Effect of pre-analytical variables on glycohemoglobin measurements in routine clinical care.
OBJECTIVE
To analyze the contribution of the labile A1C fraction (L-A1C) and sample storage conditions on GHb measurements.


METHODS
L-A1C separation (HPLC Hitachi L-9100) was evaluated before and after sample treatment by four different methods for L-A1C removal. Different sample storage conditions were analyzed.


RESULTS
L-A1C may overestimate up to 1.64% total A1C if not properly separated. Samples were stable for up to 10, <1, and at least 100 days for whole blood stored at 4, -20, and -80 degrees C, respectively.


CONCLUSIONS
The presence of L-A1C may overestimate GHb results. Samples may be kept under refrigeration up to 10 days and at -80 degrees C if long-term storage is required.
Camargo
Joíza L
JL
Clinical Pathology Department, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil. jcamargo@hcpa.ufrgs.br
Felisberto
Mariane
M
Gross
Jorge L
JL
D000704:Analysis of Variance; D001774:Blood Chemical Analysis / Q000379:methods / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000592:standards; D006442:Glycated Hemoglobin / Q000032:analysis* / Q000592:standards*; D006801:Humans; D013048:Specimen Handling / Q000379:methods / Q000592:standards*
D006442:Glycated Hemoglobin