Hb Hebei [α20 (B1) His→Leu; HBA2:C.62A > T]: A Novel Hemoglobin Variant Found during Measurement of Glycated Hemoglobin.

We report a novel hemoglobin (Hb) variant found in a 34-year-old Chinese male during a routine measurement of glycated hemoglobin. The variant resulted in a P3 peak of 27.5% of the total Hb on high performance liquid chromatography (HPLC) with a glycated hemoglobin mode. However, no abnormal Hb peaks were observed in capillary electrophoresis (CE) with 3.1% Hb A2 and 96.9% Hb A. The amino acid substitution was determined by Sanger sequencing as α20 (B1) His→Leu; the corresponding DNA mutation was identified as CAC > CTC at the first position of codon 20 of the α-chain. This is the first description of the mutation, and we have named it Hb Hebei for the region of origin of the proband.

A New Hemoglobin Variant: Hb Tangshan [HBA1: c.239C > T, CD79(GCG > GTG)(Ala > Val)] Detected by MALDI-TOF MS.

In this report we decribed a new α-chain variant found during the measurement of hemoglobin A1c (Hb A1c) using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS). MALDI-TOF MS analysis detected an α-chain variant with a mass of 15,155 Da. However, this Hb variant was not detected during Hb A1c measurement by cation-exchange high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) methods. Sanger sequencing validated the presence of a heterozygous missense mutation [HBA1: c.239C > T, CD79(GCG > GTG)(Ala > Val)]. The observed 28 Da mass difference exactly matches the theoretical mass difference (28 Da) resulting from the substitution of alanine (89.079) with valine (117.133). As this represents the initial documentation of the mutation, we named it Hb Tangshan after the proband's residence.

Longitudinal progression of diabetes mellitus in Wolfram syndrome: The Washington University Wolfram Research Clinic experience.

OBJECTIVE: (1) Describe the progression of diabetes mellitus over time in an observational study of Wolfram syndrome, a rare, genetic, neurodegenerative disorder, which often includes diabetes mellitus and is typically diagnosed during childhood or adolescence. (2) Determine whether C-peptide could be used as a marker of diabetes progression in interventional trials for Wolfram syndrome. METHODS: N = 44 (25F/19M) participants with genetically confirmed Wolfram syndrome attended the Washington University Wolfram Research Clinic annually from 2010 to 2019. Medical history, physical examinations, blood sampling, and questionnaires were used to collect data about diabetes mellitus and other components of Wolfram syndrome. Beta-cell function was assessed by determination of C-peptide during a mixed meal tolerance test. Random coefficients models evaluated the rate of progression of C-peptide over time, and power analyses were used to estimate the number of subjects needed to detect a change in C-peptide decline during an intervention trial. RESULTS: 93.2% of patients had diabetes mellitus. Mean HbA1c across all study visits was 7.9%. C-peptide significantly decreased with increasing duration of diabetes mellitus (p < 0.0001); an optimal break point in C-peptide decline was identified to occur between 0.1 and 2.3 years after diabetes mellitus diagnosis. Twenty patients per group (active vs. control) were estimated to be needed to detect a 60% slowing of C-peptide decline during the first 2.3 years following diabetes diagnosis. CONCLUSION: C-peptide declines over time in Wolfram syndrome and could potentially be used as a marker of diabetes progression in interventional studies for Wolfram syndrome, especially within the first 2 years after diabetes diagnosis.

A New Case of Hb Headington (HBB: c.217A>C) Due to a New DNA Transversion, Found in a Patient with Type 2 Diabetes Mellitus.

We here report a novel case of Hb Headington [ß72(E16)Ser→Arg, HBB: c.217A>C, p.Ser73Arg], in a 68-year-old woman with type 2 diabetes mellitus (T2DM). Glycosylated hemoglobin (Hb) was measured by capillary electrophoresis (CE). The spectrum showed abnormal peaks between the A0 and A2 peaks. DNA sequencing demonstrated a mutation on the HBB gene, which predicted a substitution of serine to arginine at position 73 in the ß-globin chain. Moreover, this amino acid substitution occurs at the same position as Hb Headington [ß72(E16)Ser→Arg, HBB: c.219T>A, p.Ser73Arg], which showed increased oxygen affinity.

