Evaluation of the Sebia Capillarys 3 Tera and the Bio-Rad D-100 Systems for the Measurement of Hemoglobin A1c

Evaluation of effects from hemoglobin variants on HbA1c measurements by different methods

OBJECTIVES

The impact of seven hemoglobin variants (Hb Q-Thailand, Hb G-Honolulu, Hb Ube-2, Hb New York, Hb J-Bangkok, Hb G-Coushatta, and Hb E) on the outcome of HbA1c was investigated for six methods by comparing with liquid chromatography-tandem mass spectrometry (LC/MS/MS) reference method.

METHODS

Twenty-nine normal and 112 variant samples were measured by LC/MS/MS, Sebia Capillarys 3 TERA, Intelligene Biosystems QuanTOF, Premier Hb9210, Arkray HA-8190V, Bio-Rad D-100, and Tosoh G11, then evaluated for correlation, consistency, and mean relative bias among six methods. The lowest biological variation bias of ±2.8 % was an acceptable standard.

RESULTS

All methods showed poor correlation and consistency with LC/MS/MS for Hb E. The unacceptable biases were observed for Capillarys 3 TERA (-14.4 to -3.7 % for Hb Q-Thailand, Hb Ube-2, Hb New York, Hb J-Bangkok and Hb E), QuanTOF (-8.3 to -2.9 % for Hb Ube-2, Hb New York and Hb G-Coushatta), Premier Hb9210 (-18.3 to -3.6 % for Hb Q-Thailand, Hb Ube-2, Hb New York, Hb J-Bangkok and Hb E), HA-8190V variant mode (-17.3 to 6.6 % for Hb G-Honolulu, Hb Ube-2, Hb New York, Hb G-Coushatta and Hb E). All variant samples showed larger biases than ±2.8 % comparing HA-8190V fast mode, D-100, and G11 with LC/MS/MS.

CONCLUSIONS

The accuracy of different HbA1c methods was influenced by some Hb variants, especially Hb Ube-2 and Hb New York. Thus, laboratories need to choose appropriate methods to measure HbA1c with different Hb variants.

A Comparative Evaluation of HbA1c Measurement Methods and Their Implications for Diabetes Management

In this study, we assessed the correlations between hemoglobin A1c (HbA1c) measurements obtained using three different diagnostic methods, namely reversed-phase cation-exchange chromatography, high-performance liquid chromatography, and lateral flow immunoassay (LIFA) with an AnyLab F instrument. HbA1c levels measured with the AnyLab F instrument and those measured with the HA8190V, HA8180, and D100 instruments were strongly correlated. High R-square values and low p-values indicated significant and reliable correlations, supporting the clinical interchangeability of these methods. Notably, demographic and clinical analyses revealed uniform HbA1c levels across age groups, suggesting minimal age-related variations in HbA1c levels in the cohort. This finding has implications for diabetes management strategies across different age groups, emphasizing the versatility of the AnyLab F instrument. Overall an average HbA1c level of 7.857% among diabetes mellitus-diagnosed participants suggests moderately elevated HbA1c levels, underscoring the need for improved diabetes management. Younger individuals exhibited lower HbA1c levels, potentially owing to heightened awareness and treatment plan adherence. Conversely, older adults had higher HbA1c levels, likely influenced by age-related changes and comorbidities. Larger sample sizes and a comprehensive evaluation of various measurement principles are needed to strengthen the findings herein. Additionally, exploring additional biomarkers and assessing LIFA performance in larger sample sets will advance the clinical utility of HbA1c measurements.

Characterization of Samples with Minor P3 Peak Elevations in a High Pressure Liquid Chromatography System for HbA1c: Contributions of Hemoglobin Variants and Storage Conditions

BACKGROUND

In the Bio-Rad D-100TM (Bio-Rad, Hercules, CA) HPLC system for hemoglobin A1c (HbA1c) measurement, 7 peaks elute: HbA1a, HbA1b, HbF, LA1c, HbA1c, P3, and HbA0. HbA1c is calculated from the ratio of the HbA1c peak area to the total area, excluding HbF and peaks after HbA0, if present. A P3 peak >10% flags for potential interferences.

METHODS

We investigated 26 samples with elevated P3 peaks to determine the presence of hemoglobin variants, the effect of prolonged specimen storage in the P3 peak. The relationship between the P3 peak and the HbA1c concentration were also investigated.

