight/obese patients is consistent with the phenomenon currently described in Chile and other countries.