Proyecto URISCAM: Evaluación multicéntrica del citómetro UF-Series en el despistaje de infecciones urinarias / URISCAM project: multicenter evaluation of the UF-Series cytometer in the urinary tract infections screening

Introducción. El urocultivo, prueba de referencia para confirmar la existencia de Infección del tracto urinario (ITU), es la solicitud más demandada a Microbiología. Nuestro objetivo fue determinar la rentabilidad diagnóstica del citómetro UF-Series como método de cribado en la detección de ITU. Material y métodos. Se analizaron las orinas remitidas a los seis laboratorios de Microbiología participantes en un periodo de 5 días laborables. Se recogieron variables demográficas y de origen de la muestra, tipo de muestra (orina de media micción, sondaje, nefrostomía), recogida con/sin ácido bórico, lectura del citómetro (leucocituria, bacteriuria, morfología bacteriana y células epiteliales) y resultado del urocultivo. Para determinar la capacidad predictiva del citómetro se representaron las curvas ROC. Resultados. Se procesaron 2.468 muestras de pacientes con edad media de 53 años (ratio mujeres:hombres 2:1). El urocultivo detectó un 23% de orinas positivas. Las variables predictoras de ITU fueron: lectura morfológica de bacilos, bacteriuria ≥ 21 bacterias/μL, edad ≥ 65 años, procedencia de las muestras recogidas en urgencias y hospitalización, y presencia de conservante. Con el punto de corte de 21 bacterias, obtuvimos una sensibilidad del 93,3% y un VPN del 94,5%, lo que permitiría dejar de sembrar el 28,9% de las orinas recibidas con 1,6% de falsos negativos. Conclusiones. Consideramos que el UF-Series es una herramienta válida y precisa para la detección de ITU, por lo que podría utilizarse como cribado previo al urocultivo en la práctica clínica, reduciendo el número de orinas a sembrar en aproximadamente un 30% con una tasa baja de falsos negativos (AU)

Introduction. Urine culture, the gold standard to confirm the presence of urinary tract infection (UTI), is the most requested assay in the microbiology department. Our objective was to determine the diagnostic yield of the UF-Series cytometer as a screening method for UTI. Material and methods. All the urine samples sent to the six Microbiology Laboratories participating in a period of 5 working days were analyzed. We collected demographic variables, apart from those variables related to urine samples: source and sample type (midstream, catheterized or nephrostomy urines), collection with/without boric acid, cytometer parameters (leukocyturia, bacteriuria, bacteria morphology and epithelial cells) and urine culture results. ROC curves were plotted to determine predictive capacity of the cytometer. Results. A sample of 2,468 patients with average age of 53 years were processed (ratio women:men 2:1). Urine culture detected 23% of positive urine samples. The predictor variables of UTI were: morphology of bacilli, bacteriuria ≥21 bacteria/μL, age ≥65 years, samples collected in the emergency service and hospitalization and preserving conditions. With 21 bacteria/ μL as a cut-off point, we obtained a sensitivity of 93.3% and 94.5% negative predictive value, then reducing the samples to be cultured by 28.9% with 1.6% false negatives. Conclusions. We consider that the UF-Series is a valid and accurate tool for the detection of UTI. Therefore, it could be used as screening method in the clinical practice prior to the urine culture, reducing culture requirement by approximately 30%, with a low false negative rate (AU)

Urinary tract infection in the oldest old: a work overload for the microbiology laboratory / Infecciones del tracto urinario en los más mayores: una sobrecarga para el laboratorio de Microbiología

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Estudio de coste-efectividad del diagnóstico microbiológico de tuberculosis mediante geneXpert MTB/RIF(R) / Cost-effectiveness study of the microbiological diagnosis of tuberculosis using geneXpert MTB/RIF(R)

