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.     

Evaluación de la precisión diagnóstica del sistema Cobas 6800 para la detección de los niveles de viremia del virus de la hepatitis C a partir de muestras de gotas de sangre seca en papel de filtro

IntroductionBecause hepatitis C virus (HCV) infection is curable in the majority of cases, the diagnosis of all infected patients has become a priority. In difficult-to-diagnose populations, simpler diagnostic methods are required such as the use of dried blood spots (DBS) as an alternative to blood drawn by venipuncture (VP). Before being able to include it as a HCV diagnostic detection method within the Spanish National Health System, the diagnostic accuracy of standard hospital equipment must be evaluated.MethodologyDBS samples were evaluated in vitro and in a field test after being processed in the Cobas 6800 system, establishing a correlation with the result by VP. Performance with different viral loads and intra-assay variability was compared.ResultsIn samples with a viral load of > 3 log₁₀ IU/ml, viraemia was detected in all cases when at least two blood spot elutions were used (94 detections out of 95 spot elutions). The performance with 2 spots was lower in samples with < 3 log₁₀ IU/ml (7/20). Correlation between VP and DBS viraemia was excellent (maximum with 2 spots, r² = 0.906, P < .001) with a coefficient of variation of 0.05%. In routine clinical practice with specimens from screened subjects (n = 61), excellent diagnostic accuracy was also observed.ConclusionViral load detection using DBS of at least two spots is a reliable method for HCV diagnosis. The standardisation of the method is feasible and our results support the incorporation of this diagnostic tool in Spain's Public Health System.     

Posición actual de la carga viral frente a la determinación de antígeno core del virus de la hepatitis C

Quantification of hepatitis C virus (HCV) RNA (viral load) is the most widely used marker to diagnose and confirm active HCV infection. The HCV core antigen forms part of the internal structure of the virus and, like HCV RNA, its detection also indicates viral replication and presents certain advantages over viral load testing such as its lower cost, the greater stability of the target, the possibility of working with the same primary tube as that used for HCV serology, and the rapidity of obtaining results, since there is no need to work in batches, unlike the situation with most viral load platforms. Although the core antigen has lower analytical sensitivity than HCV RNA for the detection of low viremia levels, several studies and guidelines have already shown their utility in the identification of patients with active HCV infection. This article summarises current platforms for viral load determination, including point-of-care systems, and also reviews the indications attributed to this marker by the main HCV treatment guidelines. The article also reviews the characteristics of HCV core antigen, the available platforms for its determination, its correlation with viral load determination, and the indications for this marker in the distinct guidelines.     

Efecto negativo del bloqueo del sistema renina-angiotensina sobre la progresión de la enfermedad renal crónica avanzada: ¿una cuestión de ajuste de dosis?

IntroductionThe renoprotective effect of renin-angiotensin (RAS) blockers (angiotensin converting enzyme inhibitors and angiotensin receptor blockers) has been questioned in patients with advanced chronic kidney disease (CKD). Moreover, combination therapy (dual RAS blockade) can further accelerate renal function decline in some populations at risk. However, it is unknown whether this adverse outcome is due to a dose-dependent effect or if it can be attributed more specifically to a drug interaction.Aim This study aims to investigate if the rate of renal function decline in advanced CKD patients is associated to the doses of RAS blockers, and if dual RAS blockade worsens renal function independently of major confounding factors.Material and methodsRetrospective, observational study in an incident cohort of adult patients with CKD stage 4 or 5 not on dialysis, treated with RAS blockers for at least 3 months prior to the study inclusion. Inclusion criteria were: having at least three consecutive measurements of estimated glomerular filtration rate (eGFR) in a follow-up period > 3 months. Decline in renal function was estimated as the slope of the individual linear regression line of eGFR over follow-up time. Equipotent doses of RAS blockers were normalised for a body weight of 70 kg or a body surface area of 1.73 m² (END-RASI). Associations of END-RASI or dual RAS blockade with the rate of renal function decline were analysed by uni- or multivariate linear regression models, accounting for major confounding variables.ResultsThe study group consisted of 813 patients (mean age 64 ± 14 years, 430 males) with a mean eGFR 14.9 ± 4.2 ml/min/1.73 m²; 729 patients were on RAS blockade monotherapy and 84 on dual RAS blockade. Median END-RASI in the whole group was 0.91 (I.Q. ranges: 0.69-1.20). Patients on dual RAS blockade had significantly higher END-RASI than the rest of study patients (1.52 ± 0.49 vs. 0.93 ± 0.44; p < 0.0001). In univariate linear regression, END-RASI were significantly correlated with eGFR decline (R = −0.149; p < 0.0001). Patients on dual RAS blockade showed a significantly faster decline of renal function than the rest of the study patients (−6.19 ± 5.57 vs. −3.04 ± 5.37 ml/min/1.73 m²/year, p < 0.0001). By multivariate linear regression, while dual RAS blockade remained independent and significantly associated with faster renal function decline (beta = −0.094; p = 0.005), END-RASI (normalised either for body weight or surface area) did not reach statistical significance.ConclusionEND-RASI are significantly associated with the rate of renal function decline in advanced CKD patients. However, the detrimental effect of dual RAS blockade on CKD progression seems to be independent of END-RASI and other major confounding factors.     

