Evaluation of stability and potential interference on the α-thalassaemia early eluting peak and immunochromatographic strip test for α-thalassaemia --SEA carrier screening
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Wing Kit Lam
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Christina Pui Ying Fan
Abstract
Objectives
α-Thalassaemia screening is crucial for identifying carriers at risk of having offspring with haemoglobin (Hb) Bart’s hydrops fetalis syndrome. This study evaluated the performance of two potential screening methods: the α-thalassaemia early eluting peak (αEEP) identified by high-performance liquid chromatography (HPLC) and an immunochromatographic strip test (ICT), focusing on stability and potential interferences.
Methods
Ninety-two peripheral blood samples were used. Thirty were for assessment of αEEP and ICT stability and interference by icterus/lipaemia, and saline washing for interference removal. Diagnostic performance of αEEP and ICT were evaluated in 40 samples with glycated Hb (P2) ≥6.0 % and 22 with Hb F≥2.0 % on HPLC, using α-globin genotyping as the gold standard.
Results
Both αEEP and ICT results remained stable for 14 days. Neither test was significantly affected by icterus or lipaemia, though 3 of 20 ICT results (15 %) showed discordance after saline washing. Elevated HbA1c and Hb F altered early eluting peak patterns but did not affect αEEP interpretation. For detecting --SEA mutation, αEEP showed 100 % sensitivity and 100 % specificity when P2≥6.0 % or Hb F≥2.0 %, while ICT a low specificity (45 %) when Hb F≥2.0 %.
Conclusions
αEEP showed reliable performance in detecting α0-thalassaemia with --SEA mutation in all conditions tested, while ICT showed low specificity when Hb F≥2.0 %. These findings support αEEP as a reliable test for routine clinical laboratory use, while cautions should be made for ICT in case of elevated Hb F levels.
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Research ethics: The study was approved by the Hospital Authority Central Institutional Review Board (Ref: CIRB-2024-162-4) and performed according to the Declaration of Helsinki.
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Informed consent: Not applicable.
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission. Lam WK: conceptualisation, data curation, formal analysis, methodology, project administration, writing original draft, review and editing; Fan CPY, Law YFW, Wong TF: data curation, formal analysis, investigation; Too DLH, Ko LN: formal analysis, investigation; Leung AYH: methodology, supervision, review and editing; Yip SF: methodology, resources, supervision, review and editing.
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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: None declared.
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Data availability: The authors confirm that the data supporting the findings of this study are available within the article [and/or] its supplementary materials.
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Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/cclm-2025-0754).
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