An admixture mapping meta-analysis implicates genetic variation at 18q21 with asthma susceptibility in Latinos.

BACKGROUND: Asthma is a common but complex disease with racial/ethnic differences in prevalence, morbidity, and response to therapies. OBJECTIVE: We sought to perform an analysis of genetic ancestry to identify new loci that contribute to asthma susceptibility. METHODS: We leveraged the mixed ancestry of 3902 Latinos and performed an admixture mapping meta-analysis for asthma susceptibility. We replicated associations in an independent study of 3774 Latinos, performed targeted sequencing for fine mapping, and tested for disease correlations with gene expression in the whole blood of more than 500 subjects from 3 racial/ethnic groups. RESULTS: We identified a genome-wide significant admixture mapping peak at 18q21 in Latinos (P = 6.8 × 10-6), where Native American ancestry was associated with increased risk of asthma (odds ratio [OR], 1.20; 95% CI, 1.07-1.34; P = .002) and European ancestry was associated with protection (OR, 0.86; 95% CI, 0.77-0.96; P = .008). Our findings were replicated in an independent childhood asthma study in Latinos (P = 5.3 × 10-3, combined P = 2.6 × 10-7). Fine mapping of 18q21 in 1978 Latinos identified a significant association with multiple variants 5' of SMAD family member 2 (SMAD2) in Mexicans, whereas a single rare variant in the same window was the top association in Puerto Ricans. Low versus high SMAD2 blood expression was correlated with case status (13.4% lower expression; OR, 3.93; 95% CI, 2.12-7.28; P < .001). In addition, lower expression of SMAD2 was associated with more frequent exacerbations among Puerto Ricans with asthma. CONCLUSION: Ancestry at 18q21 was significantly associated with asthma in Latinos and implicated multiple ancestry-informative noncoding variants upstream of SMAD2 with asthma susceptibility. Furthermore, decreased SMAD2 expression in blood was strongly associated with increased asthma risk and increased exacerbations.

Positive Mental Health Questionnaire (PMHQ) for Healthcare Workers: A Psychometric Evaluation.

The Positive Mental Health Questionnaire (PMHQ) has been validated across various populations but has displayed diverse psychometric structures depending on the procedures used. The original version of the PMHQ includes 39 items organized into 6 factors, although there are reports that indicate a reduced structure of between 1 and 4 factors. The aim of this study was to assess the psychometric properties of the PMHQ with 1, 4 and 6 factors. A total of 360 healthcare workers aged 23 to 77 (M = 37.06; SD = 10.79) participated. Construct validity was assessed through confirmatory factor analysis using weighted root mean square residual. The original 6-factor (χ2/df: 3.40; RMSEA: 0.085; CFI: 0.913; TLI: 0.906) and a reduced 4-factor (χ2/df: 2.90; RMSEA: 0.072; CFI: 0.931; TLI: 0.926) structure showed acceptable fit. The fit of the 1-factor model was unacceptable. The internal consistency was evaluated through McDonald's ω, and it was acceptable for 4 of 6 factors of the original structure and for 3 of 4 factors of the reduced structure. In conclusion, these findings suggest that the 6-factor and 4-factor models are valid for measuring positive mental health. However, issues with internal consistency must be investigated.

Burnout and Its Relationship with Work Engagement in Healthcare Professionals: A Latent Profile Analysis Approach.

The aim of this study was to use latent profile analysis to identify specific profiles of burnout syndrome in combination with work engagement and to identify whether job satisfaction, psychological well-being, and other sociodemographic and work variables affect the probability of presenting a profile of burnout syndrome and low work enthusiasm. A total of 355 healthcare professionals completed the Spanish Burnout Inventory, the Utrecht Work Engagement Scale, the Job Satisfaction Scale, and the Psychological Well-Being Scale for Adults. Latent profile analysis identified four profiles: (1) burnout with high indolence (BwHIn); (2) burnout with low indolence (BwLIn); (3) high engagement, low burnout (HeLb); and (4) in the process of burning out (IPB). Multivariate logistic regression showed that a second job in a government healthcare institution; a shift other than the morning shift; being divorced, separated or widowed; and workload are predictors of burnout profiles with respect to the HeLb profile. These data are useful for designing intervention strategies according to the needs and characteristics of each type of burnout profile.

