Validación del método inverso para la determinación del flujo de acceso con termodilución

IntroductionThermodilution is a widely used method for measuring vascular access flow (Q_A). Among the possibilities of thermodilution, the reverse method (RM) can be beneficial in the execution time, without impact on the dialysis efficacy (K_t). However, it is not a sufficiently studied technique.MethodTransversal study of 117 arteriovenous fistulas. Two Q_A measurements were taken with the method described by the manufacturer (MR) and another with RM. RM is based on the obtention of an inverted recirculation registry at the beginning of the session and a single subsequent recirculation measurement with the lines in normal position. In the concordance analysis, the Bland-Altman method and Cohen's Kappa index were used.ResultsVery good concordance between MR and RM was evidenced for Q_A below 700 ml/min, but it worsens as flow increases. The median variability between the MR measurements (intra-method variability) was 3.4% (?17.13). This value did not differ from the median variability generated between MR and RM (inter-method variability), which was 2% (?14,12) (P = .287). The degree of agreement between the 2 to identify arteriovenous fistulas susceptible to intervention was very good (Kappa = 0.834). The time spent using the RM was significantly shorter (P = .000) without evidence of variations in the K_t of the measurement sessions (P = .201).ConclusionsThe thermodilution RM is valid to determine the flow of the vascular access, especially in Q_A lower than 700 ml/min, with great time savings, simplification of the procedure and without modifying the dialysis efficiency. The variability between the measurement by MR and RM is similar to that of MR. The concordance between methods in identifying potentially pathological arteriovenous fistulas is very good.     

Validación pronóstica según los criterios de la GesEPOC 2017

IntroductionThe Spanish COPD guidelines (GesEPOC) have been recently modified. The aim of this study is to assess this revision and evaluate the prognosis of patients according to the new classification of severity.MethodsA total of 700 COPD patients (83.9% men) were prospectively followed up for a mean period of 5 years in tertiary hospitals in Spain and the USA. Anthropometric data, lung function tests, dyspnea (according to the mMRC scale), BODE and Charlson index were collected. We calculated mortality at 5 years following the risk criteria proposed by the new GesEPOC.ResultsMean age was 66 ± 9.6 years and mean FEV₁% was 59.7 ± 20.2. The proportion of patients in the low-risk group was 40.43%. Patients in the high-risk group had a significantly higher BODE index than those in the low-risk group (2.92 ± 0,66 vs. 0.52 ± 1.91, p < 0.001), while the Charlson index score was similar in both groups. Mortality at 60 months was significantly higher in the high-risk group (31.7% vs. 15.5%, p < 0.001). Dyspnea and FEV₁% were also independent predictors of mortality (p < 0.001), and neither was inferior to the risk classification proposed by GesEPOC.ConclusionsThe new severity index proposed by GesEPOC accurately predicts 5-year mortality. However, dyspnea and FEV₁% have the same strength in predicting mortality.     

Validación de una versión en español del Health Assessment Questionnaire-II para la evaluación de la capacidad funcional en pacientes mexicanos con artritis reumatoide

ObjectiveTo evaluate the validity, reliability, and performance of the Health Assessment Questionnaire-II(HAQ-II) Spanish version questionnaire to measure physical function.MethodsA cross-sectional study of 496 patients with rheumatoid arthritis, distributed in 2 samples. The construct validity was evaluated employing the confirmatory factor analysis and the validity based on the relationship with other variables. Cronbach's alpha (α) and McDonald's omega (ω) coefficient were used to determine reliability. Item performance was analysed by fitting different models of item response theory.ResultsThe one-factor model presented a poor fit in the confirmatory factor analysis; an exploratory factor analysis was carried out, which suggested a 2-factor structure. The confirmatory factor analysis in the second sample confirmed that the second-order model had a good fit to the data. The general factor explained more than 70% of the variance. The reliability indices showed adequate internal consistency (α = .92-.95; ω = .88-.93). Ninety-three percent of the contrasting hypotheses about the relationship of the HAQ-II scores with other variables were confirmed, demonstrating their convergent, divergent, and known group validity. The multidimensional graduated response model was the one that best predicted person's interaction with the items.ConclusionThe Spanish version of the HAQ-II presents adequate validity and reliability for measuring Mexican patients’ physical function with rheumatoid arthritis.     

