Performance of automated slidemakers and stainers in a working laboratory environment - routine operation and quality control

Performance of digital morphology analyzer CellaVision DC-1

OBJECTIVES

CellaVision DC-1 (DC-1, Sysmex, Kobe, Japan) is a newly launched digital morphology analyzer that was developed mainly for small to medium-volume laboratories. We evaluated the precision, qualitative performance, comparison of cell counts between DC-1 and manual counting, and turnaround time (TAT) of DC-1.

METHODS

Using five peripheral blood smear (PBS) slides spanning normal white blood cell (WBC) range, precision and qualitative performance of DC-1 were evaluated according to the Clinical and Laboratory Standards Institute (CLSI) EP15-A3, EP15-Ed3-IG1, and EP12-A2 guidelines. Cell counts of DC-1 and manual counting were compared according to the CLSI EP 09C-ED3 guidelines, and TAT of DC-1 was also compared with TAT of manual counting.

RESULTS

DC-1 showed excellent precision (%CV, 0.0-3.5%), high specificity (98.9-100.0%), and high negative predictive value (98.4-100.0%) in 18 cell classes (12 WBC classes and six non-WBC classes). However, DC-1 showed 0% of positive predictive value in seven cell classes (metamyelocytes, myelocytes, promyelocytes, blasts, plasma cells, nucleated red blood cells, and unidentified). The largest absolute mean differences (%) of DC-1 vs. manual counting was 2.74. Total TAT (min:s) was comparable between DC-1 (8:55) and manual counting (8:55).

CONCLUSIONS

This is the first study that comprehensively evaluated the performance of DC-1 including its TAT. DC-1 has a reliable performance that can be used in small to medium-volume laboratories for assisting PBS review. However, DC-1 may make unnecessary workload for cell verification in some cell classes.

Brightfield and fluorescence in-channel staining of thin blood smears generated in a pumpless microfluidic

Effective staining of peripheral blood smears by increasing contrast of intracellular components and biomarkers is essential for the accurate characterization, diagnosis, and monitoring of various diseases such as malaria. To assess the potential for automation of stained whole human blood smears at the point-of-care (POC), brightfield and fluorescence staining protocols were adapted for smears generated in channels of pumpless microchannels and compared to a standard glass smear. A 3× concentration Giemsa brightfield staining solutions (10, 33, and 50% dilution), and Acridine Orange fluorescence staining solutions (12 μg mL-1) were evaluated with human blood smears containing malaria parasites within a microfluidic channel. Giemsa staining at 33% dilution showed an optimal combination of contrast and preservation of cellular morphology, while 50% dilutions showed significant cellular crenation and 10% dilutions did not show desired contrast in brightfield imaging. Fluorescence staining at 12 μg mL-1 using Acridine Orange showed clear separability between the fluorescent intensities of the malaria parasites and that of the red blood cells (RBCs) and background. However, compared to glass smears, these exhibited reduced signal intensity as well as inverted contrast of RBCs and background. These results demonstrate that peripheral thin blood smears generated in pumpless microfluidic can be successfully stained in-channel with a simple, one-step procedure to permit brightfield and fluorescence imaging.

Smudge Cells in Chronic Lymphocytic Leukemia: Pathophysiology, Laboratory Considerations, and Clinical Significance

Chronic lymphocytic leukemia (CLL) is the most commonly encountered leukemia in the clinical laboratory. Cytoskeletal defects in CLL lymphocytes can result in the formation of up to 75% smudge cells (SCs) during blood film preparation. Failure to account for these damaged lymphocytes in the white blood cell (WBC) differential diminishes the accuracy and reproducibility of the results. Lacking clear practice standards on handling SCs in CLL, different laboratories may employ different methods to mitigate SC-induced errors. This review explores the pathophysiology of SCs, their effect on WBC differentials in CLL, and how these results can impact clinical decisions. The pros and cons of various SC corrective methods are described to assist laboratories in developing an optimized protocol to reduce errors and inconsistencies in WBC differentials. Finally, the potential utility of SC enumeration as an indicator of CLL prognosis is discussed in terms of laboratories with differing access to technology.