Behavior of immunoglobulin G antibodies for SARS-COV-2 in Mexican pediatric patients with comorbidities: a prospective comparative cohort study.

Background: More than two years after the pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) there is a great lack of information. The presence of immunoglobulin G (IgG) have been related with disease severity. Patients with comorbidities could develop more severe infection; however, the evaluation of the humoral response in pediatric population are needed especially in patients with comorbidities. Our aim was to describe the behavior of IgG in pediatric patients and to know if there is a difference between patients with comorbidities. Methods: A prospective comparative cohort study was carried out in a single center from June 2020 to January 2021, with a follow-up of 6 months. The study included all the subjects with confirmatory test for SARS-CoV-2 from 1 month to 17 years 11 months, the follow-up of the disease's evolution and measurement of IgG antibodies was collected. We obtained the clinical data, and comorbidities like arterial hypertension, diabetes, obesity, and cancer, the initial symptoms were recorded as well as the evolution regarding the severity of COVID-19 and the need for hospitalization, intensive care unit or mechanical ventilation. The follow up was carried out through medical consultation with an appointment every month that included direct interrogation, examination, and peripheral blood collection for the IgG quantification. The antibodies detection was done through peripheral blood and chemiluminescence microparticle immunoassay. Results: A total of 237 patients with positive polymerase chain reaction (PCR) for SARS-COV-2 were included, of which 147 presented IgG antibodies (62%), 112 (76%) without comorbidity and 35 (24%) with comorbidities, by the sixth month only 2.7% continue with positive antibody measurements. Patients with comorbidities reach higher IgG levels than patients without comorbidities the basal titters were: 5.17 for patients without comorbidities vs. 6.96 for the group with comorbidities (P<0.001). Conclusions: We found an association between the presence of comorbidities and high levels of IgG units in pediatric patients with COVID-19. Additionally, patients with more severe course of the disease have higher levels of IgG and by the third month less than 35% have immunity.

Genome-wide association study implicates chromosome 9q21.31 as a susceptibility locus for asthma in mexican children.

Many candidate genes have been studied for asthma, but replication has varied. Novel candidate genes have been identified for various complex diseases using genome-wide association studies (GWASs). We conducted a GWAS in 492 Mexican children with asthma, predominantly atopic by skin prick test, and their parents using the Illumina HumanHap 550 K BeadChip to identify novel genetic variation for childhood asthma. The 520,767 autosomal single nucleotide polymorphisms (SNPs) passing quality control were tested for association with childhood asthma using log-linear regression with a log-additive risk model. Eleven of the most significantly associated GWAS SNPs were tested for replication in an independent study of 177 Mexican case-parent trios with childhood-onset asthma and atopy using log-linear analysis. The chromosome 9q21.31 SNP rs2378383 (p = 7.10x10(-6) in the GWAS), located upstream of transducin-like enhancer of split 4 (TLE4), gave a p-value of 0.03 and the same direction and magnitude of association in the replication study (combined p = 6.79x10(-7)). Ancestry analysis on chromosome 9q supported an inverse association between the rs2378383 minor allele (G) and childhood asthma. This work identifies chromosome 9q21.31 as a novel susceptibility locus for childhood asthma in Mexicans. Further, analysis of genome-wide expression data in 51 human tissues from the Novartis Research Foundation showed that median GWAS significance levels for SNPs in genes expressed in the lung differed most significantly from genes not expressed in the lung when compared to 50 other tissues, supporting the biological plausibility of our overall GWAS findings and the multigenic etiology of childhood asthma.

Immunostimulants for preventing respiratory tract infection in children: A systematic review and meta-analysis.

