Cross-sectional evaluation of the association between greenness and cognitive performance in Mexican pre-pubertal boys.

BACKGROUND: Evidence shows that greenspace exposure benefits children's health and cognitive development. However, evidence assessing this association in young children in low- and middle-income economies is scarce. OBJECTIVE: To assess the association between exposure to greenness and cognitive performance in pre-pubertal boys living in Mexico City. METHODS: Cross-sectional study using data from 144 boys aged 6-11 years living in Mexico City in 2017 and enrolled in the "MetCog" study. Cognitive performance was evaluated through selected Wechsler Scale for Intelligence in Children Fourth Edition (WISC-IV) and Neuropsychological Assessment of Children (Evaluación Neuropsicológica Infantil, ENI) tests. Exposure to greenness was assessed through Normalised Difference Vegetation Index (NDVI) at 300, 500, 1500, 2000, and 3000 m buffer zones from children's residences. Multiple linear regression analysis was undertaken to assess associations between cognitive performance and greenness (aß) with 95% confidence intervals (CI) and adjusted for potential confounding variables. Significance was set at q < 0.05 after False Discovery Rate (FDR) correction. RESULTS: A positive association was found between the NDVI Interquartile Range (IQR) at 2000 m and the WISC-IV block design test score (aß 2000 = 1.18, 95% CI = 0.31, 2.06; q < 0.05), which assesses perceptual reasoning. Positive associations were found with NDVI IQR at 1500 m and WISC-IV block design (aß1500 = 1.00, 95% CI = 0.14, 1.86) and matrix reasoning (aß1500 = 0.83, 95% CI = 0.06, 1.61) scores, but neither survived FDR correction. No significant associations were found between NDVI IQR at any buffer size with other WISC-IV and ENI task scores. CONCLUSIONS: Greater exposure to greenness was associated with higher perceptual reasoning skills in 144 pre-pubertal boys living in Mexico City. Thus, urban planning should consider increasing vegetation in megacities, especially in neighbourhoods with high percentages of young children.

Natural killer cell reconstitution after hematopoietic stem-cell transplantation in children.

INTRODUCTION: After hematopoietic stem cell transplantation (HSCT), natural killer (NK) cells reconstitution is the main barrier against viral infections. OBJECTIVE: To determine that the knowledge on the kinetics of NK cell reconstitution after HSCT contributes to transplant efficient monitoring, which increases the possibility of its success. METHOD: Twenty-one patients undergoing HSCT were included, as well as a control group of clinically healthy individuals. At different time points after transplantation (range of 21 to 670 days), CD3- CD16+ CD56+ NK cells were quantified by flow cytometry in peripheral blood samples. RESULTS: NK cell recovery occurs at three to six months and 10 to 12 months post-transplantation; their number was significantly lower (in comparison with the control group) in the rest of the monitoring time. CONCLUSIONS: The first period of NK cell recovery occurs between three and six months after transplantation. Reconstitution is transient and the number of NK cells varies in the first years.

INTRODUCCIÓN: Después de un trasplante de células progenitoras hematopoyéticas (TCPH), la reconstitución de las células natural killer (NK) es la principal barrera contra las infecciones virales. OBJETIVO: Determinar que el conocimiento sobre la cinética de la reconstitución de las células NK posterior al TCPH contribuye a un eficiente monitoreo del trasplante, lo que incrementa la posibilidad de éxito de este. MÉTODO: Se incluyeron 21 pacientes sometidos a TCPH, así como un grupo control de individuos clínicamente sanos. En diferentes momentos después del trasplante (intervalo de 21 a 670 días), mediante citometría de flujo se cuantificaron las células NK CD3− CD16+ CD56+ en muestras de sangre periférica. RESULTADOS: La recuperación de las células NK ocurre a los tres a seis meses y a los 10 a 12 meses postrasplante; su número fue significativamente menor (en comparación con el grupo control) en el tiempo restante del monitoreo. CONCLUSIONES: El primer periodo de recuperación de las células NK ocurre entre los tres y seis meses posteriores al trasplante. La reconstitución es transitoria y el número de células NK varía en los primeros años.

Genetic polymorphisms associated with pediatric-onset type 2 diabetes: A family-based transmission disequilibrium test and case-control study.

