Abrogation of red blood cell G6PD enzyme activity through Heat treatment: development of survey material for the UK NEQAS G6PD scheme.

INTRODUCTION: Participation in external quality assessment (EQA) is central to the maintenance of high-quality laboratory results in patient diagnosis and clinical trials. Laboratories in the TAF112582 DETECTIVE study (ClinicalTrials.gov identifier: NCT01376167) are enrolled in the United Kingdom National Quality Assessment Scheme (UK NEQAS) for glucose-6-phosphate dehydrogenase (G6PD) quantitative assay, which utilizes ovine (sheep) blood as a readily available source of apparently G6PD-deficient survey material. A substitute for sheep blood was sought because some non-UK sites in the study encountered participation difficulties due to the strict regulations on the import of sheep blood into their countries. METHODS: G6PD activity in normal human donor blood was abrogated by the action of heat under controlled conditions. Residual G6PD activity in the heated samples was measured by UK NEQAS using the Trinity Biotech 345 kit (Trinity Biotech) and a Jenway 6715 UV/Vis spectrophotometer with external temperature control to monitor enzyme kinetics and linearity over a set time. Heat-treated material was also assayed for G6PD activity and assessed for its acceptability as EQA survey material by selected UK laboratories. RESULTS: Blood heated at 45 °C for 15 h showed a reduction in G6PD activity of 76.3 ± 4.6% (n = 6) and was considered acceptable as EQA material in terms of appearance and behaviour by the majority of UK sites in the trial. CONCLUSIONS: We have developed a simple heat-treatment procedure to produce EQA survey material with low/intermediate G6PD activity, similar to that found in females heterozygous for G6PD deficiency.

Standardization of haematology critical results management in adults: an International Council for Standardization in Haematology, ICSH, survey and recommendations.

INTRODUCTION: These recommendations are intended to develop a consensus in the previously published papers as to which parameters and what values should be considered critical. A practical guide on the standardization of critical results management in haematology laboratories would be beneficial as part of good laboratory and clinical practice and for use by laboratory-accrediting agencies. METHODS: A working group with members from Europe, America, Australasia and Asia was formed by International Council for Standardization in Haematology. A pattern of practice survey of 21 questions was distributed in 2014, and the data were collected electronically by Survey Monkey. The mode, or most commonly occurring value, was selected as the threshold for the upper and lower alert limits for critical results reporting. RESULTS: A total of 666 laboratories submitted data to this study and, of these, 499 submitted complete responses. Full blood count critical results alert thresholds, morphology findings that trigger critical result notification, critical results alert list, notification process and maintenance of critical results management protocol are described. This international survey provided a snapshot of the current practice worldwide and has identified the existence of considerable heterogeneity of critical results management. CONCLUSION: The recommendations in this study represent a consensus of good laboratory practice. They are intended to encourage the implementation of a standardized critical results management protocol in the laboratory.

ICSH guidelines for the verification and performance of automated cell counters for body fluids.

One of the many challenges facing laboratories is the verification of their automated Complete Blood Count cell counters for the enumeration of body fluids. These analyzers offer improved accuracy, precision, and efficiency in performing the enumeration of cells compared with manual methods. A patterns of practice survey was distributed to laboratories that participate in proficiency testing in Ontario, Canada, the United States, the United Kingdom, and Japan to determine the number of laboratories that are testing body fluids on automated analyzers and the performance specifications that were performed. Based on the results of this questionnaire, an International Working Group for the Verification and Performance of Automated Cell Counters for Body Fluids was formed by the International Council for Standardization in Hematology (ICSH) to prepare a set of guidelines to help laboratories plan and execute the verification of their automated cell counters to provide accurate and reliable results for automated body fluid counts. These guidelines were discussed at the ICSH General Assemblies and reviewed by an international panel of experts to achieve further consensus.

Counting platelets at transfusion threshold levels: impact on the decision to transfuse. A BEST Collaborative - UK NEQAS(H) International Exercise.