Childhood acute respiratory tract infections (ARTIs) are a significant cause of morbidity and mortality, so, immunostimulants have been used as a preventative measure. Despite this, there is no updated evidence regarding the safety and efficacy of immunostimulant drugs for this purpose. This study aimed to determine the effectiveness and safety of immunostimulants in preventing ARTIs in children based on the most recent scientific evidence. Data sources such as PubMed, Cochrane Central Register of Controlled Trials, Embase, Google Scholar, and Scopus were searched from 1965 to 10 January 2022 to identify randomized controlled trials (RCTs) comparing immunostimulants administered by any method, with placebo to prevent ARTIs on children under 18 years of age without immunodeficiencies, anatomical, genetic, or allergic conditions. In order to analyze data from the studies, we used Review Manager 5.4 (The Cochrane Collaboration, 2020), assessed the certainty of the evidence with Grading of Recommendations, Assessment, Development and Evaluations (GRADE), and assessed the quality and risk of bias of the studies using the RoB tool 1.0. Further, outcomes were combined and analyzed using meta-analysis, subgroup analysis, and sensitivity analysis. Throughout the review, we included 72 placebo-controlled clinical trials involving 12,229 children. The meta-analyses, however, included only 38 studies (52.8%) with 4643 children (38% of the total) with data on mean number of ARTIs. These studies demonstrated a reduction in the ARTIs (MD -1.12 [95%CI -1.39 to -0.85]) and ratio of means of ARTIs (0.61 [95%CI 0.54-0.69]), corresponding to a percentage reduction of 39% (95%CI, 46%-31%) with moderate-quality data. Nevertheless, since there was considerable to substantial heterogeneity and bias was unclear in all domains in 32 out of 72 trials, the quality of the evidence for efficacy was deemed low. Only 14 trials reported adverse events. The review indicates that immunostimulants reduce the incidence of ARTIs by 40% on average in susceptible children, despite low-quality evidence, heterogeneity, and the possibility of publication bias. However, further studies are needed to establish immunostimulants' safety and efficacy profiles. This review was conducted without the support of any funding and has no registered number.

Tracing COVID-19 Source of Infection Among Health Personnel in a Pediatric Hospital.

Health personnel (HP) have been universally recognized as especially susceptible to COVID-19. In Mexico, our home country, HP has one of the highest death rates from the disease. From the beginning of the SARS-CoV-2 pandemic, an office for initial attention for HP and a call center were established at a COVID-19 national reference pediatric hospital, aimed at early detection of COVID-19 cases and stopping local transmission. The detection and call center implementation and operation, and tracing methodology are described here. A total of 1,042 HP were evaluated, with 221 positive cases identified (7.7% of all HP currently working and 26% of the HP tested). Community contagion was most prevalent (46%), followed by other HP (27%), household (14%), and hospitalized patients (13%). Clusters and contact network analysis are discussed. This is one of the first reports that address the details of the implementation process of contact tracing in a pediatric hospital from the perspective of a hybrid hospital with COVID-19 and non-COVID-19 areas.

Characteristics and Outcomes of Cases of Children and Adolescents With Pediatric Inflammatory Multisystem Syndrome in a Tertiary Care Center in Mexico City.

Background: Pediatric inflammatory multisystem syndrome (PIMS) is a complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children that resembles Kawasaki syndrome and places them at high risk of cardiorespiratory instability and/or cardiac damage. This study aims to describe the clinical presentation and outcomes of patients with PIMS in Mexico City. Methods: This was an observational study of children hospitalized for PIMS based on the Centers for Disease Control and Prevention case definition criteria, in a single tertiary care pediatric center in Mexico City between May 1, 2020, and September 30, 2021. Demographic characteristics, epidemiological data, medical history, laboratory tests, cardiologic evaluations, treatment, and clinical outcomes were analyzed. Results: Seventy-five cases fulfilled the case definition criteria for PIMS [median age: 10.9 years, Interquartile range (IQR): 5.6-15.6]. Fifteen (20%) patients had a severe underlying disease, 48 (64%) were admitted to the intensive care unit, 33 (44%) required invasive mechanical ventilation and 39 (52%) received vasopressor support. The patients were clustered through latent class analysis based on identified symptoms: Cluster 1 had rash or gastrointestinal symptoms (n = 60) and cluster 2 were those with predominantly respiratory manifestations (n = 15). Two patients (2.7%) died, and both had severe underlying conditions. Five patients (6.7%), all from cluster 1, developed coronary aneurysms. Conclusion: There were a high proportion of patients with severe respiratory involvement and positive RT-PCR SARS-CoV-2 and very few cases of coronary aneurysms in our study which suggests that a high proportion of the children had severe acute COVID-19. The clinical manifestations and outcomes are comparable to previously reported international studies.

Evaluation of candidate genes in a genome-wide association study of childhood asthma in Mexicans.