BACKGROUND AND OBJECTIVE: Genetics play a very strong role in the development of pediatric-onset type 2 diabetes (T2D); however, little information exists about specific common single nucleotide polymorphisms (SNPs) associated with T2D in this age group. The aim of the study was to analyze the association and parental transmission of 64 obesity-related SNPs with pediatric-onset T2D in Mexican families. METHODS: A total of 57 pedigrees containing 171 probands with pediatric-onset T2D and 119 unrelated controls older than 18 years were included. The participants were genotyped for 64 polymorphisms. Association of each variant with pediatric-onset T2D was analyzed through a parent-offspring transmission disequilibrium test (TDT) and in a case-control comparison by χ2 analysis. RESULTS: Five SNPs exhibited associations with pediatric-onset T2D in the combined case-parent trio and case-control analysis: LINGO/rs10968576 (odds ratio [OR] 1.82, P = 0.003), POC5/rs2112347 (OR 1.96, P = 2.4E-5), RPS10-NUDT3/rs206936 (OR 1.40, P = 0.023), GLIS3/rs7034200 (OR 2.34, P = 1.2E-6), and VEGFA/rs6905288 (OR 1.58, P = 0.015). The first three were also associated with obesity status. The SNPs POC5/rs2112347 and RPS10-NUDT3/rs206936 were significantly associated through the maternal allele and GLIS3/rs7034200 through the paternal allele (P < 0.05). CONCLUSIONS: These findings suggest that certain SNPs associated with obesity and other metabolic traits may also be involved in risk of pediatric-onset T2D in Mexican families. We also identified preferential transmission of parental alleles in some variants.

Molecular analysis and distribution of multidrug-resistant Enterococcus faecium isolates belonging to clonal complex 17 in a tertiary care center in Mexico City.

BACKGROUND: Enterococcus faecium has recently emerged as a multidrug-resistant nosocomial pathogen involved in outbreaks worldwide. A high rate of resistance to different antibiotics has been associated with virulent clonal complex 17 isolates carrying the esp and hyl genes and the purK1 allele. RESULTS: Twelve clinical vancomycin-resistant Enterococcus faecium (VREF) isolates were obtained from pediatric patients at the Hospital Infantil de México Federico Gómez (HIMFG). Among these VREF isolates, 58.3% (7/12) were recovered from urine, while 41.7% (5/12) were recovered from the bloodstream. The VREF isolates showed a 100% rate of resistance to ampicillin, amoxicillin-clavulanate, ciprofloxacin, clindamycin, chloramphenicol, streptomycin, gentamicin, rifampicin, erythromycin and teicoplanin. In addition, 16.7% (2/12) of the isolates were resistant to linezolid, and 66.7% (8/12) were resistant to tetracycline and doxycycline. PCR analysis revealed the presence of the vanA gene in all 12 VREF isolates, esp in 83.3% (10/12) of the isolates and hyl in 50% (6/12) of the isolates. Phylogenetic analysis via molecular typing was performed using pulsed-field gel electrophoresis (PFGE) and demonstrated 44% similarity among the VREF isolates. MLST analysis identified four different sequence types (ST412, ST757, ST203 and ST612). CONCLUSION: This study provides the first report of multidrug-resistant VREF isolates belonging to clonal complex 17 from a tertiary care center in Mexico City. Multidrug resistance and genetic determinants of virulence confer advantages among VREF in the colonization of their host. Therefore, the prevention and control of the spread of nosocomial infections caused by VREF is crucial for identifying new emergent subclones that could be challenging to treat in subsequent years.

Clinical features and treatment outcomes of pediatric acute promyelocytic leukemia in a Mexican pediatric hospital.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct type of acute myeloid leukemia (AML) characterized by chromosomal translocations involving the retinoid acid receptor α (RARA) gene on chromosome 17. APL is a relatively rare blood disease that is highly curable with current treatment strategies; however, patient outcomes are heterogeneous in countries with limited resources. Promyelocytic leukemia accounts for 20-25% of all AML cases in Latin American countries. MATERIAL AND METHODS: We conducted a study from July 2007 to July 2012 and applied the IC-APL2006 protocol. This case study reports the results from eleven patients with AML M3 (five males and six females). In all cases, the diagnoses were made by aspirating bone marrow and evaluating the t(15:17) or t(11:17) transcript. In eight cases, the molecular biology-based diagnostics for the PLM-RARa transcript were positive, and they were negative in two cases. One patient was positive for the PLZF-RARa transcript. RESULTS: The mean WBC at the time of diagnosis was 10.1 x 10(9)/L, and the mean platelet count was 17.1 x 10(9)/L. The mean percentage of abnormal promyelocytes in the bone marrow aspirates was 68%. Of the eleven patients, four presented with disseminated intravascular coagulation. All of the patients began treatment with transretinoic acid (ATRA) (45 mg/m(2)/day), which led to 4 cases of ATRA syndrome. There were 2 relapses, and the patient died in one case. The remaining ten patients were alive after the median follow-up period of 33.6 months (range from 11 to 60 months). CONCLUSION: The authors report on a series of cases involving pediatric patients with AML M3 seen at a single institution; the patients were stratified and treated with a standard protocol to obtain satisfactory results. Although the number of patients is limited, the health outcomes are relevant. To our knowledge, this is the first series of pediatric APL patients in Mexico who were treated with the IC-APL2006 protocol.