Introducción/Objetivo: Evaluar mediante un análisis de coste-efectividad la aplicación de una técnica de biología molecular al diagnóstico de tuberculosis frente a la alternativa diagnóstica clásica. Métodos: Se realizó un análisis de coste-efectividad para evaluar la aplicación teórica de un procedimiento de biología molecular que incluye 2 alternativas de una técnica para la detección precoz de Mycobacterium tuberculosis Complex y resistencia a rifampicina (alternativa1: una determinación a pacientes seleccionados; alternativa2: 2 determinaciones a todos los pacientes). Ambas alternativas se compararon con el procedimiento habitual de diagnóstico microbiológico de tuberculosis realizado a 1972 pacientes durante 2008-2012 (microscopia y cultivo). La medida de la efectividad se hizo en QALY y la incertidumbre se trató mediante análisis de sensibilidad univariable, multivariable y probabilístico. Resultados: Para el método habitual se obtuvo un valor de 8.588€/QALY. En la alternativa1 el gasto fue de 8.487€/QALY, mientras que en la alternativa2 el cociente coste-efectivo ascendió a 2.960€/QALY. La alternativa2 fue la de mayor eficiencia diagnóstica, alcanzando una reducción del 75% del número de días que un paciente con tuberculosis permanece sin tratamiento adecuado, así como una reducción del 70% del número de días que un paciente sin tuberculosis permanece ingresado. Conclusión: La aplicación de una técnica microbiológica molecular en el diagnóstico de tuberculosis es sumamente coste-efectiva frente al método habitual. Su introducción en el procedimiento diagnóstico de rutina supondría una mejora en la calidad asistencial de los pacientes al evitar ingresos y tratamientos innecesarios, reflejándose en un ahorro económico al hospital (AU)

Introduction/Objective: To perform a cost-effectiveness analysis of a molecular biology technique for the diagnosis of tuberculosis compared to the classical diagnostic alternative. Methods: A cost-effectiveness analysis was performed to evaluate the theoretical implementation of a molecular biology method including two alternative techniques for early detection of Mycobacterium tuberculosis Complex, and resistance to rifampicin (alternative1: one determination in selected patients; alternative2: two determinations in all the patients). Both alternatives were compared with the usual procedure for microbiological diagnosis of tuberculosis (staining and microbiological culture), and was accomplished on 1,972 patients in the period in 2008-2012. The effectiveness was measured in QALYs, and the uncertainty was assessed by univariate, multivariate and probabilistic analysis of sensitivity. Results: A value of €8,588/QALYs was obtained by the usual method. Total expenditure with the alternative1 was €8,487/QALYs, whereas with alternative2, the cost-effectiveness ratio amounted to €2,960/QALYs. Greater diagnostic efficiency was observed by applying the alternative2, reaching a 75% reduction in the number of days that a patient with tuberculosis remains without an adequate treatment, and a 70% reduction in the number of days that a patient without tuberculosis remains in hospital. Conclusion: The implementation of a molecular microbiological technique in the diagnosis of tuberculosis is extremely cost-effective compared to the usual method. Its introduction into the routine diagnostic procedure could lead to an improvement in quality care for patients, given that it would avoid both unnecessary hospitalisations and treatments, and reflected in economic savings to the hospital (AU)

Cost-effectiveness study of the microbiological diagnosis of tuberculosis using geneXpert MTB/RIF®. / Estudio de coste-efectividad del diagnóstico microbiológico de tuberculosis mediante geneXpert MTB/RIF®.

INTRODUCTION/OBJECTIVE: To perform a cost-effectiveness analysis of a molecular biology technique for the diagnosis of tuberculosis compared to the classical diagnostic alternative. METHODS: A cost-effectiveness analysis was performed to evaluate the theoretical implementation of a molecular biology method including two alternative techniques for early detection of Mycobacterium tuberculosis Complex, and resistance to rifampicin (alternative1: one determination in selected patients; alternative2: two determinations in all the patients). Both alternatives were compared with the usual procedure for microbiological diagnosis of tuberculosis (staining and microbiological culture), and was accomplished on 1,972 patients in the period in 2008-2012. The effectiveness was measured in QALYs, and the uncertainty was assessed by univariate, multivariate and probabilistic analysis of sensitivity. RESULTS: A value of €8,588/QALYs was obtained by the usual method. Total expenditure with the alternative1 was €8,487/QALYs, whereas with alternative2, the cost-effectiveness ratio amounted to €2,960/QALYs. Greater diagnostic efficiency was observed by applying the alternative2, reaching a 75% reduction in the number of days that a patient with tuberculosis remains without an adequate treatment, and a 70% reduction in the number of days that a patient without tuberculosis remains in hospital. CONCLUSION: The implementation of a molecular microbiological technique in the diagnosis of tuberculosis is extremely cost-effective compared to the usual method. Its introduction into the routine diagnostic procedure could lead to an improvement in quality care for patients, given that it would avoid both unnecessary hospitalisations and treatments, and reflected in economic savings to the hospital.

