Digital morphology compared to the optical microscope: A validation study on reporting bone marrow aspirates

INTRODUCTION

This study aims to evaluate the effectiveness and reliability of the utilization for clinical reporting of the evaluation of digital images of bone marrow aspirates by morphologists and their comparability with the classic microscopic morphological evaluation.

METHODS

We scanned 180 consecutive bone marrow needle aspirates smears using the "Metafer4 VSlide" whole slide imaging (WSI) digital scanning system. We evaluated the statistical comparability and the risk of bias of the microscopic readings with those performed on the screen on the digitized medullary images.

RESULTS

The evaluation of cellularity on the screen was equivalent, with a higher frequency of "normal" than the analysis of digital preparations. The means and medians of the percentage values obtained on the different cell populations with the microscopic and digital reading were comparable as the main categories are concerned, with an average difference equal to 0 for the neutrophilic and eosinophilic granulocytic series, at -0.2% for the total myeloid cells, at 1.2% for the erythroid series, at -0.4% for the lymphocytes and at -0.4% for the blasts. Dysplastic features were consistently identified in 69/71 cell lineages.

CONCLUSION

Our study demonstrated that screen evaluation of digitized bone marrow needle aspirates provides quantitative and qualitative results comparable to traditional microscopic analysis of the corresponding slide smears. Digital images offer significant benefits in reducing the workload of experienced operators, reproducibility and sharing of observations, and image preservation. Even in routine diagnostic activities, their use does not alter the quality of the results obtained in evaluating bone marrow needle aspirates.

Agreement between one stage and chromogenic assays in samples from patients receiving recombinant porcine FVIII (Obizur, Susoctocog-alfa)

INTRODUCTION

Recombinant porcine FVIII (rpFVIII) (Obizur, Susoctcog-alfa, Takeda, Japan) is licensed for the treatment of bleeding in acquired Haemophilia A (AHA). The summary of product characteristics state that monitoring should be by one stage assay (OSA) rather than chromogenic assay (CSA). CSA have been shown to underestimate activity when rpFVIII is added to plasma in vitro.

METHODS

Samples from three AHA patients (n = 21) (pre- and post rpFVIII) were assessed using FVIII:C assays; OSA methods: Actin, Actin FS, Actin FSL and Pathromtin SL performed on CS5100i (Sysmex, Kobe, Japan); APTT-SP, SynthASil and SynthAFax performed on ACL TOP (Werfen, Barcelona, Spain). CSA methods on CS5100i: Siemens Chromogenic Assay, Biophen FVIII:C, Technochrom FVIII:C; on ACL TOP: Rox Factor VIII, Coamatic Factor VIII and CRYOcheck Factor VIII.

RESULTS

OSA and CSA varied according to reagent used median OSA 61 IU/dL (range 41.5-81 IU/dL (ANOVA p < 0.0001)) median CSA 46.5 IU/dL (range of method specific medians 36.5-84 IU/dL (ANOVA p < 0.0001)). Amongst OSA, Actin FS was associated with the highest FVIII:C, APTT-SP was associated with the lowest. Variation in CSA results by different methods was also seen with highest FVIII:C levels obtained using the Technochrom FVIII:C and the lowest levels obtained with Siemens Assay.

CONCLUSION

The relationship between OSA and CSA was not consistent between method or patient. Previously there has been reports of underestimation by CSA in in vitro spiked samples. Investigation into concentration of phospholipids in the APTT reagents may explain some of these variations.

Laboratory practice is central to earlier myeloma diagnosis: Utilizing a primary care diagnostic tool and laboratory guidelines integrated into haematology services

Treatment advances have greatly improved survival, but myeloma is among the worst of all cancers for delayed diagnosis, causing serious morbidities and early deaths. This delay is largely because the symptom profile of myeloma has very low specificity, and in primary care, myeloma is rare. However, initiating the journey to diagnosis simply requires considering myeloma and sending blood to test for monoclonal immunoglobulin. Laboratory tests reliably detect monoclonal immunoglobulin, which is present in 99% of myeloma cases, so why do health care systems have such a problem with delayed diagnosis? The Myeloma UK early diagnosis programme has brought together diverse expertise to investigate this problem, and this article was prepared by the programme's working group for laboratory best practice. It reviews evidence for test requesting, analysis and reporting, for which there is large variation in practice across the United Kingdom. It presents a 'GP Myeloma diagnostic tool' and how it can be integrated into laboratory practice alongside a laboratory best practice tool. It proposes improved requesting and integration with haematology services for reporting and interpretation. Here the laboratory has a central role in creating efficient and cost-effective pathways for appropriate and timely bone marrow examination for myeloma diagnosis.

Viscoelastic testing: Critical appraisal of new methodologies and current literature

United States Food and Drug Administration (FDA)-approved viscoelastic testing (VET) methodologies have significantly changed in the last 10 years, with the availability of cartridge-based VET. Some of these cartridge-based methodologies use harmonic resonance-based clot detection. While VET has always allowed for the evaluation of real-time clot formation, cartridge-based VET provides increased ease of use as well as greater portability and robustness of results in out-of-laboratory environments. Here we review the use of VET in a variety of clinical contexts, including cardiac surgery, trauma, liver transplant, obstetrics, and hypercoagulable states such as COVID-19. As of now, high quality randomized trial evidence for new generation VET (TEG 6s, HemoSonics Quantra, ROTEM sigma) is limited. Nevertheless, the use of VET-guided transfusion algorithms appears to result in reduced blood usage without worsening of patient outcomes. Future work comparing the new generation VET instruments and continuing to validate clinically important cut-offs will help move the field of point-of-care coagulation monitoring forward and increase the quality of transfusion management in bleeding patients.

Differential diagnosis of lymphocytosis in routine laboratory practice: Contribution of lymphocyte parameters using the Sysmex-XN9000 haematology analyzer

INTRODUCTION

This study investigates the potential contribution of structural and dispersion parameters, as well as alarms provided by Sysmex XN9000 haematology analyzer. The objective was to assess the need for a microscopic examination in the context of lymphocytosis. It also aims to contribute in differentiating rapidly lymphoproliferative disorders such as chronic lymphocytic leukaemia (CLL), non-chronic lymphocytic leukaemia (NON-CLL) and non-infectious reactive lymphocytosis (REAC).