Presence of antibodies against HLA class I and class II molecules in children before and after allo-HSCT. Alloantibodies before and after HSCT.

A severe complication of allogeneic hematopoietic stem cell transplantation (HSCT) is graft failure (GF). Among others, donor-specific anti-HLA antibodies (DSA) are associated with graft rejection after allogeneic or haploidentical transplantation in adults. Knowledge of DSA and pediatric recipients is limited. Hence, we aimed to generate more information about the presence of DSA (pre- and post-HSCT) and the clinical outcomes (graft rejection and poor function) in children. We identified DSA in 27% of the patients. We observed a higher frequency (50%) of DSA-bearing patients with a benign disease diagnosis than those diagnosed with leukemia (16.66%). We observed graft rejection in one patient (with DSA against two alleles of HLA class I molecules) and poor function in three recipients during the first 30 days after HSCT in the absence of DSA. The presence of donor and nondonor HLA-specific antibodies decreased substantially after transplantation. After the transplant, we identified two patients with DSA specific for HLA class I molecules (independent of clinical relevance), and four recipients showed PGF in the absence of DSA. We were unable to establish any association between the presence of DSA and a clinical outcome: graft failure or prevalence of viral infection.

Enrichment of effector memory T cells in the CD4 and CD8 T cell compartment during chronic graft versus host disease in children.

BACKGROUND: During allogeneic Hematopoietic stem cell transplantation (HSCT), frequent pathological scenarios include graft versus host disease (GVHD) and viral infections. We hypothesized if exogenous stimulus as alloantigen and viral antigens might impact on central and effector memory T cells in pediatric recipients. PATIENTS AND METHODS: Subjects included 21 pediatric recipients and 20 healthy children (control group). Peripheral blood samples of patients were collected along the first 712 days post-HSCT. T cell phenotyping of naïve, central, and effector memory T cells (TCMs and TEMs, respectively) was conducted using flow cytometry. Viral nucleic acids were detected using real-time PCR. RESULTS: T cell reconstitution was not reached after 1 year post-HSCT. Chronic GVHD was associated with increased numbers of naïve CD4 T cells (p < 0.05) as well as an increase in TEM and TCM cells of the CD4 (p < 0.0001 and p < 0.05, respectively) and CD8 T cell TEM (p < 0.0001). and TCM (p < 0.001) populations too. Moreover, BK and Epstein-Barr viruses were the main viral pathogens detected (<104 copies), which were associated with a decrease in all T cell compartments. CONCLUSION: During chronic GVHD, alloantigen persistence generates TEM cell enrichment among CD4 and CD8 T cells, and viral infections are associated with deficient recovery of T cells after HSCT.

Leukocyte surface expression of the endoplasmic reticulum chaperone GRP78 is increased in severe COVID-19.

Hyperinflammation present in individuals with severe COVID-19 has been associated with an exacerbated cytokine production and hyperactivated immune cells. Endoplasmic reticulum stress leading to the unfolded protein response has been recently reported as an active player in inducing inflammatory responses. Once unfolded protein response is activated, GRP78, an endoplasmic reticulum-resident chaperone, is translocated to the cell surface (sGRP78), where it is considered a cell stress marker; however, its presence has not been evaluated in immune cells during disease. Here we assessed the presence of sGRP78 on different cell subsets in blood samples from severe or convalescent COVID-19 patients. The frequency of CD45+sGRP78+ cells was higher in patients with the disease compared to convalescent patients. The latter showed similar frequencies to healthy controls. In patients with COVID-19, the lymphoid compartment showed the highest presence of sGRP78+ cells versus the myeloid compartment. CCL2, TNF-α, C-reactive protein, and international normalized ratio measurements showed a positive correlation with the frequency of CD45+sGRP78+ cells. Finally, gene expression microarray data showed that activated T and B cells increased the expression of GRP78, and peripheral blood mononuclear cells from healthy donors acquired sGRP78 upon activation with ionomycin and PMA. Thus, our data highlight the association of sGRP78 on immune cells in patients with severe COVID-19.