Performance of digital morphology analyzer Vision Pro on white blood cell differentials

OBJECTIVES

Vision Pro (West Medica, Perchtoldsdorf, Austria) is a recently developed digital morphology analyzer. We evaluated the performance of Vision Pro on white blood cell (WBC) differentials.

METHODS

In a total of 200 peripheral blood smear samples (100 normal and 100 abnormal samples), WBC preclassification and reclassification by Vision Pro were evaluated and compared with manual WBC count, according to the Clinical and Laboratory Standards Institute guidelines (H20-A2).

RESULTS

The overall sensitivity was high for normal WBCs and nRBCs (80.1-98.0%). The overall specificity and overall efficiency were high for all cell classes (98.1-100.0% and 97.7-99.9%, respectively). The absolute values of mean differences between Vision Pro and manual count ranged from 0.01 to 1.31. In leukopenic samples, those values ranged from 0.09 to 2.01. For normal WBCs, Vision Pro preclassification and manual count showed moderate or high correlations (r=0.52-0.88) except for basophils (r=0.34); after reclassification, the correlation between Vision Pro and manual count was improved (r=0.36-0.90).

CONCLUSIONS

This is the first study that evaluated the performance of Vision Pro on WBC differentials. Vision Pro showed reliable analytical performance on WBC differentials with improvement after reclassification. Vision Pro could help improve laboratory workflow.

Automatic wedge smears preparation may cause traumatic morphological changes in peripheral blood cells

In recent years, several automated analysers that prepare and stain blood smears have been introduced in clinical laboratories. Despite the use of instrumental settings based on physical characteristic of individual samples, traumatic injuries of neutrophil and lymphocytes can be observed. Some samples present a very high percentage of damaged cells, allowing the speculation that a cellular susceptibility may enhance mechanical traumatism. These artefacts can puzzle morphological evaluation in both traditional and digitised microscopy; in addition, unskilled operators can be misled.

Phosphodiesterase 10A inhibition attenuates sleep deprivation-induced deficits in long-term fear memory

Sleep, particularly rapid eye movement (REM) sleep, is implicated in the consolidation of emotional memories. In the present study, we investigated the protective effects of a phosphodiesterase 10A (PDE10A) inhibitor MP-10 on deficits in long-term fear memory induced by REM sleep deprivation (REM-SD). REM-SD caused deficits in long-term fear memory, however, MP-10 administration ameliorated the deleterious effects of REM-SD on long term fear memory. Brain-derived neurotropic factor (BDNF) and phosphorylated cAMP response element-binding protein (pCREB) were altered in specific brain regions associated with learning and memory in REM-SD rats. Accordingly, REM-SD caused a significant decrease of pCREB in hippocampus and striatum and a significant decrease of BDNF in the hippocampus, striatum and amygdala, however, MP-10 reversed the effects of REM-SD in a dose-dependent manner. Our findings suggest that REM-SD disrupts the consolidation of long-term fear memory and that administration of MP-10 protects the REM-SD-induced deficits in fear memory, which may be due to the MP-10-induced expression of BDNF in the hippocampus, striatum and amygdala, and phosphorylation of CREB in the hippocampus and striatum.

Performance evaluation of Mindray CAL 8000(BC-6800 and SC-120) hematology analyzer and slidemaker/stainer

INTRODUCTION

The Mindray CAL 8000 is a cellular analysis line that consists of the BC-6800, an automated hematology analyzer, and the SC-120, an automated slidemaker/stainer. We evaluated the performances of the BC-6800 and the SC-120.

METHODS

Four hundred and eight normal and abnormal samples were analyzed. The performance of the BC-6800 and Sysmex XE-2100 were compared, and blood films by the SC-120 and manual method were compared according to the CLSI guideline H26-A2 and H20-A2.

RESULTS

Most parameters measured by the BC-6800 matched well with the XE-2100 and manual differential. The flag efficiency of the BC-6800 for blasts (95.3%) and atypical lymphocytes (92.6%) were higher while immature granulocytes (89.7%) and NRBCs (94.1%) were lower than that of the XE-2100. Additionally, the BC-6800 detected four of five samples infected with plasmodium parasites. The SC-120 showed no carry-over and expected repeatability. There was good agreement on the five-part differential including abnormal cells between blood films by the SC-120 and manually prepared blood films. The shape of the RBC was also comparable between blood films.

