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Rheumatoid arthritis (RA) is the most common form of inammatory arthropathy sustained by autoimmune responses. This review has the objective of updating the knowledge about RA especially its molecular pathogenesis. We examine here the current knowledge of tryptophan, arginine, homoarginine and histidine metabolism and the main immunoregulatory pathways in amino acid catabolism in both RA patients and experimental models of arthritis. Of the characteristic autoantibodies of RA, those that appear earlier, are those that recognize cyclic citrullinated peptides. (CCP) and/or citrullinated brinogen. Therefore our analysis would indicate that amino acids metabolism represents a fruitful area of research for new drug targets for a more effective and safe therapy of RA.

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.

Many nonprotein amino acids (NPAAs) are plant secondary metabolites and have a similar chemical structure , size, shape and charge to protein amino acids and can be mistakenly used in protein synthesis, interfere in biochemical pathways, overstimulate receptors or chelate metal ions. The Consumption of a number of plants that contain NPAAs has been shown to have acutely toxic effects in humans. The consumption of some seeds or vegetables that contain NPAAs inuences some people as a trigger for some diseases or as an exacerbating factor. The effects of NPAAs on human health are not well understood. It has been observed that chimpanzees fed alfalfa and also a volunteer subject who have intake alfalfa tablets have both developed a disease with all the characteristics of lupus erythematosus ( an autoimmune disease) and by suppressing the consumption of alfalfa the disease disappears. Most of NPAAs are of plant origin; these do not form part of the primary structure of proteins, they act as antimetabolites and most are found in higher plants; they have the same basic structure as amino acids of animal origin. The substitution of a protein amino acid in protein synthesis produces abnormal proteins which generate antibodies and modication of autoantigens as mechanism to break immunological tolerance and trigger autoimmunity. Auto-antibodies formation is a characteristic of autoimmune disease. The toxic potential of NPAAs depend the amount ingested and the consumption time. Chronic exposure to NPAAs could contribute to autoimmune disease development in genetically susceptible individuals

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.

Background: Diagnosis of coronavirus disease 2019 (COVID-19) is mainly based on molecular testing. General population studies have shown that chest Computed Tomography (CT) can also be useful. Objective: The study aims to examine the usefulness of high-resolution chest CT for early diagnosis of patients with suspected COVID-19. Design And Setting: This is a cross-sectional study from May 1, 2020, to August 31, 2021, at the COVID Hospital, Mexico City. Methods: This study examined the clinical, high-resolution chest CT imaging, and laboratory data of 160 patients who were suspected to have COVID-19. Patients with positive Reverse Transcription- Polymerase Chain Reaction (RT-PCR) testing and those with negative RT-PCR testing but clinical data compatible with COVID-19 and positive antibody testing were considered to have COVID-19 (positive). Sensitivity and specificity of CT for diagnosis of COVID-19 were calculated. p < 0.05 was considered significant. Results: Median age of 160 study patients was 58 years. The proportion of patients with groundglass pattern was significantly higher in patients with COVID-19 than in those without COVID (65.1% versus 0%; P = 0.005). COVID-19 was ruled out in sixteen (11.1%). Only four of the 132 patients diagnosed with COVID-19 (3.0%) did not show CT alterations (p < 0.001). Sensitivity and specificity of CT for COVID-19 diagnosis were 96.7% and 42.8%, respectively. Conclusions: Chest CT can identify patients with COVID-19, as characteristic disease patterns are observed on CT in the early disease stage.

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.

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.

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.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.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%).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.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.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.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%).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.

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.

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.

Overview of the pandemic In December 2019, a new virus named SARS-CoV-2 was reported in Wuhan province, China. The first case of COVID-19 in Mexico was confirmed on February 28, 2020, and the World Health Organization declared the pandemic on March 11.