Strategies to recover blood donors during the COVID-19 pandemic: a tertiary level hospital experience.

BACKGROUND: The SARS-CoV-2 pandemic has challenged blood banks. In Mexico, donors decreased 22% between April and May 2020 compared to the same months in 2019. This study analyzed the effect of the strategies to recover donors (altruistic and family) in a tertiary pediatric care center during the pandemic. METHODS: The Blood Bank of the Hospital Infantil de México Federico Gómez implemented strategies to obtain blood components to ensure self-sufficiency. The effect of these strategies on donor recovery was analyzed. RESULTS: There were 7,315 eligible donors in 2019 and 5,070 in 2020. Blood component requirements decreased from 10,037 units in 2019 to 8,619 in 2020. The strategies aimed at attracting altruistic donors managed to increase the percentage of this type of donor when comparing the months in which these strategies were applied with the same months in 2019. In addition, it was observed that the greater the number of methods used simultaneously, the higher the percentage of altruistic donors (rho = 0.846, p = 0.002). In contrast, strategies aimed at attracting family donors did not increase the number of this type of donor. CONCLUSIONS: Actions to recruit altruistic donors increased the number of this type of donor to meet the hospital's needs.

INTRODUCCIÓN: La pandemia por SARS-CoV-2 ha representado un reto en los bancos de sangre. En México, los donadores disminuyeron el 22% entre abril y mayo del 2020 en comparación con los mismos meses del 2019. Este estudio analizó el efecto de las estrategias realizadas para recuperar donantes, altruistas y familiares, en un centro de atención pediátrica de tercer nivel durante la pandemia. MÉTODOS: El Banco de Sangre del Hospital Infantil de México Federico Gómez implementó estrategias encaminadas a la obtención de componentes sanguíneos para asegurar la autosuficiencia. Se analizó el efecto de dichas estrategias en la recuperación de donantes. RESULTADOS: Se registraron 7,315 donadores aptos en el año 2019 y 5,070 en el 2020. Los requerimientos de componentes sanguíneos disminuyeron de 10,037 unidades en 2019 a 8,619 en 2020. Las estrategias que estaban destinadas a captar donadores altruistas lograron aumentar el porcentaje de este tipo de donadores al comparar los meses en que se aplicaron dichas estrategias con los mismos meses en el 2019. Además, se observó que, a mayor número de estrategias aplicadas de manera simultánea, mayor porcentaje de donadores altruistas (rho = 0.846, p = 0.002). Por el contrario, las estrategias con la finalidad de atraer donadores familiares no lograron aumentar la cantidad de este tipo de donadores. CONCLUSIONES: Las acciones para recabar donadores altruistas aumentaron la cantidad de este tipo de donadores para satisfacer las necesidades del hospital.

Efficacy and safety of vitamin D supplementation in hospitalized COVID-19 pediatric patients: A randomized controlled trial.

Background: Some studies suggested that adequate levels of vitamin D (VD) decrease the risk of severe COVID-19. Information about the effectiveness of VD supplementation in children is scarce. Objective: To assess the efficacy and safety of VD supplementation compared to the standard of care in hospitalized children with COVID-19. Patients and methods: An open-label randomized controlled single-blind clinical trial was carried out. We included patients from 1 month to 17 years, with moderate COVID-19, who required hospitalization and supplemental oxygen. They were randomized into two groups: the VD group, which received doses of 1,000 (children < 1 year) or 2,000 IU/day (from 1 to 17 years) and the group without VD (control). The outcome variables were the progression of oxygen requirement, the development of complications, and death. Statistical analysis: For comparison between groups, we used the chi-squared test or Fisher's exact test and the Mann-Whitney U test. Absolute risk reduction (ARR) and the number needed to treat (NNT) were calculated. p ≤ 0.05 was considered statistically significant. Results: From 24 March 2020 to 31 March 2021, 87 patients were eligible to participate in the trial; 45 patients were randomized: 20 to the VD group and 25 to the control group. There was no difference in general characteristics at baseline, including serum VD levels (median 13.8 ng/ml in the VD group and 11.4 ng/ml in the control group). Outcomes: 2/20 (10%) in the VD group vs. 9/25 (36%) in the control group progressed to a superior ventilation modality (p = 0.10); one patient in the VD group died (5%) compared to 6 (24%) patients in the control group (p = 0.23). ARR was 26% (95% CI 8.8 to 60.2%) and NNT was 3 (2 to 11) for progression and ARR was 19% (95% CI -3.9 to 42.8%) and NNT was 6 (2 to 26) for death. None of the patients receiving VD had adverse effects. The trial was stopped for ethical reasons; since after receiving the results of the basal VD values, none of the patients had normal levels. Conclusion: In this trial, VD supplementation in pediatric patients seems to decrease the risk of COVID-19 progression and death. More studies are needed to confirm these findings. Clinical Trial Registration: This protocol was registered on ClinicalTrials.gov with the registration number NCT04502667.

