Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Feb;45(1):96-103.
doi: 10.1111/ijlh.13964. Epub 2022 Sep 27.

The alternative Thomas-plot: A new tool for effective anemia diagnostics

Kitty de Leur  1 , Nadine M C Pouw  1 , Jordy Lopez  1 , Lenneke Waals-Prinzen  1 , Huib Ceelie  1 , Ellen M van der Zwan-van Beek  1
Affiliations

The alternative Thomas-plot: A new tool for effective anemia diagnostics

Kitty de Leur et al. Int J Lab Hematol. 2023 Feb.

Abstract

Introduction: The Thomas-plot has proven to be a helpful tool to discriminate between different types of anemia. This plot combines the reticulocyte hemoglobin content (Ret-He) with the soluble transferrin receptor (sTfR)/log ferritin (fer) ratio. In this study, we designed an alternative Thomas-plot in which Ret-He is combined with the transferrin (Tf)/log ferritin ratio. We validated both Thomas-plots in a population of anemic patients and compared the performance to the current laboratory diagnostics of anemia.

Methods: A total of 536 anemic patients were included. The first 188 patients were used to generate ROC curves to define the optimal cut-off values for both Thomas-plots. With the following 348 patients included we studied the performance of the alternative and classical Thomas-plots compared to current anemia diagnostics.

Results: Cut-off values were defined (Ret-He: 31.2 pg, sTfR/log(fer): 0.91, and Tf/log(fer): 1.71). With both Thomas-plots the amount of e causa ignota (ECI) cases dropped from 39% to 27%. A more in depth analysis on the iron status of anemia of chronic disease (ACD) patients and a subdivision between latent and classical iron deficiencies could be made with the help of both plots. A shift from classical iron deficiency anemia (IDA) cases according to the classical Thomas-plot toward functional IDA according to the alternative Thomas-plot was observed.

Conclusion: The alternative Thomas-plot is an effective tool that gives a more in depth view on the iron status of anemic patients. In addition, it is easier to implement due to the use of transferrin rather than the soluble transferrin receptor.

Keywords: Ret-He; anemia; anemia of chronic disease; iron deficiency; thomas-plot.

PubMed Disclaimer

Similar articles

See all similar articles

References

REFERENCES

    1. McLean E, Cogswell M, Egli I, Wojdyla D, de Benoist B. Worldwide prevalence of anaemia, WHO Vitamin and Mineral Nutrition Information System, 1993-2005. Public Health Nutr. 2009;12(4):444-454.
    1. Weiss G, Ganz T, Goodnough LT. Anemia of inflammation. Blood. 2019;133(1):40-50.
    1. van de Verboeket WPHG, JFWK V, Oosterhuis WP, Leers MPG. Diagnostische waarde van een beknopt anemieprotocol gebaseerd op tien laboratoriumparameters. Ned Tijdschr Klin Chem Labgeneesk. 2011;36(4):275-276.
    1. Nairz M, Theurl I, Wolf D, Weiss G. Iron deficiency or anemia of inflammation?: Differential diagnosis and mechanisms of anemia of inflammation. Wien Med Wochenschr. 2016;166(13-14):411-423.
    1. Brugnara C, Schiller B, Moran J. Reticulocyte hemoglobin equivalent (ret he) and assessment of iron-deficient states. Clin Lab Haematol. 2006;28(5):303-308.

LinkOut - more resources