Introduction Elevated HbA2 (hemoglobin A2) level is considered the most reliable hematological parameter for the detection of β-thalassemia carriers. However, some carriers are difficult to recognize because the level of HbA2 is not in the distinctive carrier range, i.e. 4.0-6.0%; instead, some carriers have HbA2 levels between normal and carrier levels, i.e. borderline HbA2 (HbA2 = 3.1-3.9%). ...

Although delta-globin gene (HBD MIM#142000) mutations have no clinical implications, co-inheritance of beta- and delta-thalassemia may lead to misdiagnosis. Among 7,153 samples studied for beta-thalassemia, 205 samples with lower than expected HbA2 levels were selected for our analysis and 183 samples (2.5%) were positive for delta-globin gene mutations. Twelve different mutations were detected...

OBJECTIVE To define whether minor adult hemoglobin A2 (HbA2, α2δ2) exerts any protective activity in multiple sclerosis (MS). METHODS HbA2 levels were measured in 146 MS patients with high performance liquid chromatography and association with MS Severity Scores (MSSS) were determined. HbA2 associations with blood count parameters were also studied using blood counts evaluated on the same day...

Hemoglobin (Hb) A2' is a hematologically silent variant of HbA2 that is detected easily by high-performance liquid chromatography (HPLC), where it elutes in the S window. Our purposes were to define diagnostic criteria for the HbA2' trait using the Variant II (Bio-Rad, Hercules, CA) and to determine the prevalence of HbA2' in a metropolitan patient population. All Hb screens (N = 5,862) perform...

T.0b013e32835af7c1 Summary Aims: Classical carriers of b-thalassaemia are identified by a raised HbA2 level. Earlier studies indicated that the Filipino b-deletion has high raised HbA2 levels. The introduction of automated high performance liquid chromatography (HPLC) for thalassaemia screening is an important advance in technology for haematology laboratories. The BioRad Variant II Hb analyser...

HbA2' (also called Hb B2) is the most common delta-globin chain defect and is reported to occur in 1-2% of the African American population. The major clinical significance of HbA2' is that the failure to detect it might lead to an underestimation of the total HbA2, leading to failure to diagnose β-thalassemia minor. In order to diagnose β-thalassemia minor, both HbA2 and HbA2' levels must be co...

Screening for β -thalassemia trait (BTT) relies on measuring hemoglobin (Hb) A2. Since multiple factors can affect HbA2 levels, the screening can become unreliable. In 1356 healthy Arabs enrolled into a federally funded premarital BTT screening program, the effects of iron deficiency (ID), α (+)-thalassemia trait, gender, smoking, and tribalism on HbA2 were studied. The complete blood count and...

To the Editor Panyasai et al1 point out an important problem with the measurement of hemoglobin (Hb) A2. By comparing 11 cases of Hb Hope analyzed by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC; Bio-Rad β-Thalassemia Short Program, Bio-Rad, Hercules, CA), they document a much greater increase in the HbA2 value measured by CE than by HPLC. They also point out ...

Heterozygous beta-thalassemia (β-thal) carriers are characterized by microcytosis, hypochromia, and elevated HbA2 levels (≥3.5%) [1]. Although an elevated HbA2 level is a diagnostic parameter for β-thal, the interaction between d-globin gene mutation and β-thal can result in a normal HbA2 level, leading to misdiagnosis [2]. As δ-thalassemia (δ-thal) has no clinical significance, a reduced HbA2 ...

AIMS To compare high performance liquid chromatography (HPLC) with conventional methods for the estimation of blood haemoglobin A2 (HbA2) and haemoglobin F (HbF) concentrations in routine thalassemia screening. METHODS An HPLC system (the VARIANT Hemoglobin Testing System) was tested for precision and reproducibility in the measurement of HbA2 and HbF, and reference ranges were obtained for a...