Background"Rare subgroups of pediatric patients with acute myeloid leukemia (AML), such as t(16:21) (p11;q22), require international cooperation to establish a proper stratification system to assign clinical risk.Here, we report a 13-year-old female who was admitted for asthenia, fatigue, and intermittent fever. The hematological data showed thrombocytopenia and anemia, and the bone marrow test showed 82.5% blast cells, which were positive for CD13, CD33, CD38, and CD117. Blast cells showed negative myeloperoxidase staining and positive periodic acid-Schiff staining. A diagnosis of AML M6 was made. Cells were positive for the fusion transcript FUS-ERG t(16;21)(p11;q22). The patient achieved morphological remission. However, molecular remission was not achieved, and she died 11 months after diagnosis.It is essential to report this sporadic case of AML to provide clinicians with data for clinical decision-making, such as for risk-group stratification. To the best of our knowledge, this is the first association between this translocation and this morphological subtype.La leucemia mieloide aguda (LMA) infantil es una enfermedad heterogénea, por lo que existen subgrupos de rara presentación, como aquellos con t(16;21)(p11;q22). Para establecer el riesgo clínico y la estratificación pronóstica adecuada es necesaria la cooperación internacional.Se reporta el caso de una adolescente de 13 años, admitida por astenia, adinamia y fiebre intermitente. Los datos hematológicos mostraron trombocitopenia y anemia, con un 82.5% de blastos en médula ósea, los cuales fueron positivos para CD13, CD33, CD38 y CD 117. Los blastos fueron negativos para mieloperoxidasa y positivos para ácido peryódico de Schiff. Se realizó el diagnóstico morfológico de LMA M6. Las células fueron positivas para el transcrito FUS-ERG t(16;21)(p11;q22). La paciente alcanzó la remisión morfológica; sin embargo, no fue posible la remisión molecular y falleció 11 meses después del diagnóstico.Es importante reportar casos en los que se identifique un subtipo muy raro de LMA infantil para incrementar la evidencia clínica y contribuir con elementos que ayuden a tomar decisiones clínicas y lograr la estratificación en grupos de riesgo. Hasta la fecha, este el primer caso reportado en que se asocia el transcrito t(16;21)(p11;q22) con el subtipo morfológico LMA M6.

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.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 χOf 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.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.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.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 χDe 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.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.

espanolIntroduccion: Despues de un trasplante de celulas progenitoras hematopoyeticas (TCPH), la reconstitucion de las celulas natural killer (NK) es la principal barrera contra las infecciones virales. Objetivo: Determinar que el conocimiento sobre la cinetica de la reconstitucion de las celulas NK posterior al TCPH contribuye a un eficiente monitoreo del trasplante, lo que incrementa la posibilidad de exito de este. Metodo: Se incluyeron 21 pacientes sometidos a TCPH, asi como un grupo control de individuos clinicamente sanos. En diferentes momentos despues del trasplante (intervalo de 21 a 670 dias), mediante citometria de flujo se cuantificaron las celulas NK CD3− CD16+ CD56+ en muestras de sangre periferica. Resultados: La recuperacion de las celulas NK ocurre entre los tres y seis meses y entre los 10 y 12 meses postrasplante; su numero fue significativamente menor (en comparacion con el grupo control) en el tiempo restante del monitoreo. Conclusiones: El primer periodo de recuperacion de las celulas NK ocurre entre los tres y seis meses posteriores al trasplante. La reconstitucion es transitoria y el numero de celulas NK varia en los primeros anos. EnglishIntroduction: 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.

Cancer is a major cause of death in children worldwide, with B-lineage cell acute lymphoblastic leukemia (B-ALL) being the most frequent childhood malignancy. Relapse, treatment failure and organ infiltration worsen the prognosis, warranting a better understanding of the implicated mechanisms. Cortactin is an actin-binding protein involved in cell adhesion and migration that is overexpressed in many solid tumors and in adult B-cell chronic lymphocytic leukemia. Here, we investigated cortactin expression and potential impact on infiltration and disease prognosis in childhood B-ALL. B-ALL cell lines and precursor cells from bone marrow (BM) and cerebrospinal fluid (CSF) of B-ALL patients indeed overexpressed cortactin. In CXCL12-induced transendothelial migration assays, transmigrated B-ALL cells had highest cortactin expression. In xenotransplantation models, only cortactinhigh-leukemic cells infiltrated lungs, brain, and testis; and they colonized more easily hypoxic BM organoids. Importantly, cortactin-depleted B-ALL cells were significantly less efficient in transendothelial migration, organ infiltration and BM colonization. Clinical data highlighted a significant correlation between high cortactin levels and BM relapse in drug-resistant high-risk B-ALL patients. Our results emphasize the importance of cortactin in B-ALL organ infiltration and BM relapse and its potential as diagnostic tool to identify high-risk patients and optimize their treatments.

