Hemoglobins S and C: reference values for glycohemoglobin in heterozygous, double heterozygous and homozygous subjects, as established by 13 methods

Weykamp, C.W.; Martina, W. V.; vanderDijs, Fpl; Tj, Penders; Vanderslik, W; Muskiet, F D

doi:10.1016/0009-8981(94)90200-3

Cited by 21 publications

(11 citation statements)

References 14 publications

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“…The biological variation results from the fact that the composition of blood in each individual is slightly different. There are Hb derivatives such as carbamylated Hb and other adducts, and Hb forms that may interfere with the NGSP-SRL methods in particular; these are commercial methods with a broad spectrum of method principles (ion-exchange chromatography, immunoassays, affinity chromatography) (26 ). Theoretically, the influence of biological variation should be substantially reduced if the samples used are mixtures of blood from various donors rather than samples derived from single donors.…”

Section: Design and Logisticsmentioning

confidence: 99%

IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

et al. 2004

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Background: The national programs for the harmonization of hemoglobin (Hb)A1c measurements in the US [National Glycohemoglobin Standardization Program (NGSP)], Japan [Japanese Diabetes Society (JDS)/Japanese Society of Clinical Chemistry (JSCC)], and Sweden are based on different designated comparison methods (DCMs). The future basis for international standardization will be the reference system developed by the IFCC Working Group on HbA1c Standardization. The aim of the present study was to determine the relationships between the IFCC Reference Method (RM) and the DCMs. Methods: Four method-comparison studies were performed in 2001–2003. In each study five to eight pooled blood samples were measured by 11 reference laboratories of the IFCC Network of Reference Laboratories, 9 Secondary Reference Laboratories of the NGSP, 3 reference laboratories of the JDS/JSCC program, and a Swedish reference laboratory. Regression equations were determined for the relationship between the IFCC RM and each of the DCMs. Results: Significant differences were observed between the HbA1c results of the IFCC RM and those of the DCMs. Significant differences were also demonstrated between the three DCMs. However, in all cases the relationship of the DCMs with the RM were linear. There were no statistically significant differences between the regression equations calculated for each of the four studies; therefore, the results could be combined. The relationship is described by the following regression equations: NGSP-HbA1c = 0.915(IFCC-HbA1c) + 2.15% (r2 = 0.998); JDS/JSCC-HbA1c = 0.927(IFCC-HbA1c) + 1.73% (r2 = 0.997); Swedish-HbA1c = 0.989(IFCC-HbA1c) + 0.88% (r2 = 0.996). Conclusion: There is a firm and reproducible link between the IFCC RM and DCM HbA1c values.

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Section: Design and Logisticsmentioning

confidence: 99%

IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

et al. 2004

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“…Although relatively rare in Caucasians, in African-American populations the prevalence of sickle trait and HbC trait are 6-9 and 2-3%, respectively (4,5). The effects of Hb variants on several GHb methods have been investigated (6,7). The desire for rapid near-patient measurement of GHb has led to the development of rapid immunoassay methods for HbA k .. were buffer 1 from 0 to 0.8 min, buffer 2 from 0.8 to 2.2 min, and buffer 3 from 2.2 to 3.8, with a total run time of 5.4 min.…”

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confidence: 99%

Effects of Sickle Cell Trait and Hemoglobin C Trait on Determinations of HbA1c by an Immunoassay Method

1998

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“…In our present study, the A1c 2.2 Plus method exhibited no clinically significant effects with either variant Hb, but the VARIANT II method exhibited clinically significant effects for both Hb C and S traits. We have previously noted that another ion-exchange GHb method may intermittently show effects with Hb S trait samples, and we speculated that it may be attributable to variabil- Low serum concentrations of vitamin B 12 (cobalamin) have been observed in users of oral contraceptives (OCs) (1 ), in women during pregnancy (2 ), and in men treated with high doses of ethinylestradiol for prostate cancer (3 ).…”

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confidence: 99%

Effects of Hemoglobin C and S Traits on Glycohemoglobin Measurements by Eleven Methods

et al. 2005

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Patients with diabetes mellitus routinely have glycohemoglobin (GHb) testing performed to monitor glycemic control and assess risk for developing complications of their disease (1 ). The accuracy of several GHb methods can be adversely affected by the presence of hemoglobin (Hb) C or S trait (2-6 ). It has been estimated that there are at least 200 000 Americans with diabetes mellitus who also have either Hb C or S trait (6 ). We have recently shown that the presence of Hb C or S trait does not affect the accuracy of GHb measurements made by the CLC 330 boronate affinity HPLC method (7 ). We therefore evaluated the effects of Hb C and S traits on 11 commercial GHb methods, using the CLC 330 assay as the comparison method.Whole blood samples from individuals homozygous for Hb A (n ϭ 73) and heterozygous for Hb C or S (n ϭ 46 and 76, respectively) were collected in EDTA-containing tubes. After routine clinical testing had been completed, Hb variants were identified by inspection of chromatograms obtained with a VARIANT analyzer (Bio-Rad Laboratories) and the Beta Thal Short program run according to the manufacturer's instructions. Aliquots of these samples that had 4 -14% Hb A 1c were stored at 2-8°C and analyzed within 10 days of collection except for aliquots for the HA8160 and HA8160 Beta Thal (BT) methods, which were shipped on dry ice and stored frozen until analysis. Not all samples were analyzed by each analytic method. This study was approved by the Institutional Review Board of the University of Utah.Samples were analyzed by the following instruments/ methods: A1c 2.2 Plus and G7 (Tosoh); A1cNow (Metrika); D-10, DiaSTAT, and VARIANT II (Bio-Rad Laboratories); Dimension RxL (Dade Behring); HA8160 HbA1c and HA8160 BT (Menarini Diagnostics); and PDQ (Primus). All of these methods were used according to the manufacturers' instructions and have been certified by the National Glycohemoglobin Standardization Program (NGSP). The CLC 330 GHb analyzer (Primus) was used as the comparison method in an NGSP Network Laboratory with in-house calibrator materials and assigned values. Results for all methods are reported as NGSP Hb A 1c equivalents.For each test method, results obtained for each type of sample (homozygous Hb A, heterozygous Hb C, and heterozygous Hb S) were compared with those obtained by the CLC 330 comparison method. An overall test of coincidence of two least-squares linear regression lines was performed with SAS software (SAS Institute) to determine whether the presence of Hb C or S trait caused a statistically significant difference (P Ͻ0.01) in results relative to the comparison method. Deming regression analysis was performed to determine whether the presence of Hb C or S trait produced a clinically significant effect on GHb results. Given recommendations by the American Diabetes Association of an upper reference limit of 6% and an action limit of 8%, we chose Hb A 1c evaluation limits of 6% and 9%. After correcting for possible calibration bias by comparing results from the homozygous Hb A sample ...

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Hemoglobins S and C: reference values for glycohemoglobin in heterozygous, double heterozygous and homozygous subjects, as established by 13 methods

Cited by 21 publications

References 14 publications

IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

IFCC Reference System for Measurement of Hemoglobin A1c in Human Blood and the National Standardization Schemes in the United States, Japan, and Sweden: A Method-Comparison Study

Effects of Sickle Cell Trait and Hemoglobin C Trait on Determinations of HbA1c by an Immunoassay Method

Effects of Hemoglobin C and S Traits on Glycohemoglobin Measurements by Eleven Methods

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