La combinación de la determinación de parámetros bioquímicos del líquido pleural mejora la predicción diagnóstica de la infección pleural complicada/empiema

IntroductionIdentifying infectious pleural effusions (IPE) that will progress to complicated infection or empyema is challenging. The purpose of this study was to determine whether a model based on multiple biochemical parameters in pleural fluid can predict which IPEs will produce empyema.MethodsA prospective study was performed of all cases of IPEs treated in our unit. IPEs were classified as uncomplicated or complicated (empyema). Logistic regression was used to estimate the risk for complicated pleural infection (empyema). A predictive model was developed using biochemical parameters in pleural fluid. Discriminatory power (areas under the ROC curve), calibration, and diagnostic accuracy of the model were assessed.ResultsA total of 177 patients were included in the study (74 with uncomplicated infectious pleural effusion, and 103 with complicated pleural effusion/empyema). The area under the curve (AUC) for the model (pH, lactate dehydrogenase and interleukin 6) was 0.9783, which is significantly superior to the AUC of the individual biochemical parameters alone (0.921, 0.949, and 0.837, respectively; P<.001 using all parameters). The rate of correct classification of infectious pleural effusions was 96% [170/177: 72/74 (97.3%) for uncomplicated and 98/103 (95.1%) for complicated effusion (empyema)].ConclusionThe multiple-marker model showed better diagnostic performance for predicting complicated infectious pleural effusion (empyema) compared to individual parameters alone.     

Estrategias de curación de la infección por VIH

The disadvantages of the long-term administration of antiretroviral therapy as well as the huge number of affected persons have placed the cure of HIV as a primary goal of Public Health. HIV may persist in the organism by at least four mechanisms: a latently infected cellular reservoir, the persistent replication of HIV in spite of ART, anatomic sanctuaries, and the immune dysfunction. Several strategies directed against these mechanisms have been developed. With all this, a complete eradication of HIV has been achieved in a patient using the transplantation of haemopoietic stem cells that were resistant to HIV-infection, and there are examples of functional cure either spontaneously (elite controllers) or after antiretroviral therapy (post-treatment controllers). However, no strategies have been successful in reducing the reservoir size, nor in achieving constant, uniform remissions. The failure of isolated strategies makes it likely that the combination of several of them may be the future solution.     

Relación de la expresión génica de IP-10 con la actividad del lupus eritematoso sistémico

ObjectivesTo evaluate IP-10 gene expression in patients with SLE, and its possible relationship with disease activity.Patients and methodsThis study included 120 patients diagnosed with SLE and 30 healthy controls. The relative gene expression of IP-10 was investigated with the Fold Change method, which was correlated with the level of lupus activity evaluated with the SLEDAI 2-K instrument.ResultsDifferent levels of gene expression were found according to the SLE activity (p =<0.001). IP-10 gene expression levels were higher in patients with severe activity than in those with no activity, low activity, and moderate activity. The increase in gene expression in the severe activity group was significant with a Fold Change of 3.ConclusionThe significant increase in relative gene expression IP-10 may be a marker of severe lupus activity.     

FGF23: de la nefrología de salón a la cabecera del paciente

Twenty years have passed since the identification of klotho and the fibroblast growth factor 23 (FGF23), the regulatory binomial of phosphate homeostasis. Being kidney the main source of klotho as well as a target organ in the phosphate regulation, most studies involving klotho and FGF23 had a «nephrocentric» focus. Considering that circulating FGF23 can reach exaggerated levels at the end stage of chronic kidney disease (CKD), the bias of this approach allowed to recognize the harmful «off target» klotho-independent effect of FGF23. All of these findings have caused a revolution on our previous knowledge about mineral homeostasis and currently, we are facing a new scenario in the clinical management of CKD, where FGF23 emerges simultaneously as an early biomarker of phosphate retention but also as a therapeutic target. In this review, we describe the disturbances of FGF23 in the CKD and we focus on how the maintenance of circulating FGF23 into a supraphysiological adaptive range from the initial stages of CKD and the control of «unlimited hyperphosphatonism» generated by the resistance to FGF23 action at end stages should emerge as new treatment paradigms in chronic kidney disease - mineral and bone disorders (CKD-MBD). The recent development of an automated FGF23 assay, already validated for clinical use, should be the starting point to individualize all our knowledge from epidemiological studies and will allow us to use it properly for the patient's personalized care. Then, now we are in the momentum to assess the discriminating thresholds to distinguish the physiological adaptive FGF23 elevation related to each CKD stage from the exaggerated increase that would be interpreted as a poor regulatory compensation that will requires the adoption of therapeutic intervention.     

