Erythrocyte and reticulocyte indices in the assessment of erythropoiesis activity and iron availability.

INTRODUCTION: Consequence of the imbalance between the erythroid marrow iron requirements and the actual supply is a reduction in red cell hemoglobin content, which causes hypochromic mature red cells and reticulocytes. Sysmex XE 5000 analyzer (Sysmex Corporation, Kobe, Japan) reports reticulocyte hemoglobin equivalent (Ret-He) and the percentages of erythrocyte subsets, including the hypochromic fraction (%Hypo-He). We study the value of these parameters of hemoglobinization in the evaluation of erythropoiesis and iron availability. METHODS: Ninety healthy subjects, 85 patients with chronic kidney disease (CKD) and 65 patients on dialysis (HD) receiving therapy and 91 patients with iron deficiency (IDA) were analyzed. Pearson's correlation, t-test for independent, and receiver operating characteristic (ROC) curve analysis were utilized. RESULTS: The results in the IDA group reflected the state of iron depletion (low ferritin), low iron availability (low MCH and high percentage of hypochromic red cells (%Hypo-He)), and iron-restricted erythropoiesis (low Ret-He). In the HD and CKD, the reticulocyte percentage showed the increased erythropoiesis, maintained due to treatment (Ret-He over 30 pg) and good iron availability, MCH within reference range and %Hypo-He slightly increased. The results of ROC curves analysis for the diagnosis of iron deficiency (gold standard sTfR > 21 nm) were as follows: Ret-He area under curve (AUC) 0.935 cutoff 29.8 pg, sensitivity 90.7%, specificity 83.1%. % Hypo-He AUC 0.925 cutoff 3.5%, sensitivity 87.3%, specificity 88.0%. CONCLUSIONS: Percentage of hypochromic red cells and Ret-He provide information about individual cell characteristics, so the hypochromic cells are detected and quantitated improving the evaluation of erythropoiesis and iron status.

Low hemoglobin density potential marker of iron availability.

INTRODUCTION: Low hemoglobin density (LHD%) is a new parameter provided by Beckman-Coulter derived from the mean cell hemoglobin concentration, using the mathematical sigmoid transformation LHD% = 100×√(1-(1/(1 + e(1.8(30-MCHC)))). This study investigated the reliability of LHD% for the assessment of iron status in the presence of inflammation. METHODS: Healthy subjects (n = 90) and patients with iron deficiency (IDA, n = 110), chronic kidney disease (CKD, n = 65) and anemia of chronic disease (ACD, n = 85; 24 were iron deficient and 61 were iron sufficient) were analyzed on a LH 780 analyzer (Beckman Coulter Inc., Miami, FL, USA). Independent samples U test and receiver operating characteristic (ROC) curve analysis were applied. To determine the concordance between LHD% and soluble transferrin receptor (sTrR) Cohen's κ index was calculated. RESULTS: LHD % values showed no statistical difference in patients with IDA and patients with ACD accompanied with IDA (P = 0.6427); LHD% values in these patients were significantly different (P < 0.0001) compared with the iron-sufficient patients with ACD. ROC analysis for LHD% in the detection of iron deficiency showed the following: area under curve 0.903; cut off 5.5%, sensitivity 88.6%, specificity 76.9%; κ index, 0.65. CONCLUSION: LHD% is a reliable parameter for the detection of iron deficiency in patients with anemia in the presence of inflammation.

Analysis of reticulocyte parameters on the Sysmex XE 5000 and LH 750 analyzers in the diagnosis of inefficient erythropoiesis.

The reticulocyte hemoglobin equivalent (Ret He) represents an indirect measure of the functional iron available for erythropoiesis over the previous 2-3 days. Only the analyzers of a single manufacturer, Sysmex (Sysmex Corporation, Kobe, Japan), include Ret He. Red blood cell size factor (RSf) is a new parameter provided by Beckman Coulter, which joins together the volume of the erythrocytes and the volume of reticulocytes. The aims of the study were to investigate the clinical usefulness of RSf in the study of erythropoiesis status and to assess its concordance with Ret He values. Samples from 417 patients were run on both LH 780 (Beckman Coulter) and Sysmex XE 5000 analyzers. Independent samples t-test, Pearson correlation, receiver operating characteristic (ROC) analysis and inter-rater reliability (κ index) were applied. Good correlation between RSf and Ret He was observed, r = 0.8184. Significant differences (P < 0.001) were detected when groups with inefficient erythropoiesis were compared with patients undergoing therapy and healthy subjects. ROC analysis for RSf in the diagnosis of inefficient erythropoiesis, cutoff 91.1 fl, area under curve 0.963, sensitivity 91.7%, specificity 88.5%. Concordance between RSf and Ret He κ = 0.68. RSf and Ret He are suitable parameters for the assessment of erythropoiesis status.

