Home Medicine Performance evaluation of quantitative hemoglobin A2 and fetal hemoglobin testing using commercially lyophilized vs. in-house whole blood controls in Chinese clinical laboratories: a 12-year analysis of National External Quality Assessment Data
Article
Licensed
Unlicensed Requires Authentication

Performance evaluation of quantitative hemoglobin A2 and fetal hemoglobin testing using commercially lyophilized vs. in-house whole blood controls in Chinese clinical laboratories: a 12-year analysis of National External Quality Assessment Data

  • , , , , , , ORCID logo EMAIL logo and EMAIL logo
Published/Copyright: September 8, 2025
Clinical Chemistry and Laboratory Medicine (CCLM)
From the journal Clinical Chemistry and Laboratory Medicine (CCLM) Volume 64 Issue 2

Abstract

Objectives

To analyze the performance of laboratories in the China National External Quality Assessment Scheme (China NEQAS) for HbA2 and HbF testing, and to propose strategies for quality improvement.

Methods

Data were obtained from China NEQAS from 2013 to 2024 using both commercially lyophilized controls and in-house whole blood controls. The distributions of methods and instruments were analyzed. Inter-laboratory coefficient variations (CVs) and target values were compared between two types of controls and between method-instrument platforms over 12 years.

Results

The in-house controls remained homogeneous and stable for almost one month at 2–8 °C and for one year at −80 °C. Capillary electrophoresis (CE) became the dominant method, adopted by 84.3 % of labs in 2024. For HbA2, two EQA controls had comparable concentration ranges and inter-laboratory CVs. HbF in-house controls covered broader pathological concentrations than commercial ones. CE demonstrated lower inter-laboratory CVs for both analytes: HbA2 was 2.1 ± 1.8 % vs. 5.5 ± 4.8 % (high-performance liquid chromatography, HPLC) and 6.5 ± 4.1 % (agarose gel electrophoresis, AGE), while HbF was 3.2 ± 1.9 % vs. 5.0 ± 1.6 % (HPLC) and 8.6 ± 6.8 % (AGE). Significant discrepancies in maximum-to-minimum mean concentrations were observed among different method-instrument platforms when testing the same controls (up to 10 % for HbF).

Conclusions

In-house controls demonstrate homogeneity, stability and intrinsic commutability, and have an expanded concentration range, can serve as a reliable alternative to commercial controls for EQA. High-precision techniques such as CE should be favoured. Furthermore, the development of reference methods and commutable reference materials is essential for standardization.

Keywords: hemoglobin A2 ; fetal hemoglobin; external quality assessment; coefficient variation; standardization
Corresponding authors: Prof. Chenbin Li and Prof. Jie Ma, National Center for Clinical Laboratories, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing Hospital/National Center of Gerontology, NO. 1 Da Hua Road, Dong Dan, Beijing 100730, P.R. China, E-mail: (C. Li), (J. Ma)
Yating Ma and Zhongli Du contributed equally to this work.

  1. Research ethics: This study was approved by the Clinical Research Ethics Committee of Beijing Hospital (Ethical approval number: 2024BJYYEC-KY298-01).

  2. Informed consent: Fresh EDTA-anticoagulated whole blood samples with high and low concentrations of HbA2 and HbF were collected from hospitals in Guangxi after clinical testing.

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

  4. Use of Large Language Models, AI and Machine Learning Tools: None declared.

  5. Conflict of interest: The authors state no conflict of interest.

  6. Research funding: The work was supported by the Noncommunicable Chronic Diseases-National Science and Technology Major Project (Grant No. 2024ZD0523701), National High Level Hospital Clinical Research Funding [Grant No. BJ-2021-201], Guangxi Key Research and Development Program grant (Grant No. Guike-AB24010072).