Hb Alessandria [ß37(C3)Trp→Leu; HBB: c.113G>T]: a Novel Variant on the ß-Globin Chain with Slightly Increased Affinity for Oxygen Detected by Capillary Electrophoresis.

We report a novel mutation on the ß-globin gene in a 68-year-old woman of Sicilian origin living in Alessandria, Italy. This mutation produces a hemoglobin (Hb) variant of Hb A that was detected by the capillary electrophoresis (CE) method during measurement of Hb A1c. The variant Hb did not separate from Hb A using different high performance liquid chromatography (HPLC) instruments. Direct DNA sequencing revealed a G>T transversion at codon 37 and subsequent substitution of a tryptophan residue for a leucine residue. The new Hb variant was named Hb Alessandria [ß37(C3)Trp→Leu; HBB: c.113G>T]. The p50 value was slightly decreased while the stability test at 37 °C in isopropyl alcohol and the main erythrocyte parameters were normal. Overall, the patient appeared clinically normal.

Hb Kalundborg [ß79(EF3)Asp→Glu; HBB: c.240C>a], a Possible Low-affinity Hemoglobin Variant Detected during Hb A1c Measurement.

A previously unknown hemoglobin (Hb) variant was detected during measurement of glycosylated Hb (Hb A1c) after the introduction of a new high performance liquid chromatography (HPLC) apparatus. Subsequent DNA sequencing revealed a heterozygous single nucleotide substitution at codon 79 (C>A) on the ß-globin gene changing an amino acid [ß79(EF3)Asp→Glu; HBB: c.240C>A]. The new Hb variant was named Hb Kalundborg after the place of origin of the proband. Heterozygosity for this mutation appears to have no clinical significance in itself except for a possibly slightly lower oxygen affinity. However, it interferes with Hb A1c measurement by HPLC, causing a falsely high Hb A1c concentration when using the G11 apparatus with clinical implications possibly to follow.

Hb Kirikiriroa [α57(E6)Gly→Cys; HBA1: c.172G>T]: A Novel Unstable α-Globin Variant with Oxidized Derivatives Interfering with Hb A1c.

We report the identification of a novel hemoglobin (Hb) variant [α57(E6)Gly→Cys; HBA1: c.172G>T], to be referred to as Hb Kirikiriroa. The variant was detected in five subjects from two families, with familial relationship established between the families following diagnosis. A persistently elevated Hb A1c over a 1-year period prompted hemoglobinopathy screening in an adolescent male of New Zealand (NZ) European descent (case 1). Capillary electrophoresis (CE) revealed the variant was negatively charged and susceptible to oxidation, with multiple abnormal peaks detected (0.4-5.1% total Hb). Hb A1c analysis by cation exchange high performance liquid chromatography (HPLC) was the first indication of the variant in a pregnant female of NZ European descent (case 2). Cases 1 and 2 had normal complete blood counts. Isopropanol stability testing provided evidence the variant was unstable. We herein describe the characterization of Hb Kirikiriroa and clinical significance of the variant for interference with Hb A1c analysis by CE and cation exchange HPLC.

Impact of diabetes mellitus on outcome after transcatheter aortic valve replacement: Identifying high-risk diabetic population from the OCEAN-TAVI registry.

