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Evaluating the need for free glycerol blanking for serum triglyceride measurements at Charlotte Maxeke Johannesburg Academic Hospital

  • Carla van Heerden , Agnes Magwete and Dineo Mabuza ORCID logo EMAIL logo
Published/Copyright: December 7, 2019
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Clinical Chemistry and Laboratory Medicine (CCLM)
From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 58 Issue 8

Abstract

Background

The accurate and precise measurement of triglycerides is important due to the adverse effects associated with hypertriglyceridaemia. Most laboratory methods are based on enzymatic hydrolysis of triglycerides with measurement of the total glycerol. An elevated free glycerol concentration may result in overestimation of triglyceride concentrations. The removal of free glycerol by blanking may therefore be of clinical importance. The aim of this study was to compare the glycerol blanking and non-glycerol blanking triglyceride methods.

Methods

This was a method comparison study of 1518 samples from both in-patients and out-patients at Charlotte Maxeke Johannesburg Academic Hospital. Triglycerides were measured in each sample using both the blanking and the non-blanking methods. Analytical performance was assessed based on the National Cholesterol Education Program (NCEP) goals. Clinical impact was assessed according to the NCEP Adult Treatment Program III (ATP III) risk classification.

Results

The method median was significantly higher in the non-blanking compared to the blanking method (1.33 vs. 1.12 mmol/L, p < 0.0001) in all patients. The average bias was above the total allowable error of 15% across all groups. There was a significant change in NCEP ATP III risk classification, with fewer patients classified as normal (67.6% vs. 74.6%, p < 0.0001) with the non-blanking method compared to the blanking method.

Conclusions

There was a significant error when glycerol blanking for triglyceride determination was not performed. The non-blanking triglyceride method overestimates triglyceride concentrations. This does not only exceed analytical performance goals, but also impacts on patient categorisation and clinical decision making in all patients.

Keywords: blanking; free glycerol; non-blanking; potential diagnostic error; triglycerides

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: The reagents for this research study were sponsored by Roche Diagnostics South Africa.

  3. Employment or leadership: None declared.

  4. Honorarium: None declared.

  5. Competing interests: The funding organisation played no role in the study design; in the collection, analysis, and interpretation of data; in the writing of the report; or in the decision to submit the report for publication.

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Received: 2019-09-23
Accepted: 2019-10-29
Published Online: 2019-12-07
Published in Print: 2020-07-28

©2020 Walter de Gruyter GmbH, Berlin/Boston

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https://doi.org/10.1515/cclm-2019-0991
Keywords for this article
blanking; free glycerol; non-blanking; potential diagnostic error; triglycerides

Articles in the same Issue

  1. Frontmatter
  2. Editorial
  3. Quality controls for serology: an unfinished agenda
  4. A modern and pragmatic definition of Laboratory Medicine
  5. Reviews
  6. Blood biochemical characteristics of patients with coronavirus disease 2019 (COVID-19): a systemic review and meta-analysis
  7. ISO/TS 20914:2019 – a critical commentary
  8. Mini Review
  9. Reporting of D-dimer data in COVID-19: some confusion and potential for misinformation
  10. Opinion Paper
  11. Implementation of metrological traceability in laboratory medicine: where we are and what is missing
  12. IFCC Recommendation
  13. Recommendation for performance verification of patient-based real-time quality control
  14. Genetics and Molecular Diagnostics
  15. Comparison of BCR-ABL1 quantification in peripheral blood and bone marrow using an International Scale-standardized assay for assessment of deep molecular response in chronic myeloid leukemia
  16. General Clinical Chemistry and Laboratory Medicine
  17. Risk assessment of the total testing process based on quality indicators with the Sigma metrics
  18. Determination of hemolysis cut-offs for biochemical and immunochemical analytes according to their value
  19. A computer model for professional competence assessment according to ISO 15189
  20. Traceability validation of six enzyme measurements on the Abbott Alinity c analytical system
  21. Evaluating the need for free glycerol blanking for serum triglyceride measurements at Charlotte Maxeke Johannesburg Academic Hospital
  22. Challenges of LC-MS/MS ethyl glucuronide analysis in abstinence monitoring of liver transplant candidates
  23. Changes in the result of antinuclear antibody immunofluorescence assay on HEp-2 cells reflect disease activity status in systemic lupus erythematosus
  24. Reference Values and Biological Variations
  25. Long-term biological variation estimates of 13 hematological parameters in healthy Chinese subjects
  26. Age-specific reference values improve the diagnostic performance of AMH in polycystic ovary syndrome
  27. Establishment of reference intervals for immunoassay analytes of adult population in Saudi Arabia
  28. Hematology and Coagulation
  29. Total haemoglobin – a reference measuring system for improvement of standardisation
  30. Laboratory testing for activated protein C resistance: rivaroxaban induced interference and a comparative evaluation of andexanet alfa and DOAC Stop to neutralise interference
  31. Cancer Diagnostics
  32. Identification of a four-gene methylation biomarker panel in high-grade serous ovarian carcinoma
  33. Performance comparison of two next-generation sequencing panels to detect actionable mutations in cell-free DNA in cancer patients
  34. Diabetes
  35. Availability and analytical quality of hemoglobin A1c point-of-care testing in general practitioners’ offices are associated with better glycemic control in type 2 diabetes
  36. Infectious Diseases
  37. Validation of a chemiluminescent assay for specific SARS-CoV-2 antibody
  38. Dynamic profile and clinical implications of hematological parameters in hospitalized patients with coronavirus disease 2019
  39. Does a change in quality control results influence the sensitivity of an anti-HCV test?
  40. Letters to the Editor
  41. Variability between testing methods for SARS-CoV-2 nucleic acid detection 16 days post-discharge: a case report
  42. L-index, more than a screening tool for hypertriglyceridemia
  43. Neutralization of biotin interference: preliminary evaluation of the VeraTest Biotin™, VeraPrep Biotin™ and BioT-Filter®
  44. Counting and reporting band count is unreliable practice due to the high inter-observer variability
  45. Cigarette smoking prior to blood sampling acutely affects serum levels of the chronic obstructive pulmonary disease biomarker surfactant protein D
  46. How reliable is the detection of anti-mitochondrial antibodies on murine triple-tissue?
  47. Further advices on measuring lipoprotein(a) for reducing the residual cardiovascular risk on statin therapy
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