METHODS

We prospectively assessed lymphocyte parameters (Ly-X, Ly-Y, Ly-Z, Ly-WX, Ly-WY, Ly-WZ) provided by the Sysmex XN9000 analyzer; they were measured in the white blood cell differential (WDF) channel which also provides alarms via the precursor/pathological cellular channel (WPC). Blood samples from 71 subjects with CLL, NON-CLL lymphoproliferative and REAC non-infectious reactive lymphocytosis, as well as a control (NORM) group of 12 subjects without any abnormalities were analyzed.

RESULTS

The most discriminating parameters to distinguish the different groups were Ly-X, Ly-Z and Ly-WZ. The lymphoid structural parameters Ly-X and Ly-Z significantly discriminated the CLL group from the other groups (p < 0.001), and the CLL group from the REAC group (p < 0.01), respectively. The Ly-WZ parameter discriminated the CLL group from the NON-CLL, REAC (p < 0.001) and NORM (p < 0.01) groups. Alarms were higher in all study groups compared to the NORM group. An algorithm integrating these structural and alarm parameters is proposed.

CONCLUSION

This study demonstrated that Ly-X, Ly-Z, and Ly-WZ lymphocyte parameters are useful for detecting morphological changes in lymphocytes; they provide useful information for the differential diagnosis of lymphocytosis, and this before the examination of the blood smear. An algorithm combining the WDF (parameters) and the WPC (alarms) makes it possible to decide whether or not to use a microscopic examination or flow cytometry immunophenotyping.

How to assess parallelism in factor assays: coefficient of variation of results with different dilutions or slope ratio?

INTRODUCTION

Non-parallelism in factor assays can lead to incorrect factor activities. Parallelism can be assessed by calculating the coefficient of variation (CV) of results obtained on 3 dilutions of the same sample. Some authors have proposed that if there is <15% then the average activity is reportable. Some analysers use a slope ratio (SR) to calculate parallelism, with an acceptance range of approximately 0.9-1.1.

METHODS

We evaluated CV and SR in one stage FII-FXII assays on Sysmex CS5100i using Innovin or Actin FS. Frozen normal and pathological plasmas, plasmas containing Direct Oral Anticoagulants, Direct Thrombin Inhibitors or Lupus Anticoagulant were analysed to assess possible non-parallelism.

RESULTS

In plasmas with factor levels >25 IU/dl (plus no interfering substances) all CVs were < 15%. One sample (low factor activities 10-15 IU/dl), had CVs > 15% in FII, FVII and FXII assays only. SR outside of 0.9-1.1 were seen in FII and FXII assays at different levels of clotting factor including some within the normal range. Non-parallelism was detected more frequently with SR than CV for those with interfering substances.

CONCLUSIONS

SR outside of 0.9-1.1 were seen in different levels of clotting factors, including samples which did not contain interfering substances. The target of 15% CV was a better discriminator than a SR for acceptance. When factor levels were reduced to around 10-15 IU/dl, a target 20 %CV was more appropriate than 15%. It might be appropriate for laboratories to assess locally whether their acceptance criteria need to be wider at low levels of clotting factors.

Cytological Diagnosis of Classic Myeloproliferative Neoplasms at the Age of Molecular Biology

Myeloproliferative neoplasms (MPN) are clonal hematopoietic stem cell-derived disorders characterized by uncontrolled proliferation of differentiated myeloid cells. Two main groups of MPN, BCR::ABL1-positive (Chronic Myeloid Leukemia) and BCR::ABL1-negative (Polycythemia Vera, Essential Thrombocytosis, Primary Myelofibrosis) are distinguished. For many years, cytomorphologic and histologic features were the only proof of MPN and attempted to distinguish the different entities of the subgroup BCR::ABL1-negative MPN. World Health Organization (WHO) classification of myeloid neoplasms evolves over the years and increasingly considers molecular abnormalities to prove the clonal hematopoiesis. In addition to morphological clues, the detection of JAK2, MPL and CALR mutations are considered driver events belonging to the major diagnostic criteria of BCR::ABL1-negative MPN. This highlights the preponderant place of molecular features in the MPN diagnosis. Moreover, the advent of next-generation sequencing (NGS) allowed the identification of additional somatic mutations involved in clonal hematopoiesis and playing a role in the prognosis of MPN. Nowadays, careful cytomorphology and molecular biology are inseparable and complementary to provide a specific diagnosis and to permit the best follow-up of these diseases.

Evaluation of the WBC-differential flagging performances and accuracy of the HORIBA Yumizen H2500 cell counter in oncology patients from a single institution

INTRODUCTION

The Yumizen H2500 (YH2500) cell analyser was compared to the Pentra DX Nexus (both from HORIBA Medical) to evaluate the efficiency of the new YH2500 technology for the WBC-differential in samples from oncology patients with WBC-diff abnormalities.

MATERIAL AND METHODS

The 220 samples with slide review criteria on the Nexus were systematically analysed on the YH2500. The WBC-diff was compared to flow cytometry (FCM). The 100 additional samples with Monocyte/Neutrophil separation flags were evaluated. The flagging performance and the accuracy of the WBC-diff were analysed.

RESULTS

The YH2500 generated fewer flags than the Nexus (47.73% vs 66.64%; p < .0001), except for Monocyte/Neutrophil flag (15.5% vs. 2.7%; p < 0.0001). Overall performances were higher on the YH2500 (Sensitivity, 100 vs. 89.6%; Specificity 81.0% vs. 50.9%; PPV, 74.3% vs. 62.9%; NPV, 100% vs. 69.5%; Efficiency, 87.7% vs. 69.5%). YH2500 showed a statistically significant better correlation with FCM for the 6-part differential than the Nexus. On 134 samples with Monocyte/Neutrophil separation flag, it was shown that, in samples with less than 10% monocytes on the YH2500, the results of monocyte and neutrophil counts were comparable to the manual count, and that these samples did not need a slide review if no other main criterion for review was present.

