Degradation of glycated hemoglobin. Role of erythrocytic proteolytic enzymes and oxidant damage

Spectrum of hemoglobin disorders in southern Odisha, India: a hospital based study

Background:

Hemoglobin disorders are the leading health concern in the world including India. There is a paucity of literature on the spectrum of hemoglobin disorders in southern districts of Odisha state. This study was undertaken to elucidate the occurrence of different hemoglobin disorders in a tertiary health care facility of Odisha state, India.

Methods:

The study cases were suspected patients of all age groups advised for screening of different hemoglobin disorders. Hemoglobin disorders were screened by sickling slide test and high-performance liquid chromatography (HPLC) using the Variant-II hemoglobin testing system as per the manufacturer's guidelines.

Results:

Over 2 years, 2332 blood samples (including 1102 pediatric and 1230 adult cases) were investigated, out of which, 1380 (59.2%) of cases had abnormal hemoglobin disorders. The most common was sickle cell disorders (48.67%, 1135/2332) followed by β-thalassemia (11.32%, 264/2332). Some rare variants were detected as hemoglobin D^-Punjab, hemoglobin E, hemoglobin Lepore, hereditary persistence of fetal hemoglobin, hemoglobin with high P2 window, hemoglobin with high P3 window etc, Among the cases with abnormal hemoglobin disorders, 744 (53.9%), 545 (39.5%) and, 91 (6.6%) cases were found to have the heterozygous, homozygous and, double heterozygous state. Of the 188 ante-natal cases screened, 31.4% of cases had abnormal hemoglobin variants with sickle cell disorders being the most prevalent one.

Conclusion:

Along with the high occurrence of sickle cell disorders in the study area, some other rare hemoglobin disorders are also prevalent which calls for a large community-based cohort study.

P3 Fraction: Effect on HbA1c Values by HPLC

INTRODUCTION

The availability of the haemoglobin A1c test has been a major advance in diabetic care and its measurement has become an integral part for the management of diabetes. When glycated haemoglobin (HbA1c) is estimated by High Performance Liquid Chromatography (HPLC), one of the fractions that are eluted is known as "P3" fraction which is labelled as "degenerated haemoglobin". The P3 fraction is not taken into account while estimating HbA1c or HbA values.

AIM

To study the effect of P3 on the final reported value of HbA1c by HPLC and the significance of this fraction in the final chromatogram. The possibility that HbA1c fraction is under reported due to increase in P3 fraction was also examined.

MATERIALS AND METHODS

HbA1c, various fractions of HbA1 and P3 were estimated by HPLC method in 430 subjects. Patient data was divided into 3 groups on the basis of HbA1c% (group I - <6%, group II - 6 - 12%, group III - >12%).

RESULT

P3% as well as P3 area increases as the HbA1c increases (p-value - <0.001). Statistical significant increase was seen as HbA1c% increases, P3% also increases and correlation (r = 0.6) became stronger with increasing HbA1c levels. HbA1a%, HbA1b% fraction increases with increase in HbA1c% and HbA1a area, HbA1b area also shows the same increase with increasing HbA1c%.

CONCLUSION

From this study we conclude that sub fractions of glycated haemoglobin and P3 fraction influence the final reported value of HbA1c by HPLC. P3 fraction might indicate the possible presence of variant haemoglobin in the sample.