Pernet Pascal, Cuzon Gaëlle, Lim Soo-Kyung, Labau Nicole, Laghzal Aïcha, Vaubourdolle Michel
Service de Biochimie A, Hôpital Saint-Antoine, AP-HP, Paris, France.
Med Princ Pract. 2006;15(2):149-52. doi: 10.1159/000090921.
We evaluated ion exchange chromatography (IEC) on the Jeol Aminotac 500 analyzer for total homocysteine (tHcy) determination and compared it with an immunoassay method using fluorescence polarization on an Abbott IMx analyzer.
IEC method validation (linearity, limit of detection, precision, interference) was made according to the French Biology Society guidelines (Société Française de Biologie Clinique). Moreover, during a 2-month period, 55 plasma samples from patients scheduled for routine tHCy measurement were assayed by both methods for determining correlation.
The IEC method was found linear up to at least 190 micromol/l, and the limit of detection was 1.6 micromol/l. Precision was studied with 3 controls at 6, 15 and 30 micromol/l. Intra-assay coefficients of variation (n = 14) were 8.3, 3.1 and 2.3%, respectively, and inter-assay coefficients of variation (n = 15) were 9.6, 5.1 and 4.9%, respectively. No interference was found with other sulfur-containing amino acids (methionine, cysteine). An excellent agreement was found between IEC and fluorescence polarization (Deming regression; y = 0.99x - 1.23; r = 0.97; p < 0.001).
The IEC method for tHcy measurement shows adequate precision and correlates highly with the IMx assay. The IEC method is more time-consuming but less expensive in reagent cost and allows simultaneous determination of plasma methionine concentration which may help to explain the underlying mechanism responsible for hyperhomocysteinemia.
我们评估了在日本电子株式会社Aminotac 500分析仪上采用离子交换色谱法（IEC）测定总同型半胱氨酸（tHcy），并将其与在雅培IMx分析仪上采用荧光偏振免疫分析法进行比较。
根据法国生物学会指南（法国临床生物学会）进行IEC方法验证（线性、检测限、精密度、干扰）。此外，在为期2个月的时间里，对55例计划进行常规tHCy检测的患者的血浆样本采用两种方法进行检测以确定相关性。
发现IEC方法线性至少可达190微摩尔/升，检测限为1.6微摩尔/升。采用6、15和30微摩尔/升的3种对照品研究精密度。批内变异系数（n = 14）分别为8.3%、3.1%和2.3%，批间变异系数（n = 15）分别为9.6%、5.1%和4.9%。未发现与其他含硫氨基酸（蛋氨酸、半胱氨酸）存在干扰。发现IEC法与荧光偏振法之间具有极好的一致性（戴明回归；y = 0.99x - 1.23；r = 0.97；p < 0.001）。
用于tHcy检测的IEC方法显示出足够的精密度，且与IMx检测法高度相关。IEC方法耗时更长，但试剂成本更低，并且能够同时测定血浆蛋氨酸浓度，这可能有助于解释高同型半胱氨酸血症的潜在机制。
