Xeptagen SpA, Marghera, Venice, Italy.
Clin Chem Lab Med. 2010 Feb;48(2):217-23. doi: 10.1515/CCLM.2010.044.
Squamous cell carcinoma antigen-immunoglobulin M (SCCA-IgM) is a useful biomarker for the risk of development of hepatocellular carcinoma (HCC) in patients with cirrhosis due to its progressive increase associated to HCC evolution. In patients with cirrhosis, other assays have been affected by interfering reactivities of IgM. In this study, the analytical specificity of the SCCA-IgM assay was assessed by evaluating SCCA-IgM measurement dependence on different capture phases, and by measuring the recovery of SCCA-IgM reactivity following serum fractionation.
Serum samples from 82 patients with cirrhosis were analyzed. SCCA-IgM was measured using the reference test (Hepa-IC, Xeptagen, Italy) that is based on rabbit oligoclonal anti-squamous cell carcinoma antigen (SCCA) and a dedicated ELISA with a mouse monoclonal anti-SCCA as the capture antibody.
SCCA-IgM concentrations measured with the reference assay (median value=87 AU/mL) were higher than those measured with the mouse monoclonal test (median value=78 AU/mL). However, the differences in the SCCA-IgM distribution were not statistically significant (p>0.05). When SCCA-IgM concentrations measured with both tests were compared, a linear correlation was found (r=0.77, p<0.05). Fractionation of the most reactive sera by gel-filtration chromatography showed that total recovery of SCCA-IgM reactivity was seen only in the fractions corresponding to components with a molecular weight higher than IgM and SCCA (>2000 kDa) with both tests.
The equivalence of both SCCA-IgM assays and the absence of reactivity not related to immune complexes support the analytical specificity of SCCA-IgM measurements. The results validate the assessment of SCCA-IgM for prognostic purposes in patients with cirrhosis.
由于与 HCC 演变相关的进行性增加，鳞状细胞癌抗原-免疫球蛋白 M（SCCA-IgM）是肝硬化患者发生肝细胞癌（HCC）风险的有用生物标志物。在肝硬化患者中，其他检测方法受到 IgM 干扰反应的影响。在这项研究中，通过评估 SCCA-IgM 测量对不同捕获阶段的依赖性，以及测量血清分级分离后 SCCA-IgM 反应性的恢复情况，评估了 SCCA-IgM 检测的分析特异性。
分析了 82 例肝硬化患者的血清样本。使用参考检测（Hepa-IC，Xeptagen，意大利）测量 SCCA-IgM，该检测基于兔多克隆抗鳞状细胞癌抗原（SCCA）和专用 ELISA，其捕获抗体为鼠单克隆抗 SCCA。
参考检测测量的 SCCA-IgM 浓度（中位数=87 AU/mL）高于鼠单克隆检测测量的浓度（中位数=78 AU/mL）。然而，SCCA-IgM 分布的差异无统计学意义（p>0.05）。当比较两种检测方法测量的 SCCA-IgM 浓度时，发现存在线性相关性（r=0.77，p<0.05）。通过凝胶过滤色谱对最具反应性的血清进行分级分离显示，仅在用两种检测方法均可见到 SCCA-IgM 反应性的总回收率，这仅出现在对应于分子量高于 IgM 和 SCCA（>2000 kDa）的组分的级分中。
两种 SCCA-IgM 检测方法的等效性以及与免疫复合物无关的反应性缺失支持 SCCA-IgM 测量的分析特异性。这些结果验证了在肝硬化患者中评估 SCCA-IgM 用于预后目的的方法。