The role of automated measurement of red cell subpopulations on the Sysmex XE 5000 analyzer in the differential diagnosis of microcytic anemia.

Cell counter-based formulae have been used in the differential diagnosis of microcytic anemia. The measurement of new red cell parameters is now available on the Sysmex XE 5000 analyzer. Derived from the percentages of microcytic and hypochromic red cells, the authors describe the new formula %microcytic-%hypochromic, M-H index. The aim of this study was to assess the discriminant value of this new index in the differential diagnosis of microcytic anemia and thalassemia screening compared to the published indices. Receiver operating characteristic curves, sensitivity, specificity and Youden index were calculated for a set of 170 iron-deficiency anemia patients and 200 ß thalassemia carriers. % microcytic-% hypochromic index showed the best area under the curve (area under curve AUC, 0.994) and Youden index (93.9%), among considered indices; 98% sensitivity, 95.9% specificity, at a cutoff value >11.5; Green and King index ranked second (AUC 0.99, Youden index 90.8%). Because of high sensitivity and specificity, the new index %microcytic-%hypochromic was the most reliable index evaluated. M-H index could be a useful tool in the differential diagnosis of microcytic anemia, and samples with M-H>11.5 can be chosen for further analysis to confirm the diagnosis of thalassemia.

Under-recognized renal insufficiency in hospitalized patients: implications for care.

BACKGROUND: The consequences of undetected low glomerular filtration rate (GFR) are important in hospitalized patients who receive potentially nephrotoxic drugs or undergo major surgery. This study estimated the prevalence of estimated GFR (eGFR) <60mL/min/1.73m(2) in hospitalized patients. METHODS: This cross-sectional descriptive study included 14,658 adults hospitalized at 10 centers in Spain. Serum samples were analyzed for hemoglobin, creatinine, albumin and urea nitrogen. eGFR was estimated using Modification of Diet in Renal Disease (MDRD) 4 or MDRD IDMS, and MDRD 6 when serum albumin and BUN were included (n=8611). Individuals were classified as having GFR>or=60mL/min/1.73m(2), stages 3, 4 and 5 (GFR 30-59, 15-29 and <15mL/min/1.73m(2), respectively). Additionally, stages 3a and 3b (GFR 45-59 and 30-44mL/min/1.73m(2), respectively) were assessed. RESULTS: MDRD 4 eGFR showed that 28.3% of patients had renal insufficiency stages 3-5 and 14.2% had stages 3b, 4 or 5, which represents important-severe renal deterioration. Forty-three percent of patients with stages 3-5 had hemoglobin or=60mL/min/1.73m(2). A good correlation was observed between eGFR MDRD 4 and MDRD 6. CONCLUSIONS: A high percentage of hospitalized patients in Spain have deteriorated renal function stages 3-5. Using eGFR equations to assess eGFR could identify more hospitalized patients with renal insufficiency, potentially leading to improved care.

Diseño e implementación de una práctica de metacognición en la asignatura de Fisiología Humana (Facultad de Medicina) / Designing and implementing a practical on metacognition as part of the subject of Human Physiology (Faculty of Medicine)

Objetivo. Presentar el diseño y los resultados obtenidos enana práctica sobre metacognición en Fisiología Humana(Facultad de Medicina). Sujetos y métodos. Ciento diecinueveestudiantes (95 mujeres y 24 varones) asistieron a una práctica sobre metacognición en la asignatura de Fisiología Humana (Facultad de Medicina). La práctica se dividió en dos partes: en la primera, los estudiantes se determinaron el estilo de aprendizaje (test de Kolb) para poner de manifiesto que no todos aprenden de la misma manera, y se les hizo reflexionar sobre las características esenciales de cada estilo encontrado; en la segunda, escribieron las recomendaciones que harían a su mejor amigo/a sobre cómo estudiar fisiología y, posteriormente, las expusieron ante el resto. Resultados y conclusiones. Los resultados respecto a los modos de aprender mostraron dos hechos: uno, que la mayor puntuación se obtuvo en la conceptualización abstracta, tanto para varones como para mujeres, y, otro, referente a la segunda opción, que las mujeres señalaron la experimentación activa (significativamente mayor que en los varones), mientras que para éstos fue la observación reflexiva. Los estilos de aprendizaje de los estudiantes fueron convergentes y asimiladores, con escasa diferencia entre ambos. Por sexos, se observó que en los varones predominó el estilo asimilador (13 frente a 8),mientras que en las mujeres fue más frecuente el convergente(44 frente a 36). En la segunda parte de la práctica(metacognición) ambos grupos manifestaron utilizar las mismas estrategias, con independencia del estilo al que pertenecían. Determinadas estrategias fueron utilizadas por los estudiantes con niveles de sofisticación diferentes (AU)