CONCLUSION

The YH2500 demonstrated better performance characteristics than the previous cell counter, the Nexus. Its implementation in our laboratory routine work significantly improved the practice workflow, decreased the number of manual cell counts and increased the pertinence of slide review and reporting of the microscopic count.

Practical application of mathematical calculations and statistical methods for the routine haematology laboratory

BACKGROUND

Statistical analyses are embedded as critical functions in the routine haematology laboratory.

AIM

This educational article is aimed at providing an overview of these topics and practical application examples.

MATERIALS, METHODS, AND RESULTS

Topics covered include mathematical conversion between units, maintaining a quality control (QC) system, statistical methods for reagent validation, and determining uncertainty of measurement (UoM).

DISCUSSION

Additional considerations may be required when a regional laboratory program is in place, such as the harmonization of INR results and determination of therapeutic reference intervals for unfractionated heparin therapy.

CONCLUSION

The coauthors of this manuscript are fortunate to be part of regional network of hospital laboratories, the Eastern Ontario Regional Laboratory Association (EORLA).

Laboratory and clinical teaching experience of nursing professors in the COVID-19 pandemic era: Now and the future

Nursing professors must constantly interact with students, maintain a high level of professional performance, and meet targets and deadlines, even during a pandemic. Considering the changing educational environment, it is essential to identify contemporary limitations and problems to provide feedback for improvement. This study aimed to explore the laboratory and clinical teaching experiences of nursing professors during the COVID-19 pandemic. Focus group interviews were conducted with professors from the nursing departments of universities in Korea. In total, 19 professors who had laboratory and clinical experience participated in this study. The collected data were analyzed using thematic analysis. The analysis identified four themes. The themes included feeling helpless in the infection management system, uncertainty about the effectiveness of alternative practice training, acceptance of changes, and preparation for future practice training. As the necessity and possibility of non-face-to-face education have been confirmed by the pandemic, it is expected that classes using technology will be actively developed in nursing practice education. The roles and attitudes of teachers and educational institutions also need to change. Nursing professors should reflect upon and evaluate challenges to prepare for post-pandemic practical education.

[The strategic management of laboratory diagnostic service: analysis of organization models]

The modern trends in health care (strategies of optimizing costs, value-oriented medical care) require systematic development of laboratory services for administrative territories. The study was carried out to provide support for decision-making by systematizing models of laboratory services on the basis of principles of systematic approach. Four basic models (centralization, outsourcing, horizontal integration, point-of-care) were analyzed. The study applied such research methods as analytical and strategic SWOT-analysis. The SWOT-analysis was implemented using list of standard characteristics for each model of laboratory service organization. Each model is distinguished by complex combination of strengths, weaknesses, lines of functioning and development. The availability of implementing particular model depends on delicate balance of opportunities and risks against the background of local characteristics of administrative subject. The dynamics of the social economic and infrastructural development of administrative subject can significantly affect effectiveness of model implementation. The objective set of characteristics was obtained for each model of laboratory service organization. Actually it is impossible to select particular model for specific administrative subject. Hence, scientific substantiation of "flexible" model is needed to implement.

Open Online Courses for Strengthening Laboratory-Based Detection of Antimicrobial Resistance in Pakistan

Introduction

Quality-assured antimicrobial susceptibility testing (AST) depends upon the knowledge and skills of laboratory staff. In many low- and middle-income countries (LMICs), including Pakistan, such types of knowledge and skills are limited. Therefore, the objective of this study was to use openaccess online courses to improve the knowledge of laboratory staff involved in the detection and reporting of antimicrobial resistance (AMR).

Methodology

Seven online modules comprising 22 courses aimed at strengthening the laboratory detection of Antimicrobial resistance (AMR) were developed. The courses were uploaded onto the website www.parn.org.pk. Participants had an option of selecting courses of their interest. Online registration and completion of a pre-course assessment (pre-test) were essential for enrolment. However, participation in post-course assessment (post-test) was optional. The number of registered participants and the proportion of participants who completed each course were computed. A paired t-test was used to assess the increase between mean pre- and post-test scores. The association between the participants working in public vs. private laboratories and course completion rates were determined using the chi-square test.

Results

A total of 227 participants from Pakistan (March 2018 to June 2020) were registered. The largest number of registered participants and the highest completion rate were noted for AST and biosafety courses, while quality-related courses attracted a lower interest. A comparison of pre- and post-test performance using the paired mean score for the individual courses showed a statistically significant (the value of p < 0.05) improvement in 13/20 assessed courses. A higher course completion rate was observed in participants from public vs. private sector laboratories (56.8 vs. 30.8%, the value of p = 0.005).

Conclusions

Our study suggests a promising potential for open online courses (OOCs) toward addressing knowledge gaps in laboratory practice in resource limited settings.

Different Strategies for the Identification of SARS-CoV-2 Variants in the Laboratory Practice

A considerable effort has been devoted in all countries to react to the COVID-19 pandemic by tracing infected individuals, containing the spread of the disease, identifying therapies, and producing and distributing vaccines. Currently, a significant concern is the appearance of variants of the virus that may frustrate these efforts by showing increased transmissibility, increased disease severity, reduced response to therapy or vaccines, and ability to escape diagnosis. All countries have therefore devoted a massive attempt to the identification and tracking of these variants, which requires a vast technological effort to sequence a large number of viral genomes. In this paper, we report our experience as one of the Italian laboratories involved in SARS-CoV-2 variant tracing. We summarize the different approaches used, and outline a potential model combining several techniques to increase tracing ability while at the same time minimizing costs.

Laboratory approach to investigation of anemia in pregnancy

Anemia is a global health problem in all age groups. According to World Health Organization (WHO), approximately 40% of pregnant women are anemic. Iron deficiency anemia (IDA) due to nutritional deficiency is the most common cause. The incidence of IDA varies worldwide depending on the socioeconomic status, but it remains the leading cause even in developed countries. Physiologic anemia of pregnancy due to relatively higher expansion of blood volume in comparison with elevated red blood cell mass also occurs frequently. Complete blood count (CBC) in the first trimester is recommended for all pregnant women to screen for anemia. The screening of pregnant women for IDA in absence of anemia is still debatable. If IDA is suspected, ferritin level of <30 ng/ml is diagnostic. Iron supplementation is recommended for all pregnant women to compensate the increased demand.

