Wing Kit Lam¹, Winnie Yim Fong Law¹, Tsz Fung Wong¹, Vivian Hoi Kei Woo¹, Aves Hui Hsuan Wu², Eudora Yu De Chow², Ka Ngai Lau¹, Alice Ching Ching Wong¹, Sze Fai Yip¹

¹Department of Clinical Pathology, Tuen Mun Hospital, Hong Kong; ²Department of Pathology, United Christian Hospital, Hong Kong

 

Background: Detection of α-thalassaemia trait with Southeast Asian deletion (--SEA) traditionally based on haemoglobin H inclusion test (HbHi) is labour-intensive and time-consuming. We aim to investigate the use of a novel α-thalassaemia early eluting peak (αEEP) observed at the retention time of 0.24 min generated by Variant II high-performance liquid chromatography as a potential alternative for α-thalassaemia screening in our Chinese population.¹ 

Methods: 303 archived blood samples for haemoglobin pattern study were analysed for αEEP and HbHi results with blinded observers. The performance characteristics of αEEP and HbHi in detecting --SEA was compared.

Results: The αEEP and HbHi showed concordance rate of 96.0% (κ=0.921, p<0.001). Among the 74 cases with molecular results available, αEEP showed superior performance for detecting --SEA (sensitivity 93.8%, specificity 100%) compared to HbHi (sensitivity 81.3%, specificity 95.2%). Staff operation time of αEEP (10 minutes per 100 cases) was significantly shorter than HbHi (1800 minutes per 100 case).

Conclusion: The novelly-described αEEP was found to be more sensitive and specific than the HbHi in detecting α-thalassaemia trait with --SEA. The αEEP could be an alternative of HbHi for α-thalassaemia screening, with over 98% reduction in reagent and labour cost.

 

Reference: ^1. Lam WK, Law WYF, Wong TF, et al. A specific early eluting peak in Bio-Rad Variant II cation-exchange high-performance liquid chromatography (CE-HPLC) for the screening of alpha-thalassaemia in a Chinese population. Pathology. 2023 Oct;55(6):835-842.
 
Author Contribution Statement: Lam WK conceptualised the study, designed the study and drafted the abstract; Lam WK, Law WYF, Wong TF, Woo HKV, Wu AHH collected and analysed the data; Chow EYD, Lau KN, Wong ACC, Yip SF analysed the data. All authors reviewed and approved the abstract.