Resistance to chemotherapy hinders the successful treatment of acute lymphoblastic leukemia (ALL). The multi-drug resistance-1 (MDR1/ABCB1) gene encodes P-glycoprotein (P-gp), which plays an important role in chemoresistance; however, its transcriptional regulation remains unclear. We investigated the role of YY1 in the regulation of MDR1 and its relation to ALL outcomes. Analysis of the MDR1 promoter revealed four putative YY1-binding sites, which we analyzed using a reporter system and ChIP analysis. YY1 silencing resulted in the inhibition of MDR1 expression and function. The clinical roles of YY1 and MDR1 expression were evaluated in children with ALL. Expression of both proteins was increased in ALL patients compared to controls. We identified a positive correlation between YY1 and MDR1 expression. High levels of YY1 were associated with decreased overall survival. Our results demonstrated that YY1 regulates the transcription of MDR1. Therefore, YY1 may serve as a useful prognostic and/or therapeutic target.

The knowledge of the participation of different subpopulations of T lymphocytes in various pathologies helps to make therapeutic decisions, having as reference the presence of the different subpopulations of the T lymphocytes associated with the disease.A profile standardization of surface molecules for the characterization of subpopulations of T cells was conducted: naïve, activated and memory, as well as natural killer (CD3- CD56+) cells in peripheral blood of clinically healthy individuals.Naïve (CD3+, CD4+ or CD8+, CD45RA+, CD62L+, CCR7+), activated (CD3+, CD4+ or CD8+, CD45RA+ or CD45RO+, CD69+ and/or CRTAM+), effectors (CD3+, CD4+ o CD8+, CD45RA+, CD62L-, CCR7-), central memory (CD3+, CD4+ o CD8+, CD45RO+, CD62L+, CCR7+), memory effectors (CD3+, CD4+ or CD8+, CD62RO+, CD62L-, CCR7-) subpopulations were analyzed by flow cytometry. Descriptive statistics parameters were calculated (minimum values, maximum values, mean values, median).This panel can be very useful for monitoring patients in whom the immunological status from a cellular perspective is needed. Particularly, it can support the follow-up of patients who require an immunological reconstitution (T-cell component) evaluation.La determinación de las diferentes subpoblaciones de los linfocitos T en las diversas patologías y el monitoreo postratamiento ayuda a que el médico tome decisiones terapéuticas teniendo como referencia la cinética de los linfocitos T localizados en sangre periférica.Se realizó la estandarización de un perfil de moléculas de superficie para la caracterización de subpoblaciones de linfocitos T: naïve, activados y de memoria, así como las células natural killer o asesinas naturales (CD3− CD56+) en sangre periférica de individuos clínicamente sanos.Se identificaron las subpoblaciones de linfocitos: naïve (CD3+, CD4+ o CD8+, CD45RA+, CD62L+, CCR7+), activados (CD3+, CD4+ o CD8+, CD45RA+ o CD45RO+, CD69+ y/o CRTAM+), efectores (CD3+, CD4+ o CD8+, CD45RA+, CD62L−, CCR7−), de memoria central (CD3+, CD4+ o CD8+, CD45RO+, CD62L+, CCR7+) y de memoria efectora (CD3+, CD4+ o CD8+, CD45RO+, CD62L−, CCR7−) en las poblaciones de linfocitos T CD4+ y CD8+. Se integraron los datos obtenidos con estadística descriptiva (valores mínimos, valores máximos, media, mediana).Este panel será de gran utilidad para monitorear pacientes en quienes se requiera valorar el estado inmunológico desde el punto de vista celular. Particularmente, puede apoyar en el seguimiento de los pacientes en los que se requiera evaluar la reconstitución inmunológica (componente celular de estirpe T).

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.

Introduction: Healthcare-associated infections are an important cause of morbidity and mortality, are among the most common adverse events in healthcare, and of them, pneumonia is the most commonly reported. Our objective was to evaluate the incidence and clinical outcome of respiratory viruses in hospital-acquired pneumonia (HAP). Methods: This was a prospective cohort study, include patients aged between 0 and 18 who fulfilled Centers for Diseases Control and Prevention (CDC) criteria for HAP. Demographic and clinical data were obtained, and a nasopharyngeal swab specimen was taken for the detection of respiratory viruses. All included patients were monitored until discharge to collect data on the need for mechanical ventilation, intensive care unit (ICU) admission, and mortality. All-cause 30-day mortality was also ascertained. Results: Four thousand three hundred twenty-seven patients were followed for 42,658 patient-days and 5,150 ventilator-days. Eighty-eight patients (2.03%) met the CDC criteria for HAP, 63 patients were included, and clinical and epidemiological characteristics showed no statistically significant differences between patients with virus associated healthcare-associated pneumonia (VAHAP) and those with non-viral healthcare-associated pneumonia (NVHAP). At least one respiratory virus was detected in 65% [95% CI (53-77)] of episodes of HAP, with a single viral pathogen observed in 53.9% and coinfection with 2 viruses in 11.1% of cases. The outcome in terms of ICU admission, mechanical ventilation and the 30-day mortality did not show a significant difference between groups. Conclusions: In two-thirds of the patients a respiratory virus was identified. There was no difference in mortality or the rest of the clinical outcome variables. About half of the patients required mechanical ventilation and 10% died, which emphasizes the importance of considering these pathogens in nosocomial infections, since their identification can influence the decrease in hospital costs and be taken into account in infection control policies.