Review of coagulation preanalytical variables with update on the effect of direct oral anticoagulants

There are many preanalytical variables (PAV) that are known to affect coagulation testing. The more commonly acknowledged PAV addressed by the clinical laboratory tend to start with their influence on blood collection, but realistically coagulation PAV starts with the patient, where the laboratory has less influence or control. Patient selection and appropriate timing for blood collection may be integral for assuring proper diagnosis and management. Laboratory control and assurance for ideal phlebotomy practice would mitigate most PAVs related to blood collection to minimize suboptimal sample collection. Laboratory oversight of sample transportation, processing and storage will assure sample integrity until testing can be facilitated. The purpose of this document is to review common PAV that should be taken into consideration when ordering, performing and interpreting a coagulation test result, with additional attention to the effect of direct oral anticoagulants (DOACs).

Diagnosing heparin-induced thrombocytopenia: The need for accuracy and speed

Heparin-induced thrombocytopenia (HIT) is a prothrombotic condition resulting from pathogenic antibodies to complexes of heparin and platelet factor 4 (PF4). The diagnosis of HIT can be challenging due to the widespread use of heparin and the frequency of thrombocytopenia in hospitalized patients. Laboratory testing for HIT typically includes an immunoassay to detect antibodies to PF4-heparin and a functional assay. Current HIT diagnostic algorithms recommend using the 4Ts score to determine the need for HIT laboratory testing. Automated calculation of HIT clinical prediction scores in the electronic health record may improve the identification of patients who should undergo HIT testing. Another challenge in the management of patients with suspected HIT is the turnaround time of the laboratory testing needed to confirm the diagnosis. Due to the high daily thrombotic risk of HIT, clinicians must treat patients with intermediate to high pretest likelihood of HIT empirically while awaiting the test results. Treatment for HIT often involves alternative anticoagulants that lack reversal agents, which may increase bleeding risk, prolong hospital stays, and increase costs for patients suspected of having HIT. Rapid immunoassays hold promise to improve the speed of HIT diagnosis. These assays must retain a very high sensitivity for this "can't miss" diagnosis, yet have sufficient specificity to be of diagnostic value. A Bayesian approach has been proposed using two rapid immunoassays in succession, which decreased analytic turnaround time to 60 minutes. Such an approach has the potential to be a much-needed clinical advance in improving accuracy and speed in the diagnosis of HIT.

Thrombin generation in children using ThromboScreen reagent kit with ST Genesia-A pilot study

INTRODUCTION

Thrombin generation assays assess overall coagulation system and are widely used in research; however, they still need standardization and clinical validation. The new ST Genesia is a benchtop, automated analyzer that normalizes each thrombin generation parameter using a reference plasma. The ThromboScreen reagent kit has two triggers, one of which contains thrombomodulin to assess the effect of the protein C pathway. This study aimed to make a pilot approach to the ThromboScreen reference range in children and evaluate the impact of sex, age, and pro- and anticoagulant plasma proteins on thrombin generation parameters.

METHODS

This study included 55 healthy children from the following age groups: 1-6 years (n = 14), 7-11 years (n = 15), and 12-17 years (n = 26). Children younger than 1 year were excluded from the study. We measured thrombin generation using ThromboScreen, coagulation routine and test, pro- and anticoagulant proteins.

RESULTS

Age did not influence ThromboScreen results. Males showed significantly lower endogenous thrombin potential and peak height values than females. The strongest determinants of endogenous thrombin potential were von Willebrand factor parameters, whereas for endogenous thrombin potential inhibition, the strongest determinants were protein C and protein S. No statistically significant differences were found between groups on temporal parameters.

CONCLUSIONS

For the ThromboScreen reagent kit, it may not be necessary to subdivide reference ranges according to age for children (>1 year).

Plasma levels do not predict thrombin generation in patients taking direct oral anticoagulants

BACKGROUND

The antithrombotic effect of direct oral anticoagulants (DOAC) in specific clinical scenarios is difficult to assess.

OBJECTIVE

This study aimed to evaluate the effect of DOAC on thrombin generation (TG) in relation to their plasma level.

METHODS

Eighty patients newly started on anticoagulation were included, 20 patients for each DOAC-apixaban, edoxaban, rivaroxaban, and dabigatran. Plasma was sampled before DOAC (baseline), at plasma peak time, 6 and 12 hours after starting DOAC for quantification of drug levels and TG.

RESULTS

The baseline TG before DOAC intake showed inter-individual variability. All DOACs significantly prolonged lag time (LT) and time to peak (TTP), but did not change endogenous thrombin potential (ETP). Anti-Xa inhibitors but not dabigatran reduced thrombin peak, but the effect of apixaban at plasma peak was less pronounced (factor 1.6). LT and TTP prolongation of dabigatran was lower compared to anti-Xa inhibitors. All DOACs showed a nonlinear dose-response relationship, with the greatest antithrombotic effect at lower DOAC plasma levels. The inhibition of TG parameters between baseline and peak was parallel between individual patients but the coefficient of variation of TG was lower compared to drug levels.

CONCLUSION

The antithrombotic effect at DOAC peak plasma level measured by TG depends on the patient-specific baseline TG level and the drug-specific inhibition by the particular DOAC. Although peak plasma levels have a high variability, the variation of TG is lower compared to drug levels. Therefore, TG assays may be superior to plasma levels in the assessment of the intensity of anticoagulation.

Laboratory practices for manual blood film review: Results of an IQMH patterns of practice survey

INTRODUCTION

Examination of a blood film is the second most common hematology test, after the complete blood count. Interpretation of a peripheral blood film by trained laboratory professionals provides valuable diagnostic information. The Institute for Quality Management in Healthcare (IQMH) Hematology Scientific Committee developed a questionnaire to gather information regarding current practices for manual blood film review and reporting from laboratories participating in IQMH Morphology proficiency testing (PT) surveys.

METHODS

An online survey was distributed to 174 laboratories, 97% submitted results.