Aim. To present the design and results found in a practical lecture on met cognition in the subject of Human Physiology(School of Medicine). Subjects and methods. The practical lecture was attended by 119 students (95 women and 24men). This one was divided into two parts: in the first, students determined by themselves their learning style (Kolb test) in orderto show that not everyone learns the same way and makes them reflect on the essential features of each style found; in the second, they wrote on the recommendations made to his/her best friend on how to study the Physiology and then put them to rest. Results and conclusions. The results respect to the learning modes showed two facts: one, the highest score was obtained by abstract conceptualization, for both men and women; and another, in relation to the second option the active experimentation was reported by women (significantly greater than men) versus reflective observation indicated by men. Regarding learning styles of students, these were assimilator and converger, with little difference between them. By gender, the following fact was found: in men predominated assimilator style (13 versus 8), whereas women were the most converge one (44 versus 36). In the second part of the practical lecture(metacognition) both groups expressed to use the same learning strategies, independently of the learning style. Some strategies were used by students with different sophistication levels (AU)

Comparison of BNP and NT-proBNP assays in the approach to the emergency diagnosis of acute dyspnea.

N-terminal pro-brain natriuretic peptide (NT-proBNP) and BNP measurement could have a significant role in differentiating dyspnea between cardiac or pulmonary origin in the emergency room. The development of new and different commercial assays for these B-type natriuretic peptides offers the possibility of improving and simplifying their measurements but this could be defaulted due to the differences in methodology and the lack of assay standardization. We compared four available methods of measuring NT-proBNP and BNP and evaluated their usefulness in diagnosing the causes of breathlessness in the emergency room. The correlation of BNP with different assays was strong with r>0.98 (P<0.0001). Comparison studies between NT-proBNP and BNP procedures were in good agreement with r>0.87. The area under the receiver-operating characteristic curve (ROC) for BNP or NT-proBNP for detecting any cardiac dysfunction was higher than 0.96 (95% CI). A BNP value of 116 pg/mL measurement with the Access BNP assay (Beckman Coulter Inc., Fullerton, CA), a BNP value of 79 pg/mL with Advia Centaur BNP assay (Bayer Diagnostics, Tarrytown, NY), and an NT-proBNP level of 817 pg/mL in Elecsys NT-proBNP assay (Roche Diagnostic, Mannheim, Germany), showed both high sensitivity (>92%) and high specificity (>93%). We have found that NT-proBNP and BNP present similar diagnostic accuracies for the differential diagnosis of dyspnea.

[Susceptibility of Enterococcus genus to new antimicrobial agents]. / Sensibilidad del género Enterococcus a nuevos antimicrobianos.

The aim of this study was to determine the prevalence of resistance to different antibiotics in 109 clinical strains of Enterococcus isolated consecutively in hospital over a four-month period in 2002. The strains were identified by species using the semiautomatic system Microscan walk away 40 (Dade Behring) and the API20 STREP system (Biomerieux). Three different methods for the susceptibility study were used: Sensititre, E-test and disc diffusion. The percentage of Enterococcus faecalis and Enterococcus faecium isolated was 92% and 8%, respectively. The following resistance to Enterococcus faecalis was detected: erythromycin (53%), telithromycin (36%), penicillin (2%), ampicillin (1%), vancomycin, teicoplanin and linezolid (0%), high level resistance to streptomycin (51%) and gentamicin (32%). A high percentage of strains resistant to penicillin and ampicillin was detected in E. faecium (six of nine strains). For two species, high susceptibility to linezolid and glycopeptides was found.

Amino, chloromethyl and acetal-functionalized latex particles for immunoassays: a comparative study.

Latex particles with different functionalized surface groups (amino, acetal and chloromethyl) for the covalent linking of protein molecules were synthesized and characterized. Immunopurified anti-ferritin antibodies were then covalently coupled with a mean efficiency rate (protein covalently bound to latex particles with respect to the total amount of protein added) of 60%. The reagents developed were applied to the measurement of serum ferritin concentration in a turbidimetric procedure, showing a good measuring range and a lowest detection limit of 3.5 ng/ml in the case of the amino-modified particles. These immunological reagents were compared with a commercial nephelometric method, showing a good linear correlation in all cases but no transferability in the acetal and chloromethyl latex with additional carboxyl groups, probably due to interference with other serum components. The differences among latex found in this study indicate that it would be necessary to optimize the assay conditions for each type of particle, in order to achieve a maximum immunoreactivity.

