Rose A M, Tongate C, Valdes R
Department of Pathology, University of Louisville, KY 40292, USA.
Ann Clin Lab Sci. 1995 Jan-Feb;25(1):13-9.
Hemoglobin A1C (HbA1C) methods based on charge separation of Hb species are subject to interference from carbamylated Hb (carb Hb). Carb Hb adducts are formed via interaction of terminal amino groups of HbA with isocyanic acid, after the spontaneous dissociation of urea to cyanate. It is hypothesized that a new immunoassay method, using a monoclonal antibody that recognizes the N-terminus of the Hb beta-chain and its sugar moiety, should be refractory to cross-reactive interference from carb Hb. To test this hypothesis, Hb was carbamylated in vitro and co-migration of carb Hb assessed with HbA1C using an electrophoretic method. Densitometric scans - post sodium cyanate incubation and electrophoretic separation - showed a 5 to 7 fold elevation of the HbA1C peak only, while HbA1C values obtained using immunoassay were unaffected. Also assessed was carbamylation interference in vivo, and a positive proportional bias with the electrophoretic system (Y) was observed compared to the immunoassay system (X) (y = 1.2x - 0.21 percent). Others have shown that carb Hb may cause a clinically significant false elevation in patient HbA1C values, when methods based on charge separation of Hb species are used. It is our conclusion, however, that while carb Hb may play a role, the differences observed in this study are largely due to calibration.
基于血红蛋白（Hb）种类电荷分离的糖化血红蛋白（HbA1C）检测方法容易受到氨甲酰化血红蛋白（carb Hb）的干扰。在尿素自发解离为氰酸盐后，carb Hb加合物通过HbA的末端氨基与异氰酸的相互作用形成。据推测，一种使用识别Hbβ链N端及其糖部分的单克隆抗体的新型免疫测定方法，应该对carb Hb的交叉反应干扰具有抗性。为了验证这一假设，在体外对Hb进行氨甲酰化，并使用电泳方法评估carb Hb与HbA1C的共迁移情况。氰酸钠孵育和电泳分离后的光密度扫描显示，仅HbA1C峰升高了5至7倍，而使用免疫测定法获得的HbA1C值未受影响。还评估了体内氨甲酰化干扰情况，与免疫测定系统（X）相比，观察到电泳系统（Y）存在正的比例偏差（y = 1.2x - 0.21%）。其他人已经表明，当使用基于Hb种类电荷分离的方法时，carb Hb可能会导致患者HbA1C值出现临床上显著的假性升高。然而，我们的结论是，虽然carb Hb可能起作用，但本研究中观察到的差异很大程度上是由于校准所致。