RESULTS

Of the respondents, the majority (82%) indicated affiliation with small- or medium-sized hospitals (<500 beds). 80% of respondents had core laboratory technologists performing manual blood film reviews, while only 2% utilized dedicated hematology technologists with morphology expertise. All respondents had a policy for manual blood film review by a technologist, 70% did not have blood films reviewed by a senior/charge technologist prior to review by a physician. The majority (88%) of participants included morphological findings in their critical result list; of these, 98% include malaria and 88% include the first-time finding of blasts as critical results. 59% of participants indicated that they have a procedure in place to ensure that interpretation and confirmation of first-time potentially significant morphological findings are available from a physician at all times.

CONCLUSION

This survey identified significant variation in blood film review and reporting practices across participating laboratories. The IQMH Hematology Scientific Committee will develop best practice recommendations to guide and standardize practice.

Use of Sysmex XN-10 red blood cell parameters for screening of hereditary red blood cell diseases and iron deficiency anaemia

Introduction

In daily practice in haematology laboratories, red blood cell (RBC) abnormalities are frequent and their management is a real challenge. The aim of this study is to establish a “decision tree” using RBC and reticulocyte parameters from the SYSMEX XN‐10 analyser to distinguish between patients with a hereditary RBC disease from iron deficiency anaemia and other patients.

Methods

We analysed results of complete RBC counts in a cohort composed of 8217 adults divided into 5 different groups: iron deficiency anaemia (n = 120), heterozygous haemoglobinopathy (n = 92), sickle cell disease syndrome (n = 56), hereditary spherocytosis (n = 18) and other patients (n = 7931). A Classification And Regression Tree (CART) analysis was used to obtain a two‐step decision tree in order to predict these previous groups.

Results

Five parameters and the calculated RBC score were selected by the CART method: mean corpuscular haemoglobin concentration, percentage of microcytes, distribution width of the RBC histogram, percentage of nucleated red blood cells, immature reticulocytes fraction and finally RBC Score. When applying the tree and recommended flowchart, 158/166 of the RBC hereditary disease patients and 114/120 iron deficiency anaemia patients are detected. Overall, the correct classification rate reached 99.4%. Sensitivity and specificity for RBC disease detection were 95.2% and 99.9%, respectively. These results were confirmed in an independent validation cohort.

Conclusion

Based on the XN‐10 RBC and reticulocyte parameters, we propose a two‐step decision tree delivering a good prediction and classification of hereditary RBC diseases. These results can be used to optimize additional reticulocyte analysis and microscopy review.

A practical method for reducing the interference due to lipaemia in coagulation tests

Introduction

Plasma samples with gross lipaemia present a challenge for coagulation laboratories using optical analysers. High‐speed centrifugation may be used to remove excess lipids but it has not established whether this affects haemostasis tests. The aims were to determine whether the removal of lipid by centrifugation affects PT, APTT, fibrinogen, D‐dimer and von Willebrand factor activity measurements.

Methods

Twenty‐six lipaemic samples (median [range]): triglyceride 4.6 mmol/L [0.5‐17.0]; cholesterol: 4.06 mmol/L [2.20‐9.41] and 20 plasmas spiked with Intralipid 20 or lipid isolated from patient plasmas (median triglyceride of 11.95 mmol/L [5.0‐17.0] and cholesterol 4.33 [3.22‐7.06]), were tested before and after the removal of the lipid layer by centrifugation (10000 g for 10 minutes). Tests were performed using the CS‐5100 (Sysmex) coagulation analyser.

Results

Thirteen, 9, 3 and 1 of the lipaemic or spiked samples failed to give PT, APTT, fibrinogen and D‐dimer results, respectively. Centrifugation significantly reduced triglyceride (median 2.7, [0‐6.1 mmol/L]) and cholesterol (median 0.52 [0‐3.5]), allowing clot detection in all tests. There were no statistically significant differences in fibrinogen, D‐dimer or VWF levels in samples before and after lipid removal. A small but clinically insignificant change in PT and APTT was observed after lipid removal.

Conclusion

High‐speed centrifugation reduces lipaemia sufficiently to allow testing on an optical coagulation analyser without introducing clinically significant differences PT, APTT, fibrinogen, D‐dimer or VWF activity values.

Update on diagnostic testing for platelet function disorders: What is practical and useful?

INTRODUCTION

Platelet function disorders (PFD) are an important group of bleeding disorders that require validated and practical laboratory strategies for diagnosis.

METHODS

This review summarizes the authors' experiences, current literature, and an international survey to evaluate the practices of diagnostic laboratories that offer tests for PFD.

RESULTS

Blood counts, blood film review, and aggregation tests are the most commonly performed investigations for PFD and help determine whether there is thrombocytopenia and/or defective platelet function due to a variety of causes. The performance characteristics of tests for PFD, and the level of evidence that these tests detect bleeding problems, are important issues to determine where tests are useful for diagnostic or correlative purposes, or research only uses. Platelet aggregation assays, and quantitative analysis of platelet dense granule numbers, are tests with good performance characteristics that detect abnormalities associated with increased bleeding in a significant proportion of individuals referred for PFD investigations. Lumiaggregometry estimates of platelet adenosine triphosphate release show greater variability which limits the diagnostic usefulness. Diagnostic laboratories report that fiscal and other constraints, including a lack of high-quality evidence, limit their ability to offer an expanded test menu for PFD.

CONCLUSION

PFD are clinically important bleeding disorders that remain challenging for diagnostic laboratories to investigate. While some PFD tests are well validated for diagnostic purposes, gaps in scientific evidence and resource limitations influence diagnostic laboratory decisions on which PFD tests to offer.

An update on laboratory assessment for direct oral anticoagulants (DOACs)

The first direct oral anticoagulant (DOAC) to be approved for clinical use was dabigatran, a direct thrombin inhibitor, in 2010. Since that time, four additional DOACs, all direct anti-Xa inhibitors, have been approved, including rivaroxaban, apixaban, edoxaban and betrixaban. Our knowledge about the effect of DOACs on laboratory testing, as well as the use of the laboratory for measuring DOACs has been an evolving process. These drugs are not routinely monitored in the same fashion as coumadin, but there is an increasing demand on the laboratory to have the capacity to adequately assess DOAC anticoagulant effect (pharmacodynamics) or levels (pharmacokinetics) in either emergent or the routine situations. This manuscript provides an update on laboratory guidance and progress of methods for measuring DOACs.