Staphylococcus aureus resistente a la meticilina, prevalencia en La Rioja / Methicillin-resistant staphylococcus aureus. Prevalence in La Rioja

Las cepas de Staphylococcus aureus resistentes a meticilina (SARM) suponen un problema en el medio hospitalario. Conocer la prevalencia de estas cepas es importante para aplicar una terapia empírica adecuada cuando se sospeche la implicación de SARM en la infección. Se estudió todas las cepas de Staphylococcus aislados en La Rioja desde febrero de 2001 hasta Febrero de 2002, incluyendo un solo aislamiento por paciente. Tras su identificación fueron valoradas frente a 13 antibióticos, hallándose una elevada insensibilidad a la oxacilina (34.81 por ciento), observándose también elevada resistencia a otros antimicrobianos como el ciprofloxacino (36.12 por ciento) y la eritromicina (21.98 por ciento) . No se encontró ningún aislamiento de SARM resistente a vancomicina. Los aislamientos se produjeron de forma más frecuente en muestras de orina (63 por ciento). SARM es un problema grave en La Rioja y su prevalencia sigue aumentando progresivamente, así como la mutiresistencia, es necesario ampliar las medidas de vigilancia y control (AU)

Diagnóstico serológico de la artritis reumatoide. Utilidad de los anticuerpos anti-CCP / Serologic diagnosis of rheumatoid arthritis. Anti-CCP antibodies utility

No disponible

Comparación del método de microdilución (sensititre®) con el E-test® para el estudio de sensibilidad de Streptococcus pneumoniae / Comparison of the microdilution methos (Sensititre) with E-Test to study of susceptibility of streptococcus pneumoniae

La aparición de resistencias frente Streptococcus pneumoniae ha incrementado la necesidad de procesos seguros para estudiar la sensibilidad. Se han estudiado las características analíticas de dos sistemas comerciales de sensibilidad: E-test® (Ab Biodisk, Solna, Suecia) y Sensititre® (AcuMed, Westlake, Ohio). Cuando se usa E-test®, el 77 por ciento de los aislamientos mostraron resistencia de alto nivel a la penicilina y eritromicina. Por otra parte, cuando se emplea Sensititre® los resultados de resistencia obtenidos fueron: 83 por ciento y 79 por ciento para penicilina y eritromicina, respectivamente. Cuando se compara los resultados de los dos métodos, para la eritromicina, se encontraron dos discrepancias graves. El método Sensititre® permite analizar la resistencia de otros trece antibióticos (AU)

Estudio de la sensibilidad de Streptococcus pneumoniae en La Rioja / Study of the susceptibility of Streptococcus pneumoniae in La Rioja

No disponible

Sensibilidad de Streptococcus pneumoniae a nuevos fármacos / Susceptibility of Sreptococcus pneumoniae to new antibiotics

La resistencia de Streptococcus pneumoniae a diferentes antimicrobianos ha aumentado en todo el mundo. Nuevos antibióticos como estreptograminas, ketólidos y oxazolidinonas pueden ser una buena alternativa a otros antimicrobianos, beta-lactámicos o macrólidos. La sensibilidad a Quinupristin/Dalfopristin, Telitromicina y Linezolid fue determinada en 54 cepas de Streptococcus pneumoniae aisladas en el laboratorio de microbiología del Hospital San Millán-San Pedro. Ninguna fue resistente. Todas las cepas tenían valores de CMI <_ 1 mg/l para la Quinupristin/Dalfopristin. Los diámetros de inhibición obtenidos para Telitromicina y Linezolid oscilaron entre 23 y 37 mm para la Telitromicina y 28 y 45 mm para Linezolid. Por lo tanto, estos antibióticos pueden utilizarse en un futuro en el tratamiento de infecciones del tracto respiratorio. (AU)

Evaluación del tiempo de respuesta global de un laboratorio de urgencias con impresión remota / Evaluation of the global turnaround time in an emergency laboratory with remote printing

En el presente artículo se realiza una evaluación del tiempo de respuesta (TR) global de un laboratorio de urgencias, en el que el envío de resultados desde el laboratorio hasta el Servicio de Urgencias es mediante impresión remota, y se compara con los tiempos de respuesta obtenidos en el mismo laboratorio cuando el envío de resultados era mediante celadores. Se estudiaron 225 peticiones repartidas en los tres turnos laborales ( mañana, tarde y noche), en las que se analiza el tiempo transcurrido desde la solicitud del análisis hasta su recepción en el laboratorio y el tiempo intralaboratorio. Se considera importante realizar estudios periódicos del tiempo de respuesta y proponer medidas de mejora, así como reevaluar el resultado de la implantación de estas medidas. (AU)

