结直肠癌患者血清抗-癌胚抗原抗体的检测及其临床意义

Measurement and clinical implication of circulating antibodies against carcinoembryonic antigen in patients with colorectal carcinoma

目的探讨结直肠癌患者血清抗-癌胚抗原(CEA)特异性抗体的存在情况及其临床意义。方法随机选取69例初治、无免疫系统疾病、资料完整的结直肠癌病例分为观察组,对照组为28例良性肠道疾病患者和37例健康体检者。所有病例治疗前检测血清CEA(ECLIA)、IgG、IgA、IgM(免疫透视比浊法定量测定)、抗-CEA抗体(间接-ELISA法),免疫组化(LSAB)检测肿瘤组织CEA。用竞争抑制法检测抗体的特异性。结果结直肠癌患者血清CEA含量升高者(≥5ng/mL)为37.7%(26/69),抗-CEA(IgG或IgM)抗体阳性者为63.8%(44/69),两者联合检测阳性率升至84.0%(58/69)。良性肠道疾病患者和健康体检者无血清CEA升高者,血清抗-CEA抗体阳性者分别为10.7%(3/28)、10.8%(4/37)。血清抗-CEA抗体与血清CEA、淋巴结转移、Dukes’分期和免疫球蛋白含量有显著相关关系(P<0.05)。抗-CEA抗体阳性与阴性患者的5年生存率差异有显著性(P<0.05)。结论结直肠癌患者血中存在抗-CEA抗体,是一种比CEA更敏感的肿瘤标记物。它作为肿瘤标记物和预后因素有待在进一步的大型多中心随机临床研究证实。

Objective To evaluate the clinical significance of anti - CEA antibodies in the serum of patients with colorectal carcinoma. Methods In the prospective study, complete data of 69 patients with colorectal carcinoma in 2002 were collected. Control groups included 28 patients with benign intestinal conditions and 37 healthy volunteer blood donors. CEA was tested by electrochemiluminescence immunoassay （ECLIA）. The immune globulin was measured by immunonphelometry. Tumor tissue CEA was detected by immunohistochemistry. Circulating antibodies against CEA were measured by an indirect enzyme -linked immunosorbent assay （ELISA）. The specificity of the anti -CEA antibodies was performed by inhibition assay. Results CEA was elevated （ ≥5 ng/mL） in 26 out of 69 patients （ 37.7% ） and was not undetectable among the control groups. Anti - CEA antibodies of the IgG or IgM isotype were detected in 44 out of 69 pa- tients （63.8%） , whereas in 3 out of 28 benign intestinal conditions （ 10. 7% ） and in 4 out of 37 health blood donors （10. 8% ）. All the differences were statistically significant （P 〈 0.05 ）. Anti- CEA antibody had statistically correlation with CEA levels, lymph nodes metastasis and the staging of Dukes＇（ P 〈 0. 05 ）. Anti - CEA antibody was a statistically significant independent favorable factor in recurrence - free survival. Conclusion Anti - CEA antibodies can be detected in a significant proportion of the colorectal cancer patients as a as a tumor marker complementary to CEA. Their presence is associated with improved recurrence - free survival. These results need to be confirmed in large well - controlled ran- domized clinical trials （RCT）.