Validación de una nueva estrategia para la identificación de variantes de SARS-CoV-2 mediante secuenciación del gen espiga por Sanger

IntroductionThe emergence of multiple variants of SARS-CoV-2 during the COVID-19 pandemic is of great world concern. Until now, their analysis has mainly focused on next-generation sequencing. However, this technique is expensive and requires sophisticated equipment, long processing times, and highly qualified technical personnel with experience in bioinformatics. To contribute to the analysis of variants of interest and variants of concern, increase the diagnostic capacity, and process samples to carry out genomic surveillance, we propose a quick and easy methodology to apply, based on Sanger sequencing of 3 gene fragments that code for protein spike.MethodsFifteen positive samples for SARS-CoV-2 with a cycle threshold below 25 were sequenced by Sanger and next-generation sequencing methodologies. The data obtained were analyzed on the Nextstrain and PANGO Lineages platforms.ResultsBoth methodologies allowed the identification of the variants of interest reported by the WHO. Two samples were identified as Alpha, 3 Gamma, one Delta, 3 Mu, one Omicron, and 5 strains were close to the initial Wuhan-Hu-1 virus isolate. According to in silico analysis, key mutations can also be detected to identify and classify other variants not evaluated in the study.ConclusionThe different SARS-CoV-2 lineages of interest and concern are classified quickly, agilely, and reliably with the Sanger sequencing methodology.     

Validación de un método seguro y sencillo para la elaboración de secuencias consenso del virus de la inmunodeficiencia humana a partir de los datos de secuenciación masiva 454

Objective

To show how to generate a consensus sequence from the information of massive parallel sequences data obtained from routine HIV anti-retroviral resistance studies, and that may be suitable for molecular epidemiology studies.

Construcción y validación de la escala EsVida para la valoración del requerimiento de manejo en urgencias de una gastroenteritis infecciosa

IntroductionInfectious gastroenteritis can result in unnecessary emergency room consultations. Instruments are needed to detect the risks for unfavorable progression.AimTo develop and validate a comprehensive severity scale for acute gastroenteritis in children.Materials and methodsData associated with complications (probable items) were determined through a MeSH search. The EsVida scale was developed with 4 theoretic domains: personal history (3 items), social problems (2 items), risks for severe gastroenteritis (4 items), and signs of fluid and electrolyte imbalance (4 items). The items were evaluated as present (one point) or absent (zero points) on a 0 to 13-point scale. To validate the instrument, an observational study was conducted at the emergency service on children from one to 13 years of age with acute gastroenteritis. The scale was re-developed utilizing the risks calculated by logistic regression analysis.ResultsNinety-seven pediatric patients were evaluated using the EsVida scale (theoretic development). Its initial version showed an area under the ROC curve of 0.69 (95% CI of 0.6 to 0.79). After risk adjustment, it was simplified to a total of 5 items, with a score of 0 to 42.5. The new scale produced an area under the ROC curve of 0.85 (95% CI of 0.75 to 0.90). At a cutoff value of 12 points, the scale had 69.8% sensitivity and 70.5% specificity. A score below 6 indicated that patients could be managed at home at no risk.ConclusionsThe modified EsVida scale could be used as an aid in deciding on at-home management in cases of acute infectious gastroenteritis.     

Importancia de la imagen en la valoración de la respuesta al tratamiento con inmunoterapia del cáncer de pulmón

Immunotherapy (particularly immune checkpoint inhibitors) in the treatment of patients with lung cancer has aroused great interest in recent years, revolutionized the management of patients with locally advanced/metastatic disease, and given hope to both patients and treating physicians. These drugs, in combination or in monotherapy, have become the standard treatment for many patients with lung cancer, and their use is expected to increase significantly in the near future. In this article, we will review the growing importance of imaging techniques in the evaluation of therapeutic response to immunotherapy in lung cancer patients, with emphasis on the new specific radiological criteria on response to immunotherapy, atypical radiological responses (pseudoprogresion, dissociative responses, hyperprogresion), and the main radiological manifestations of adverse events associated with immunotherapy (sarcoid reactions, pulmonary toxicities, etc.). Pulmonologists must be familiar not only with atypical radiological responses to immunotherapy and their prognostic implications, but also with their effects and the new radiological criteria of response to assess treatment response. In this study, we will address key concepts such as “pseudoprogresion”, “paradoxical response”, “hyperprogresion”, or “unconfirmed progression”, and their significance in the management of patients with lung cancer treated with immunotherapy.     