Quality management and accreditation in laboratory hematology: Perspectives from India

Quality management (QM), including quality assurance and quality control, was developed in clinical laboratories in North America and Western Europe, but must be implemented worldwide to ensure accurate, reproducible, and clinically useful results. India, a middle income country with a population of over 1.34 billion, has limited budget allotted to health care. As yet accreditation for clinical laboratories is not mandatory, which contributes to challenges in implementing good laboratory practice. This review provides a summary of internationally laid down QM principles and their application in a middle income country like India.

Validation of immunohistochemical tests performed on cytology cell block material: Practical application of the College of American Pathologists' guidelines

The advent of fiberoptic endoscopy with biopsy has revolutionized procurement of specimens from deep sites. This has translated into more cytologic specimens whereby the material is limited and best handled by cytology laboratory staff. While the diagnosis of the pathologic process is of utmost importance, there is increasing expectation that the diagnosis be specific and accurate as not to require additional biopsy for initiation of treatment. This expectation has driven demand in immunohistochemical (IHC) and molecular studies conducted specifically on material processed as cytology specimens. The Clinical Laboratory Improvement Amendments of 1988 requires laboratories in the United States of America to verify the performance of patient tests. Due to varying laboratory practices with respect to validation of IHC assays, the College of American Pathologists introduced guidelines for analytic validation of IHC tests. These guidelines address how to perform validation by recommending the number of cases in the validation set, comparator concordance, and when to revalidate. The main thrust of the guidelines is based on formalin-fixed paraffin-embedded tissue with only one expert consensus opinion referring to validation of IHC tests on cytology specimens which delegates to the medical director, the determination of number of positive and negative cases to be tested. This article will outline how an academic center approaches validation of IHC studies performed on cytology cell block specimens using the College of American Pathologists guidelines. A stepwise approach from selection of antibodies to validate followed by building the validation panel and evaluating the stain results for concordance against the gold standard of histology tissue specimen will be described. A rationale for dealing with discordant results and future innovations will conclude the report.

Results of a cross Canada survey of blood film review practice patterns by technologists and pathologists

INTRODUCTION

No common or widely accepted criteria exist for physician review of blood films or for reported standards of physician rate of blood film review. Individual institutions generally have internal criteria for physician review of blood films. To better understand how and why blood film reviews are performed at different institutions across Canada, with a specific interest in physician blood film review, we undertook a survey to assess the current practise patterns of physician review of blood films across Canada.

METHODS

A 15 question survey was developed and sent to 24 academic, large community and corporate laboratories across Canada by e-mail to laboratory directors of those institutions. Centres were chosen to include all provinces in Canada and most of the major academic centres. Twenty of the 24 centres responded.

RESULTS

The mean rate of physician review of blood films as a percentage of all CBCs processed per day was 4.1% (range 0.35%-13%) and of all blood films made per day was 28.8% (range 1.9%-66.5%). Data on factors which might affect physician review rates, physician preferences regarding what percentage of physician blood film review rates is reasonable and physician perspectives on the role of physician blood film review are discussed.

CONCLUSION

This survey reveals that there is varying practise patterns and opinions with respect to blood film review by physicians in Canada.

Testing anti-neutrophil cytoplasmic antibodies (ANCA): analysis of the European EASI survey on the daily practice of the French laboratories

Anti-neutrophil cytoplasmic antibodies (ANCA) are mainly searched for the diagnosis of autoimmune vasculitis. They may be found also in other conditions with chronic inflammation. Testing ANCA is based on two main technics: indirect immunofluorescence (IFI) and immunochemical technics to identify the antigenic specificity of the autoantibodies. There is heterogeneity among the laboratories' daily practice. An international group called EASI (European autoimmunity standardisation initiative), composed of 15 countries, comprising France, works to harmonize the practices of the biological diagnosis of the autoimmune diseases. It elaborated a survey consisting of 54 questions related to the analytic parameters of the technics, the algorithms for their use and their biological interpretation; and submitted it to European laboratories. We propose an analysis of the answers obtained from 36 French laboratories specialized in autoimmunity. We compare them to the ones obtained from the other countries and discussed them according to the international recommendations. The analysis reveals a predominant use of IFI as a first step with variable strategies for the identification of the antigenic specificity of the autoantibodies. Overall, the practices are chiefly conformed to the recommendations for the diagnosis of vasculitis, but they are less consensual when the ANCA are performed in other clinical situations.

Present status and perspective of laboratory hematology in Japan: On the standardization of blood cell morphology including myelodysplasia: On behalf of the Japanese Society for Laboratory Hematology

The Japanese Society for Laboratory Hematology (JSLH) was launched in 2000 and has been developed by a mutual collaboration of hematologists, medical technologists, and the companies involved in hematological laboratory testing. The aim of JSLH is the progress and development of laboratory hematology by academic conferences, periodic publication of academic journal, training and education (in the meeting, the journal, or the website), promotion of the standardization of laboratory hematology, and certification of the laboratory hematology specialists. Among 3 specialized committees organized for the standardization of laboratory hematology, the standardization committee on blood cell morphology has been dealing with the various projects on peripheral/bone marrow blood cells and normal/abnormal morphology. Another independent organization, the Japanese National Research Group on idiopathic bone marrow failure syndromes (BMF), has raised the importance of the dysplasia of myelodysplastic syndromes (MDS) and has been conducting the prospective registration, central review, and follow-up study of MDS. This group recently proposed the grading system for diagnostic accuracy of MDS, and the detailed procedure of morphological diagnosis of MDS is presented in the specialized color atlas with typical photographs of various dysplasia. JSLH has also approved the grading system for diagnostic accuracy of MDS and adopted this standardized diagnostic system to the educational item for certification of the laboratory hematology specialists, aiming at a nationwidely expanding morphological evaluation of myelodysplasia. Further and significant progress in the standardization of blood cell morphology will be expected in Japan through the activity of JSLH.

