EHA Library - The official digital education library of European Hematology Association (EHA)

CYTOMETRY OF HBA1C
Author(s): ,
Fabrice Malergue
Affiliations:
Beckman Coulter Immunotech,MARSEILLE,France
,
Andreas Van Agthoven
Affiliations:
Beckman Coulter Immunotech,MARSEILLE,France
,
Christophe Godefroy
Affiliations:
Beckman Coulter Inc,Miami,United States
Enrique M Rabellino
Affiliations:
Beckman Coulter Inc,Miami,United States
(Abstract release date: 05/19/16) EHA Library. Malergue F. 06/09/16; 135101; PB2201
Dr. Fabrice Malergue
Dr. Fabrice Malergue
Contributions
Abstract
Abstract: PB2201

Type: Publication Only

Background
In the field of routine diabetes testing, flow cytometry does not play an important role.

Aims
In an innovative effort we try to show that the application of flow cytometry of a widely accepted parameter as HbA1c can improve the understanding of the course of the disease and can be applied to other diseases as well.

Methods
In a new experimental assay, blood was diluted in an environment that removed the red cell membrane and precipitated hemoglobin. The particles of precipitated and condensate hemoglobin look similar to normal red cells in flow cytometry. The precipitation is irreversible and the particles in physiological conditions can be stained with a fluorescent conjugated monoclonal antibody against HbA1c. In an inhibition assay with hemoglobin in solution it was shown that the accessibility of the HbA1c antigen did not differ between soluble and condensate hemoglobin. Another property of the condensate particle in flow cytometry is that the side scatter of the particles reflects the hemoglobin content of the original red cell. The cellular hemoglobin content of samples that were analyzed on a Sysmex hematologic analyzer and the mean values of the side scatter of the same samples that were treated as above for flow cytometry showed good correlation.

Results
A good correlation was also found with conventional HbA1c measurements. From 120 diabetic patients, the HbA1c percentage values were obtained by taking the mean of three different methods as measured by a reference laboratory. The blood samples of these patients were also analyzed by cytometry and the quotients of the side scatter and the HbA1c staining reflecting the HbA1c percentage were compared with the HbA1c reference values. Frozen hemoglobin particles with a known HbA1c percentage were used as a reference. The novelty of this assay is that using flow cytometry, the HbA1c percentage can be measured cell by cell. This permits to see beyond the mean value of HbA1c percentage of a sample. Presenting a lower deformability, cells with the highest HbA1C concentration may play a crucial role toward microvasculature obstruction.To further assess the validity of the approach of red cell age measurement, we collected from 26 diabetic patients the booklets in which they had administrated several glucose values every day over a time-span of several months. At the moment of collection of the booklets, blood samples were taken and cytometry of HbA1c was performed. The glucose values of the booklets, showed considerable varieties during a day. Therefore a mean daily glucose was used. The comparison of the two sets of data showed a striking correlation.

Conclusion
Showing proof of principle of HbA1c cytometry and the possibility to read the memory of the blood, other parameters can be read. Within the assay cellular hemoglobin content can be read against time. Also the representation of cells of a certain age can be established. Both these parameters could be of interest for diseases like anemia.

Session topic: E-poster

Keyword(s): Hematopoiesis, Hematotoxicity, Hemoglobin
Abstract: PB2201

Type: Publication Only

Background
In the field of routine diabetes testing, flow cytometry does not play an important role.

Aims
In an innovative effort we try to show that the application of flow cytometry of a widely accepted parameter as HbA1c can improve the understanding of the course of the disease and can be applied to other diseases as well.

Methods
In a new experimental assay, blood was diluted in an environment that removed the red cell membrane and precipitated hemoglobin. The particles of precipitated and condensate hemoglobin look similar to normal red cells in flow cytometry. The precipitation is irreversible and the particles in physiological conditions can be stained with a fluorescent conjugated monoclonal antibody against HbA1c. In an inhibition assay with hemoglobin in solution it was shown that the accessibility of the HbA1c antigen did not differ between soluble and condensate hemoglobin. Another property of the condensate particle in flow cytometry is that the side scatter of the particles reflects the hemoglobin content of the original red cell. The cellular hemoglobin content of samples that were analyzed on a Sysmex hematologic analyzer and the mean values of the side scatter of the same samples that were treated as above for flow cytometry showed good correlation.

Results
A good correlation was also found with conventional HbA1c measurements. From 120 diabetic patients, the HbA1c percentage values were obtained by taking the mean of three different methods as measured by a reference laboratory. The blood samples of these patients were also analyzed by cytometry and the quotients of the side scatter and the HbA1c staining reflecting the HbA1c percentage were compared with the HbA1c reference values. Frozen hemoglobin particles with a known HbA1c percentage were used as a reference. The novelty of this assay is that using flow cytometry, the HbA1c percentage can be measured cell by cell. This permits to see beyond the mean value of HbA1c percentage of a sample. Presenting a lower deformability, cells with the highest HbA1C concentration may play a crucial role toward microvasculature obstruction.To further assess the validity of the approach of red cell age measurement, we collected from 26 diabetic patients the booklets in which they had administrated several glucose values every day over a time-span of several months. At the moment of collection of the booklets, blood samples were taken and cytometry of HbA1c was performed. The glucose values of the booklets, showed considerable varieties during a day. Therefore a mean daily glucose was used. The comparison of the two sets of data showed a striking correlation.

Conclusion
Showing proof of principle of HbA1c cytometry and the possibility to read the memory of the blood, other parameters can be read. Within the assay cellular hemoglobin content can be read against time. Also the representation of cells of a certain age can be established. Both these parameters could be of interest for diseases like anemia.

Session topic: E-poster

Keyword(s): Hematopoiesis, Hematotoxicity, Hemoglobin

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