miRNAs in multiple sclerosis: A clinical approach.

Micro-RNAs (miRNAs) are noncoding, single stranded segments of RNA measuring 19 to 25 nucleotides in length. They play an active role in autoimmune diseases, including multiple sclerosis (MS). These structures have been studied given their implication in the process of diagnosis, disease development, treatment and prognosis of MS. Given the progressive and neurodegenerative nature of MS, miRNAs have been identified as critical mediators and molecular pinpoints of the disease, which poses them as excellent candidates for the obtention of suitable biomarkers and treatment targets. This review condenses recent findings on the role of miRNAs in multiple sclerosis, including their role in MS etiology and molecular mechanisms of the disease, exploitation of miRNAs as diagnostic tools and biomarkers, miRNAs as treatment option or target for MS, and their significance as predictors of disease prognosis.

Cell surface expression of GRP78 and CXCR4 is associated with childhood high-risk acute lymphoblastic leukemia at diagnostics.

Acute lymphocytic leukemia is the most common type of cancer in pediatric individuals. Glucose regulated protein (GRP78) is an endoplasmic reticulum chaperone that facilitates the folding and assembly of proteins and regulates the unfolded protein response pathway. GRP78 has a role in survival of cancer and metastasis and cell-surface associated GRP78 (sGRP78) is expressed on cancer cells but not in normal cells. Here, we explored the presence of sGRP78 in pediatric B-ALL at diagnosis and investigated the correlation with bona fide markers of leukemia. By using a combination of flow cytometry and high multidimensional analysis, we found a distinctive cluster containing high levels of sGRP78, CD10, CD19, and CXCR4 in bone marrow samples obtained from High-risk leukemia patients, which was absent in the compartment of Standard-risk leukemia. We confirmed that sGRP78+CXCR4+ blood-derived cells were more frequent in High-risk leukemia patients. Finally, we analyzed the dissemination capacity of sGRP78 leukemia cells in a model of xenotransplantation. sGRP78+ cells emigrated to the bone marrow and lymph nodes, maintaining the expression of CXCR4. Testing the presence of sGRP78 and CXCR4 together with conventional markers may help to achieve a better categorization of High and Standard-risk pediatric leukemia at diagnosis.

Herpesvirus Screening in Childhood Hematopoietic Transplant Reveals High Systemic Inflammation in Episodes of Multiple Viral Detection and an EBV Association with Elevated IL-1ß, IL-8 and Graft-Versus-Host Disease.

Infections remain a major cause of morbidity and mortality among hematopoietic stem cell transplant (HSCT) recipients. Unlike Epstein-Barr Virus (EBV) and Human Cytomegalovirus (HCMV), Human Herpesvirus (HHV) 6, HHV7 and HHV8 are not routinely monitored in many centers, especially in the pediatric population of low-medium income countries. We screened EBV, HCMV, HHV6, HHV7 and HHV8 in 412 leukocytes-plasma paired samples from 40 pediatric patients assisted in a tertiary hospital in Mexico. Thirty-two underwent allo-HSCT, whereas eight received auto-HSCT. Overall viral detection frequencies in allo- and auto-HSCT were: EBV = 43.7% and 30.0%, HCMV = 5.0% and 6.7%, HHV6 = 7.9% and 20.0% and HHV7 = 9.7% and 23.3%. HHV8 was not detected in any sample. Interestingly, HHV6 and HHV7 were more frequent in auto-HSCT, and HHV6 was observed in all episodes of multiple detection in auto-HSCT patients. We found EBV DNA in plasma samples, whereas HCMV, HHV6 and HHV7 DNA were predominantly observed in leukocytes, indicative of their expansion in cellular compartments. We also found that IL-1ß, IL-2, IL-6 and IL-8 were significantly increased in episodes in which multiple viruses were simultaneously detected, and samples positive for EBV DNA and graft-versus-host disease had a further increase of IL-1ß and IL-8. In conclusion, the EBV, HCMV, HHV6 and HHV7 burdens were frequently detected in allo- and auto-HSCT, and their presence associated with systemic inflammation.

