Automated white blood cell counts in cerebrospinal fluid using the body fluid mode on the platform Sysmex XE-5000

Canine Cerebrospinal Fluid Analysis Using Two New Automated Techniques: The Sysmex XN-V Body Fluid Mode and an Artificial-Intelligence-Based Algorithm

Cerebrospinal fluid analysis is an important diagnostic test when assessing a neurological canine patient. For this analysis, the total nucleated cell count and differential cell counts are routinely taken, but both involve time-consuming manual methods. To investigate faster automated methods, in this study, the Sysmex XN-V body fluid mode and the deep-learning-based algorithm generated by the Olympus VS200 slide scanner were compared with the manual methods in 161 canine cerebrospinal fluid samples for the total nucleated cell count and in 65 samples with pleocytosis for the differential counts. Following incorrect gating by the Sysmex body fluid mode, all samples were reanalyzed with manually set gates. The Sysmex body fluid mode then showed a mean bias of 15.19 cells/μL for the total nucleated cell count and mean biases of 4.95% and -4.95% for the two-part differential cell count, while the deep-learning-based algorithm showed mean biases of -7.25%, -0.03% and 7.27% for the lymphocytes, neutrophils and monocytoid cells, respectively. Based on our findings, we propose that the automated Sysmex body fluid mode be used to measure the total nucleated cell count in canine cerebrospinal fluid samples after making adjustments to the predefined settings from the manufacturer. However, the two-part differential count of the Sysmex body fluid mode and the deep-learning-based algorithm require some optimization.

Accuracy of automated analyzers for the estimation of CSF cell counts: A systematic review and meta-analysis

This systematic review evaluates the evidence for accuracy of automated analyzers that estimate cerebrospinal fluid (CSF) white blood cell counts (WBC) compared to manual microscopy. Inclusion criteria of original research articles included human subjects, English language, and manual microscopy comparator. PUBMED, EMBASE and Cochrane Review databases were searched through 2019 and QUADAS-2 Tool was used for assessment of bias. Data were pooled and analyzed by comparison method, using random effects estimation. Among 652 titles, 554 abstracts screened, 104 full-text review, 111 comparisons from 41 studies were included. Pooled estimates of sensitivity and specificity (n = 7) were 95% (95%-CI 93%-97%) and 84% (95%-CI: 64%-96%), respectively. Pooled R2 estimates (n = 29) were 0.95 (95%-CI: 0.95-0.96); Pooled spearman rho correlation (n = 27) estimates were 0.95 (95% CI 0.95-0.96). Among those comparisons using Bland-Altman analysis (n = 11) pooled mean difference was estimated at 0.98 (95% CI-0.54-2.5). Among comparisons using Passing-Bablok regressions (n = 14) the pooled slope was estimated to be 1.05 (95% CI 1.03-1.07). Q tests of homogeneity were all significant with the exception of the Bland-Altman comparisons (I2 10%, p value 0.35). There is good overall accuracy for CSF WBC by automated hematologic analyzers. These findings are limited by the small sample sizes and inconsistent validation methodology in the reviewed studies.

A Near-Infrared Fluorescent Probe for Recognition of Hypochlorite Anions Based on Dicyanoisophorone Skeleton

A novel near-infrared (NIR) fluorescent probe (SWJT-9) was designed and synthesized for the detection of hypochlorite anion (ClO^-) using a diaminomaleonitrile group as the recognition site. SWJT-9 had large Stokes shift (237 nm) and showed an excellent NIR fluorescence response to ClO^- with the color change under the visible light. It showed a low detection limit (24.7 nM), high selectivity, and rapid detection (within 2 min) for ClO^-. The new detection mechanism of SWJT-9 on ClO^- was confirmed by ¹H NMR, MS spectrum, and the density functional theory (DFT) calculations. In addition, the probe was successfully used to detect ClO^- in HeLa cells.

Automated Analysis of Cerebrospinal Fluid Cells Using Commercially Available Blood Cell Analysis Devices-A Critical Appraisal

The analysis of cells in the cerebrospinal fluid (CSF) is a routine procedure that is usually performed manually using the Fuchs–Rosenthal chamber and cell microscopy for cell counting and differentiation. In order to reduce the requirement for manual assessment, automated analyses by devices mainly used for blood cell analysis have been also used for CSF samples. Here, we summarize the current state of investigations using these automated devices and critically review their limitations. Despite technical improvements, the lower limit for reliable leukocyte counts in the CSF is still at approximately 20 cells/µL, to be validated depending on the device. Since the critical range for clinical decisions is in the range of 5–30 cells/µL this implies that cell numbers < 30/µL require a manual confirmation. Moreover, the lower limit of reliable erythrocyte detection by automated devices is at approximately 1000/µL. However, even low erythrocyte numbers may be of clinical importance. In contrast, heavily hemorrhagic samples from neurosurgery may be counted automatically at an acceptable precision more quickly. Finally, cell differentiation by automated devices provides only a rough orientation for lymphocytes, granulocytes and monocytes. Other diagnostically important cell types such as tumor cells, siderophages, blasts and others are not reliably detected. Thus, although the automation may give a gross estimate sufficient for the emergency room situation, each CSF requires a manual microscopy for cytological evaluation for the final report. In conclusion, although automated analysis of CSF cells may provide a first orientation of the cell profile in an individual sample, an additional manual cell count and a microscopic cytology are still required and represent the gold standard.

