Ca 72‐4 radioimmunoassay for the detection of the tag‐72 carcinoma‐associated antigen in serum of patients

Abstract

Monoclonal antibody (MAb)B72.3 has been used to detect the presence of TAG-72 in the serum of carcinoma patients. We have developed new anti-TAG-72 MAbs and have selected one of these, CC49, as the "catcher" MAb with 125I-B72.3 as the detecting antibody in a double-determinant immunoradiometric assay. This combination enabled the development of a sequential assay (designated CA 72-4) that showed optimal quantitative properties as demonstrated by such parameters as linear dose-response, high re-producibility, and lack of serum-matrix and "hook-back" effects. Only 3.5% of 744 normal sera and 6.7% of 134 sera from patients with benign gastrointestinal diseases had TAG-72 levels greater than 6 U/ml. Approximately 40% of 303 patients with gastrointestinal malignancies had serum TAG-72 levels of greater than 6 U/ml (55% of the patients with advanced disease). Thirty-six percent of patients with adenocarcinomas of the lung and 24% of patients with ovarian cancer (53% stage IV patients) also had elevated serum TAG-72 levels. A poor correlation was found between the carcinoembryonic antigen (CEA) and TAG-72 values of sera obtained from gastric cancer patients. Thirty-four percent of CEA negative cases were scored positive in the CA 72-4 assay, suggesting the complementarity of the CA 72-4 assay to CEA assays in the analysis of sera from patients with certain malignancies.

Concentration and distribution of tumor associated antigens TAG-72 and CEA in stomach cancer

“…2121 Double histochemical staining with antibodies to CEA and TAG-72 revealed that the two antibodies, in combination, reacted 26 In addition, Ohuchi et al confirmed that when monoclonal antibodies B72.3 and COL-6 (anti-CEA antibody) were simultaneously reacted with the gastric carcinoma tissue, more carcinomas were detected than with each individual antibody allone. 2 ' We found that CEA was expressed in 90% of the gastric tumors and TAG-72 was in 72.5% of lesions.…”

Apocrine Carcinoma, Adenopathies, and Raised TAG-72 Serum Tumor Marker

“…At this time, TAG‐72 is widely recognized as a serum tumor marker, in the monitoring of gastrointestinal adenocarcinomas 8 . The limit values usually employed in the literature range between 4.0 and 10 U/mL, the most common being 6.0 U/mL 9 . The information provided in the ELSA CA 72–4 kit indicates that in a group of 200 healthy adult subjects, 98.5% showed values lower than 4 U/mL.…”

Microplate chemiluminescence enzyme immunoassay for the quantitative evaluation of carbohydrate antigen 72-4 in human serum

“…At present, immunoassay for the determination of CA72-4 is mainly radioimmunoassay (RIA) [2,[13][14][15] and enzyme-linked immunoadsorbent assay (ELISA) [16,17] . The disadvantages in using the RIA methods [2,[13][14][15] , however, are that it requires special disposal and demonstrates a stability problem and long detection period. On the other hand, ELISA methods [16,17] show low detection limit (0.31 U/mL), narrow linear range (0-100 U/mL), and long conduction time.…”