BACKGROUND: More than 200 asthma candidate genes have been examined in human association studies or identified with knockout mouse approaches. However, many have not been systematically replicated in human populations, especially those containing a large number of tagging single nucleotide polymorphisms (SNPs). OBJECTIVE: We comprehensively evaluated the association of previously implicated asthma candidate genes with childhood asthma in a Mexico City population. METHODS: From the literature, we identified candidate genes with at least 1 positive report of association with asthma phenotypes in human subjects or implicated in asthma pathogenesis using knockout mouse experiments. We performed a genome-wide association study in 492 asthmatic children aged 5 to 17 years and both parents using the Illumina HumanHap 550v3 BeadChip. Separate candidate gene analyses were performed for 2933 autosomal SNPs in the 237 selected genes by using the log-linear method with a log-additive risk model. RESULTS: Sixty-one of the 237 genes had at least 1 SNP with a P value of less than .05 for association with asthma. The 9 most significant results were observed for rs2241715 in the gene encoding TGF-beta1 (TGFB1; P = 3.3 x 10(-5)), rs13431828 and rs1041973 in the gene encoding IL-1 receptor-like 1 (IL1RL1; P = 2 x 10(-4) and 3.5 x 10(-4)), 5 SNPs in the gene encoding dipeptidyl-peptidase 10 (DPP10; P = 1.6 x 10(-4) to 4.5 x 10(-4)), and rs17599222 in the gene encoding cytoplasmic FMR1 interacting protein 2 (CYFIP2; P = 4.1 x 10(-4)). False discovery rates were less than 0.1 for all 9 SNPs. Multimarker analysis identified TGFB1, IL1RL1, the gene encoding IL-18 receptor 1 (IL18R1), and DPP10 as the genes most significantly associated with asthma. CONCLUSIONS: This comprehensive analysis of literature-based candidate genes suggests that SNPs in several candidate genes, including TGFB1, IL1RL1, IL18R1, and DPP10, might contribute to childhood asthma susceptibility in a Mexican population.

[Food allergy]. / Alergia a alimentos.

Food allergy is defined as an abnormal immunological reaction to food proteins, which causes an adverse clinical reaction. Most of the people become tolerant to many foods; however some time these tolerances fail and become an immunologic reaction. This is the first clinical expression of allergy, beginning with dermal o gastric manifestations and continues with asthma and rhinitis (the allergy march) and represents a very severe health problem, not only for many children and parents, but also for the entire medical and paramedical community. The evaluation of a child with suspected food allergy includes detailed medical history, physical examination, screening tests and response to elimination diet and to oral food challenge. None of the screening tests, alone or in combination, can definitively diagnose or exclude it. Regarding to the differential diagnosis, the clinician must know the different groups of foods. The treatment includes the exclusion of the involved food and the use of symptomatic medication when it is needed.

Association of Genetic Polymorphisms and Serum Levels of IL-6 and IL-8 with the Prognosis in Children with Neuroblastoma.

There is evidence that high circulating levels of IL-6 and IL-8 are markers of a poor prognosis in various types of cancer, including NB. The participation of these cytokines in the tumor microenvironment has been described to promote progression and metastasis. Our objective was to evaluate the prognostic role of genetic polymorphisms and serum levels of IL-6 and IL-8 in a cohort of Mexican pediatric patients with NB. The detection of the SNPs rs1800795 IL-6 and rs4073 and rs2227306 IL-8 was carried out by PCR-RFLP and the levels of cytokines were determined by the ELISA method. We found elevated circulating levels of IL-8 and IL-6 in NB patients compared to the control group. The genotype frequencies of the rs1800795 IL-6 and rs4073 IL-8 variants were different between the patients with NB and the control group. Likewise, the survival analysis showed that the GG genotypes of rs1800795 IL-6 (p = 0.014) and AA genotypes of rs4073 IL-8 (p = 0.002), as well as high levels of IL-6 (p = 0.009) and IL-8 (p = 0.046), were associated with lower overall survival. We confirmed the impact on an adverse prognosis in a multivariate model. This study suggests that the SNPs rs1800795 IL-6 and rs4073 IL-8 and their serum levels could be promising biomarkers of a poor prognosis, associated with overall survival, metastasis, and a high risk in Mexican children with NB.