CONCLUSION

The CAL-8000 analysis line is beneficial for precise, fast hematology work, and even more useful in malaria endemic areas.

Guidelines for May-Grünwald-Giemsa staining in haematology and non-gynaecological cytopathology: recommendations of the French Society of Clinical Cytology (SFCC) and of the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP)

OBJECTIVE

Since the guidelines of the International Committee for Standardisation in Haematology (ICSH) in 1984 and those of the European Committee for External Quality Assessment Programmes in Laboratory Medicine (EQALM) in 2004, no leading organisation has published technical recommendations for the preparation of air-dried cytological specimens using May-Grünwald-Giemsa (MGG) staining.

DATA SOURCES

Literature data were retrieved using reference books, baseline-published studies, articles extracted from PubMed/Medline and Google Scholar, and online-available industry datasheets.

RATIONALE

The present review addresses all pre-analytical issues concerning the use of Romanowsky's stains (including MGG) in haematology and non-gynaecological cytopathology. It aims at serving as actualised, best practice recommendations for the proper handling of air-dried cytological specimens. It, therefore, appears complementary to the staining criteria of the non-gynaecological diagnostic cytology handbook edited by the United Kingdom National External Quality Assessment Service (UK-NEQAS) in February 2015.

White blood cell differential counts in severely leukopenic samples: a comparative analysis of different solutions available in modern laboratory hematology

Background

We evaluated the efficacy of white blood cell (WBC) differential counts in severely leukopenic samples by the Hematoflow method and by automated hematology analyzers and compared the results with manual counts.

Methods

EDTA-anticoagulated blood samples (175 samples) with WBC counts of 40-990/µL were selected. Hematoflow differential counts were performed in duplicates employing flow cytometry using the CytoDiff reagent and analysis software. Differential counts were also performed using the DxH 800 (Beckman Coulter) and XE-2100 (Sysmex) automated hematology analyzers. The sum of the manual counts by a hematology technician and a resident were used as the manual counts.

Results

The total analysis time and hands-on time required by the Hematoflow method were shorter than those required by manual counting. Hematoflow counts were reproducible, showed a good correlation with automated analyzers, and also showed strong correlation with manual counts (r > 0.8) in neutrophils, lymphocytes, and monocytes. None of the cases containing less than 4% blasts as analyzed by the Hematoflow method had blasts in the manual counts, but 8 cases of 21 cases (38.1%) with over 4% blasts by Hematoflow had blasts in manual counts.

Conclusion

Hematoflow counts of severely leukopenic samples were reproducible and showed a good correlation with manual counts in terms of neutrophil, lymphocyte, and monocyte counts. The Hematoflow method also detected the presence of blasts. Manual slide review is recommended when over 4% blasts are found by Hematoflow.

Initial performance evaluation of the UniCel® DxH slide maker/stainer Coulter® cellular analysis system

INTRODUCTION

Despite the advancements in instrumentation within hematology laboratories, there is still a need for review of a peripheral blood film (PBF). For a thorough PBF evaluation, it is critical that a well spread and stained film is available.

METHODS

In this study, we evaluated an automatic slide maker/stainer (DxH-SMS, Beckman Coulter) compared with manually prepared blood films on 124 normal and abnormal samples. The primary goal of the study was to determine whether or not the DxH-SMS was able to consistently and reproducibly prepare and stain blood films of exemplary quality, without carryover between specimens. Additionally, repeatability of white blood cell distribution, comparability of morphology to reference methodologies, and grading of acceptance criteria outlined in the CLSI document H20-A2 were assessed.

RESULTS

Carryover was not an issue and repeatability was within expected limits. There was excellent agreement of the 5-part differential between the automated blood films made by the DxH-SMS compared with the manually prepared reference blood film. There was no difference in identification and enumeration of blasts, variant lymphocytes, or nucleated red blood cells (P < 0.05). Red cell morphology showed excellent agreement.

CONCLUSION

Blood films prepared by the DxH-SMS are of excellent quality, reproducible, and compare well with manually prepared slides. Introduction to our laboratory has improved and standardized slide quality.

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA(A) α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.