Reflex Testing Rules for Cell Count and Differentiation of Nucleated Elements in Pleural and Ascitic Fluids on Sysmex XE-5000

Abstract

Flow cytometry is widely used in many laboratories for automated nucleated cell counts and their differentiation in body fluids. The implementation of new reflex testing rules on these automated instruments could open new frontiers in laboratory workflow, improving characterization of body fluids and clinical diagnosis and decreasing costs. Ascitic (150) and pleural (33) fluids were collected and assessed by XE-5000 and optical microscopy. Cell counts performed with the methods showed a Pearson's correlation of 0.98 (p < 0.0001), Passing-Bablok regression y = 0.99x + 2.44, and bias of 32.3. In ascitic fluids, the best diagnostic performance was found for polymorphonuclear and neutrophil counts on XE-5000, which exhibited areas under the curve (AUCs) 0.98 (p < 0.0001) and 0.99 (p < 0.0001), respectively. In pleural fluids the best diagnostic performance was found for polymorphonuclear percent parameter, which displayed 0.97 (p < 0.0001). Specific reflex test rules based on these parameters were characterized by 92% diagnostic concordance, 1.00 sensitivity, and 0.84 specificity with optical microscopy. The application of a set of reflex testing rules may improve the diagnostic performance of XE-5000, increasing its reliability for routine automated cell count in body fluids. We acknowledge that further studies should be planned to validate our findings according to clinical data.

Two‐site evaluation of the diagnostic performance of the Sysmex XN Body Fluid (BF) module for cell count and differential in Cerebrospinal Fluid

“…Notably, the discrepancies observed between TC‐BF, WBC‐BF, and HF‐BF may help defining a set of validation rules or identifying reliable criteria for reflex testing (eg, based on LM analysis) or second‐level testing (eg, flow cytometry or cytological evaluation). This especially applies to all those cases in which the XN‐BF results could not be routinely accepted, as described in previously studies using the XE‐5000‐BF and XN‐BF analyzers …”

Evaluation of Mindray BC-6800 body fluid mode for automated cerebrospinal fluid cell counting

“…microscopic review) whenever the results given by BC-6800-BF should not be accepted by default. As a described in previous studies on XE-5000 and XN-9000 analyzers [40,41].…”

Lack of harmonization in high fluorescent cell automated counts with body fluids mode in ascitic, pleural, synovial, and cerebrospinal fluids

“…The following OM criteria were applied for classifying positive samples: Presence of bacterial flora and/or mycetes; Disrupted cells ≥20%; Abnormal cells count >5% (ie, morphologically aberrant elements, cells with specific morphological characteristics such as lipophages, erythrophages, activated mesothelial cells, and so forth, as reported in the CLSI document H56‐A; Atypical cells count ≥1% (including blasts), as reported in the CLSI document H56‐A; Cell agglutination. …”