Analytical recommendations for SARS-CoV-2 identification by RT-PCR in pediatric patients.

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2) and is currently listed as a global public health emergency. Timely identification and protocol implementations for molecular detection of this virus are vital for medical decision-making. Identification of SARS-CoV-2 infection cases is based on detection of the virus RNA by molecular tests, particularly real-time reverse transcription-polymerase chain reaction (RT-PCR). Technical and operational details specific to each center must be considered to perform the molecular diagnosis of SARS-CoV-2 in pediatric patients. The term "qualified laboratories" involves laboratories in which all users, analysts, and anyone reporting results are trained to develop and interpret results through a procedure implemented previously by an instructor. Such knowledge is essential in detecting and identifying errors during each of its phases: pre-analytical, analytical, and post-analytical, which allow the establishment of continuous improvement policies to ensure the quality of the results, but above all, the physical integrity of health workers.

Respiratory viral infections in pediatric patients with hematopoietic stem cell transplantation.

Background: Viral respiratory infections in pediatric patients with hematopoietic stem cell transplantation (HSCT) significantly impact morbidity and mortality. It is necessary to determine the viral agents and their frequency of presentation to understand their impact on transplantation patients' evolution. Methods: From January 2017 to December 2019, we conducted a cross-sectional, descriptive, and observational study of patients who underwent HSCT with a viral respiratory infection. Viral identification was performed using multiplex polymerase chain reaction for nine respiratory viruses. Descriptive statistics were performed with a report of central tendency measures and percentages. Results: Of the 54 pediatric patients who underwent HSCT, 59.2% presented an airway infection; in turn, at least one viral agent was identified in 59.3% of these patients. The most frequent viral agents were influenza (25.9%), human rhinovirus (18.5%), and respiratory syncytial virus (18.5%). Viral co-infections occurred in 36.8% of the cases. The reported complications were supplemental oxygen requirement (73.6%), support with mechanical ventilation (21%), admission to the pediatric intensive care unit (15.7%), and mortality associated with a viral respiratory infection (10.5%). Conclusions: Viral respiratory infections are frequent in pediatric patients with HSCT; influenza A/B virus was the most frequent agent. As morbidity and mortality increase due to these infections in patients with HSCT, strategies are necessary for its prevention and timely treatment after transplantation.

Introducción: Las infecciones respiratorias virales en los pacientes pediátricos con trasplante de células progenitoras hematopoyéticas (TCPH) impactan significativamente la morbilidad y la mortalidad. Para comprender su impacto en la evolución de los pacientes receptores de trasplantes es necesario conocer la frecuencia de presentación y los agentes virales. Métodos: De enero de 2017 a diciembre de 2019 se llevó a cabo un estudio transversal, descriptivo y observacional de los pacientes sometidos a TCPH que tuvieron una infección viral de vías respiratorias. La identificación de los virus se realizó por medio de la prueba de reacción en cadena de la polimerasa multiplex para nueve virus respiratorios. Se realizó estadística descriptiva con reporte de medidas de tendencia central y porcentajes. Resultados: De los 54 pacientes incluidos, el 59.2% presentaron una infección de vías respiratorias y se identificó al menos un agente viral en el 59.3% de estos casos. Los virus más frecuentes fueron influenza (25.9%), rinovirus humano (18.5%) y virus sincitial respiratorio (18.5%). En el 36.8% de los casos se detectaron coinfecciones virales. Se presentaron las siguientes complicaciones: requerimiento de oxígeno suplementario (73.6%), soporte con ventilación mecánica (21%), ingreso a la unidad de cuidados intensivos pediátricos (15.7%) y muerte asociada a infección por virus respiratorios (10.5%). Conclusiones: Las infecciones respiratorias virales en los pacientes pediátricos con TCPH son frecuentes; el virus influenza A/B es el agente más habitual. Debido a que estas infecciones se asocian con mayor morbimortalidad en los pacientes con TCPH, son estrategias necesarias para su preven­ción y tratamiento oportuno posterior al trasplante.