  7. Data availability: The raw data can be obtained on request from the corresponding author.

References

1. Mosca, A, Arsene, C, Paleari, R, Kaiser, P, Harteveld, K, Daniel, Y, et al.. Standardization of hemoglobin A(2) and hemoglobin F: achievements and perspectives. Clin Chim Acta 2025;567:120087. https://doi.org/10.1016/j.cca.2024.120087.Search in Google Scholar PubMed

2. Vidali, M, Paleari, R, Ceriotti, F, Bernardini, S, Giambini, I, Brugnoni, D, et al.. Analysis of annual distributions of hemoglobin A(2) values as a method to test for HbA(2) standardization. Clin Chim Acta 2023;550:117564. https://doi.org/10.1016/j.cca.2023.117564.Search in Google Scholar PubMed

3. Colaco, S, Colah, R, Nadkarni, A. Significance of borderline HbA(2) levels in β thalassemia carrier screening. Sci Rep 2022;12:5414. https://doi.org/10.1038/s41598-022-09250-5.Search in Google Scholar PubMed PubMed Central

4. Ala, C, Ramalingam, S, Kondapalli Venkata Gowri, CS, Sankaranarayanan, M. A critique review of fetal hemoglobin modulators through targeting epigenetic regulators for the treatment of sickle cell disease. Life Sci 2025;369:123536. https://doi.org/10.1016/j.lfs.2025.123536.Search in Google Scholar PubMed

5. Giambona, A, Passarello, C, Renda, D, Maggio, A. The significance of the hemoglobin A(2) value in screening for hemoglobinopathies. Clin Biochem 2009;42:1786–96. https://doi.org/10.1016/j.clinbiochem.2009.06.026.Search in Google Scholar PubMed

6. Paleari, R, Giambona, A, Cannata, M, Leto, F, Maggio, A, Mosca, A. External quality assessment of hemoglobin A2 measurement: data from an Italian pilot study with fresh whole blood samples and commercial HPLC systems. Clin Chem Lab Med 2007;45:88–92. https://doi.org/10.1515/cclm.2007.002.Search in Google Scholar PubMed

7. Paleari, R, Caruso, D, Kaiser, P, Arsene, CG, Schaeffer-Reiss, C, Van Dorsselaer, A, et al.. Developing a reference system for the IFCC standardization of HbA(2). Clin Chim Acta 2017;467:21–6. https://doi.org/10.1016/j.cca.2016.05.023.Search in Google Scholar PubMed

8. Landin, B, Sisowath, C, Strålfors, A. Factors affecting the evaluation and use of a hemoglobin A(2) method – lot-to-lot variation, long-term deviation and carry-over. Clin Chim Acta 2023;544:117332. https://doi.org/10.1016/j.cca.2023.117332.Search in Google Scholar PubMed

9. UK, NEQAS.; 2025. Available from: https://ukneqas.org.uk/programmes/?keyword=pathological+haemoglobins&centre=15#find-a-programme-block [Accessed Sep 2025].Search in Google Scholar

10. Mosca, A, Paleari, R, Wild, B. Analytical goals for the determination of HbA2. Clin Chem Lab Med 2013;51:937–41. https://doi.org/10.1515/cclm-2012-0575.Search in Google Scholar PubMed

11. Ricos, C, Alvarez, V, Cava, F, Garcia-Lario, JV, Hernandez, A, Jimenez, CV, et al.. Desirable specifications for total error, imprecision, and bias, derived from intra- and inter-individual biologic variation. The 2014 update. Original publication available from (Spanish only). http://www.seqc.es/es/comisiones/comisionde-calidad-analitica/_id:4/ [Accessed Jan 2019]. Also available on (English): http://www.westgard.com/biodatabase1.htm [Accessed Jan 2019]. 2014.Search in Google Scholar

12. Haeckel, R, Carobene, A, Wosniok, W. Problems with estimating reference change values (critical differences). Clin Chim Acta 2021;523:437–40. https://doi.org/10.1016/j.cca.2021.10.006.Search in Google Scholar PubMed

13. Molina, A, Alcaraz, J, Guiñón, L, Pérez, A, Segurana, A, Reverter, JC, et al.. Study of the analytical performance at different concentrations of hematological parameters using Spanish EQAS data. Clin Chem Lab Med 2019;57:1980–7. https://doi.org/10.1515/cclm-2019-0108.Search in Google Scholar PubMed

14. Pornprasert, S, Kongthai, K, Waneesorn, J, Jaiping, K, Treesuwan, K. Development of control material for hemoglobin analysis. Clin Chem Lab Med 2011;50:351–6. https://doi.org/10.1515/cclm.2011.777.Search in Google Scholar

15. Stephens, AD, Angastiniotis, M, Baysal, E, Chan, V, Fucharoen, S, Giordano, PC, et al.. ICSH recommendations for the measurement of haemoglobin A2. Int J Lab Hematol 2011;34:1–13. https://doi.org/10.1111/j.1751-553x.2011.01368.x.Search in Google Scholar PubMed