Seroprevalence survey of zoonoses in Extremadura, southwestern Spain, 2002-2003.

Our aims were to determine the seroprevalence rates for the most common types of zoonosis among the population of Extremadura (southwestern Spain) and to identify the associated risk factors. We conducted a seroepidemiological survey to collect information on family background and the habits of people residing in Extremadura between 2002 and 2003. Antibodies to Brucella were determined by Rose Bengal staining and a standard tube agglutination test; a titer of 1/80 was considered to be positive. Antibody titers for spotted fever, leishmaniasis, echinococcosis, and toxoplasmosis were determined by enzyme-immunoassays. Independent risk factors identified were age (younger age for brucellosis), male gender (brucellosis, spotted fever, and toxoplasmosis), occupation and contact with animals (brucellosis and spotted fever for those in contact with goats, hydatidosis for those in contact with sheep, leishmaniasis for those in contact with dogs, and toxoplasmosis for those in contact with cats and pigs), and consuming contaminated food (brucellosis by eating fresh cheese, hydatidosis by eating homemade sausages, and toxoplasmosis by eating pork). Except for leishmaniasis, the other zoonoses were more prevalent in rural areas, and, with the exception of brucellosis, they were all more prevalent in Badajoz. The distribution of zoonoses in Extremadura was strongly influenced by keeping livestock and eating habits. Thus, brucellosis was more prevalent in Caceres (associated with cheese consumption), while toxoplasmosis (pork consumption) and spotted fever (from hunting) were more common in Badajoz.

Nonsynonymous polymorphisms of histamine-metabolising enzymes in patients with Parkinson's disease.

OBJECTIVE: To analyze genetically based impairment in histamine-metabolising enzymes in patients with Parkinson's disease (PD). METHODS: Leukocytary DNA from 214 PD patients and a control group of 295 unrelated healthy individuals was studied for nonsynonymous histamine N-methyltransferase (HNMT) and diamine oxidase (ABP1) polymorphisms by using amplification-restriction analyses. RESULTS: An association of the HNMT Thr105Ile polymorphism, but not of the ABP1 His645Asp polymorphism, with PD was observed. Patients with PD showed a higher frequency of homozygous HNMT genotypes leading to high activity with a gene-dose effect (P < 0.001), as compared to healthy subjects. These findings were independent of gender, but the association with the HNMT polymorphism is higher among patients with late-onset PD (P < 0.0001). CONCLUSION: These results, combined with previous findings indicating alterations in histamine levels in patients with PD, suggest that alterations of histamine homeostasis in the SNC are associated with the risk for PD.

GSTT1 and GSTM1 null genotypes may facilitate hepatitis C virus infection becoming chronic.

Oxidative stress contributes to hepatitis C virus (HCV)-induced liver damage. The activity of antioxidant glutathione S-transferases (GSTs) T1 and M1 is polymorphic. The GSTT1 and GSTM1 genotypes were identified in 139 HCV-infected patients and in 329 healthy individuals. Among patients, there was an excess of GSTT1 (odds ratio [OR], 2.76 [95% confidence interval [CI], 1.77-4.30]; P<.001) and GSTM1 (OR, 1.54 [95% CI, 1.02-2.35]; P=.032) null genotypes and of double-null haplotypes (OR, 3.65 [95% CI, 1.98-6.75]; P<.001). The GSTT1 null genotype, particularly if associated with the GSTM1 null genotype, may facilitate HCV infection becoming chronic.

