A comparative evaluation of the analytical performances of premier resolution-high-performance liquid chromatography (PR-HPLC) with capillary zone electrophoresis (CZE) assays for the detection of hemoglobin variants and the quantitation of HbA0, A2, E, and F

OBJECTIVES

Hemoglobinopathies, including thalassemia and hemoglobin (Hb) variants, are common hematological disorders in tropical countries. Accurate and precise separation of hemoglobin types and reliable quantitation are necessary for differential diagnosis of these disorders.

METHODS

We have evaluated the analytical performances of premier resolution-high-performance liquid chromatography (PR-HPLC; Trinity Biotech, Co. Wicklow, Ireland) to assist in the presumptive diagnosis of thalassemia and Hb variants commonly found in Southeast Asian countries. HbA0, HbA2, HbE, and HbF levels were separated and quantified in 120 blood samples from unrelated adult subjects and compared with those analyzed by capillary zone electrophoresis (CZE; CAPILLARYS™ 2, Sebia, Norcross, GA, US). The Hb analysis patterns of Hb variants obtained from the PR-HPLC system were also compared to those obtained from HPLC (VARIANT II, β-thalassemia Short Program, Bio-Rad, Laboratories, Hercules, CA, US) and CZE systems.

RESULTS

The PR-HPLC had excellent precision with a coefficient of variation (CV) for HbA2 quantitation of 3.8 % within-run and 5.2 % between-run. The levels of HbA2/E quantified by the PR-HPLC system correlated well with those of the CZE system (r=0.997). In addition, thalassemia interpretation results obtained from the PR-HPLC and the CZE showed 100 % agreement. Moreover, chromatograms of the PR-HPLC were also comparable to those of VII-HPLC and CAP2-CZE electropherograms.

CONCLUSIONS

The PR-HPLC system would be applicable to diagnose common forms of thalassemia and Hb variants in Southeast Asia.

Proficiency testing program for hemoglobin E, A2 and F analysis in Thailand using lyophilized hemoglobin control materials

Background:

There is no external quality assessment (EQA) program for hemoglobin analysis that uses lyophilized hemoglobin control materials with HbA2/E in levels as high as those found in people with the β-thalassemia trait, HbE trait, β-thalassemia/HbE disease or homozygous HbE; these are all found frequently in the southeast Asian population. The aim of this study was to evaluate the efficiency of the control materials used in the established proficiency testing (PT) program at the Associated Medical Sciences-Clinical Service Center (AMC-CSC), Chiang Mai University, Chiang Mai, Thailand.

Methods:

The PT program for Hb analysis and the thalassemia interpretation was established in compliance with ISO/IEC17043:2010. Three cycles per year were performed in 2015 and 2016. In each cycle, three different types of control material were provided to the participants. Each participant analyzed the control materials in the same manner as in their routine practices. Hb analysis results and their thalassemia interpretation codes were entered into the report form and sent back to AMC-CSC.

Results:

The number of participants increased from 63 in 2015 to 76 in 2016. In addition, the number of participants who took part in all three cycles increased from 95.2% (60/63) in 2015 to 100% (76/76) in 2016. All participants reported the correct Hb measurement and type; however, misinterpretations in thalassemia diagnosis were noted.

Conclusions:

The lyophilized hemoglobin control materials prepared at AMC-CSC were used successfully in our PT program. However, the study results indicate the need for further improvement in thalassemia interpretation skills for laboratory staff.