RESULTS

No hemoglobin variants were identified when the P3 peak was <14% (n = 14). Hemoglobin variants were detected in 7 of 12 with a P3 peak between 17.0% and 28.2%. Sample storage at room temperature had minimum impact on the P3 peak area (n = 20); the average P3 bias was -0.5 (-8.1% bias) after 3 days and 0.6 (12.2% bias) after 5 days. P3 increased with increasing HbA1c concentrations in samples with P3 < 10%. Most samples with P3 above 10 and up to 14% had marked HbA1c elevations.

CONCLUSIONS

Minor elevations of the P3 peak were due only in part to hemoglobin variants, particularly in samples with P3 above 17% (below 28.2%). These elevations caused a decrease in HbA1c, whether hemoglobin variants are detected or not. Prolonged storage at room temperature did not cause P3 peaks to increase above 10%.

Identification of Hemoglobin Variants Prevalent in China and Their Effects on Hemoglobin A1c Measurements

OBJECTIVES

We aimed to evaluate the effects of hemoglobin (Hb) variants prevalent in China on HbA1c measurements and to identify them during HbA1c measurements.

METHODS

We evaluated a cation-exchange high-performance liquid chromatography (HPLC) method (Bio-Rad D-100), a capillary electrophoresis (CE) method (Capillarys 3 TERA), an immunoassay (Cobas c501), and a boronate affinity method (Premier Hb9210, as a comparative method) for HbA1c measurements in the presence of Hb variants prevalent in China.

RESULTS

The Bio-Rad D-100 and Capillarys 3 TERA gave specific retention times and numeric migration positions for each Hb variant, respectively, showing excellent interindividual reproducibility. All methods showed statistically significant differences (P < .01) for several variants. Clinically significant effects were observed for the Bio-Rad D-100 (Hb New York and Hb J-Bangkok), Capillarys 3 TERA (Hb New York and Hb J-Bangkok), and Cobas c501 (Hb New York). Among 297 samples with Hb variants, there were 75 (25.3%) unacceptable results for Bio-Rad D-100, 28 (9.4%) for Capillarys 3 TERA, and 19 (6.4%) for Cobas c501 compared with the results from Premier Hb9210.

CONCLUSIONS

Some Hb variants prevalent in China affect HbA1c measurements. The HPLC retention time and CE migration position can aid in the presumptive identification of Hb variants.

Comparison of Turbidimetric Inhibition Immunoassay, High-Performance Liquid Chromatography, and Capillary Electrophoresis Methods for Glycated Hemoglobin Determination

OBJECTIVE

The purpose of this study was to compare the performances of and evaluate the agreement among glycated hemoglobin values analyzed by using National Glycohemoglobin Standardization Program-certified and International Federation of Clinical Chemistry-standardized analyzers.

THIS CROSS-SECTIONAL STUDY WAS CONDUCTED AT THE

Armed Forces Institute of Pathology, Department of Chemical Pathology from March 2019 to May 2019.

METHODS

Glycated hemoglobin (HbA1c) was measured in the blood specimens from 100 patients on an ADVIA 1800 by a turbidimetric inhibitory immunoassay (TINIA), Sebia instrument by electrophoresis, and Bio-Rad Variant II Turbo system by high-performance liquid chromatography (HPLC). Quantitative variables were calculated as the mean ± standard deviation (SD). Precision and method comparisons were carried out according to Clinical and Laboratory Standards Institute recommendations. The results obtained from each analyzer were compared by correlation analysis. Method comparison was done by linear regression and Bland-Altman plots using the SPSS software version 24.

RESULTS

The mean ± SD HbA1c values from TINIA, electrophoresis, and HPLC were 7.188% ± 1.89%, 7.164% ± 1.866%, and 7.160% ± 1.85%, respectively. The between-run coefficients of variation for TINIA, electrophoresis, and HPLC were 0.64%, 0.61%, and 0.60%, respectively. All 3 showed good correlation (TINIA, R2 = .994, P = .00; electrophoresis, R2 = .992, P = 0.00; and HPLC, R2 = .994, P = 0.00).

CONCLUSION

The good clinical agreements of HbA1c and strong correlations between analyzers indicate that these analyzers can be used interchangeably.

