Application of monoclonal antibody, NCC-ST-439 for serodiagnosis of carcinoma patients

NCC-ST-439是一种抗胃癌移植瘤的单抗。NCC-ST-439确定的抗原为大分子糖蛋白，分子量大于5×10~(-6)DA，以唾液酸糖残基为抗原表位。为了评价其作为肿瘤标记物的有效性，建立了一种新的肿瘤相关碳水化合物抗原的夹心放射免疫分析方法。检测了600多份正常献血员和各种恶性和非恶性疾病患者的血清样本。在正常献血员中，除7例年轻女性外，97.0%(226/233)的血清抗原值均为阴性。在恶性疾病患者中，抗原值阳性率为34.2%(82/240)，其中胰腺癌为64.0%(16/25)，复发性结直肠癌为66.7%(16/24)，乳腺癌为54.5%(6/11)。在非恶性疾病中，抗原值阳性率为6.0%(7/116)，但低于20单位/毫升。良性肝胆疾病如胆结石、肝炎、肝硬变的抗原值阳性率尤其低，仅为4.3%(1/23)。对结直肠癌患者血清的系列检测表明，抗原值随病情变化而变化。我们认为，联合检测血清NCC-ST-439抗原和CEA和/或CA19-9可用于多种肿瘤的监测。

NCC-ST-439 is a monoclonal antibody raised against a gastric carcinoma xenograft. The antigen defined by NCC-ST-439 was found to be high molecular glycoprotein, had a molecular weight more than 5x10^6Da., with sialyl-sugar residue as its epitope. A sandwich radio-immunometric assay for this new tumor-associated carbohydrate antigen was developed in order to evaluate its usefulness as a tumor marker. More than 600 serum samples from normal donors and patients with various malignant and non-malignant disorders were assayed. The cut-off value was set at 12 units/ml. In normal donors, 97.0%(226/233) of sera had a negative antigen value except for 7 serum samples from young females. In patients with malignant disorders, 34.2%(82/240) had a positive antigen value, particularly 64.0% (16/25) of patients with pancreatic carcinoma, 66.7% (16/24) of patients with recurrent colorectal carcinoma and 54.5% (6/11) of patients with recurrent breast carcinoma. In patients with non-malignant disorders, 6.0% (7/116) had a positive antigen value, but this was lower than 20 units/ml.The positive rate in benign hepatobiliary disorders including gallstones, hepatitis and liver cirrhosis was especially low at 4.3%(1/23). Serial examinations of sera from patients with colorectal carcinoma revealed that antigen value changed according to disease status. We concluded that determination of serum NCC-ST-439 antigen in combination with CEA and/or CA19-9 would be useful for monitoring a wide variety of carcinomas.