Comparison between optical microscopy and automation for cytometric analysis of pericardial fluids in a cohort of adult subjects undergoing cardiac surgery

Abstract

AimsLimited information is available on number and type of cells present in the pericardial fluid (PF). Current evidence and has been garnered with inaccurate application of guidelines for analysis of body fluids. This study was aimed at investigating the performance of automate cytometric analysis of PF in adult subjects.MethodsSeventy-four consecutive PF samples were analysed with Sysmex XN with a module for body fluid analysis (XN-BF) and optical microscopy (OM). The study also encompassed the assessment of limit of blank, limit of detection and limit of quantitation (LoQ), imprecision, carryover and linearity of XN-BF module.ResultsXN-BF parameters were compared with OM for the following cell classes: total cells (TC), leucocytes (white blood cell [WBC]), polymorphonuclear (PMN) and mononuclear (MN) cells. The relative bias were −4.5%, 71.2%, 108.2% and −47.7%, respectively. Passing and Bablok regression yielded slope comprised between 0.06 for MN and 5.8 for PMN, and intercept between 0.7 for PMN and 220.3 for MN. LoQ was comprised between 3.8×106 and 6.0×106 cells/L for WBC and PMN. Linearity was acceptable and carryover negligible.ConclusionsPF has a specific cellular composition. Overall, automated cell counting can only be suggested for total number of cells, whereas OM seems still the most reliable option for cell differentiation.

El recuento automatizado de células en líquidos biológicos: una revisión

“…Aunque algunos estudios describen una tendencia a la sobreestimación del recuento de algunas poblaciones celulares [13,15], estas diferencias no son clínicamente significativas, dado el alto grado de acuerdo (95%) del recuento de leucocitos obtenido por ambos métodos para la clasificación de los líquidos [15], siendo el grado de concordancia entre ambos métodos superior en muestras con baja celularidad [8,15]. Un estudio reciente evaluando la utilidad de estos analizadores para el estudio de la celularidad en líquidos pericárdicos obtenidos en pacientes sometidos a cirugía cardiaca ha confirmado su valor para el recuento de células totales, pero cuestiona su utilización para el recuento diferencial, dada la falta de transferibilidad de los resultados, que los autores atribuyen a la composición peculiar de este líquido, en comparación con otros líquidos serosos, con un elevado porcentaje de células mesoteliales, con tendencia a agregarse; por ello, los autores recomiendan la microscopía óptica como el método más fiable para su estudio [18].…”

Adequate scattergram interpretation increases the reliability of automated polymorphonuclear (pmn) cell counts from ascitic fluid of patients with liver cirrhosis

“…2 Reports on the accuracy of automated differential counts are ambivalent, especially for body fluids with low cell counts. [2][3][4][5][6] Spontaneous bacterial peritonitis (SBP) is a life-threatening complication of liver cirrhosis. Current guidelines define the threshold for diagnosis of SBP at an ascitic polymorphonuclear cell (PMN) count above 0.250 10 9 /L.…”

“…Examples of scattergram features (indicated by white circles) that were analyzed for their association with deviating results of microscopic and automated PMN counts. A) Inconspicuous scattergram with marked cell populations, B) misclassification (eg, MN obviously classified as PMN), C) diagonal population between monocytes and PMN designated as MN, D) increased debris area, E) misclassification (2) within a diagonal cell population (1) (classified for both, MN and PMN) and increased debris area (3), and F) increased frequency of High Fluorescent (HF-)cells (4) and discrete misclassification (5). Green spots denote cellular events designated as MN; light blue spots denote cellular events designated as PMN; strong blue spots denote events designated as debris (D, E) or HF (F); SFL… side fluorescent light; SSC… side-scattered light Reports on the accuracy of automated differential counts are ambivalent, especially for body fluids with low cell counts.…”

“…Green spots denote cellular events designated as MN; light blue spots denote cellular events designated as PMN; strong blue spots denote events designated as debris (D, E) or HF (F); SFL… side fluorescent light; SSC… side-scattered light Reports on the accuracy of automated differential counts are ambivalent, especially for body fluids with low cell counts. [2][3][4][5][6] Spontaneous bacterial peritonitis (SBP) is a life-threatening complication of liver cirrhosis. Current guidelines define the threshold for diagnosis of SBP at an ascitic polymorphonuclear cell (PMN) count above 0.250 10 9 /L.…”

“… 2 Reports on the accuracy of automated differential counts are ambivalent, especially for body fluids with low cell counts. 2 , 3 , 4 , 5 , 6 …”