Air pollution, airway inflammation, and lung function in a cohort study of Mexico City schoolchildren.

BACKGROUND: The biological mechanisms involved in inflammatory response to air pollution are not clearly understood. OBJECTIVE: In this study we assessed the association of short-term air pollutant exposure with inflammatory markers and lung function. METHODS: We studied a cohort of 158 asthmatic and 50 nonasthmatic school-age children, followed an average of 22 weeks. We conducted spirometric tests, measurements of fractional exhaled nitric oxide (Fe(NO)), interleukin-8 (IL-8) in nasal lavage, and pH of exhaled breath condensate every 15 days during follow-up. Data were analyzed using linear mixed-effects models. RESULTS: An increase of 17.5 microg/m(3) in the 8-hr moving average of PM(2.5) levels (interquartile range) was associated with a 1.08-ppb increase in Fe(NO) [95% confidence interval (CI), 1.01-1.16] and a 1.07-pg/mL increase in IL-8 (95% CI 0.98-1.19) in asthmatic children and a 1.16 pg/ml increase in IL-8 (95% CI, 1.00-1.36) in nonasthmatic children. The 5-day accumulated average of exposure to particulate matter <2.5 microm in aerodynamic diamter (PM(2.5)) was significantly inversely associated with forced expiratory volume in 1 sec (FEV(1)) (p=0.048) and forced vital capacity (FVC) (p=0.012) in asthmatic children and with FVC (p=0.021) in nonasthmatic children. Fe(NO) and FEV(1) were inversely associated (p=0.005) in asthmatic children. CONCLUSIONS: Exposure to PM(2.5) resulted in acute airway inflammation and decrease in lung function in both asthmatic and nonasthmatic children.

Traffic-related air pollution and respiratory symptoms among asthmatic children, resident in Mexico City: the EVA cohort study.

BACKGROUND: Taffic-related air pollution has been related to adverse respiratory outcomes; however, there is still uncertainty concerning the type of vehicle emission causing most deleterious effects. METHODS: A panel study was conducted among 147 asthmatic and 50 healthy children, who were followed up for an average of 22 weeks. Incidence density of coughing, wheezing and breathing difficulty was assessed by referring to daily records of symptoms and child's medication. The association between exposure to pollutants and occurrence of symptoms was evaluated using mixed-effect models with binary response and poisson regression. RESULTS: Wheezing was found to relate significantly to air pollutants: an increase of 17.4 microg/m3 (IQR) of PM2.5 (24-h average) was associated with an 8.8% increase (95% CI: 2.4% to 15.5%); an increase of 34 ppb (IQR) of NO2 (1-h maximum) was associated with an 9.1% increase (95% CI: 2.3% to 16.4%) and an increase of 48 ppb (IQR) in O3 levels (1 hr maximum) to an increase of 10% (95% CI: 3.2% to 17.3%). Diesel-fueled motor vehicles were significantly associated with wheezing and bronchodilator use (IRR = 1.29; 95% CI: 1.03 to 1.62, and IRR = 1.32; 95% CI: 0.99 to 1.77, respectively, for an increase of 130 vehicles hourly, above the 24-hour average). CONCLUSION: Respiratory symptoms in asthmatic children were significantly associated with exposure to traffic exhaust, especially from natural gas and diesel-fueled vehicles.

Parental smoking modifies the relation between genetic variation in tumor necrosis factor-alpha (TNF) and childhood asthma.

BACKGROUND: Polymorphisms in the proinflammatory cytokine genes tumor necrosis factor-alpha (TNF) and lymphotoxin-alpha (LTA, also called TNF-beta) have been associated with asthma and atopy in some studies. Parental smoking is a consistent risk factor for childhood asthma. Secondhand smoke and ozone both stimulate TNF production. OBJECTIVES: Our goal was to investigate whether genetic variation in TNF and LTA is associated with asthma and atopy and whether the association is modified by parental smoking in a Mexican population with high ozone exposure. METHODS: We genotyped six tagging single nucleotide polymorphisms (SNPs) in TNF and LTA, including functional variants, in 596 nuclear families consisting of asthmatics 4-17 years of age and their parents in Mexico City. Atopy was determined by skin prick tests. RESULTS: The A allele of the TNF-308 SNP was associated with increased risk of asthma [relative risk (RR) = 1.54; 95% confidence interval (CI), 1.04-2.28], especially among children of non-smoking parents (RR = 2.06; 95% CI, 1.19-3.55; p for interaction = 0.09). Similarly, the A allele of the TNF-238 SNP was associated with increased asthma risk among children of nonsmoking parents (RR = 2.21; 95% CI, 1.14-4.30; p for interaction = 0.01). LTA SNPs were not associated with asthma. Haplotype analyses reflected the single SNP findings in magnitude and direction. TNF and LTA SNPs were not associated with the degree of atopy. CONCLUSIONS: Our results suggest that genetic variation in TNF may contribute to childhood asthma and that associations may be modified by parental smoking.