Laboratory screening of connective tissue diseases by a new automated ENA screening assay (EliA Symphony) in clinically defined patients.

BACKGROUND: The measurement of antinuclear antibodies (ANA) is used in the autoimmune laboratory for the screening of connective tissue diseases (CTD). ANA measurements are mainly performed by indirect immunofluorescence (IIF) on HEp-2 cells or by enzyme immunoassay (EIA). The objective of this study was to clinically evaluate an automated EIA for extractable nuclear antigens (ENA) which lacks anti-dsDNA for the screening of CTD. METHODS: The study involved a total of 170 serum samples, 54 from patients with CTD, 26 from patients with other autoimmune diseases, and 90 from patients with non-autoimmune diseases. For all sera, ANA detection was performed by IIF and by EliA Symphony (Pharmacia Diagnostics, Freiburg, Germany), an ENA screening which detects the following autoantibodies: SSA/Ro, SSB/La, U1RNP (70 kDa, A, C), Scl-70, JO-1, centromere B and Sm. Also, anti-dsDNA (EliA dsDNA, Pharmacia Diagnostics, Freiburg, Germany) was measured on all samples. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), efficiency, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. RESULTS: Diagnostic efficiency was similar for IIF (82.6%) and EliA Symphony (82.3%), as well as PLR (6.5 for IIF, and 7.3 for Eli Symphony), and NLR (0.35 for IIF, and 0.41 for EliA Symphony). The combined measurement of EliA Symphony and dsDNA increased sensitivity but not PLR. Area under receiver operator characteristic (ROC) curve was similar for IIF (0.847) and EliA Symphony (0.823). CONCLUSIONS: The results of the study demonstrate that EliA Symphony solely or combined with anti-dsDNA detection has an efficiency similar to HEp-2 cells IIF with a cut-off of 1:160 for the diagnosis of CTD.

Anti-nucleosome, anti-chromatin, anti-dsDNA and anti-histone antibody reactivity in systemic lupus erythematosus.

Anti-nucleosome (anti-chromatin) antibodies play a key role in the pathogenesis of systemic lupus erythematosus (SLE). The objective of the present study was to determine the clinical significance of anti-nucleosome (anti-chromatin) antibodies, anti-dsDNA antibodies and anti-histone antibodies in patients with SLE in relation to patients with positive nuclear antibodies and healthy controls. We measured anti-nucleosome (anti-chromatin) antibodies, anti-dsDNA antibodies and anti-histone antibodies in 70 patients with SLE, 35 antinuclear antibody (ANA)-positive subjects without autoimmune disease and 35 blood donors. All antibodies were determined by enzyme-linked immunosorbent assay (ELISA). We obtained the receiver operating characteristic (ROC) curve and the area under the curve (AUC) for each autoantibody. Likewise, we obtained the sensitivity, specificity and positive and negative likelihood ratios for each autoantibody. The highest AUC was obtained for anti-nucleosome (0.898) and the lowest AUC for a kit for anti-dsDNA (0.725). Stratification of the control group (ANA-positive subjects without autoimmune disease and blood donors) produced significant changes in the AUCs; all AUCs decreased when ANA-positive patients without autoimmune disease were considered as controls and all AUCs increased when blood donors were considered as controls. These effects were less marked in anti-dsDNA antibodies. We observed discrepancies between kits (anti-nucleosome and anti-chromatin and two for anti-dsDNA). The highest sensitivity for SLE was obtained for anti-nucleosome antibodies (86%) and the highest specificity was obtained for anti-dsDNA antibodies (90%). In conclusion, anti-nucleosome and anti-chromatin kits show different degrees of clinical accuracy due to the cut-off selected by the manufacturer. Once the kits with the best performance and the optimal cut-offs have been selected, anti-nucleosome antibodies and anti-dsDNA antibodies provide similar information in established SLE.