Valoración de sueros con bajo índice S/CO utilizando 2 sistemas de quimioluminiscencia para la detección de anticuerpos frente al virus de la hepatitis C y su correlación con la detección de ARN viral

Objective

All commercial assays used to measure the presence of Hepatitis C virus (HCV) antibodies set cut-off points to categorise the results, but the problem of false positive results in screening hepatitis C sera is well known.The aim of this study was to evaluate the results obtained by two chemiluminescent assays in selected sera, and compare these results with the detection of viral RNA in the specimens studied.

Tratamiento del cáncer de pulmón con invasión de la pared torácica

The aim of this study was to analyze chest wall invasion, the indication and multidisciplinary nature of treatment, the methods used for parietal reconstruction and the technical problems posed by this procedure in patients with lung cancer and chest wall invasion.Chest wall invasion from adjacent malignancies affects 5% of patients with a bronchogenic carcinoma. Preoperative determination of parietal invasion aids the planning of an appropriate therapeutic approach. Positron emission tomography combined with computed tomography (PET/CT) improves the study of T-factor and metastatic nodal involvement and distant metastases. As a rule, surgical treatment should attempt complete tumoral resection: lobectomy, resection of the parietal pleura and/or of the chest wall –ensuring tumor-free margins– and hilar and mediastinal lymphadenectomy. We also analyzed the distinct prognostic factors for survival, as well as the indication for induction or adjuvant therapy.Chest wall reconstruction involves recreating the most anatomical and physiological conditions possible in the chest cavity and surrounding muscles. The ideal reconstruction would achieve adequate parietal stability and coverage to preserve functionality, with the cosmetic result being an important, but secondary, consideration. Many materials are available for reconstruction and the choice of material should be individualized in each patient. A multidisciplinary team able to plan and perform the resection and subsequent reconstruction, oversee postoperative management and treat complications early is essential.     

Asociación del polimorfismo rs5186 del gen AGTR1 con disminución de la TFGe en pacientes con diabetes tipo 2 de la Ciudad de México

BackgroundEarly biomarkers search for Diabetic Kidney Disease (DKD) in patients with Type 2 Diabetes Mellitus (T2DM), as genetic markers to identify vulnerable carriers of the disease even before Glomerular Filtration Rate (GFR) decline or microalbuminuria development, has been relevant during the last few years.The rs5186 (A116C) polymorphism of the Angiotensin II Receptor Type I gene (AGTR1), has been associated to multiple effects of renal injury risk, commonly detected in patients with Diabetes Mellitus (DM). It has been described that rs5186 could have an effect in stability proteins that assemble Angiotensin II Receptor Type I (AT1), modifying its action, which is why it should be considered as a risk factor for Chronic Kidney Disease (CKD), characterized by a GFR progressive reduction. Even though, the association between rs5186 AGTR1 gene polymorphism and DKD in patients with T2DM has been controversial, inconclusive, and even absent. This disputable issue might be as a result of association studies in which many and varied clinical phenotypes included are contemplated as CKD inductors and enhancers. Although, the sample sizes studied in patients with T2DM are undersized and did not have a strict inclusion criteria, lacking of biochemical markers or KDOQI classification, which have hindered its examination.ObjectiveThe aim of our study was to establish an association between rs5186 AGTR1 gene polymorphism and GFR depletion, assessed as a risk factor to DKD development in patients with T2DM.MethodsWe analyzed 297 not related patients with T2DM, divided into 221 controls (KDOQI 1) and 76 cases (KDOQI 2). Arterial pressure, anthropometric and biochemical parameters were measured. rs5186 of AGTR1 genotyping was performed by TaqMan assay real-time PCR method. Allele and genotype frequencies, and Hardy-Weinberg equilibrium were measured. Normality test for data distribution was analyzed by Shapiro-Wilk test, variable comparison by Student's t-test for continuous variables, and Chi-squared test for categorical variables; ANOVA test was used for mean comparison of more than two groups. Effect of rs5186 to DKD was estimated by multiple heritability adjustment models for risk variables of DKD. Statistical significance was indicated by p < 0.05. Data was analyzed using Statistical Package STATA v11 software.ResultsDominant and Over-dominant models showed a likelihood ratio to GFR depletion of 1.89 (1.05-3.39, p = 0.031) and 2.01 (1.08-3.73, p = 0.023) in patients with T2DM. Risk factor increased to 2.54 (1.10-5.89) in women in Over-dominant model.ConclusiónIn clinical practice, most of nephropathies progress at a slow pace into a total breakdown of renal function, even asymptomatic. This is the first study, reporting that rs5186 polymorphism of AGTR1 gene contribution to GFR depletion, and this could be evaluated as a predisposing factor for DKD in patients with T2DM.