BACKGROUND AND OBJECTIVES: Obtaining accurate and precise platelet enumeration in automatic platelet analysers at low platelet counts is a challenge. To explore the performance of current haematology analysers in counting platelet concentrations usually used as platelet transfusion threshold. MATERIAL AND METHODS: An international exercise where four blood samples with platelet levels near usual platelet transfusion thresholds was prepared and distributed. RESULTS: The samples shipped had a platelet count of 6·3, 13·3, 21·6 and 53·0 × 10(9) /l according to the international reference method. We received 82 sets of results from nine countries. Instruments from six different manufacturers were represented. Although the mean count for each of the four samples was very similar to the values, according to the reference method (9·0, 16·2, 23·0 and 57·6 × 10(9) /l), significant variability in the results was found. Assuming that these were patient samples and the result of the count used to indicate a prophylactic platelet transfusion, undertransfusion would have occurred for 24·5% of the LP1 samples at a transfusion threshold of 10 × 10(9) /l and, at a threshold of 20 × 10(9) /l, undertransfusion would have occurred for 7·2% of the LP1 and 16·2% of the LP2 samples and overtransfusion would have occurred with 23·1% of the LP3 samples. CONCLUSION: The results suggest that significant inaccuracy exists in counting low levels of platelets and that this inaccuracy might have a significant impact in under- and overtransfusion of platelet concentrates to patients.

ICSH review of the measurement of the erythocyte sedimentation rate.

In recognition of the need for a standardization of the measurement of the erythrocyte sedimentation rate (ESR), the International Council for Standardization in Haematology makes the following recommendations: (i) The reference method for measurement of the ESR should be based on the Westergren method, which is a specific test for the ESR, with modifications, (ii) The reference method for measurement of the ESR should use either whole blood anticoagulated with EDTA and later diluted with sodium citrate or saline (4 : 1) or whole blood anticoagulated with sodium citrate (4 : 1) in Westergren pipettes, (iii) The ESR pipettes can be of glass or plastic (with specific characteristics). It must be colourless; a minimum sedimentation scale of 200 mm, a minimum bore of 2.55 mm, which should be constant within 5%. A protocol for the evaluation of alternative methodologies against the reference method is outlined: The new technologies must be tested over a range of ESR values of 2-120 mm. In this comparison, 95% of the differences should be 5 mm or less, with larger differences associated with higher ESR values. A minimum of 40 samples should be tested in 3 different groups of values: 1-20, 21-60 and more than 60 mm. The statistical methods recommended for ESR evaluations are the coefficient of correlation, the Passing-Bablock regression and the Bland-Altman statistical method. This reference method replaces all earlier standardized and reference methods.

Review of the UK NEQAS (H) digital morphology pilot scheme for continuing professional development accessed via the internet.

UK NEQAS (H) developed and instigated a pilot scheme for digital morphology, which was accessed by participants over the internet in order to assess the viability of using high quality images as an educational tool for continuing professional development. The pilot scheme was trialled over a 2-year period with eight releases totalling 16 morphology cases. Digital images allowed participating individuals to examine and comment on exactly the same cells and compare their findings with those of other participants, consensus data from traditional glass slide surveys and expert opinion. Feedback from participants on their experience was then relayed back to the development team by UK NEQAS (H) in order to drive the educational format and to ensure that any new scheme would meet the requirements of the users.

The use of digital 'virtual slides' in the quality assessment of haematological morphology: results of a pilot exercise involving UK NEQAS(H) participants.

We report the results of a pilot study assessing the use of digital 'virtual slides' in haematological quality assessment. Conducted together with the UK National External Quality Assessment Scheme for General Haematology, the study involved 166 separate participants, using the format of a typical assessment exercise. The results revealed substantial concordance of observations made using digital slides with those reported in previous glass slide surveys that used identical cases. Participant feedback strongly supported the use of electronic slides in teaching and assessment roles. Our results suggest roles for this new electronic resource in external quality assessment (EQA), education and continuing professional development.