OBJECTIVES: To identify the vulnerable diabetic cohort in patients undergoing transcatheter aortic valve replacement (TAVR). BACKGROUNDS: Considerable controversy remains about whether specific cohort exists in which presence of diabetes mellitus (DM) carries adverse risk of mortality after TAVR. METHODS: Of the 2588 patients who were enrolled in the OCEAN-TAVI registry, 2526 patients with glycohemoglobin data were analyzed. The individuals were divided into DM and non-DM groups according to previous medical history of DM or using diabetic medicine, and increased HbA1c values (≥6.5%) at baseline. The primary endpoint of this study was 2-year all-cause mortality after TAVR. RESULTS: The follow up rate of clinical outcome at 1-year was 2514/2526 (99.5%) and median follow-up period was 22.5 months. DM group had 699 (27.7%) patients, in which 153 (21.9%) was diagnosed by increased HbA1c levels without previous medical history of DM. Kaplan-Meier curve of 2-year all-cause mortality presented significant difference between patients with and without DM (p = 0.029). In addition, patients with low-density lipoprotein cholesterol (LDL-C) levels > 100 mg/dl and left ventricular ejection fraction (LVEF) < 40% had great risk of mortality after TAVR (LDL-C: hazard ratio [HR] 1.82, p < 0.001; LVEF: HR 2.61, p = 0.002, respectively). CONCLUSIONS: Presence of DM was significantly associated with poor outcome after TAVR and adverse effect of DM was remarkable in patients with relatively higher LDL-C levels and reduced LVEF under 40%. These subtypes may need intensive control of cardiovascular risk factors, including DM, before and after TAVR.

Association between Hb A1c and Severity of COVID-19 Patients.

This study aimed to examine the relationship between Hb A1c levels and the clinical course of coronavirus-19 (COVID-19) patients. Sixty-six COVID-19(+) patients with high Hb A1c and 46 with average Hb A1c and 30 COVID-19(-) patients with average Hb A1c were included. Hb A1c levels and parameters examined in COVID-19(+) patients were compared between groups, and correlation analysis was performed between these parameters and Hb A1c levels. The effect of Hb A1c levels on intensive care unit (ICU) admission and mortality rate in COVID-19 patients was analyzed with the χ2 test. It was observed that hemoglobin (Hb) and arterial oxygen saturation (SaO2) levels of the COVID-19 (+) groups was lower than the COVID-19 (-) group, while ferritin, D-dimer, procalcitonin (PCT), and C-reactive protein (CRP) levels were higher. The COVID-19 (+) group with high Hb A1c had higher lactate dehydrogenase (LDH), PCT and D-dimer levels than the other two groups, while Hb, partial arterial oxygen pressure (PaO2) levels were lower. The Hb A1c levels of the COVID-19 (+) groups were positively correlated with absolute neutrophil count (ANC), LDH, PCT and (K+) levels, while negatively correlated with Hb and PaO2 levels. Hb A1c was found to be associated with the inflammation process, coagulation disorders and low PaO2 in COVID-19 patients. The COVID-19 patients with high Hb A1c levels had a higher mortality rate than other COVID-19 patients. Using Hb A1c measurements with other prognostic markers would contribute to the patient's risk of death assessment.

Hb A2-Calderdale [δ2(NA2)His→Asn; HBD: c.7C>A] and Misdiagnosis of Type 2 Diabetes Mellitus Due to Interference with Hb A1c When Using Cation Exchange High Performance Liquid Chromatography: A Case Report.

The Hb A2-Calderdale variant [δ2(NA2)His→Asn, HBD: c.7C>A] was described as a novel variant in 2014. However, a high performance liquid chromatography (HPLC) peak was never identified indicating that this fraction could be 'hiding' somewhere else in the chromatogram. In this case report, we present evidence that the physiochemical properties of Hb A2-Calderdale resemble those of Hb A1c, resulting in a coelution in variant mode on the Tosoh G8 but not the Tosoh G11. This coelution results in an overestimation of Hb A1c and can potentially cause misdiagnosis of type 2 diabetes mellitus (T2DM).

Hb Jishui [HBA1: c.225C>G, Codon 74 (GAC>GAG), Asp→Glu]: A Novel α Chain Hemoglobin Variant Detected During Hb A1c Measurement.

Here we report a novel α chain hemoglobin (Hb) variant found in a 74-year-old Chinese male. We accidentally discovered this Hb variant during the measurement of Hb A1c by a capillary electrophoresis (CE) method (Hb A1c program, CapillaryS3 TERA). However, Hb analysis with the Hb program of CapillaryS3 TERA and the VARIANT II™ ß-Thalassemia Short Program showed no indication of the Hb variant. Sanger sequencing revealed a new missense mutation on the HBA1 gene [HBA1: c.225C>G, codon 74 (GAC>GAG), Asp→Glu]. We named it Hb Jishui after the birthplace of the proband.

