Evaluation and comparison of automated hematology analyzer, flow cytometry, and digital morphology analyzer for monocyte counting

Myelodysplastic Syndromes in the Postgenomic Era and Future Perspectives for Precision Medicine

Simple Summary

With demographic ageing, improved cancer survivorship and increased diagnostic sensitivity, incident cases of patients with Myelodysplastic Syndromes (MDS) are continuously rising, leading to a relevant impact on health care resources. Disease heterogeneity and various comorbidities are challenges for the management of the generally elderly patients. Therefore, experienced physicians and multidisciplinary teams should be involved in the establishment of the correct diagnosis, risk-assessment and personalized treatment plan. Next-generation sequencing allows for early detection of clonal hematopoiesis and monitoring of clonal evolution, but also poses new challenges for its appropriate use. At present, allogeneic hematopoietic stem cell transplantation remains the only curative treatment option for a minority of fit MDS patients. All others receive palliative treatment and will eventually progress, having an unmet need for novel therapies. Targeting compounds are in prospect for precision medicine, however, abrogation of clonal evolution to acute myeloid leukemia remains actually out of reach.

Abstract

Myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal disorders caused by sequential accumulation of somatic driver mutations in hematopoietic stem and progenitor cells (HSPCs). MDS is characterized by ineffective hematopoiesis with cytopenia, dysplasia, inflammation, and a variable risk of transformation into secondary acute myeloid leukemia. The advent of next-generation sequencing has revolutionized our understanding of the genetic basis of the disease. Nevertheless, the biology of clonal evolution remains poorly understood, and the stochastic genetic drift with sequential accumulation of genetic hits in HSPCs is individual, highly dynamic and hardly predictable. These continuously moving genetic targets pose substantial challenges for the implementation of precision medicine, which aims to maximize efficacy with minimal toxicity of treatments. In the current postgenomic era, allogeneic hematopoietic stem cell transplantation remains the only curative option for younger and fit MDS patients. For all unfit patients, regeneration of HSPCs stays out of reach and all available therapies remain palliative, which will eventually lead to refractoriness and progression. In this review, we summarize the recent advances in our understanding of MDS pathophysiology and its impact on diagnosis, risk-assessment and disease monitoring. Moreover, we present ongoing clinical trials with targeting compounds and highlight future perspectives for precision medicine.

Acute stress increases monocyte levels and modulates receptor expression in healthy females

There has been a growing recognition of the involvement of the immune system in stress-related disorders. Acute stress leads to the activation of neuroendocrine systems, which in turn orchestrate a large-scale redistribution of innate immune cells, such as monocytes. Even though acute stress/monocyte interactions have been well-characterized in mice, this is not the case for humans. As such, this study aimed to investigate whether acute stress modulates blood monocyte levels in a subtype-dependent manner and whether the receptor expression of stress-related receptors is affected in humans. Blood was collected from healthy female volunteers at baseline and 1 h after the socially evaluated cold pressor test, after which blood monocyte levels and receptor expression were assessed by flow cytometry. Our results reveal a stress-induced increase in blood monocyte levels, which was independent of monocyte subtypes. Furthermore, colony stimulating factor 1 receptor (CSF-1R) and CD29 receptor expression was increased, while CD62L showed a trend towards increased expression. These results provide novel insights into how acute stress affects the innate immune system.

Performance evaluation of the new hematology analyzer UniCel DxH 900

INTRODUCTION

UniCel DxH900 (Beckman Coulter, Miami, Florida, USA) is a quantitative, multi-parameter, automated hematology analyzer for in vitro diagnostic use in clinical laboratories. The aim of this study was to evaluate the analytical performance of the new DxH900 analyzer to verify its diagnostic and clinical utility in the hematology laboratory of a tertiary care hospital in Spain. The most important and novel feature offered by DxH900 analyzer is providing MDW (monocyte distribution width), a new hematologic parameter which is being clinically validated as an early sepsis indicator with promising results.

METHODS

We evaluated imprecision (including MDW), linearity, and carryover of DxH900. Method comparison for cell blood count (CBC) was performed in relation to DxH800 with 100 samples. We compared leukocyte differential (DIFF) from DxH900 with manual 400-cell differential. 390 samples were assessed for flag performance.

RESULTS

Results obtained for between days and within-run imprecision were good. DxH900 showed excellent linearity (R = 1.00) over analytical range for white blood cells, red blood cells, hemoglobin, platelets, and reticulocyte count (RET) (R = 0.96) and no significant carryover effect. CBC and RET on the DxH900 correlated well with DxH800 (R ≥ 0.99). Comparison with manual differential showed excellent correlation (R ≥ 0.88), except for basophils. Flagging performance exhibited sensitivity over 90% for majority of alarm messages and very high negative predictive value (over 95%).

CONCLUSION

UniCel DxH900 Coulter analyzer provides reliable results and fully comparable to DxH800. DxH900 is an accurate, highly precise analyzer with good analytical performances to be used effectively in high-volume laboratories.

