Aplicación práctica de las especificaciones mínimas de la calidad analítica obtenidas por consenso / Application of the minimum specifications for analytical quality obtained by consensus

Cuatro sociedades científicas españolas, organizadoras de programas de garantía externa de la calidad en el ámbito del laboratorio clínico, crearon un grupo de trabajo para definir y divulgar especificaciones mínimas de la calidad analítica obtenidas por consenso (EMC) elaboradas con base en los resultados de sus programas de garantía externa de la calidad durante el período 2005-2010. Se definieron EMC para 60 magnitudes. En este trabajo se dan unas directrices sobre cómo utilizar estas especificaciones en la práctica diaria del laboratorio clínico. Se concluye que ante un resultado de un programa de evaluación externa con un error total superior a la EMC el laboratorio realizará un análisis de causas y establecerá las acciones correctivas oportunas para evitar que esta circunstancia vuelva a ocurrir. El cumplimiento de las EMC es un requisito necesario pero no suficiente en el sistema de la calidad del laboratorio. Debido a su condición de mínimas no deberían utilizarse como un objetivo de la calidad (AU)

A working group was created to define and explain the minimum specifications for analytical quality obtained by consensus (MSC) by the four Spanish scientific societies that organise external quality assurance programs in laboratory medicine. The basis of these MSC were results obtained in the external programs of the 2005-2010 period, and were defined for 60 analytes. This paper gives guidelines on how the individual laboratory should use these specifications in its daily routine. It is concluded that laboratories should perform a cause analysis study and take the appropriate corrective action when a single result in an external program falls outside the MSC for an analyte. Fulfilling MSC is a necessary -but not sufficient- requirement in the laboratory quality system, but due to its condition of ‘minimum quality’ they should not be used as quality goals (AU)

Automated assessment of the neutrophil and platelet activation status in patients with essential thrombocythemia.

Neutrophil and platelet activation are consistently found in essential thrombocythemia (ET), but the techniques employed to demonstrate such abnormalities are complex. To ascertain whether the ADVIA 120 analyzer can be employed to assess neutrophil and platelet activation status in ET, 55 such patients and the same number of matched healthy individuals were studied and the results correlated with neutrophil CD11b and platelet P-selectin expressions measured by flow cytometry. Compared with controls, ET patients had significantly higher values of neutrophil myeloperoxidase index (MPXI), mean platelet volume (MPV), platelet distribution width (PDW), and platelet component distribution width, and significantly lower values of neutrophil lobularity index and mean platelet component (MPC). Patients with the JAK2 mutation had significantly lower values of MPC and higher values of MPV and PDW than those with wild-type allele. A positive correlation was observed between MPXI and neutrophil CD11b expression and a negative correlation between MPC and platelet P-selectin expression. The intensity of the agreement between the variables obtained by the two methods was moderate. These results support the possible value of MPC as surrogate parameter of platelet activation in ET.

mTOR inhibition and erythropoiesis: microcytosis or anaemia?

BACKGROUND: Anaemia and microcytosis are common post kidney transplantation. The aim of this study was to evaluate the potential role of mammalian target of rapamycin (mTOR) inhibition in the development of anaemia and microcytosis in healthy animals and in human erythroid cultures in vitro. METHODS: Rats with normal kidney function were treated with sirolimus (n = 7) or vehicle (n = 8) for 15 weeks. Hemograms were determined thereafter. In the sirolimus withdrawal part of the study, rats received sirolimus (SRL) for 67 days (n = 4) 1 mg/kg three times per week or for 30 days (n = 4) and were observed until Day 120. Hemograms were performed regularly. Peripheral blood mononuclear cells from healthy controls (HC; n = 8), kidney transplant patients with sirolimus treatment with (SRL + MC; n = 8) or without microcytosis (SRL - MC; n = 8) were isolated and cultured in the absence or presence of SRL (5 ng/mL). RESULTS: SRL-treated animals had a reduced mean corpuscular volume (MCV) and elevated erythrocyte count compared with control animals after 15 weeks of treatment. This effect was evident as early as 4 weeks (MCV: 61.5 ± 1.8 versus 57 ± 1.7 fL; P = 0.0156; Red blood count 7.4 ± 0.3 × 10(9)/L versus 8.6 ± 0.5 × 10(9)/L; P = 0.0156) and was reversible 90 days after SRL withdrawal. SRL in the culture medium of erythroid cultures led to fewer colonies in cultures from HC as well as from kidney transplant patients (without SRL: 34.2 ± 11.4 versus with SRL: 27.5 ± 9.9 BFU-E-derived colonies P = 0.03), regardless if the cultures were derived from recipients with normocytic or with microcytic erythrocytes. The presence of tacrolimus in the culture medium had no influence on the number and size of colonies. CONCLUSION: mTOR inhibition induces microcytosis and polyglobulia, but not anaemia in healthy rats. This might be caused by growth inhibition of erythroid precursor cells.

Performance evaluation of the ADVIA 2120 hematology analyzer: an international multicenter clinical trial.

Automated cell counters are widely used in modern clinical laboratories to provide reliable, fast, and cost-effective complete blood counts (CBCs), white blood cell differentials, and reticulocyte measurements. In addition, some advanced instruments provide novel parameters, such as the hemoglobin content of reticulocytes or the percentage of hypochromic cells, and are capable of analysis of a variety of body fluids. Bayer recently introduced the ADVIA 2120 system as an automation-ready cell counter for mid- to high-volume testing in the clinical laboratory. This instrument, which builds on the established technology of the ADVIA 120 system, operates with a cyanide-free method for hemoglobin measurement, has a new user interface, and can routinely analyze biological fluid samples in addition to blood. We used 749 samples from 6 worldwide trial sites to evaluate the clinical performance of this new device. Accuracy of the ADVIA 2120 system versus its predecessor model, the ADVIA 120 system, was excellent for all CBC and white cell differential parameters and reticulocyte counts (all correlation coefficients except for basophils >0.9). Correlation of the white cell differential with the standard manual method and within-run precision of the ADVIA 2120 system also was very good. Use of the novel cyanide-free method for hemoglobin measurement had no clinically significant impact on hemoglobin results, even in patients with hemoglobinopathies. We concluded that the ADVIA 2120 system has clinically equivalent performance to the ADVIA 120 system.