A Novel α-Globin Chain Variant, Hb Nanchang [HBA2: c.46G>A, Codon 15 (GGT>AGT) (Gly→Ser)], Detected by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Here we report a new α chain variant accidentally discovered during Hb A1c measurement by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) that revealed the presence of a variant α chain with a mass of 15155 Da. However, this hemoglobin (Hb) variant cannot be detected by the first-line methods such as cation exchange high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). Sanger sequencing confirmed the presence of a heterozygous missense mutation [HBA2: c.46G>A, codon 15 (GGT>AGT), (Gly→Ser)]. The theoretical mass difference (30 Da) due to the substitution of amino acid glycine to serine matched the actual measured mass difference (29 Da). As this is the first report of the mutation, we named it Hb Nanchang after the place of residence of the proband.

The Effect of a Customized Nutrient-Profiling Approach on the Glycated Hemoglobin Levels of Patients With Type 2 Diabetes: Quasi-Experimental Study.

BACKGROUND: Presently, dietary management approaches are mostly oriented toward using calorie-counting and diet-tracking tools that draw our attention away from the nutritional value of our food. To improve individuals' dietary behavior, primarily that of people with type 2 diabetes, a simple technique is needed to increase their understanding of the nutritional content of their food. OBJECTIVE: This study aimed to design, develop, and evaluate a customized nutrient-profiling tool called EasyNutrition. EasyNutrition was built to introduce the new concept of nutrient profiling by applying the Intelligent Nutrition Engine, an algorithm that we developed for ranking different food recipes based on their nutritional value. This study also aimed to investigate the efficacy of EasyNutrition in lowering glycated hemoglobin (HbA1c) levels and improving dietary habits among people with type 2 diabetes. METHODS: We evaluated the utility of EasyNutrition using design science research in three sequential stages. This paper has elaborated on the third stage to investigate the efficacy of EasyNutrition in managing type 2 diabetes. A quasi-experimental study was conducted in a diabetes treatment center (n=28). The intervention group utilized EasyNutrition over 3 months, whereas participants in the control group utilized the standard of care provided by the center. Dietary habits and HbA1c levels were measured to capture any change before and after experimenting with EasyNutrition. RESULTS: The intervention group (n=9) exhibited a statistically significant change between the pre- and postexposure results of their HbA1c (t9=2.427; P=.04). Their HbA1c dropped from 8.13 to 6.72. This provided preliminary evidence of the efficacy of using a customized nutrient-profiling app in reducing HbA1c for people with type 2 diabetes. CONCLUSIONS: This study adds to the evidence base that a nutrient-profiling strategy may be a modern adjunct to diabetes dietary management. In conjunction with reliable dietary education provided by a registered dietician, EasyNutrition may have some beneficial effects to improve the dietary habits of people with type 2 diabetes.

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 HbA1c 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 A1c determination by VARIANT II Turbo 2.0 and D100. We named the new Hb variant Hb Heilongjiang for the birthplace of the proband.

Antenatal haemoglobin A1c centiles: does one size fit all?