[Knowledge of asthma: educational intervention with the 2014 GINA guide in primary care physicians]. / Conocimiento de asma: intervención educativa con la guía GINA 2014 en médicos de primer contacto.

BACKGROUND: Asthma is a public health problem in the world, so updating the guidelines for the diagnosis and treatment of asthma is based primarily on the practice of primary care physicians. Educational interventions are useful for increasing knowledge. OBJECTIVE: To compare the level of knowledge of asthma before and after an educational intervention. METHODS: A quasi-experimental prospective study was conducted in general and family practitioners and pediatricians who attended a training workshop on general aspects of asthma and current guidelines for diagnosis and treatment (GINA 2014). A questionnaire consisting of 11 multiple choice questions relating to fundamental aspects of the disease and diagnosis, classification, treatment and management of attacks, was used in two assessments, baseline and post-intervention. RESULTS: A total of 178 patients participated in the study, with knowledge pre-intervention at 25.5 points and post-intervention at 97.5 points on a scale of 100, with p < 0.05. CONCLUSION: Educational interventions are inexpensive and effective tools to increase the knowledge of health professionals, and they have an impact on improving patient care.

Introducción: El asma en un problema de salud pública en el mundo, por ello, la actualización de las guías para el diagnóstico y tratamiento de asma se realiza en función principalmente de la práctica de los médicos de primer contacto. Las intervenciones educativas son útiles para el incremento del conocimiento. Objetivo: Comparar el nivel de conocimiento acerca de asma antes y después de una intervención educativa. Métodos: Se realizó un estudio prospectivo cuasiexperimental, en médicos generales, familiares y pediatras que asistieron a un curso-taller relativo a aspectos generales del asma y las guías actuales para su diagnóstico y tratamiento (GINA 2014). Mediante un cuestionario constituido por 11 preguntas de opción múltiple que abordaban aspectos fundamentales de la enfermedad como diagnóstico, clasificación, tratamiento y manejo de exacerbaciones, se realizaron dos evaluaciones, una basal y otra posintervención. Resultados: Un total de 178 paciente participaron en el estudio, con un conocimiento preintervención de 25.5 puntos y posintervención de 97.5 puntos de una escala de 100, con una p<0.05. Conclusión: Las intervenciones educativas son maniobras de bajo costo y efectivas que incrementan el conocimiento de los profesionales de la salud y tienen impacto en la mejoría de la atención al paciente.

[Radiographic changes in children with primary immunodeficiency]. / Alteraciones radiográficas en niños con inmunodeficiencia primaria.

BACKGROUND: Although we have epidemiological information on primary immunodeficiencies (PID), the available information is meager in Mexico. OBJECTIVE: To provide epidemiological information on the delay in the diagnosis of PID and its correlation to chronic lung damage. MATERIAL AND METHOD: A retrospective, analytical study was done in patients 0-18 year old age diagnosed with PID for 11 years at the HIMFG (Hospital Infantil de Mexico Federico Gomez). The variables studied were: age at symptom onset, age at diagnosis, time from onset of symptoms to diagnosis, number of previous pneumonias and studies with radiographic chronic lung damage data. RESULTS: 48 patients were obtained after meeting inclusion criteria; 33 showed lung damage at diagnosis, antibody deficiency being the most affected group. Relating age of onset of symptoms and the time difference of the onset of symptoms to diagnosis showed a strong correlation (p < 0.001, Rho > 0.80). A moderate correlation between the observed time difference vs number of pneumonias (p=0.005, Rho=0.495) and correlation between number of pneumonia and lung damage was highly significant (p <0.001, Rho=0.704). CONCLUSION: A strong relationship between the elapsed time from onset of symptoms and the number of pneumonia with lung injury time was found. So, the recurrent pneumonia (> 2) must make suspect the diagnosis of PID, as recommended in the literature.

