Variation in Hemoglobin A1c Linked to Hemoglobin S: Comparison of Analysis Results from ion Exchange Chromatography and an Immunoturbidimetric Method
Niokhor Ndane Diouf *
Department of Biology and Functional Explorations, Assane Seck University of Ziguinchor, Senegal.
O. Boye
Department of Biochemistry, Iba Der Thiam University of Thiès, Senegal.
M. N. Coly
Department of Biology and Functional Explorations, Assane Seck University of Ziguinchor, Senegal.
M. B. Touré
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
M. Djité
Pharmaceutical Biochemistry Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
N. F. Coly
Biochemistry Department, Iba Der Thiam University of Thiès, Senegal.
I. Y. Soumah
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
F. Diédhiou
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
A. Samba
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
I. Faye
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
M. M. Guèye
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
H. H. M. Agossou
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
R. Ba
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
S. Thiam
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
A. Ndiaye
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
F. Cissé
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
F. Diallo
Immunology Laboratory, Cheikh Anta Diop University of Dakar, Senegal.
M. Sylla-Niang
Department of Biochemistry, Iba Der Thiam University of Thiès, Senegal and Medical Biology Laboratory of the Idrissa Pouye General Hospital, Dakar, Senegal.
A. Diatta
Department of Biology and Functional Explorations, Assane Seck University of Ziguinchor, Senegal.
*Author to whom correspondence should be addressed.
Abstract
Hemoglobin S can interfere with the measurement of glycated hemoglobin, an essential tool for diagnosing and monitoring diabetes. The objective of this study is to evaluate the analytical performance of 2 glycated haemoglobin assay methods.
A prospective cross-sectional study was conducted where 186 patients (61 homozygous sickle cell disease, 61 AA type subjects and 64 AS type subjects) were recruited. Glycated hemoglobin was measured by immunoturbidimetry method and ion exchange chromatography.
The coefficient of variation (CV) of the repeatability is 2.34% and 1.13% (normal rate) ; 2.32% and 1.65% (high rate) respectively for the immunoturbidimetric method and ion exchange chromatography. In reproducibility, the CV obtained are 3.23% and 2.64% (normal rate) and 3.27% and 2.22% (high rate), respectively for the immunoturbidimetric method and the ion exchange chromatography. Linearity is satisfactory for both methods. Mean glycated hemoglobin values show no significant difference (the P-value is equal to 0.09, 0.17 and 0.70 respectively in subjects AA, AS and SS) in the 2 methods for patients with the same hemoglobin electrophoretic profile.
The analytical performances of the 2 methods are good but their use is not recommended in the biological diagnosis of diabetes and pre-diabetes due to interference from hemoglobin S, especially in the case of homozygous sickle cell disease or in the case of composite heterozygosity.
Keywords: Hemoglobin S, glycated hemoglobin, immunoturbidimetric method, ion exchange chromatography