Vitamin A Positively Correlates with Secretory Immunoglobulin A: A Cross-Sectional Study in Omicron COVID-19 Outpatients.

Background: Respiratory tract infections remain among the leading causes of mortality worldwide. The COVID-19 pandemic has highlighted the importance of mucosal immunity in defending against infectious agents. Vitamin A is known to influence the production of secretory immunoglobulin A (SIgA) predominantly in the gut, where it is a critical component of the first line of defense on mucosal surfaces. Methods: This cross-sectional study, conducted 14 days post-positive COVID-19 diagnosis, aimed to determine the relationship between the nutritional status of vitamin A and SIgA levels in COVID-19 outpatients. Serum and saliva samples were collected. Vitamin A nutritional status was determined based on the assessment of dietary intake and the analysis of retinol-binding protein 4 (RBP4). SIgA levels were analyzed from salivary samples. In addition, serum antibodies were analyzed. Results: Dietary vitamin A intake and RBP4 levels positively correlated with SIgA. Patients with higher vitamin A intake showed higher SIgA/IgG1 and SIgA/IgG3 ratios, while those with higher RBP4 levels showed higher SIgA/IgM, SIgA/IgG1, and SIgA/IgG2 ratios. Conclusions: These findings underscore a significant correlation between vitamin A nutritional status and SIgA levels in COVID-19 outpatients, which may suggest the potential importance of maintaining optimal vitamin A levels for the prevention of viral infections.

Seroprevalence of IgM/IgG and Neutralizing Antibodies against SARS-CoV-2 in Unvaccinated Young Adults from Mexico Who Reported Not Having Had a Previous COVID-19 Infection.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19). It is estimated that more than half of new infections are transmitted by asymptomatic people; therefore, the isolation of symptomatic people is not enough to control the spread of the disease. Methods: A total of 171 unvaccinated young adults (18-35 years) from Sonora, Mexico, who underwent a structured survey to identify prior COVID-19 infections, were included in this study. A qualitative determination of anti-SARS-CoV-2 antibodies in serum was performed by lateral flow immunoassay (Certum IgG/IgM Rapid Test™ cassette kit) and neutralizing antibodies were also determined (GenScript cPass assay). Results: A total of 36 people reported a history of COVID-19 infection, and 135 reported no history of COVID-19. In contrast, 49.6% (67/135) of individuals who had not reported a previous SARS-CoV-2 infection were seropositive to the rapid anti-SARS-CoV-2 antibody test, and 48.1% (65/135) of them had neutralizing antibodies. Conclusions: These results suggest that in young adults, SARS-CoV-2 infections could be asymptomatic in a high percentage of individuals, which could contribute in part to the slow control of the current pandemic due to the large number of asymptomatic cases that are contagious and that could be a silent spread of the virus.

The work-health balance questionnaire: cultural adaptation and validation in Spanish

El objetivo de este estudio fue hacer una adaptación cultural del cuestionario del balance trabajo-salud (WHBq; (Gragnano et al., 2017) al idioma español y proporcionar evidencia mediante el análisis factorial, la confiabilidad y validez. Este instrumento se compone de tres escalas: Incompatibilidad trabajo-salud (WHI), clima de salud (HC) y apoyo externo (ES), con un total de 17 ítems. Este se aplicó a una muestra de trabajadores mexicanos (n = 316). El análisis factorial confirmatorio reveló un modelo de tres factores reproducido en la estructura original, el cual mostró un buen ajuste (CFI = 0.950; SRMR = 0.051; RMSEA = 0.069). La confiabilidad de cada factor y del cuestionario en su totalidad fue satisfactorio (ω mayor a 0.70). El AVE fue inferior a 0.50 solo en ES. Se discuten las soluciones para este problema. La validez de constructo se evaluó por criterio externo. El WHBq en su versión al español mostró adecuadas propiedades psicométricas y su relación teórica consistente con variables externas. Con estos resultados se confirma que este instrumento es una herramienta válida y confiable para su uso en México.(AU)

This study aimed to adapt the Work-Health Balance question-naire (WHBq; (Gragnano, Miglioretti, Frings-Dresen, & de Boer, 2017)in-to Spanish and to provide evidence for its factorial structure, reliability, and validity. WHBq comprises 17 itemswith three scales: Work-Health In-compatibility (WHI), Health Climate (HC) and External Support (ES). It was applied to a sample of Mexican workers (n =316). Confirmatory factor analysis revealed that the three-factor model replicating the original struc-ture provided good fit (CFI = 0.950; SRMR = 0.051; RMSEA = 0.069). The reliability of each factor and the whole questionnaire were satisfactory (α and ω higher than0.70). The AVE was lower than 0.50 only for ES. So-lutions to this problem are discussed. Concurrent and differential validitywas examined with external criteria.The WHBq in its Spanishversion shows good psychometric properties and theoretically consistent relation-ships with external variables. These findings provide support for its use as a valid and reliable tool in Mexico.(AU)

[Rheumatic diseases and allergies, the duality of the immune system]. / Enfermedades reumáticas y alergias, la dualidad del sistema inmunológico.