Platelets Promote Thromboinflammation in SARS-CoV-2 Pneumonia

OBJECTIVE

Pulmonary thrombosis is observed in severe acute respiratory syndrome coronavirus 2 pneumonia. Aim was to investigate whether subpopulations of platelets were programmed to procoagulant and inflammatory activities in coronavirus disease 2019 (COVID-19) patients with pneumonia, without comorbidities predisposing to thromboembolism. Approach and Results: Overall, 37 patients and 28 healthy subjects were studied. Platelet-leukocyte aggregates, platelet-derived microvesicles, the expression of P-selectin, and active fibrinogen receptor on platelets were quantified by flow cytometry. The profile of 45 cytokines, chemokines, and growth factors released by platelets was defined by immunoassay. The contribution of platelets to coagulation factor activity was selectively measured. Numerous platelet-monocyte (mean±SE, 67.9±4.9%, n=17 versus 19.4±3.0%, n=22; P<0.0001) and platelet-granulocyte conjugates (34.2±4.04% versus 8.6±0.7%; P<0.0001) were detected in patients. Resting patient platelets had similar levels of P-selectin (10.9±2.6%, n=12) to collagen-activated control platelets (8.7±1.5%), which was not further increased by collagen activation on patient platelets (12.4±2.5%, P=nonsignificant). The agonist-stimulated expression of the active fibrinogen receptor was reduced by 60% in patients (P<0.0001 versus controls). Cytokines (IL [interleukin]-1α, IL-1β, IL-1RA, IL-4, IL-10, IL-13, IL, 17, IL-27, IFN [interferon]-α, and IFN-γ), chemokines (MCP-1/CCL2 [monocyte chemoattractant protein 1]), and growth factors (VEGF [vascular endothelial growth factor]-A/D) were released in significantly larger amounts upon stimulation of COVID-19 platelets. Platelets contributed to increased fibrinogen, VWF (von Willebrand factor), and factor XII in COVID-19 patients. Patients (28.5±0.7 s, n=32), unlike controls (31.6±0.5 s, n=28; P<0.001), showed accelerated factor XII-dependent coagulation.

CONCLUSIONS

Platelets in COVID-19 pneumonia are primed to spread proinflammatory and procoagulant activities in systemic circulation.

On detection thresholds-a review on diagnostic approaches in the infectious disease laboratory and the interpretation of their results

Diagnostic testing in the infectious disease laboratory facilitates decision-making by physicians at the bedside as well as epidemiological assessments and surveillance at study level. Problems may arise if test results are uncritically considered as being the same as the unknown true value. To allow a better understanding, the influence of external factors on the interpretation of test results is introduced with the example of prevalence, followed by the presentation of strengths and weaknesses of important techniques in the infectious disease laboratory like microscopy, cultural diagnostics, serology, mass spectrometry, nucleic acid amplification and hypothesis-free metagenomic sequencing with focus on basic, high-technology and potential future approaches. Special problems like multiplex testing as well as uncertainty of test evaluations, if no gold standard is available, are also stressed with a final glimpse on emerging future technologies for the infectious disease laboratory. In the conclusions, suitability for point-of-care-testing and field laboratory applications is summarized. The aim is to illustrate the limitations of diagnostic accuracy to both clinicians and study planners and to stress the importance of close cooperation with experts in laboratory disciplines so as to avoid potentially critical misunderstandings due to inappropriate interpretation of diagnostic test results.

Preliminary evaluation of a new flow cytometry method for the routine hematology workflow

Background In a generalist laboratory, the integration of the data obtained from hematology analyzers (HAs) with those from multiparametric flow cytometry (FMC) could increase the specificity and sensitivity of first level screening to identify the pathological samples. The aim of this study was to perform a preliminary evaluation of a new simple hybrid method (HM). The method was obtained by integration between HAs reagents into FCM, with a basic monoclonal antibodies panel for the leukocytes differential count. Methods Eighty-one peripheral blood samples, collected in K3EDTA tubes, were analyzed by XN-module, and CyFlow Space System, using both standard MoAbs and HM method analysis, and with the optical microscopy (OM). Within-run imprecision was carried out using normal samples, the carryover was evaluated, data comparison was performed with Passing-Bablok regression and Bland-Altman plots. Results The within-run imprecision of HM methods ranged between 1.4% for neutrophils (NE) and 10.1% for monocytes (MO) always equal or lower to the OM. The comparison between HM methods vs. OM shows Passing-Bablok regression slopes comprised between 0.83 for lymphocyte (LY) and 1.14 for MO, whilst the intercepts ranged between -0.18 for NE and 0.25 for LY. Bland-Altman relative bias was comprised between -12.43% for NE, and 19.77% for eosinophils. In all 11 pathological samples the agreement between the methods was 100%. Conclusions The new hybrid method generates a leukocytes differential count suitable for routine clinical use and it is also useful for identifying morphological abnormalities with a reduction in cost and improvement of screening for first level hematology workflow.