16. Stephens, AD, Angastiniotis, M, Baysal, E, Chan, V, Davis, B, Fucharoen, S, et al.. ICSH recommendations for the measurement of haemoglobin F. Int J Lab Hematol 2011;34:14–20. https://doi.org/10.1111/j.1751-553x.2011.01367.x.Search in Google Scholar

17. Satthakarn, S, Panyasai, K, Phasit, A, Panyasai, S. Reliability of hemoglobin A(2) value as measured by the premier resolution system for screening of β-thalassemia carriers. Clin Chem Lab Med 2023;62:453–63. https://doi.org/10.1515/cclm-2023-1006.Search in Google Scholar PubMed

18. Mosca, A, Paleari, R, Harteveld, CL. A roadmap for the standardization of hemoglobin A(2). Clin Chim Acta 2020;512:185–90. https://doi.org/10.1016/j.cca.2020.11.008.Search in Google Scholar PubMed

19. Li, YQ, Wei, JH, Liang, L. Detection of Hb A(2) and Hb constant spring (HBA2: c.427T>C) by capillary electrophoresis in a patient with Hb H-Hb CS disease. Hemoglobin 2019;42:342–3. https://doi.org/10.1080/03630269.2018.1551232.Search in Google Scholar PubMed

20. Kaur, G, Tyagi, S, Seth, T, Mahapatra, M, Viswananthan, GK, Dass, J, et al.. Comparison of HbA2 using high performance liquid chromatography versus haemoglobin capillary zone electrophoresis. Indian J Hematol Blood Transfus 2023;39:572–8. https://doi.org/10.1007/s12288-023-01648-z.Search in Google Scholar PubMed PubMed Central

21. Batterbee, H, De La Salle, B, McTaggart, P, Doré, CJ, Wild, BJ, Hyde, K. Evaluation of UK NEQAS (H) Hb A2 and related performance data. Watford: UK National External Quality Assessment Scheme for General Haematology; 2010.Search in Google Scholar

22. De la Salle, B, Stephens, AD, Wild, BJ, Harteveld, CL, Hyde, K. Evaluation of the suitability of the World Health Organization International Reference Reagent for Hb A(2) quantitation (89/666) for continued use. Int J Lab Hematol 2019;41:262–70. https://doi.org/10.1111/ijlh.12966.Search in Google Scholar PubMed

23. Paleari, R, Muñoz, A, Mosca, A. Towards the development of a certified reference material for hemoglobin A2. Clin Chem Lab Med 2010;48:1611–8. https://doi.org/10.1515/CCLM.2010.317.Search in Google Scholar PubMed

24. Wild, BJ, Chohan, DK, Harteveld, CL, De la Salle, B. Further evaluation of the world health organization international reference reagent for haemoglobin A(2) measurement. Int J Lab Hematol 2021;43:494–9. https://doi.org/10.1111/ijlh.13403.Search in Google Scholar PubMed

25. Pornprasert, S, Tookjai, M, Punyamung, M, Pongpunyayuen, P, Treesuwan, K. Proficiency testing program for hemoglobin E, A2 and F analysis in Thailand using lyophilized hemoglobin control materials. Clin Chem Lab Med 2018;56:602–8. https://doi.org/10.1515/cclm-2017-0581.Search in Google Scholar PubMed

Supplementary Material

This article contains supplementary material (https://doi.org/10.1515/cclm-2025-0683).

Received: 2025-06-20
Accepted: 2025-08-26
Published Online: 2025-09-08
Published in Print: 2026-01-29