25-Hydroxyvitamin D level is associated with mortality in patients with critical COVID-19: a prospective observational study in Mexico City.

BACKGROUND/OBJECTIVES: Considering the high number of deaths from coronavirus disease 2019 (COVID-19) in Latin American countries, together with multiple factors that increase the prevalence of vitamin D deficiency, we aimed to determine 25-hydroxyvitamin D (25[OH]D) levels and its association with mortality in patients with critical COVID-19. SUBJECTS/METHODS: This was a prospective observational study including adult patients with critical COVID-19. Data, including clinical characteristics and 25(OH)D levels measured at the time of intensive care unit admission, were collected. All patients were followed until hospital discharge or in-hospital death. The patients were divided into those surviving and deceased patient groups, and univariate and multivariate logistic regression analyses were performed to determine independent predictors of in hospital mortality. RESULTS: The entire cohort comprised 94 patients with critical COVID-19 (males, 59.6%; median age, 61.5 years). The median 25(OH)D level was 12.7 ng/mL, and 15 (16%) and 79 (84%) patients had vitamin D insufficiency and vitamin D deficiency, respectively. The median serum 25(OH)D level was significantly lower in deceased patients compared with surviving (12.1 vs. 18.7 ng/mL, P < 0.001). Vitamin D deficiency was present in 100% of the deceased patients. Multivariate logistic regression analysis revealed that age, body mass index, other risk factors, and 25(OH)D level were independent predictors of mortality. CONCLUSIONS: Vitamin D deficiency was present in 84% of critical COVID-19 patients. Serum 25(OH)D was independently associated with mortality in critical patients with COVID-19.

Analysis of the Behaviour of Immunoglobulin G Antibodies in Children and Adults Convalescing From Severe Acute Respiratory Syndrome-Coronavirus-2 Infection.

The pandemic caused by SARS CoV-2 (COVID-19) has affected millions of people since 2020. There are clinical differences and in mortality between the adult and paediatric population. Recently, the immune response through the development of antibodies has gained relevance due to the risk of reinfection and vaccines' development. Objective: Was to compare the association of clinical history and the clinical presentation of the disease with the development of IgG antibodies against SARS-CoV-2 in paediatric and adult patients with a history of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results. Methods: Cross-sectional observational study carried out in a Paediatric Hospital in Mexico City included patients under 18 years of age and health personnel with positive RT-PCR for COVID-19 comparing antibody expression. The development of specific IgG antibodies was measured, the presence of comorbidities, duration, and severity of symptoms was determined. Results: Sixty-one subjects (20 < 18 years and 41 > 18 years) were analysed. The median sample collection was 3 weeks. There were no differences in the expression of specific antibodies; no differences were shown according to the symptoms' severity. A positive correlation (r = 0.77) was demonstrated between the duration of symptoms and antibody levels. Conclusions: In conclusion, there is a clear association between the duration of the symptoms associated with SARS-CoV-2 infection and the IgG units generated in paediatric and adult patients convalescing from COVID-19.

Genotyping of the Major SARS-CoV-2 Clade by Short-Amplicon High-Resolution Melting (SA-HRM) Analysis.

The genome of the SARS-CoV-2 virus, the causal agent of the COVID-19 pandemic, has diverged due to multiple mutations since its emergence as a human pathogen in December 2019. Some mutations have defined several SARS-CoV-2 clades that seem to behave differently in terms of regional distribution and other biological features. Next-generation sequencing (NGS) approaches are used to classify the sequence variants in viruses from individual human patients. However, the cost and relative scarcity of NGS equipment and expertise in developing countries prevent studies aimed to associate specific clades and variants to clinical features and outcomes in such territories. As of March 2021, the GR clade and its derivatives, including the B.1.1.7 and B.1.1.28 variants, predominate worldwide. We implemented the post-PCR small-amplicon high-resolution melting analysis to genotype SARS-CoV-2 viruses isolated from the saliva of individual patients. This procedure was able to clearly distinguish two groups of samples of SARS-CoV-2-positive samples predicted, according to their melting profiles, to contain GR and non-GR viruses. This grouping of the samples was validated by means of amplification-refractory mutation system (ARMS) assay as well as Sanger sequencing.

Risk conditions in healthcare workers of a pediatric coronavirus disease center in Mexico City.