Autoimmune rheumatic diseases are multisystemic disorders that mainly affect joints and muscles; some examples of these conditions are: rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren's syndrome (SS). In general, autoimmune rheumatic diseases have a high prevalence worldwide and are highly disabling for those who have them. At present, one of the main limitations for the management of these diseases is that their triggering factor continues to be unknown in most cases and the knowledge of the factors associated with their exacerbation is limited. In this review, the possible link of allergies as a possible trigger for autoimmune rheumatic diseases will be explored. We will also analyze the basic and general aspects of both diseases and the development of allergic processes and hypersensitivity reactions to drugs used in the treatment of rheumatic diseases.

Las enfermedades reumáticas autoinmunes son trastornos multisistémicos que afectan principalmente las articulaciones y los músculos; algunos ejemplos de estas afecciones son la artritis reumatoide, el lupus eritematoso sistémico y el síndrome de Sjögren. En general, las enfermedades reumáticas autoinmunes tienen una alta prevalencia en todo el mundo y son altamente incapacitantes para quienes las padecen. Una de las principales limitaciones en la actualidad para el manejo de estas enfermedades es que su factor desencadenante sigue siendo desconocido en la mayoría de los casos y el conocimiento de los factores asociados con su exacerbación es limitado. En esta revisión se explorará la posible relación de las alergias como desencadenante de enfermedades reumáticas autoinmunes. También analizaremos los aspectos básicos y generales de ambas enfermedades y el desarrollo de procesos alérgicos y reacciones de hipersensibilidad a los fármacos utilizados en el tratamiento de enfermedades reumáticas.

A review: Antibody-dependent enhancement in COVID-19: The not so friendly side of antibodies.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents an unprecedented global public health emergency with economic and social consequences. One of the main concerns in the development of vaccines is the antibody-dependent enhancement phenomenon, better known as ADE. In this review, we provide an overview of SARS-CoV-2 infection as well as the immune response generated by the host. On the bases of this principle, we also describe what is known about the ADE phenomenon in various viral infections and its possible role as a limiting factor in the development of new vaccines and therapeutic strategies.

[The involvement of vitamin A in the production of secretory IgA in the respiratory epithelium for potential protection against SARS-CoV-2 infection]. / Participación de la vitamina A en la producción de IgA secretora en el epitelio del tracto respiratorio para la potencial protección de infección por SARS-CoV-2.

SARS-CoV-2 continues to infect thousands of people around the world. It has been established that the main transmission mechanism of this virus is via airborne route, which is why it initially infects the respiratory tract. Currently, the effectiveness of medications used against COVID-19 is limited, and although immunization programs have been initiated, there is international inequality in the distribution of vaccines. Accordingly, the search for adjuvant therapies continues to be an alternative for research. Supplementation with vitamin A has been associated to the decrease of mortality from infection; this effect could be mediated by retinoic acid (RA), which is the active metabolite of vitamin A that exerts immunomodulatory functions. According to preclinical studies, RA favors the production of secretory immunoglobulin A (IgA) in the respiratory tract. In addition to this, the retinol-binding protein has been correlated with the concentration of IgA and neutralizing antibodies in patients with influenza. Therefore, this review aims to address the involvement of vitamin A in the production of secretory IgA in the respiratory epithelium in order to highlight its potential protection against SARS-CoV-2 infection.

El SARS-CoV-2 continúa infectando a miles de personas a nivel mundial. Se ha establecido que el principal mecanismo de transmisión del SARS-CoV-2 es por vía aérea, por lo que infecta inicialmente el tracto respiratorio. Actualmente, la eficacia de los fármacos utilizados contra COVID-19 es limitada y a pesar de que los programas de inmunización han iniciado, existe una desigualdad internacional en la distribución de vacunas. En este sentido, la búsqueda de terapias coadyuvantes continúa siendo una alternativa para su investigación. La suplementación con vitamina A se ha asociado con la reducción de mortalidad por infecciones; este efecto podría ser mediado por el ácido retinoico (AR), un metabolito activo de esta vitamina, que ejerce funciones inmunomoduladoras. De acuerdo con estudios preclínicos, el AR favorece la producción de inmunoglobulina A (IgA) secretora en el tracto respiratorio. Aunado a esto, la proteína de unión a retinol se ha correlacionado con la concentración de IgA y anticuerpos neutralizantes en pacientes con influenza. Por lo tanto, la presente revisión tiene como objetivo abordar la participación de la vitamina A en la producción de la inmunoglobulina A secretora en el epitelio del tracto respiratorio para resaltar su potencial función protectora contra la infección por SARS-CoV-2.