Improving bone marrow biopsy quality through peer discussion and data comparisons: A single institution experience

INTRODUCTION

Bone marrow biopsy (BMB) is crucial for the diagnosis, staging, and monitoring of a variety of hematologic diseases. Obtaining an adequate BMB can be challenging given the need to balance patient comfort with acquisition of high quality specimens. We had observed variable BMB quality at our institution with poor quality specimens sometimes affecting diagnosis. We thus undertook this quality improvement (QI) project to improve the quality of diagnostic BMB specimens.

METHODS

We used an A3 QI process to identify factors possibly influencing BMB quality. We collected baseline data on 211 BMB, with short and long-term follow-up data on a further 382 cases. We used clinical conferences to discuss data, perform peer comparisons and identify strategies to create a sustainable improvement in BMB quality.

RESULTS

Baseline data showed that BMB length was influenced most by the individual performer, with some influence of needle gauge. Other factors such as sedation, BMB indication were noncontributory. BMB lengths improved following performer education and individual performer data comparisons (15.2 mm post vs 12.8 mm baseline, P < .0001) and with use of an 8- rather than 11-gauge needle (18.3 mm 8-gauge vs 13.3 mm 11-gauge P < .0001), and were sustained over the long term.

CONCLUSIONS

Education on BMB standards, sharing of performer data, and changing needle gauge are relatively straightforward methods to improve BMB quality, leading to easier pathology diagnosis.

Proper experimental design requires randomization/balancing of molecular ecology experiments

Properly designed (randomized and/or balanced) experiments are standard in ecological research. Molecular methods are increasingly used in ecology, but studies generally do not report the detailed design of sample processing in the laboratory. This may strongly influence the interpretability of results if the laboratory procedures do not account for the confounding effects of unexpected laboratory events. We demonstrate this with a simple experiment where unexpected differences in laboratory processing of samples would have biased results if randomization in DNA extraction and PCR steps do not provide safeguards. We emphasize the need for proper experimental design and reporting of the laboratory phase of molecular ecology research to ensure the reliability and interpretability of results.

Designing easy DNA extraction: Teaching creativity through laboratory practice

Subject material concerning Deoxyribose Nucleic Acid (DNA) structure in the format of creativity-driven laboratory practice offers meaningful learning experience to the students. Therefore, a laboratory practice in which utilizes simple procedures and easy-safe-affordable household materials should be promoted to students to develop their creativity. This study aimed to examine whether designing and conducting DNA extraction with household materials could foster students' creative thinking. We also described how this laboratory practice affected students' knowledge and views. A total of 47 students participated in this study. These students were grouped and asked to utilize available household materials and modify procedures using hands-on worksheet. Result showed that this approach encouraged creative thinking as well as improved subject-related knowledge. Students also demonstrated positive views about content knowledge, social skills, and creative thinking skills. This study implies that extracting DNA with household materials is able to develop content knowledge, social skills, and creative thinking of the students. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):216-225, 2017.

The impact of providing blood to the scene of an accident on transfusion laboratory practice

BACKGROUND

Haemorrhage is the leading cause of mortality during trauma. In 2012, London's Air Ambulance introduced Blood on Board (BOB), transfusing group O red cells (RBC) to trauma patients at the scene.

OBJECTIVES

This study assessed the impact of BOB on the number of mixed field samples received by the laboratory, the number of group O RBC transfused to non-group O patients and the ratio of RBC to fresh frozen plasma (FFP) transfused in the initial 24 h.

METHODS

Three major trauma centres collected data on patients for whom the major haemorrhage protocol was activated between August 2008 and February 2012 pre-BOB and March 2012 and December 2013 post-BOB.

RESULTS

A total of 233 trauma patients were identified pre-BOB and 119 post-BOB. There was no significant difference in the percentage of group O units transfused to non-group O patients (75 vs 82%, P = 0·21) or the RBC : FFP ratio (pre-BOB mean 1·6 [interquartile range (IQR) 1·0-2·0]; post-BOB mean 1·7 [IQR 1·1-2·2], P = 0·24). There was no significant difference in the percentage of mixed field samples received (23% vs 27%, P = 0·3).

CONCLUSION

The introduction of BOB did not change the proportion of group O RBC transfused or the RBC : FFP ratio; however, the proportion of acceptable samples decreased. This is largely due to an increase in blood samples not received from the post-BOB cohort, which we believe is probably due to patients who died at the scene. We have introduced robust systems to indicate reasons for not obtaining samples.

Report of the results of the International Clinical Cytometry Society and American Society for Clinical Pathology workload survey of clinical flow cytometry laboratories

BACKGROUND

Thorough review of current workload, staffing, and testing practices in clinical laboratories allows for optimization of laboratory efficiency and quality. This information is largely missing with regard to clinical flow cytometry laboratories. The purpose of this survey is to provide comprehensive, current, and accurate data on testing practices and laboratory staffing in clinical laboratories performing flow cytometric studies.

METHODS

Survey data was collected from flow cytometry laboratories through the ASCP website. Data was collected on the workload during a 1-year time period of full-time and part-time technical and professional (M.D./D.O./Ph.D. or equivalent) flow cytometry employees. Workload was examined as number of specimens and tubes per full time equivalent (FTE) technical and professional staff. Test complexity, test result interpretation, and reporting practices were also evaluated.

RESULTS

There were 205 respondent laboratories affiliated predominantly with academic and health system institutions. Overall, 1,132 FTE employees were reported with 29% professional FTE employees and 71% technical. Fifty-one percent of the testing performed was considered high complexity and 49% was low complexity. The average number of tubes per FTE technologist was 1,194 per year and the average number of specimens per FTE professional was 1,659 per year. The flow cytometry reports were predominantly written by pathologists (57%) and were typically written as a separate report (58%).

CONCLUSIONS

This survey evaluates the overall status of the current practice of clinical flow cytometry and provides a comprehensive dataset as a framework to help laboratory departments, directors, and managers make appropriate, cost-effective staffing decisions. © 2016 International Clinical Cytometry Society.

