Measurement of HbA and HbA by Capillarys 2 Flex Piercing HbA programme for simultaneous management of diabetes and screening for thalassemia.

Introduction: Thalassemia could interfere with some assays for haemoglobin A (HbA) measurement, therefore, it is useful to be able to screen for thalassemia while measuring HbA. We used Capillarys 2 Flex Piercing (Capillarys 2FP) HbA programme to simultaneously measure HbA and screen for thalassemia.

Materials And Methods: Samples from 498 normal controls and 175 thalassemia patients were analysed by Capillarys 2FP HbA programme (Sebia, France). For method comparison, HbA was quantified by Premier Hb9210 (Trinity Biotech, Ireland) in 98 thalassaemia patients samples. For verification, HbA from eight thalassaemia patients was confirmed by IFCC reference method.

Results: Among 98 thalassaemia samples, Capillarys 2FP did not provide an HbA result in three samples with HbH due to the overlapping of HbBart's with HbA fraction; for the remaining 95 thalassaemia samples, Bland-Altman plot showed 0.00 ± 0.35% absolute bias between two systems, and a significant positive bias above 7% was observed only in two HbH samples. The HbA values obtained by Capillarys 2FP were consistent with the IFCC targets (relative bias below ± 6%) in all of the eight samples tested by both methods. For screening samples with alpha (α-) thalassaemia silent/trait or beta (β-) thalassemia trait, the optimal HbA cut-off values were ≤ 2.2% and > 2.8%, respectively.

Conclusions: Our results demonstrated the Capillarys 2FP HbA system could report an accurate HbA value in thalassemia silent/trait, and HbA value (≤ 2.2% for α-thalassaemia silent/trait and > 2.8% for β-thalassemia trait) and abnormal bands (HbH and/or HbBart's for HbH disease, HbF for β-thalassemia) may provide valuable information for screening.