COVID-19 Screening by Anti-SARS-CoV-2 Antibody Seropositivity: Clinical and Epidemiological Characteristics, Comorbidities, and Food Intake Quality.

Developing countries have reported lower molecular diagnostic testing levels due to a lack of resources. Therefore, antibody tests represent an alternative to detect exposure to SARS-CoV-2 and analyze possible risk factors. We aimed to describe and compare the clinical-epidemiological characteristics and the quality of food intake in Mexican individuals with a positive or negative test to antibodies against SARS-CoV-2. We carried out antibody tests and applied a survey to 1799 individuals; 42% were positive, and diabetes was more prevalent in these cases (p < 0.01). No differences were identified in the blood type nor influenza vaccination between groups. Coughing, respiratory distress, muscle pain, joint pain, and anosmia were the most prevalent symptoms among seropositive cases (p < 0.0001). Food intake quality was similar in both groups, except for the most consumed type of fat (p = 0.006). In conclusion, this study supports the association of diabetes as a principal risk factor for SARS-CoV-2 infection in the Mexican population. The results do not support previous associations between blood group or influenza vaccination as protective factors against SARS-CoV-2 infection. However, frequent consumption of polyunsaturated fats is highlighted as a new possible associated factor with COVID-19, which more studies should corroborate as with all novel findings.

Association of Food Intake Quality with Vitamin D in SARS-CoV-2 Positive Patients from Mexico: A Cross-Sectional Study.

One of the micronutrients that has attracted the most attention in relation to COVID-19 is vitamin D. Although several factors affect its sufficiency; it has been argued that an optimal diet can ensure the intake of micronutrients with effects on immune response. Therefore, in this work we aimed to evaluate the food intake quality of SARS-CoV-2 positive Mexican patients and some of the common factors related to vitamin D deficiency. We conducted a cross-sectional study in 40 SARS-CoV-2 positive patients. Serum samples and clinical parameters were collected. Micronutrient intake and food intake quality were assessed with a 24-h dietary recall and the Mini-ECCA v.2, respectively. Thirty-eight percent of the sample had a healthy food intake. The median 25(OH)D concentration was 22.7 ng/mL. A considerable insufficient intake of micronutrients with immunomodulatory effects such as vitamin D (p < 0.0001), vitamin E (p < 0.0001), and zinc (p < 0.0001) was shown. Patients with 25(OH)D sufficiency, defined as a concentration >30 ng/mL, had better food intake quality (p = 0.02) and an intense physical activity (p = 0.03). In conclusion, a better level of food intake quality and intense physical activity are associated with 25(OH)D sufficiency in SARS-CoV-2 positive Mexican patients.

Vitamin D Levels in COVID-19 Outpatients from Western Mexico: Clinical Correlation and Effect of Its Supplementation.

BACKGROUND: The immunomodulatory effects of vitamin D are known to be beneficial in viral infections; it is also known that its deficiency is associated with a prognosis more critical of Coronavirus Disease 2019. This study aimed to determine baseline vitamin D serum concentrations and the effects of its supplementation in asymptomatic or mildly symptomatic Coronavirus Disease 2019 outpatients. METHODS: 42 outpatients were included, 22 of which received a supplement of 10,000 IU of vitamin D3 for 14 days; the remaining 20 outpatients were designated as a control group. Serum levels of transferrin, ferritin, vitamin D, and D-dimer were measured at baseline in both groups. After 14 days, serum levels of total vitamin D were determined in the supplemented group. RESULTS: At baseline, only 19% of infected outpatients had vitamin D levels corresponding to sufficiency. All outpatients with vitamin D insufficiency had at least one symptom associated with the disease, while only 75% of patients with symptoms presented sufficiency. On the seventh and fourteenth day of follow-up, the supplemented group presented fewer symptoms with respect to those non-supplemented. A vitamin D3 dose of 10,000 IU/daily for 14 days was sufficient to raise vitamin D serum concentrations. CONCLUSIONS: Immunomodulatory effects of vitamin D appear to be linked to the development of symptoms in positive outpatients. Vitamin D supplementation could have significant benefits in the Western Mexican population.

Potential immunomodulatory effects of vitamin D in the prevention of severe coronavirus disease 2019: An ally for Latin America (Review).

