[Comparison of plasma total homocysteine determinations in 9 French hospital laboratories by using 6 different methods].
A lot of methods are now available for total plasma homocysteine (tHcy) determination. Commercial kits using immunoassay, easier to use, begin to supplant in-house laboratory methods. Our aim is to evaluate the interchangeability of tHcy measurements in 9 French hospital laboratories. Six different method types were used: 2 gas chromatography-mass spectrometry (GC-MS), 2 HPLC with fluorescence detection subdivided in one in-house method and one commercial kit (Bio-Rad ), 3 fluorescence polarization immunoassays (FPIA), 1 enzyme immunoassay, 1 amino acid analyser, 1 capillary electrophoresis coupled with laser-induced fluorescence detection (EC-LIF). Each laboratory analysed 41 patient's plasma samples in which 8 samples contained added homocystine. Results were analysed for imprecision, recovery, and methodological differences. The mean among-laboratory imprecision (CV) ranged from 12.5 to 18% in function of plasma sample type and was identical to the mean among-method variation. In terms of recovery, we obtained underestimated results with immunoassays. The bias relative to the GC-MS method was less than   12.5% except for two laboratories, one using FPIA assay and the other EC-LIF. In conclusion, the interchangeability of tHcy results between laboratories is not satisfactory and does not allow us to evaluate cardiovascular risk linked to moderate increases of tHcy.
Ducros
V
V
Département de biologie intégrée, CHU Grenoble.
Candito
M
M
Caussé
E
E
Couderc
R
R
Demuth
K
K
Diop
M E
ME
Drai
J
J
Gerhardt
M F
MF
Quillard
M
M
Read
M H
MH
Sauvant
M P
MP
D001774:Blood Chemical Analysis / Q000379:methods* / Q000592:standards; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D019075:Electrophoresis, Capillary; D005453:Fluorescence; D016231:Fluorescence Polarization Immunoassay; D005602:France; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D007755:Laboratories, Hospital / Q000592:standards; D007834:Lasers; D013058:Mass Spectrometry; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic; D006710:Homocysteine