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Report of the International Council for Standardization in Haematology working group for standardization of reticulocyte parameters

December 2023

The International Council for Standardisation in Haematology is pleased to announce the publication of a new report of the ICSH working group for Standardization of Reticulocyte Parameters

The ICSH Working Group Contributors

Amrom E. Obstfeld | Bruce H. Davis | Jin-Yeong Han | Eloisa Urrechaga


Introduction: The International Council for Standardization in Haematology

convened a working group to assess and propose improvements upon the state of

standardization and harmonization of reticulocyte parameters among commercial

hematology analyzers.

Methods: An international group of laboratory hematologists prospectively collected

and analyzed clinical samples using locally available IVD commercial hematology analyzers. Eight hundred and fifty-five total samples were collected at 6 sites using 9 distinct analyzer types. Samples were assessed for reticulocyte percent (RET%),

immature reticulocyte fraction (IRF), and reticulocyte hemoglobin content (RHC).

Method comparison and regression statistics were calculated. These analyses were

used to determine whether statistical recalibration offered a potential avenue for

increasing comparability between these methods.

Results: While methods producing reticulocyte percent were the most comparable in

this study, the state of harmonization for the IRF and RHC was reduced with pearson

correlation coefficients ranging from 0.955 to 0.77 and 0.927 and 0.680, respectively. Nevertheless, use of parameters from the Passing Bablok regression substantially improved the comparability of the results. In addition, precision data was

derived which also demonstrated substantial differences between analyzer systems.

Conclusion: While reticulocyte counting is correlated between the automated

methods evaluated in this study, the current state of harmonization of other reticulocyte parameters is not as strong. A major challenge in moving this field forward is the

need for commutable materials to facilitate comparisons between analyzers not

co-located. A potential alternate approach to improve the current state would be

instrument re-calibration. However, this is challenging both technically and due to

national regulatory frameworks.

....continue reading at Wiley Online Library -

First published: 06 December 2023

The publication is available to:



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