A New α Chain Variant, Hb Heilongjiang (HBA2: c.49A>C), Found During Hb A1c Measurement

We here report a new hemoglobin (Hb) variant found in a Chinese woman. The presence of the Hb variant can be easily recognized by HbA_1c procedures based on ion exchange high performance liquid chromatography (HPLC) or capillary electrophoresis (CE) techniques. DNA sequencing revealed a new point mutation (HBA2: c.49A>C) at codon 16, resulting in an amino acid substitution from lysine to glutamine. Moreover, the Hb variant affected Hb A_1c determination by VARIANT II Turbo 2.0 and D100. We named the new Hb variant Hb Heilongjiang for the birthplace of the proband.

Strong correlation and high comparability of capillary electrophoresis and three different methods for HbA1c measurement in a population without hemoglobinopathy

The present study aimed to investigate the comparability of capillary electrophoresis (CE) and three different methods for HbA1c measurement. The 270 whole blood samples with normal hemoglobin profiles were analyzed for HbA1c values by the Roche turbidimetric inhibition immunoassay (TINIA), the Mindray enzymatic assay (EA), the Arkray high-performance liquid chromatography (HPLC) in comparison with the Sebia CE. The within-laboratory coefficient of variation of all four methods was within the accepted goal (<2%), showing good performance of all of these methods. Pairwise comparisons of HbA1c values obtained by CE and other methods were determined in both total group and subgroups (HbA1c levels of <6.5%, 6.5-8% and >8%). Mean differences of HbA1c values in all groups were very small in which the mean HbA1c value measured by EA was lower while those by TINIA and HPLC were higher than that of CE. The majority of different values were within the limits of agreement in Bland-Altman analysis, indicating good agreement between CE and the others. Less than 5% of percentage differences were out of the total allowable error limit in all groups, showing that differences of HbA1c values between CE and other methods were not clinically significant. Pairwise comparisons of HbA1c values of CE and the others in Passing-Bablok regression and Spearman rank correlation studies displayed high concordance and strong correlation in all groups. In conclusion, the present study showed strong correlation, high comparability and consistent results for HbA1c measurement between capillary electrophoresis and the other three different methods.

HbA1c: a review of non-glycaemic variables

Identification of the correlation between HbA1c and diabetic complications has yielded one of the most clinically useful biomarkers. HbA1c has revolutionised the diagnosis and monitoring of diabetes mellitus. However, with widespread adoption of HbA1c has come increasing recognition that non-glycaemic variables can also affect HbA1c, with varying clinical significance. Furthermore, the identification of a discrepancy between predicted and measured HbA1c in some individuals, the so-called 'glycation gap', may be clinically significant. We aimed to review the current body of evidence relating to non-glycaemic variables to quantify any significance and provide subsequent suggestions. A PubMed-based literature search was performed, using a variety of search terms, to retrieve articles detailing the non-glycaemic variables suggested to affect HbA1c. Articles were reviewed to assess the relevance of any findings in clinical practice and where possible guidance is given. A range of non-glycaemic variables have statistically significant effects on HbA1c. While the clinical implications are generally irrelevant, a small number of non-glycaemic variables do have clinically significant effects and alternative biomarkers should be considered instead of, or in addition to, HbA1c. There are a small number of non-glycaemic variables which have a clinically significant effect on HbA1c, However, the vast majority of non-glycaemic variables have no clinical relevance. While clinicians should have an awareness of those non-glycaemic variables with clinical significance, in the vast majority of clinical scenarios HbA1c should continue to be used with confidence.

Comparison of Enzymatic Assay for HBA1C Measurement (Abbott Architect) With Capillary Electrophoresis (Sebia Minicap Flex Piercing Analyser)

Objective

To compare the analytical performances of the enzymatic method (EM) and capillary electrophoresis (CE) for hemoglobin A1c (HbA1c) measurement.

Methods

Imprecision, carryover, stability, linearity, method comparison, and interferences were evaluated for HbA1c via EM (Abbott Laboratories, Inc) and CE (Sebia).

Results

Both methods have shown overall within-laboratory imprecision of less than 3% for International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) units (<2% National Glycohemoglobin Standardization Program [NGSP] units). Carryover effects were within acceptable criteria. The linearity of both methods has proven to be excellent (R2 = 0.999). Significant proportional and constant difference were found for EM, compared with CE, but were not clinically relevant (<5 mmol/mol; NGSP <0.5%). At the clinically relevant HbA1c concentration, stability observed with both methods was acceptable (bias, <3%). Triglyceride levels of 8.11 mmol per L or greater showed to interfere with EM and fetal hemoglobin (HbF) of 10.6% or greater with CE.

Conclusion

The enzymatic method proved to be comparable to the CE method in analytical performances; however, certain interferences can influence the measurements of each method.