Comparación de parámetros hematológicos y morfología celular en muestras de sangre con EDTA K2 y EDTA K3 / Comparison of hematological parameters and cellular morphology in blood samples with EDTA K2 and EDTA K3

El EDTA es el anticoagulante de elección en los laboratorios de hematología para la conservación de la muestra de sangre total. Existen dos tipos, EDTA K2 y EDTA K3, y su diferencia radica en la cantidad de moléculas de potasio. Algunas guías sugieren que hay diferencias entre el anticoagulante EDTA K2 y el K3 para el proceso del hemograma; sin embargo, con las nuevas presentaciones de los tubos que traen las casas comerciales, no se tiene claro si en realidad aún hay diferencia entre los dos anticoagulantes, y si esto puede alterar el resultado del hemograma, tanto en el resultado cuantitativo, como en el cualitativo. Objetivo. Comparar los recuentos leucocitarios, la hemoglobina, el hematocrito, el volumen corpuscular medio, las plaquetas y la morfología celular en muestras de sangre periférica con EDTA K2 y EDTA K3, en diferentes tiempos (0, 1 y 2 horas). Materiales y métodos. Se realizó un estudio cuasi-experimental, multivariado, multifactorial, que tiene como unidad de análisis la sangre anticoagulada con EDTA K2 y EDTA K3, extraída de 53 individuos a través de un muestreo no probabilístico por conveniencia. Resultados. Al comparar los resultados del estudio morfológico por medio del extendido de sangre periférica y los datos cuantitativos del hemograma, se encontró que no hay diferencias estadísticamente significativas usando EDTA K2 o K3. Conclusión. Se evidenció que el uso del EDTA K2 o EDTA K3 como anticoagulante de elección, procesando las muestras en un tiempo adecuado después de su recolección, no afecta los parámetros cuantitativos del hemograma automatizado ni los morfológicos.

EDTA is the anticoagulant of choice in hematology laboratories for the conservation of whole blood samples. There are two types, K2 EDTA and K3 EDTA, and their difference lies in the amount of potassium molecules. Some guidelines suggest that there are differences between K2 and K3 EDTA for the blood analysis process. However, with the new collection tubes offered by the commercial suppliers, it is not clear if in fact there is a difference between the two anticoagulants that would result in changes in blood parameters and cell morphology. Objective. To compare leukocyte counts, hemoglobin, hematocrit, mean corpuscular volume, platelets and cell morphology in peripheral blood samples collected with K2 EDTA and K3 EDTA, at different times (0, 1 and 2 hours). Materials and methods. A quasi-experimental, multivariate, multifactorial study was carried out, with anticoagulated blood as the unit of analysis, either with K2 EDTA or K3 EDTA, extracted from 53 subjects through a non-probabilistic sampling for convenience. Results. There was no statistically significant difference when comparing results of the peripheral blood smear and the quantitative hematological parameters using K2 or K3 EDTA. Conclusion. The use of either K2 EDTA or K3 EDTA as the anticoagulant of choice, when processing samples within a suitable time after their collection, proved equally satisfactory for both quantitative and morphological parameters

Use of circulating tumor cells in prospective clinical trials for NSCLC patients - standardization of the pre-analytical conditions.

BACKGROUND: Circulating tumor cells (CTCs) hold potential for noninvasive diagnosis, prognosis and prediction testing in non-small cell lung cancer (NSCLC) patients. Minimizing degradation or loss of CTCs is pivotal for detection and profiling of the low abundance and fragile CTCs, particularly in clinical trials. We prospectively investigated (NCT02372448) whether a new blood collection device performed better compared to commonly used K3EDTA tubes, when subjected to long-term sample storage. METHODS: Blood samples were drawn into K3EDTA and blood collection tubes (BCT) (Streck), and filtered by the Isolation by SizE of Tumor/Trophoblastic Cells (ISET® system), for CTC detection in two study populations of NSCLC patients; the training set of 14 patients with stage II/IV NSCLC, and the validation set of 36 patients with stage IV NSCLC). MET expression was evaluated by immunocytochemistry (ICC) and anaplastic lymphoma kinase (ALK) gene rearrangement by break-apart fluorescence in situ hybridization (FISH) on ISET-enriched CTCs. RESULTS: Blood processed after 24 h and 48 h in BCT tubes showed stable CTCs counts and integrity, whereas CTCs in K3EDTA tubes showed an altered morphology in all patients. CTCs recovered in BCT or K3EDTA tubes at 24 and 48 h were evaluable by ICC for MET expression and by FISH for ALK rearrangement. CONCLUSIONS: The BCT tubes gave a high yield and preserved the integrity of CTCs after 24 and 48 h of storage at room temperature, which facilitate their molecular characterization in NSCLC patients entering clinical trials.