Evaluation of the Idexx ProCyte Dx® for analysis of canine cerebrospinal fluid

OBJECTIVES

To assess the utility of the Idexx ProCyte Dx® haematology analyser for assessing total nucleated cell count and differential cell counts in canine cerebrospinal fluid.

MATERIALS AND METHODS

Seventy-three client-owned dogs undergoing investigations for pyrexia and/or neurological signs were prospectively included. Cerebrospinal fluid samples were assessed using an Idexx ProCyte Dx® analyser and the results were compared to those obtained with the external laboratory reference standard.

RESULTS

The Idexx ProCyte Dx® performed with good sensitivity (92.6%) and moderate specificity (67.4%) for total nucleated cell count when compared to the reference standard. Qualitative assessment of the Idexx ProCyte Dx® scatter plots, and quantitative assessment of differential cell counts where available, appeared to correlate well with the external laboratory manual differential cell counts, with a good-to-high agreement in 25 of 26 samples (96.2%).

CLINICAL SIGNIFICANCE

The Idexx ProCyte Dx® analyser performed well in determining the total nucleated cell count and differential cell counts in canine cerebrospinal fluid when compared to a reference standard of external laboratory analysis, except for cell counts higher than ~1000/μL. As the Idexx ProCyte Dx® currently only provides a cell count in 10 cells/μL increments, software modification may improve agreement between the two methods. As in human medicine, automated methods may prove useful in the future for cerebrospinal fluid analysis in addition to manual assessment, particularly in an emergency setting.

Effect of sample processing and time delay on cell count and chemistry tests in cerebrospinal fluid collected from drainage systems

Introduction

Cerebrospinal fluid (CSF) from extra-ventricular drainage (EVD) systems is routinely analysed to diagnose EVD–related bacterial meningitis. We investigated the effect of time delay and sample processing on cell count and basic biochemistry results in EVD CSF to define optimal turnaround time and whether manual and automated cell counting are comparable in such samples.

Materials and methods

In total, 32 EVD CSF samples were analysed. Baseline testing included cell counting (Fuchs-Rosenthal chamber and Sysmex XE5000) and biochemistry analyses (glucose, lactate, proteins). Manual cell counting was also performed at intervals of 61-90 and 91-150 minutes from baseline in the residual sample. Biochemistry analyses were performed in samples before and after centrifugation at baseline and at 91-150 minutes interval.

Results

At 91-150 minutes total cell count (P < 0.001), large lymphocytes (P = 0.007), neutrophils (P < 0.001) and phagocytes (P = 0.006) obtained by manual counting decreased and the number of disintegrated cells count increased (P = 0.016) compared to the baseline values. Considering method comparison, proportional difference between methods for all cell (sub)groups was obtained, whereas polymorphonuclears also showed the constant difference (y = 11.21 + 1.22x). Compared to centrifuged CSF, lower concentration of glucose and lactates were obtained in uncentrifuged samples (P < 0.001) at baseline.

Conclusions

Manual cell counting should be performed within 60 minutes as any delay can alter results. The same counting technique should be used to obtain longitudinally assessable results. Biochemistry tests are stable in uncentrifuged CSF up to 2.5 hours.

Automated cell counts on CSF samples: A multicenter performance evaluation of the GloCyte system

OBJECTIVES

Automated cell counters have replaced manual enumeration of cells in blood and most body fluids. However, due to the unreliability of automated methods at very low cell counts, most laboratories continue to perform labor-intensive manual counts on many or all cerebrospinal fluid (CSF) samples. This multicenter clinical trial investigated if the GloCyte System (Advanced Instruments, Norwood, MA), a recently FDA-approved automated cell counter, which concentrates and enumerates red blood cells (RBCs) and total nucleated cells (TNCs), is sufficiently accurate and precise at very low cell counts to replace all manual CSF counts.

METHODS

The GloCyte System concentrates CSF and stains RBCs with fluorochrome-labeled antibodies and TNCs with nucleic acid dyes. RBCs and TNCs are then counted by digital image analysis. Residual adult and pediatric CSF samples obtained for clinical analysis at five different medical centers were used for the study. Cell counts were performed by the manual hemocytometer method and with the GloCyte System following the same protocol at all sites. The limits of the blank, detection, and quantitation, as well as precision and accuracy of the GloCyte, were determined.

RESULTS

The GloCyte detected as few as 1 TNC/μL and 1 RBC/μL, and reliably counted as low as 3 TNCs/μL and 2 RBCs/μL. The total coefficient of variation was less than 20%. Comparison with cell counts obtained with a hemocytometer showed good correlation (>97%) between the GloCyte and the hemocytometer, including at very low cell counts.

