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
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Yating Ma
and
Jie Ma
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.
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Research ethics: This study was approved by the Clinical Research Ethics Committee of Beijing Hospital (Ethical approval number: 2024BJYYEC-KY298-01).
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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.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Use of Large Language Models, AI and Machine Learning Tools: None declared.
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Conflict of interest: The authors state no conflict of interest.
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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).
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Data availability: The raw data can be obtained on request from the corresponding author.
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Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/cclm-2025-0683).
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