BACKGROUND: The new evere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by its high capacity to transmit. Health-care personnel is highly susceptible to becoming infected. This study aimed to determine the characteristics and known risk factors for contagion and severe outcomes of SARS-CoV-2 disease in health-care personnel of a pediatric coronavirus disease (COVID) center in Mexico City. METHODS: In the last week of March 2020 (at the beginning of phase 2 of the Ministry of Health's national campaign in Mexico), a study was conducted on healthcare workers of a pediatric COVID hospital in Mexico City. Using a virtual interview, we evaluated comorbidities, mobility, areas and functions where they carry out the activities, protection measures, contact history, and vaccination. According to their activities, healthcare workers were classified into the following areas: medical, nursing, other health-care personnel (researchers, nutritionists, rehabilitation, imaging, and laboratory), administrative, and other services. We compared the variables between the groups of healthcare workers with the X2 test. RESULTS: We included 812 participants. The mean age was 41 ± 11 years, and 33% were overweight or obese, 18% were over 60 years old, and 19% had high blood pressure. Medical and nursing personnel presented a higher proportion in the use of standard protection measures. CONCLUSIONS: Among healthcare workers, there are risk conditions for the development of complications in case of SARS-CoV-2 infection. Most medical and nursing personnel use standard protective measures.

Clinical risk profile associated with SARS-CoV-2 infection and complications in the emergency area of a pediatric COVID-19 center.

Background: In February 2020, the disease caused by the novel coronavirus (SARS-CoV-2), was classified as a pandemic. In the pediatric population, coronavirus disease (COVID)-19 has a reported mortality of less than 6% in complicated cases; however, the clinical characteristics and severity are not the same as those presented in the adult population. This study aimed to describe the clinical manifestations of patients younger than 18 years old and their association with the confirmation of the test and outcomes. Methods: We conducted an analytical cross-sectional study of symptoms suggestive for SARS-CoV-2 infection. All subjects with a confirmatory test for SARS-CoV-2 were included. Initial symptoms, history of influenza vaccination, and previous contact were documented, and mortality and the requirement for assisted mechanical ventilation were identified. The proportions of the variables were compared with the χ2 test. The odds ratio for a positive test and the requirement of intubation was calculated. Results: Of a total of 510 subjects, 76 (15%) were positive for SARS-CoV-2. The associated symptoms were chest pain, sudden onset of symptoms, and general malaise. The variable most associated with contagion was the exposure to a relative with a confirmed diagnosis of COVID-19. Infants and subjects without the influenza vaccine showed an increased risk for respiratory complications. Conclusions: The frequency of positivity in the test was 15% (infants and adolescents represented 64% of the confirmed cases), and the associated factors identified were contact with a confirmed case, sudden onset of symptoms, and chest pain.

Introducción: En 2019 se reportaron los primeros casos de SARS-CoV-2 (coronavirus tipo 2 del síndrome respiratorio agudo grave), causante de la COVID-19, que alcanzó el grado de pandemia en febrero de 2020. La presentación en la etapa pediátrica reporta una mortalidad menor del 6% en los casos complicados; sin embargo, las características clínicas y su gravedad no son iguales que en la población adulta. El objetivo de este estudio fue describir las manifestaciones clínicas de los pacientes menores de 18 años y su asociación con la confirmación de la prueba, la intubación endotraqueal y la muerte. Métodos: Estudio transversal analítico por cuadro sugestivo de infección por SARS-CoV-2. Se incluyeron sujetos positivos para SARS-CoV-2. Se documentaron los síntomas iniciales, los antecedentes de vacunación contra la influenza y los contactos previos, y se identificaron los desenlaces de mortalidad y requerimiento de ventilación mecánica asistida. Se compararon las proporciones de las variables con la prueba χ2 y se calculó la razón de momios para la presencia de una prueba positiva y requerir intubación. Resultados: De un total de 510 sujetos, 76 (15%) fueron positivos para SARS-CoV-2. Los síntomas asociados fueron dolor precordial, inicio súbito y malestar general. La variable asociada con mayor frecuencia el contagio fue la exposición a un familiar con COVID-19 confirmada. Los sujetos sin vacuna de la influenza presentaron un riesgo mayor de complicaciones respiratorias. Conclusiones: La frecuencia de positividad en la prueba fue del 15%. Se identificaron como factores asociados a prueba positiva el contacto con un caso confirmado de COVID-19, el inicio súbito de los síntomas y el dolor precordial.