CONCLUSIONS

The GloCyte instrument is a precise, accurate, and stable system to obtain red cell and nucleated cell counts in CSF samples. It allows for the automated enumeration of even very low cell numbers, which is crucial for CSF analysis. These results suggest that GloCyte is an acceptable alternative to the manual method for all CSF samples, including those with normal cell counts.

Evaluation of biological fluid analysis using the sysmex XN automatic hematology analyzer

BACKGROUND

Hematological cytometers with a biological fluid module could potentially correct the limitations of the manual chamber method. This study evaluates the agreement between the manual technique and the Sysmex XN-1000 analyzer for white blood cell (WBC) and red blood cell (RBC) counts, as well as for leukocyte differentiation in different types of fluids. This study also evaluates the advantages of incorporating the technique in routine laboratory work.

METHODS

One hundred and three fluid samples examined were 45 ascite (AF), 21 synovial (SF), 33 pleural (PF), and 31 cerebrospinal (CSF) fluid samples. All cell counting was performed with a Sysmex XN-1000 and a Fuchs-Rosenthal counting chamber. May Gründwald-Giemsa stain was used for manual WBC differentiation. The manual analysis data were obtained in duplicate by the same two observers. Passing-Bablok regression and the Kappa index were used to evaluate the interchangeability and concordance.

RESULTS

Good agreement was observed for WBC differentiation in all fluids and for WBC counts in SF and PF. An optimal Kappa index was obtained, which indicated agreement and clinical significance for WBC and RBC counts in CSF and for RBC counts in PF. There was disagreement for WBC and RBC analysis in AF, with significantly higher results from the Sysmex XN-1000 than from the manual method. A reduction in laboratory response time was observed when using the automatic method.

CONCLUSIONS

Except for AF, the Sysmex XN-1000 results agree with those of the manual method, although to different degrees depending on the fluid type. © 2017 International Clinical Cytometry Society.

Laboratory testing of extravascular body fluids in Croatia: a survey of the Working group for extravascular body fluids of the Croatian Society of Medical Biochemistry and Laboratory Medicine

INTRODUCTION

We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts.

MATERIALS AND METHODS

An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared.

RESULTS

The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF's test reports.

CONCLUSIONS

Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety.

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

Background:

Cellular analysis in cerebrospinal fluid (CSF) provides important diagnostic information in various medical conditions. The aim of this study was to evaluate the application of Mindray BC-6800 body fluid (BF) mode in cytometric analysis of CSF compared to light microscopy (LM).

Methods:

One hundred and twenty-nine consecutive CSF samples were analyzed by BC-6800-BF mode as well as by LM. The study also included limits of blank (LoB), limit of detection (LoD), limit of quantitation (LoQ), carryover and linearity.

Results

White blood cells LoQ was 4.0×10

Conclusions:

BC-6800-BF offers rapid and accurate counts in clinically relevant concentration ranges, replacing LM for most samples. However, in samples with abnormal cell counts or with abnormal white blood cell differential scattergrams the need to microscopic review for a correct clinical outcome remains.

Automated Cerebrospinal Fluid Cell Counts Using the New Body Fluid Mode of Sysmex UF-1000i

BACKGROUND

We evaluated the new body fluid module on Sysmex UF1000-i (UF1000i-BF) for analysis of white blood cell (WBC) and red blood cell (RBC) in cerebrospinal fluid (CSF).

METHODS

WBC and RBC counting were compared between UF1000i-BF and Fuchs-Rosenthal counting chamber in 67 CSF samples. This study also included the evaluation of between-day precision, limit of blank (LoB), limit of detection (LoD), functional sensitivity (limit of quantitation, LoQ), carryover and linearity. Diagnostic agreement for differentiation between normal and increased WBC counts (≥5.0 × 10(6) /L) was also assessed.

RESULTS

The agreement between UF1000i-BF and manual WBC counts was otpiaml in all CSF samples (r = 0.99; y = 1.05x + 0.09). A modest overestimation was noticed in samples with WBC < 30 × 10(6) /L (r = 0.95; y = 1.21x - 0.15). A good agreement was observed for RBC counts (r = 0.98; y = 1.15x + 0.55), particularly in samples with RBC ≥ 18 × 10(6) /L (r = 0.98; y = 1.01x + 8.90). Between-day precision was good, with coefficient of variations (CVs) lower than 7.2% for both WBC and RBC. The LoBs were 0.1 × 10(6) WBC/L and 1.2 × 10(6) RBC/L, the LoDs were 0.7 × 10(6) WBC/L and 5.5 × 10(6) RBC/L, the LoQs were 2.4 × 10(6) WBC/L and 18.0 × 10(6) RBC/L, respectively. Linearity was excellent (r = 1.00 for both WBC and RBC). Carryover was negligible. Excellent diagnostic agreement was obtained at 4.5 × 10(6) WBC/L cut-off (sensitivity, 100%; specificity, 97.4%).

CONCLUSION

The UF1000i-BF provides rapid and accurate WBC and RBC counts in clinically relevant values of CSF cells. The use of UF1000i-BF may hence allow to replace routine optical counting, except for samples displaying abnormal WBC counts or abnormal scattergram distribution, for which differential cell counts may still be required.