Herpesviruses are common components of the human microbiome that become clinically relevant when a competent immunosurveillance is compromised, such as in transplantation. Members of the beta and gamma subfamilies are associated with a wide diversity of pathologies, including end-organ disease and cancer. In this study, we developed a multiplex qPCR technique with high specificity, sensitivity, efficiency and predictability that allowed the simultaneous detection and quantification of beta and gamma human herpesviruses. The technique was tested in a cohort of 34 kidney- or liver-transplanted pediatric patients followed up for up to 12 months post-transplant. Viral load was determined in 495 leukocyte-plasma paired samples collected bi-weekly or monthly. Human herpesvirus (HHV) 7 was the herpesvirus most frequently found in positive samples (39%), followed by Epstein-Barr virus (EBV) (20%). Also, EBV and HHV7 were present in the majority of coinfection episodes (62%). The share of positive samples exclusively detected either in leukocytes or plasma was 85%, suggesting that these herpesviruses tended to take a latent or lytic path in an exclusive manner. Infection by human cytomegalovirus (HCMV) and HHV6, as well as coinfection by EBV/HHV7 and EBV/HHV6/HHV7, were associated with graft rejection (RR = 40.33 (p = 0.0013), 5.60 (p = 0.03), 5.60 (p = 0.03) and 17.64 (p = 0.0003), respectively). The routine monitoring of beta and gamma herpesviruses should be mandatory in transplant centers to implement preventive strategies.

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.

Introduction Survival of transplant patients and grafts depends largely on the use of immunosuppressive drugs. However, a balance remains to be established among immunosuppression, transplant rejection and cytomegalovirus (CMV) infection, which results in a high rate of morbidity and mortality. The aim of this study was to define a better strategy for monitoring transplanted patients based on the analysis of the blood concentration of sirolimus and tacrolimus and the burden of CMV. Methods Fifty five post-transplant (kidney and liver) pediatric patients, nine treated with sirolimus and 46 treated with tacrolimus, were included. A total of 541 measurements were obtained. In each measurement the concentration of immunosuppressant in whole blood and CMV viral load in plasma and whole blood was quantified by real-time PCR. Pearson correlation coefficient (r) was estimated. Results Values of r ≤0.0747 were found for the relationship between dose and concentration of immunosuppressant; r = 0.9406 for the relationship between viral load in whole blood and plasma, and r ≤0.4616 for the relationship between concentration of immunosuppressant and viral load. Conclusions These data support that the doses of immunosuppressive drugs do not correlate with the levels of the same in whole blood. Therefore, systemic levels of immunosuppressant should be constantly monitored together with CMV load. Meanwhile, a high correlation between viral load measured in whole blood and plasma was found.

ResumenIntroducciónHace algunos años, el motivo principal para la solicitud del diagnóstico parasitológico era la sospecha de una etiología de base parasitaria. En la actualidad, el motivo de consulta y la solicitud del diagnóstico se encuentran asociados con una comorbilidad hemato-oncológica, autoinmune, inmunodeficiente o una condición postrasplante.MétodoSe analizaron los resultados del laboratorio de parasitología clínica del Hospital Infantil de México Federico Gómez de enero de 1990 a diciembre del 2010, para obtener la frecuencia y distribución de parásitos y comensales por año y década.ResultadosSe analizaron 211,600 muestras del periodo estudiado, con una media anual de 10,100 y desviación estándar de 3,500. El porcentaje de parásitos y comensales fue del 37.73%, y la frecuencia de positividad solo a parásitos fue del 21.4%. La diferencia de proporciones entre décadas resultó significativa, con una p