Lack of precision in HbA(1c) values on variant II in cases of hemoglobin Q India

Incidental Detection of Hemoglobin Variants During Evaluation of HbA1c

HemoglobinA1c (HbA1c) is used to diagnose Diabetes mellitus and monitor glycemic control over the previous eight to twelve weeks in diabetic patients. Detection of HbA1c by cation exchange-high performance liquid chromatography (CE-HPLC) gives a chromatogram by which abnormal hemoglobin variants are also picked up. Some of these may interfere with HbA1c values affecting clinical management. Due to increased inter-state migration as well as medical tourism, there is a high possibility of finding various hemoglobin variants in any part of India. We did a prospective analysis over 1.5 years, of the hemoglobin variants detected during all the HbA1c runs. The HbA1c was tested on Bio-Rad D10 dual HbA2/F/A1c platform, which uses the CE-HPLC method. Every chromatogram was carefully studied to look for unknown peaks. The samples showing unknown peaks >6% were re-run in extended HbA2/F mode to categorize the hemoglobin variants. We had 9595 HbA1c samples, of which 70 cases showed a variant window. There were 40 males and 30 females, age ranging from 28 to 76 years. The different hemoglobin variants detected were HbD, HbE and HbS in heterozygous state, high HbF (with a differential diagnosis of HPFH heterozygous and delta-beta thalassemia heterozygous), HbE homozygous, HbQ heterozygous and HbJ heterozygous. We conclude that in the process of monitoring glycemic control using HbA1c, we can also pick-up hemoglobin variants. Hence, it is essential to review HbA1c graphs, so that the diagnosis of hemoglobin variants is not missed and the HbA1c reported is reliable.

Hemoglobin variants detected by hemoglobin A1c (HbA1c) analysis and the effects on HbA1c measurements

Background:

Hemoglobin (Hb) A1c is a tool widely used to monitor long-term glycemic control in diabetic patients. The objective of our study is to compare the HbA1c values measured on high performance liquid chromatography (HPLC) and immunoassay in patients who were detected to have hemoglobin variant after HbA1c analysis.

Materials and Methods:

We compared the HbA1c values measured using the Arkray Adams A1c HA-8160 (HPLC method) and Roche Cobas Integra (immunoturbidimetric method) from diabetic patients who were diagnosed with hemoglobin variants.

Results:

Forty-three diabetic patients were diagnosed with hemoglobin variants: 13 elevated Hb F, 12 Hb E trait, seven Hb S trait, seven Hb D trait, two Hb E / beta-Thalassemia, one Hb C trait, and one homozygous Hb S.

Conclusion:

Knowledge of hemoglobin variants affecting HbA1c measurements is essential, in order to avoid mismanagement of diabetic patients.

Identification of hemoglobin Q India (alpha 1-64 Asp-His) through ARMS-PCR. First report from Pakistan

Various hemoglobinopathies have been reported from Pakistan excepting the rare ones like hemoglobin Q India. Our purpose of study was to identify the mutation (alpha 1 64 aspartate to histidine) through amplification restriction mutation system-polymerase chain reaction (ARMS-PCR) in patients where hemoglobin Q has been detected via high performance liquid chromatography (HPLC) and also to evaluate the cost effectiveness of the two technologies. All patients irrespective of age and gender who underwent HPLC for identification of their hemoglobin variant during January 1, 2006 to January 30, 2007 were studied. The blood samples with unknown peak at a retention time of 4.7 min were evaluated at the molecular level. Analysis of HPLC tracings of 11,008 subjects over a thirteen-month period identified ten individuals with hemoglobin Q. Male to female ratio was 1:1.5 and their age was variable ranging from 1 to 49 (mean 22.8) years. The mean hemoglobin level was 11.3 g/dl while MCV (fl) and MCH (pg) were 73.0 and 20.8 respectively. HPLC showed an unknown peak of 17.7% which was detected as Hb Q. ARMS based PCR showed Hb Q specific product of 370 bp and also an amplified product of 766 bp as the control fragment in these samples. This is the first ever report that documents the presence of Hb Q India (alpha 64 Asp to His) in Pakistani population. We recommend that HPLC be used as a useful screening tool especially in developing countries where PCR facilities may not be accessible.