癌胚抗原单克隆抗体放射免疫分析和临床初步应用

应用杂交瘤技术,获得了8种CEA单克隆抗体(McAb),这8中McAb经~(125)I标记NCA,NFA,NCA(J)抑制试验,证明是针对CEA抗原决定簇的,取其中的三种 McAb混合后,其亲和常数为2×10~(-8)M,应用此混合McAb检测239例人次血清标本,85例正常人的CEA 平均值为3.6±9.1ng/ml,其中96％少于30mg/ml,而 5％位于30～50ng/ml。在 128 例肿瘤患者中,81例结直肠癌,阳性检出率为44％;22 例胃癌为55％;21例肺癌为57％;4例肝癌为25％。在91 例消化道肿瘤病理检测中阳性率达79％,正常胃对照18例皆为阴性。

RADIOIMMUNOASSAY OF CEA MONOCLONAL ANTIBODIES AND ITS CLINICAL APPLICATION

Eight monoclonal antibodies (McAb) to carcinoembryonic antigen (GEA) were obtained by fusion'&i mouse spleen fells immunized with purified CEA that extracted from a hepatic metastaic tumor mass of a colon-carcinoma and from mouse myeloma cells (SP 2/0) .It was proved that these McAbs were all specific to CEA antigenicepitopes as examined with 125I-NGA and 125I-NFA inhibition test. All of these 8 McAbs 3 were mixed to form a mixture with am affinity constant of 2×10-8M (Scatchart plot). In a preliminary radioimmunoassay of the mixture with 239 serum samples, the average value of 85 normal healthy cases was 3.6 ±9.1 ng/ml. 95% of them were <30 ng/ml,while 5% were 30-50ng/ml. Therefore, 50ng/ml is defined as the upper limit of the normal range. Among 128 cancer patients,the positive rates were 44% in 81 colorectal carcinomas,55% in 22 gastric carcinomas,57% in 21 lung cancers and 25% in 4 liver carcinomas. No positive case was found in 26 non-maligant diseases. The results were analysed statistically with very significant difference between normal and cancer groups (P<0.01).