Currently, the world is under a pandemic of severe acute respiratory syndrome coronavirus 2 (SARS­CoV­2), responsible for coronavirus disease 2019 (COVID­19). This disease is characterized by a respiratory syndrome that can progress to an acute respiratory distress syndrome. To date, limited effective therapies are available for the prevention or treatment of COVID­19; therefore, it is necessary to propose novel treatment options with immunomodulatory effects. Vitamin D serves functions in bone health and has been recently reported to exert protective effects against respiratory infections. Observational studies have demonstrated an association between vitamin D deficiency and a poor prognosis of COVID­19; this is alarming as vitamin D deficiency is a global health problem. In Latin America, the prevalence of vitamin D deficiency is unknown, and currently, this region is in the top 10 according to the number of confirmed COVID­19 cases. Supplementation with vitamin D may be a useful adjunctive treatment for the prevention of COVID­19 complications. The present review provides an overview of the current knowledge of the potential immunomodulatory effects of vitamin D in the prevention of COVID­19 and sets out vitamin D recommendations for the Latin American population.

The Relevance of Selenium Status in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease that can cause joint damage. Among the environmental risk factors, diet plays an important role because it can aggravate or attenuate inflammation. Selenium (Se) is considered an essential trace element since it is a structural component of antioxidant enzymes; however, its concentration can be affected by diet, drugs and genetic polymorphisms. Studies have reported that RA patients have a deficient diet in some food groups that is associated with parameters of disease activity. Furthermore, it has been shown that there is an alteration in serum Se levels in this population. Although some clinical trials have been conducted in the past to analyze the effect of Se supplementation in RA, no significant results were obtained. Contrastingly, experimental studies that have evaluated the effect of novel Se nanoparticles in RA-induced models have shown promising results on the restoration of antioxidant enzyme levels. In particular, glutathione peroxidase (GPx) is an important selenoprotein that could have a modulating effect on inflammation in RA. Considering that RA patients present an inflammatory and oxidative state, the aim of this review is to give an overview of the current knowledge about the relevance of Se status in RA.

Downregulation of Inflammatory Cytokine Release from IL-1ß and LPS-Stimulated PBMC Orchestrated by ST2825, a MyD88 Dimerisation Inhibitor.

The inflammatory process implicates homeostasis disruption and increased production of inflammatory mediators. Myeloid differentiation primary response 88 (MyD88) is an essential protein recruited after lipopolysaccharide (LPS) and interleukin (IL)-1ß stimulation, a process that converges in nuclear factor kappa B (NF-κB) activation, as well as a transcription of several genes of both pro- and anti-inflammatory cytokines. The inhibition of MyD88 has shown efficacy by decrease inflammatory response, and has demonstrated potential application as a therapeutic target in chronic diseases. In this study, we investigate the effect of MyD88 dimerisation inhibitor ST2825 on cytokine production from rhIL-1ß and LPS-stimulated peripheral blood mononuclear cells (PBMC) from healthy blood donors (HBD). ST2825 significantly downregulates the production of IFN-γ, IL-6, IL-12, IL-2, IL-15, IL-7, VEGF, IL-1Ra, IL-4, IL-5, IL-13 and IL-9 (p < 0.05) in LPS-stimulated PBMC. Moreover, ST2825 had a relatively low impact on IL-1ß signalling pathway inhibition, showing that only a few specific cytokines, such as IFN-γ and IL-1Ra, are inhibited in rhIL-1ß-stimulated PBMC (p < 0.01). In conclusion, MyD88 dimerisation inhibitor ST2825 showed high efficacy by inhibiting pro- and anti-inflammatory cytokine production in LPS-stimulated PBMC. Moreover, although rhIL-1ß induced a sustained cytokine production (p < 0.05), ST2825 did not show a significant effect in the secretion of neither pro- nor anti-inflammatory cytokines in rhIL-1ß-stimulated PBMC.

Factors related to road system organisation and its association with mortality due to motor vehicle-pedestrian collisions in Guadalajara Metropolitan Area.

INTRODUCTION: Traffic events are one of the five leading causes of mortality in Mexico. Pedestrians are one of the main road users involved in such incidents and have the highest mortality rate, which is regularly analysed in relation to vehicles and pedestrians, but not the built environment. The purpose of this study was to analyse the elements of the road system organisation that influences the mortality rate of pedestrians hit by motor vehicles in the Guadalajara Metropolitan Area. METHOD: We designed a case and control study in which the cases were sites where a pedestrian died during 2012. The controls were sites close to where the death occurred, as well as those with road infrastructure characteristics similar to those where the events took place. We obtained the pedestrian data from the death certificates and assessed some of the environmental elements of the road sites. A logistic regression analysis was used to estimate OR; 95% CI. RESULTS: Road system factors related with pedestrian mortality in close locations were: the presence of bus stops on intersections in one street or both, and road system features, such as the presence of traffic islands, vehicle flow and pedestrian flow. CONCLUSIONS: According to the urban network theory and multiple theory, the final elements resulted as risk factors due to a fault in connectivity between the nodes. A temporal analysis of urban features will help urban planners make decisions regarding the safety of pedestrians and other road users.