Nuevo procedimiento colorimétrico para la determinación de adenosina desaminasa en líquidos biológicos / New colorimetric procedure of determining adenosine deaminase in body fluids

Se ha evaluado un nuevo reactivo para la determinación del enzima adenosina desaminasa (ADA) en los analizadores Cobas Mira S (Roche) y Synchron CX7 (Beckman), utilizando un método cinético colorimétrico basado en la cuantificación de inosina. La precisión expresada como coeficientes de variación fue menor del 3 por ciento (intradía) y menor del 2.7 por ciento (interdía) para valores de ADA entre 15.4 y 112 U/L. El método resultó lineal hasta valores de 395 U/L y presentó un límite de detección menor de 0.5 U/L. No se han observado interferencias debidas a bilirrubina (hasta 25 mg/dL), ni lípidos (Ivelip® hasta 2 por ciento), pero sí se observan aumentos significativos en la actividad de ADA debidos a hemolisis. Al comparar este método con un método comercial basado en la detección del amoniaco liberado, se obtuvieron coeficientes de correlación superiores a 0.97 en todos los casos. En conclusión, el nuevo procedimiento evaluado presenta una buena practicabilidad junto con una precisión y sensibilidad satisfactorias; por lo que resulta adecuado para las determinaciones urgentes y de rutina de adenosina desaminasa en fluídos biológicos (AU)

Longitudinal study of serum copper and zinc levels and their distribution in blood proteins after acute myocardial infarction.

The levels and distribution of serum Cu and Zn were studied in patients diagnosed with acute myocardial infarction from the day of admission to the Cardiovascular Intensive Care Unit until the 10th day following the attack. The results obtained show that Cu increases significantly (p < 0.01) after the 5th day after the acute myocardial infarction, while Zn decreases significantly (p < 0.01) with respect to the control group from the first day on, with the lowest values being found on the 3rd day after the attack. Further, total serum Cu showed an excellent correlation with the albumin-bound and globulin-bound Cu (ceruloplasmin), as well as with the concentrations of both serum protein fractions. In contrast, total serum Zn only presents this correlation with Zn bound to albumin, but not with Zn bound to globulin nor with the albumin concentration. These findings suggest the existence of some type of relationship between the two fractions of the element bound to protein. This relationship is probably different for both metals.

Utilidad de diversas proteínas en el diagnóstico diferencial de las meningitis bacterianas / The utility of several proteins within the differential diagnosis of bacterian meningitis

Con el fin de realizar una evaluación de su utilidad en el diagnóstico rápido de las meningitis bacterianas se han determinado, en líquido cefalorraquídeo y en plasma, los siguientes parámetros relacionados con procesos inflamatorios: proteína C reactiva, proteína A amiloide sérica, procalcitonina y lisozima. De los 48 pacientes seleccionados, 10 presentaron meningitis bacteriana, 18 meningitis vírica y 20 se tomaron como grupo control. En los dos tipos de muestras utilizadas, se obtuvieron diferencias significativas en los valores medios de todas las proteínas determinadas, entre el grupo de meningitis bacteriana y los grupos vírico y control. Todas las sensibilidades diagnósticas resultaron iguales o mayores del 80 por ciento, destacando las de SAA n líquido cefalorraquídeo procalcitonina plasmática que fueron del 100 por ciento. Esta excelente sensibilidad, junto con la amplia diferencia de valores obtenidos entre el grupo bacteriano y el resto de grupos (las concentraciones medidas de procalcitonina y SAA en el grupo de meningitis bacterianas fueron respectivamente, 24 y 10 veces superiores a la correspondiente a los grupos meníngeo vírico y control), podrían permitir a estos parámetros ser utilizados como marcadores para el despistaje rápido de las meningitis bacterianas. Teniendo en cuenta el reducido tamaño del grupo de meningitis bacterianas. Teniendo en cuenta el reducido tamaño del grupo de meningitis bacterianas estudiado, se considera necesaria una reevaluación de estos parámetros en un grupo de pacientes más amplio. Sería interesante el desarrollo de un método inmunonefelométrico para la determinación de procalcitonina sérica que fuera totalmente automatizado y rápido, lo que permitiría su fácil implantación en los laboratorios de rutina y de urgencias. También se considera conveniente el establecimiento de un valor definido de punto de corte de procalcitonina, con el fin de disminuir las diferencias entre los diversos valores de sensibilidad y especificidad diagnóstica encontrados en la bibliografía (AU)