BACKGROUND: In New Zealand, haemoglobin A1c measurements are routinely offered at booking, preferably before 20 weeks gestation, to detect pre-existing hyperglycaemia. A haemoglobin A1c <5.9% (41 mmol/mol) is considered normal based on the reference range for the non-pregnant population. AIMS: To determine pregnancy-specific haemoglobin A1c centiles by gestation and ethnicity. MATERIALS AND METHODS: This is a population-based observational study of pregnancies uncomplicated by diabetes (pre-existing or gestational) with ≥1 haemoglobin A1c measurement. Haemoglobin A1c centiles were calculated from data extracted from electronic laboratory and clinical records for pregnancies during 2008-2010. RESULTS: Included were 6800 pregnancies, European 80% (5462), Maori 6% (415), Pacific Islander 3% (196) and 11% (727) 'Others' (mostly Asian). Haemoglobin A1c levels fell with increasing gestation, reaching a nadir at 24 weeks, a trend verified by longitudinal data from 112 women. The 97.5th centile for haemoglobin A1c in European women was 5.76% (39.5 mmol/mol) at 8+0  weeks, 5.70% (38.8 mmol/mol) at 16+0  weeks, and 5.65% (38.3 mmol/mol) at 24+0  weeks. Non-European women had both higher plasma glucose levels (although within the range considered normal) and higher mean haemoglobin A1c levels compared with Europeans; mean (SD) difference in haemoglobin A1c in Maori +0.13% (0.05) (+1.4 mmol/mol (0.5)), Pacific +0.20% (0.03) (+2.2 mmol/mol (0.3)), 'Others' +0.10% (0.03) (+1.1 mmol/mol (0.3)). CONCLUSIONS: The New Zealand haemoglobin A1c cut-point ≥5.9% (41 mmol/mol) for identifying hyperglycaemia in early pregnancy is greater than the 97.5th centile in European and 'Other' women. Utilising population haemoglobin A1c centiles adjusted by gestation may thus better guide management decisions.

The role of socio-economic and clinical factors on HbA1c in children and adolescents with type 1 diabetes: an Italian multicentre survey.

OBJECTIVE: To identify the role of the family's socio-economic and clinical characteristics on metabolic control in children and adolescents with type 1 diabetes. METHODS: In this cross-sectional, multicentre study, 768 subjects with type 1 diabetes under 18 years of age were consecutively recruited from January 2008 to February 2009. Target condition was considered for HbA1c values <7.5% (<58 mmol/mol). A multiple correspondence analysis (MCA) was performed to analyze the association between the socio-economic and clinical characteristics of the participants. A logistic regression analysis was performed to identify factors associated with the subjects metabolic control. In both analyses, the family's socio-economic status was represented, measured by the Hollingshead Four-Factor Index of Social Status (SES) or by parental years of education. RESULTS: A total of 28.1% of subjects reached target HbA1c values. The MCA identified a strong association between at-target condition and several factors: high levels of SES or high levels of parental education, the use of the carbohydrate counting system, the use of insulin pumps, the use of the insulin delivery system over a short period of time, a normal body mass index. The logistic regression analysis showed that SES and the mother's years of education were significantly associated with the target condition [odds ratio (OR): 1.01, 95% confidence interval (CI): 1.01-1.03, p = 0.029; OR: 1.05, 95% CI: 1.01-1.10, p = 0.027, respectively). CONCLUSIONS: Personal, clinical, and family characteristics were found to be associated with HbA1c target. Their identification can be crucial in addressing strategies to optimize metabolic control and improve diabetes management.

Hb Belluno [ß111(G13)Val→Gly;ß133(H11)Val→Val (HBB: c.335T > G;402G > C)]: Incidental Detection of a New Clinically Silent ß Chain Variant During Hb A1c Determination by High Performance Liquid Chromatography.

A previously unreported ß chain variant, Hb Belluno [ß111(G13)Val→Gly;ß133(H11)Val→Val (HBB: c.335T > G;402G > C)], was incidentally discovered in a woman suffering from diabetes, during glycated hemoglobin (Hb A1c) assay. Its presence was suspected because of a small abnormal peak with a retention time just shorter than that of normal Hb A1c. Standard high performance liquid chromatography (HPLC), capillary zone electrophoresis (CZE) and agarose gel electrophoresis did not allow to separate the variant from Hb A. The reversed phase HPLC of globin chains showed the presence of a heterozygous ß-globin variant amounting to approximately 43.5% of the total ß chains. Later, this variant was found in five other members of the same family and DNA sequencing analysis confirmed a ß-globin gene mutation. The variant is clinically silent in all patients and showed a slight instability with both heat and isopropanol tests. The other three mutations at this locus also affect stability. Hemoglobin (Hb) variants may invalidate the results of Hb A1c analysis and could result in mismanagement of diabetes. A comment alerting the requesting clinician to the presence of the Hb variant must be appended to the Hb A1c result. Additionally, many Hb variants can be chromatographically and/or electrophoretically silent. Therefore, when the clinician suspects a variant Hb, it is not sufficient to get a negative response from an HPLC screening test to rule it out. A dialogue with the pathologist is essential, involving exchange of information and sharing a diagnostic work-up including surveys to assess Hb stability and oxygen affinity, as much as DNA sequencing.