Refining peripheral blood smear review rules for neonatal inpatients in a South African academic laboratory

INTRODUCTION

Peripheral blood smear review (PBSR) is a labour-intensive test, and skilled morphologists are in short supply. It is therefore helpful for laboratories to establish rules for PBSR to improve laboratory efficiency. Previously published guidelines in this regard are useful, but make few recommendations specific to neonates. Neonatal blood is characterized by several peculiarities which would be considered pathological if present in adults. Consequently, smear review rules (SRR) are often triggered in neonates without significant value being added on review. This study aimed to assess and fine-tune the SRR triggered in neonatal samples in order to improve laboratory efficiency.

METHODS

Full blood counts collected from 188 neonatal inpatients of the Chris Hani Baragwanath Academic Hospital in South Africa were retrospectively reviewed, the triggered rules documented, and the value added on PBSR determined.

RESULTS

Smear review rules were triggered in 148 (78.7%) samples, with significant morphological abnormalities identified in 84 (54.4%), and a false-positive rate of 34.0%. In patients with unhelpful review, the commonest rules triggered were the flags querying the presence of abnormal lymphocytes, blasts or nucleated red blood cells. When one or more of these flags were triggered in the absence of any other SRR, PBSR was always noncontributory. Disregarding these flags in the current cohort would reduce both the review and the false-positive rates by >20% without increasing the false-negative rate.

CONCLUSION

False-positive smear review is common in neonates, and minor modifications to SRR can substantially reduce the smear review rate without increasing the false-negative rate.

Assessing nonvitamin K antagonist oral anticoagulants (NOACs) in the laboratory

Nonvitamin K antagonist oral anticoagulants (NOACs) are being used with increasing frequency due to their safety profile, ease of use, and given that therapeutic monitoring is not required. As these agents have only recently been FDA approved, their effect on routine and specialty coagulation assays is not well appreciated. This article discusses NOAC effect on routine coagulation assays and whether these assays can be used to estimate drug concentration as well as which assays are suitable to quantitate drug concentration in plasma. Also reviewed is the use of manufactured drug calibrators to determine reagent responsiveness and the effect of these agents on various special coagulation assays.

Critical appraisal in the practice of laboratory medicine

Critical appraisal is a key skill employed across the spectrum of laboratory medicine practice. It underpins the use of information that is relevant, of good quality and is meaningful. Relevance is answering the right question for the right patient at the right time, with quality ensuring provision of the right information. Meaningful is making the right decisions in order to deliver the right outcomes. Critical appraisal is about minimizing the risk of bias or 'departures from trueness' in all of the facets of laboratory medicine practice. It can be summarized in four steps: (i) a clear understanding and articulation of the problem being addressed - whether it be an analytical challenge, individual patient care or policymaking; (ii) verifying the methodological approach employed; (iii) assuring the reliability of the results and (iv) ensuring the applicability and implications of the results. Reference is made to a number of checklists that can be used to assist in the process of critical appraisal.

Hemoglobin H identification by high-performance liquid chromatography in confirmed hemoglobin H disease

INTRODUCTION

Among hemoglobin (Hb) H disease cases diagnosed by DNA testing in our hemoglobinopathy laboratory, we have noted instances of unreported Hb H from high-performance liquid chromatography (HPLC) results of referring laboratories.

METHODS

To characterize these issues, we identified all cases of genotypic Hb H disease diagnosed in our laboratory. HPLC chromatograms were reviewed to determine the presence and retention time of the Hb H peak.

RESULTS

Hemoglobin H was not reported in 24.2% of patients (23 of 95) with genotypic Hb H disease. The characteristic prerun peak of Hb H was present on review of all eight Variant or Variant II β-thalassemia short-program chromatograms. Elevated Hb F (≥3%) was reported in 14 cases. The Hb H peak was found in the Hb F window in 11 dual program cases. The incorrect identification of Hb H as elevated Hb F resulted in two testing referrals for 'δβ-thalassemia'.

CONCLUSIONS

Hemoglobin H may go unreported due to failure to examine for or recognize its peak on Variant or Variant II β-thalassemia short-program chromatograms. Elution of Hb H in the Hb F window resulted in misidentification of Hb H for Hb F and may indicate a Variant II HbA2 /HbA1C program software error. Our findings highlight the need for careful chromatogram inspection and clinical correlation in the diagnosis of Hb H disease.

Comprehensive experiment-clinical biochemistry: determination of blood glucose and triglycerides in normal and diabetic rats

For second year medical students, we redesigned an original laboratory experiment and developed a combined research-teaching clinical biochemistry experiment. Using an established diabetic rat model to detect blood glucose and triglycerides, the students participate in the entire experimental process, which is not normally experienced during a standard clinical biochemistry exercise. The students are not only exposed to techniques and equipment but are also inspired to think more about the biochemical mechanisms of diseases. When linked with lecture topics about the metabolism of carbohydrates and lipids, the students obtain a better understanding of the relevance of abnormal metabolism in relation to diseases. Such understanding provides a solid foundation for the medical students' future research and for other clinical applications.

The evaluation of two automated soluble fibrin assays for use in the routine hospital laboratory

INTRODUCTION

The soluble fibrin monomer (sFM) assay, like the D-dimer (DDi) assay, has the potential to be used both as an aid in the diagnosis of disseminated intravascular coagulation (DIC) and as a thrombotic marker. It differs from DDi in that it is a much earlier produced fragment produced only by thrombin action on fibrinogen, whereas DDi is a much later produced fragment formed by plasmin cleavage of cross-linked fibrin.

METHODS

In our study, we compared two commercially available automated sFM assays in the routine hospital setting using samples obtained from the general hospital ward and the emergency room. The results obtained with the two automated assays (Stago LIA sFM assays and the LPIA-Iatro SF assay) were compared with each other and with the results obtained using the routine semiquantitative hemagglutination assay.

RESULTS

The study showed that both automated assays were comparable with each other. No patient sample previously classified as positive would be missed, but with the higher sensitivity in the automated tests, more samples are positive.

CONCLUSION

In conclusion, we suggest that both automated tests are suitable for routine laboratory use. Both assays had the advantage over the hemagglutination assay in that previously frozen samples could be used, and the assays are easier and quicker to perform. The LIA sFM Stago has slightly better sensitivity but has a tendency to lower specificity than the Iatro SF test.