© 2025 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. Editorials
  3. Counting cells is not enough: toward a global vision for quality and training in hematology
  4. Multi-cancer early detection revisited: insights and lessons from the PATHFINDER 2 study
  5. Review
  6. Automated reticulocyte counting: advances, standardization challenges, and clinical accessibility
  7. Opinion Papers
  8. Expert opinion within the context of the targeted evaluation of Regulation (EU) 2017/746 on in vitro diagnostic medical devices pursuant to Article 111 and Regulation (EU) 2024/1860
  9. Value is equal to outcome/costs: how to apply to laboratory medicine
  10. Does patient-based data monitoring allow us to reconsider the relationship between IQC and EQA?
  11. Genetics and Molecular Diagnostics
  12. Predictive genomic medicine enlarges the spectrum of predisposing mutations for head and neck cancers via a panel of 56 genes selected for human neoplasia in Southern Italy: a pilot study
  13. Failure Mode and Effects Analysis (FMEA) integrating quality indicators for risk assessment of the total testing process in human papillomavirus genotyping testing: a proactive risk analysis model for molecular diagnostics
  14. Impact of pneumatic tube system transport and blood collection tubes on cell-free DNA analysis of plasma samples
  15. General Clinical Chemistry and Laboratory Medicine
  16. Requiem for the Passing–Bablok nonparametric regression in assessing the agreement between two measurement methods
  17. Comparative analysis of ISO 15189:2022 with earlier versions with reference to ethics
  18. Estimated waste generation from 1 million basic metabolic panels: a multisite U.S. study
  19. Performance of GFAP and UCH-L1 compared to S100B in detecting intracranial injury: influence of age, hemolysis, neurodegenerative diseases, and extracranial fractures in a prospective cohort of over 1,000 patients
  20. Post-analytical practices in clinical mass spectrometry laboratories: an international survey across 57 countries
  21. Towards harmonization of autoantibody detection in relation to paraneoplastic neurological syndromes (PNS): a European Survey on laboratory practices
  22. Staining and serological characteristics of the AC-30 pattern in HEp-2 IIFA: a comparative study with AC-2 pattern
  23. Measuring neurofilament light in human plasma and cerebrospinal fluid: a comparison of five analytical immunoassays
  24. ADORE: the performance characteristics of five automated platforms in the analysis of urinary dysmorphic erythrocytes and pathological casts
  25. Influence of remnant cholesterol on direct LDL and HDL cholesterol measurement accuracy
  26. Dental amalgams and blood mercury concentrations in American adults
  27. Reference Values and Biological Variations
  28. Establishing reference intervals for high-sensitivity cardiac troponin T in neonates and infants
  29. Serum neuron-specific enolase – reference interval in Danish children and the impact of preanalytical factors
  30. Performance evaluation of quantitative hemoglobin A2 and fetal hemoglobin testing using commercially lyophilized vs. in-house whole blood controls in Chinese clinical laboratories: a 12-year analysis of National External Quality Assessment Data
  31. Hematology and Coagulation
  32. EQALM recommendations for the analytical performance specifications for blood smear interpretation in hematology: a need for standardization
  33. Cancer Diagnostics
  34. Flow cytometry, cytology and histology in the diagnosis of ocular hematologic neoplasms: a 15-year monocentric experience with a focus on ocular lymphomas
  35. Cardiovascular Diseases
  36. Comparison of the cardiac troponin I-cardiac troponin T-troponin C complex and cardiac troponin I and T in distinguishing myocardial infarction using a single sample at presentation
  37. Letters to the Editor
  38. Critical appraisal of presepsin for diagnosing late-onset sepsis in critically ill neonates
  39. Beyond cut-offs: optimizing presepsin for neonatal late-onset sepsis
  40. Pleural effusion with a thyroid signature: diagnostic utility of pleural fluid thyroglobulin
  41. Early autoimmune signature in a young woman: palmar erythema, capillaroscopic abnormalities, and triple autoantibody positivity including anti-nucleosome
  42. Confirmation of the value of the labile HbA1c/HbA1c-ratio in the presence of a Hb J-Baltimore variant: a clinical case
  43. Adverse analytical finding with trimetazidine after ingesting contaminated melatonin tablets sold in pharmacies… leading to the suspension of the athlete
  44. Ionized calcium in serum exposed to air
  45. Congress Abstracts
  46. Annual meeting of the Royal Belgian Society of Laboratory Medicine (RBSLM): “Beyond the Surface – Clinical biology of the apparently healthy individual”
https://doi.org/10.1515/cclm-2025-0683
Keywords for this article
hemoglobin A2; fetal hemoglobin; external quality assessment; coefficient variation; standardization