Antecedentes: si bien se cuenta con información epidemiológica de las inmunodeficiencias primarias, la información disponible en México es escasa. Objetivos: dar información epidemiológica del retraso del diagnóstico de las inmunodeficiencias primarias y de su correlación con daño pulmonar crónico. Material y método: estudio retrospectivo, analítico, efectuado en pacientes de 0 a 18 años de edad con diagnóstico de inmunodeficiencias primarias durante 11 años en el Hospital Infantil de México Federico Gómez; las variables estudiadas fueron: edad al inicio de los síntomas, edad al diagnóstico, tiempo desde el inicio de los síntomas al diagnóstico, número de neumonías previas y estudios radiográficos con datos de daño pulmonar crónico. Resultados: se incluyeron 48 pacientes que cumplieron los criterios de inclusión; 33 tenían daño pulmonar al diagnóstico, el déficit de anticuerpos fue el grupo con mayor afectación. Al correlacionar la edad de inicio de los síntomas y la diferencia de tiempo del inicio de los síntomas al diagnóstico se obtuvo una fuerte correlación (p <0.001, Rho > 0.80). Se observó una correlación moderada entre la diferencia en tiempo vs número de neumonías (p=0.005, Rho=0.495) y la correlación entre número de neumonías y daño pulmonar mostró significación alta (p <0.001, Rho=0.704). Conclusión: se encontró una relación estrecha entre el tiempo transcurrido desde el inicio de los síntomas y el número de neumonías con el daño pulmonar, por lo que las neumonías de repetición (más de dos) deben hacer sospechar el diagnóstico de inmunodeficiencia primaria, como se recomienda en la bibliografía mundial.

[Antihistamines for the treatment of urticaria in Mexico]. / Antihistamínicos en el tratamiento de la urticaria en México.

There are four types of histamine receptors. Allergic symptoms, especially those in rhinoconjunctivitis and urticaria, are mainly caused by activation of histamine receptor 1 (H1). Consequently, oral H1-antihistamines form and integral part of the treatment of these diseases. Antihistamines are inverse agonists that stabilize the non-active configuration of the histamine receptor. First generation H1-antihistamines cause a variety of adverse effects via several mechanisms: sedation (accumulation in the central nervous system), dry mouth, urinary retention, weight gain (low selectivity: stimulation of serotonin/muscarinic/alpha-adrenergic receptors) and drug interactions (substrate of CYP450-3A4). Generally second generation H1-antihistamines have a better safety profile. New guidelines on allergic rhinitis and urticaria recommend second generation H1-antihistamines as first line drugs, with -if necessary- four-times updosing to obtain control in urticaria. The enhanced efficacy of quadruple doses in urticaria, while maintaining a good safety profile, has been shown for bilastine, desloratadine and levocetirizine (rupatadine). For ebastine and fexofenadine only the safety of quadruple doses has been shown till now. Extreme precaution should be taken with astemizol and terfenadine that never should be up-dosed, as high serum concentrations can cause potentially fatal ventricular tachycardia. First generation antihistamines are not recommended as first line treatment and updosing is not safe.

Existen cuatro tipos de receptores histaminérgicos. Los síntomas de alergia, especialmente rinoconjuntivitis alérgica y urticaria, son principalmente causados por activación del receptor H1; por ende, los antihistamínicos H1 orales (anti-H1) forman parte integral del tratamiento de estas enfermedades. Los antihistamínicos son agonistas inversos, porque estabilizan la forma inactiva del receptor. Los antihistamínicos H1 de primera generación producen efectos adversos por varios mecanismos: sedación (fijación a receptores H1 cerebrales), boca seca, retención urinaria, aumento de peso (baja selectividad: estimulación de los receptores de serotonina, muscarina y alfa-adrenérgicos) e interacciones medicamentosas (con sustrato de citocromo P450-3A4). Los antihistamínicos H1 de segunda generación son generalmente más seguros. Las nuevas guías de tratamiento de la rinitis alérgica y urticaria recomiendan como manejo de primera intención a los antihistamínicos H1 de segunda generación. En urticaria se recomienda hasta cuadruplicar su dosis en caso necesario. El aumento de la eficacia en el control de la urticaria con cuádruple dosis, sin que se afecte la seguridad, se ha documentado para bilastina, desloratadina y levocetirizina (rupatadina). Respecto de ebastina y fexofenadina, hasta ahora, sólo se comprobó la seguridad de cuádruple dosis. Una rigurosa excepción son astemizol y terfenadina, que a concentraciones séricas elevadas pueden causar taquicardia ventricular. No se recomiendan los antihistamínicos H1 de primera generación y aumentar su dosis no es seguro.

