Evaluation of pleural and ascitic fluid analysis on the Sysmex XE-5000 hematology analyzer

Introduction: Body fluid (BF) analysis is critical to the diagnosis and monitoring of several pathological conditions. The limitations of manual cell counts have led to greater interest in the development of automated BF analysis. Objective: To evaluate the analytical performance of the Sysmex XE-5000 hematology analyzer in the analysis of pleural and ascitic fluids in the laboratory routine of a large university hospital. Methods: A total of 56 samples (35 ascitic and 21 pleural fluids) were analyzed by manual optical microscopy (OM) and XE-5000. Analytical performance includes linearity, carryover, functional sensitivity and comparison of patient samples. Results: Performance studies showed linearity up to 25,825 WBC-BF/μl (r = 0.999), WBC-BF showed carryover of 0.18%, and the lower limit of quantitation was set at 22 WBC-BF/μl. Good correlations between the methods were observed just for total cell (TC-BF) and white blood cell (WBC-BF) counts in pleural and ascitic fluids. The high-fluorescence cell count (HF-BF) showed poor correlation but high positive predictive value (PPV) for both fluids (94.74% for pleural and 96.97% for ascitic fluid). Conclusion: XE-5000 provides accurate and precise count for TC-BF, WBC-BF and polymorphonuclear cells (PMN-BF) in pleural and ascitic fluids in medical decision levels, but the morphological differentiation should continue to be held by OM. Histogram and scattergram displayed on XE-5000 must always be analyzed to assess if there is any interference or flag. The HF-BF parameter is a potential tool for screening.