Validación del KDRI/KPDI para la selección de donantes renales con criterios expandidos

Introduction

KDRI / KDPI are tools use in kidney donor evaluation. It has been proposed as a substitute of, or complementary to preimplantation renal biopsy. These scores has not been validated in Spain.

Evaluación del retiro progresivo y/o la suspensión de la terapia anti-TNF-α en la enfermedad inflamatoria intestinal

Anti-tumour necrosis factor α therapy in inflammatory bowel disease has been shown to be effective in clinical practice.After more than a decade using these therapies the question arises about whether there is an appropriate time to suspend these therapies, and how this should be done. This review aims to evaluate the current evidence on these topics concerning anti-tumour necrosis factor α therapies, and eventually identify conditions and subgroups of patients that could potentially be candidates for withdrawal.     

Contribución de la microbiología al diagnóstico de la tuberculosis en Castilla y León: conclusiones del estudio GRUMICALE 2013

Introduction and objectives

A retrospective study was conducted by collecting microbiological tuberculosis (TB) data in Castile and León during the year 2013 in order to determine the incidence and distribution of TB, and resistance to the tuberculostatic drug, and compare them with the epidemiological data provided by the Department of Epidemiological Surveillance (SIVE).

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.

Propuestas para la incorporación del rol de enfermería en la certificación de unidades de espondiloartritis axial. Revisión bibliográfica y consenso entre expertas

ObjectiveTo analyse the role of nursing in the approach to axial spondyloarthritis (axSpA) and to make proposals to include the role of rheumatology nursing consultations (RECs) in the quality certification of these specialized units.MethodsA systematic review of the nursing role in quality certification systems in the management of axSpA was conducted. Subsequently a consensus conference was held with the participation of 3 rheumatology nurses to determine elements that should be considered in future revisions of certification standards.ResultsThe systematic review yielded 5 papers as relevant. None of the publications reviewed explicitly proposed standards applicable to nursing care in the management of patients with axSpA, although they contemplated the activities of this professional group. The proposals agreed upon to incorporate the role of RECs in the certification standards for axSpA monographic units included the following: basic equipment and resources, organization, administration of pharmacological treatments and promotion of adherence, standardized programmes for axSpA, telematic consultation (e-consultation) for monitoring the stable patient and promoting continuity of care and registry of patient-reported outcome measures.ConclusionsThe literature on quality standards and certification standards for axSpA monographic units is scarce and hardly reflects the role of RECs in providing quality care. The consensus proposals in this study would incorporate RECs into quality certification standards. In the future, the increased presence of RECs in Spain should be accompanied by a review of the indicators regarding their role.     

Predictores de disfunción del stent metálico autoexplandible en la obstrucción de salida gástrica maligna

Introduction and objectivesSelf-expanding metallic stents (SEMS) are the ideal treatment for malignant gastric outlet obstruction (MGOO) in patients with a short life expectancy, but stent dysfunction is frequent. The primary aim of our study was to identify the predictive factors of SEMS dysfunction in MGOO and the secondary aim was to determine the technical success, clinical success, and nutritional impact after SEMS placement.Material and methodsA retrospective, longitudinal study was conducted at the gastrointestinal endoscopy department of the Instituto Nacional de Cancerología in Mexico City. Patients diagnosed with MGOO that underwent SEMS placement within the time frame of January 2015 to May 2018 were included. We utilized the gastric outlet obstruction scoring system (GOOSS) to determine clinical success and SEMS dysfunction.ResultsThe study included 43 patients, technical success was 97.7% (n = 42), and clinical success was 88.3% (n = 38). SEMS dysfunction presented in 30.2% (n = 13) of the patients, occurring in < 6 months after placement in 53.8% (n = 7) of them. In the univariate analysis, the histologic subtype, diffuse gastric adenocarcinoma (p = 0.02) and the use of uncovered SEMS (p = 0.02) were the variables associated with dysfunction. Albumin levels and body mass index did not increase after SEMS placement. Medical follow-up was a mean 5.8 months (1-24 months).ConclusionsSEMS demonstrated adequate technical and clinical efficacy in the treatment of MGOO. SEMS dysfunction was frequent and diffuse type gastric cancer and uncovered SEMS appeared to be dysfunction predictors.