Articles in the same Issue

  1. Frontmatter
  2. Editorials
  3. Counting cells is not enough: toward a global vision for quality and training in hematology
  4. Multi-cancer early detection revisited: insights and lessons from the PATHFINDER 2 study
  5. Review
  6. Automated reticulocyte counting: advances, standardization challenges, and clinical accessibility
  7. Opinion Papers
  8. Expert opinion within the context of the targeted evaluation of Regulation (EU) 2017/746 on in vitro diagnostic medical devices pursuant to Article 111 and Regulation (EU) 2024/1860
  9. Value is equal to outcome/costs: how to apply to laboratory medicine
  10. Does patient-based data monitoring allow us to reconsider the relationship between IQC and EQA?
  11. Genetics and Molecular Diagnostics
  12. Predictive genomic medicine enlarges the spectrum of predisposing mutations for head and neck cancers via a panel of 56 genes selected for human neoplasia in Southern Italy: a pilot study
  13. Failure Mode and Effects Analysis (FMEA) integrating quality indicators for risk assessment of the total testing process in human papillomavirus genotyping testing: a proactive risk analysis model for molecular diagnostics
  14. Impact of pneumatic tube system transport and blood collection tubes on cell-free DNA analysis of plasma samples
  15. General Clinical Chemistry and Laboratory Medicine
  16. Requiem for the Passing–Bablok nonparametric regression in assessing the agreement between two measurement methods
  17. Comparative analysis of ISO 15189:2022 with earlier versions with reference to ethics
  18. Estimated waste generation from 1 million basic metabolic panels: a multisite U.S. study
  19. Performance of GFAP and UCH-L1 compared to S100B in detecting intracranial injury: influence of age, hemolysis, neurodegenerative diseases, and extracranial fractures in a prospective cohort of over 1,000 patients
  20. Post-analytical practices in clinical mass spectrometry laboratories: an international survey across 57 countries
  21. Towards harmonization of autoantibody detection in relation to paraneoplastic neurological syndromes (PNS): a European Survey on laboratory practices
  22. Staining and serological characteristics of the AC-30 pattern in HEp-2 IIFA: a comparative study with AC-2 pattern
  23. Measuring neurofilament light in human plasma and cerebrospinal fluid: a comparison of five analytical immunoassays
  24. ADORE: the performance characteristics of five automated platforms in the analysis of urinary dysmorphic erythrocytes and pathological casts
  25. Influence of remnant cholesterol on direct LDL and HDL cholesterol measurement accuracy
  26. Dental amalgams and blood mercury concentrations in American adults
  27. Reference Values and Biological Variations
  28. Establishing reference intervals for high-sensitivity cardiac troponin T in neonates and infants
  29. Serum neuron-specific enolase – reference interval in Danish children and the impact of preanalytical factors
  30. Performance evaluation of quantitative hemoglobin A2 and fetal hemoglobin testing using commercially lyophilized vs. in-house whole blood controls in Chinese clinical laboratories: a 12-year analysis of National External Quality Assessment Data
  31. Hematology and Coagulation
  32. EQALM recommendations for the analytical performance specifications for blood smear interpretation in hematology: a need for standardization
  33. Cancer Diagnostics
  34. Flow cytometry, cytology and histology in the diagnosis of ocular hematologic neoplasms: a 15-year monocentric experience with a focus on ocular lymphomas
  35. Cardiovascular Diseases
  36. Comparison of the cardiac troponin I-cardiac troponin T-troponin C complex and cardiac troponin I and T in distinguishing myocardial infarction using a single sample at presentation
  37. Letters to the Editor
  38. Critical appraisal of presepsin for diagnosing late-onset sepsis in critically ill neonates
  39. Beyond cut-offs: optimizing presepsin for neonatal late-onset sepsis
  40. Pleural effusion with a thyroid signature: diagnostic utility of pleural fluid thyroglobulin
  41. Early autoimmune signature in a young woman: palmar erythema, capillaroscopic abnormalities, and triple autoantibody positivity including anti-nucleosome
  42. Confirmation of the value of the labile HbA1c/HbA1c-ratio in the presence of a Hb J-Baltimore variant: a clinical case
  43. Adverse analytical finding with trimetazidine after ingesting contaminated melatonin tablets sold in pharmacies… leading to the suspension of the athlete
  44. Ionized calcium in serum exposed to air
  45. Congress Abstracts
  46. Annual meeting of the Royal Belgian Society of Laboratory Medicine (RBSLM): “Beyond the Surface – Clinical biology of the apparently healthy individual”
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Winner of the OpenAthens UX Award 2026
Winner of the OpenAthens UX Award 2026
Have an idea on how to improve our website?
Please write us.
© 2026 De Gruyter Brill
Downloaded on 26.3.2026 from https://www.degruyterbrill.com/document/doi/10.1515/cclm-2025-0683/html
Scroll to top button