Meteorological conditions, climate change, new emerging factors, and asthma and related allergic disorders. A statement of the World Allergy Organization.

The prevalence of allergic airway diseases such as asthma and rhinitis has increased dramatically to epidemic proportions worldwide. Besides air pollution from industry derived emissions and motor vehicles, the rising trend can only be explained by gross changes in the environments where we live. The world economy has been transformed over the last 25 years with developing countries being at the core of these changes. Around the planet, in both developed and developing countries, environments are undergoing profound changes. Many of these changes are considered to have negative effects on respiratory health and to enhance the frequency and severity of respiratory diseases such as asthma in the general population. Increased concentrations of greenhouse gases, and especially carbon dioxide (CO2), in the atmosphere have already warmed the planet substantially, causing more severe and prolonged heat waves, variability in temperature, increased air pollution, forest fires, droughts, and floods - all of which can put the respiratory health of the public at risk. These changes in climate and air quality have a measurable impact not only on the morbidity but also the mortality of patients with asthma and other respiratory diseases. The massive increase in emissions of air pollutants due to economic and industrial growth in the last century has made air quality an environmental problem of the first order in a large number of regions of the world. A body of evidence suggests that major changes to our world are occurring and involve the atmosphere and its associated climate. These changes, including global warming induced by human activity, have an impact on the biosphere, biodiversity, and the human environment. Mitigating this huge health impact and reversing the effects of these changes are major challenges. This statement of the World Allergy Organization (WAO) raises the importance of this health hazard and highlights the facts on climate-related health impacts, including: deaths and acute morbidity due to heat waves and extreme meteorological events; increased frequency of acute cardio-respiratory events due to higher concentrations of ground level ozone; changes in the frequency of respiratory diseases due to trans-boundary particle pollution; altered spatial and temporal distribution of allergens (pollens, molds, and mites); and some infectious disease vectors. According to this report, these impacts will not only affect those with current asthma but also increase the incidence and prevalence of allergic respiratory conditions and of asthma. The effects of climate change on respiratory allergy are still not well defined, and more studies addressing this topic are needed. Global warming is expected to affect the start, duration, and intensity of the pollen season on the one hand, and the rate of asthma exacerbations due to air pollution, respiratory infections, and/or cold air inhalation, and other conditions on the other hand.

Ozone exposure among Mexico City outdoor workers.

In researching health effects of air pollution, pollutant levels from fixed-site monitors are commonly assigned to the subjects. However, these concentrations may not reflect the exposure these individuals actually experience. A previous study of ozone (O3) exposure and lung function among shoe-cleaners working in central Mexico City used fixed-site measurements from a monitoring station near the outdoor work sites as surrogates for personal exposure. The present study assesses the degree to which these estimates represented individual exposures. In 1996, personal O3 exposures of 39 shoe-cleaners working outdoors were measured using an active integrated personal sampler. Using mixed models, we assessed the relationship between measured personal O3 exposure and ambient O3 measurements from the fixed-site monitoring station. Ambient concentrations were approximately 50 parts per billion higher, on average, than personal exposures. The association between personal and ambient O3 was highly significant (mixed model slope p < 0.0001). The personal/ambient ratio was not constant, so use of the outdoor monitor would not be appropriate to rank O3 exposure and evaluate health effects between workers. However, the strong within-worker longitudinal association validates previous findings associating day-to-day changes in fixed-site O3 levels with adverse health effects among these shoe-cleaners and suggests fixed-site O3 monitors may adequately estimate exposure for other repeated-measure health studies of outdoor workers.