Hb A1c Determination by Capillary Electrophoresis is an Efficient Method for Detecting ß-Thalassemias and Hemoglobin Variants.

Glycated hemoglobin (Hb A1c) determination by multicapillary zone electrophoresis (MZE) can additionally be used to detect Hb A2, Hb F and most common hemoglobin (Hb) variants. We assessed the effectiveness of this method for detecting ß-thalassemia (ß-thal), δß-thalassemia (δß-thal) and most common Hb variants. Moreover, Hb F/Hb A2 is evaluated as an index for discriminating between ß- and δß-thal traits. The theoretical ß-thalassemia major (ß-TM) birth rate in our healthcare area is calculated and contrasted with real data. A MZE technique was used for Hb A1c measurements in 27,724 patients. Previous criteria for carrier detection were established and subsequently confirmed by molecular biology techniques. Positive predictive value (PPV) was 100.0%. The prevalence of ß-thal trait (including δß-thal) was 0.34%. The most prevalent mutations (estimated per 100,000 population) were HBB: c.118C > T (57.7%), HBB: c.93-21G>A (50.5%), HBB: c.92 + 1G > A (43.3%), HBB: c.92 + 6T > C (32.5%) and HBB: c.20delA (18.0%) for ß-thalassemias, and Hb S (HBB: c.20A > T) (32.5%) and Hb J-Baltimore (HBB:c.3880T>A) (28.9%) for Hb variants. We found a paradoxical result between the theoretical ß-TM birth rate and real data. We calculated an optimal Hb F/Hb A2 index cutoff of 0.71 for discriminating between ß- and δß-thal traits. This method is highly cost-effective for detecting ß-thalassemias and common Hb variants. Prevalence results match previous data for the Spanish population. Heterogeneity of mutations in Spain has markedly increased as a consequence of migration. The Hb F/Hb A2 index cutoff could be used to predict δß-thal trait.

Hb Kalavasos [HBA2: c.275T > A; p.Leu92His]: a Novel α Chain Hemoglobin Variant.

We present a case of a novel pathogenic variant, Hb Kalavasos [α91(FG3)Leu→His (α2); HBA2: c.275T > A; p.Leu92His (NM_000517.4)]; this codon was previously numbered 91 on the α2-globin gene that was discovered following routine Hb A1c testing on a 65-year-old female of Cypriot origin. The band, seen by high performance liquid chromatography (HPLC) but not capillary zone electrophoresis (CZE), was confirmed as a hitherto undescribed a chain variant, that we have named Hb Kalavasos for the Cypriot village of family origin of the proband.

A Mosaic Expression of a Hb J-Amiens (HBB: c.54G > T; p.Lys18Asn) and its Interference with Hb A1c Analysis.

We report the case of a 56-year-old Caucasian woman in whom hemoglobinopathy screening was triggered following an aberrant Hb A1c analysis. Preliminary diagnosis of the hemoglobin (Hb) variant was obtained through cation exchange high performance liquid chromatography (HPLC) and gel electrophoresis. DNA analysis confirmed the presence of Hb J-Amiens [ß17(A14)Lys→Asn; HBB: c.[54G > C or 54G > T)]. However, an unbalanced ratio between wild type and mutant signal after direct sequencing and a lower than expected percentage of this Hb variant led to the suggestion of a mosaic expression. Furthermore, different methods [capillary zone electrophoresis (CZE), cation exchange HPLC and boronate affinity] were tested to study the possible interference of this variant with Hb A1c measurements. These investigations showed a clinically relevant difference between the methods tested. Hb A1c analysis may lead to the discovery of new Hb variants or mosaicism for previously described Hb variants. This may have genetic consequences for the offspring of carriers and brings about the question of partner testing.