Evidence for fetal antigen in human sarcoma

The interaction of Kaposi's sarcoma with monoclonal antibodies to human sarcoma and connective tissue differentiation antigens

Four monoclonal antibodies (McAbs) previously generated against human soft tissue sarcomas and reacting with connective tissue differentiation antigens were evaluated for their interaction with tissues obtained from patients with classic Kaposi's sarcoma. Biopsy was performed on active neoplastic lesions from the skin of 26 patients, frozen sections were prepared, and the binding of the McAbs was tested using the indirect immunofluorescence assay. Clinically uninvolved skin from the same patients as well as skin and muscle from eight non-cancer patients were treated similarly and served as controls. McAbs IXG11, 23H7, IIIE5, and 15G5 interacted strongly with the Kaposi's sarcoma lesions and weakly with the uninvolved skin in 22 of 26 (84%), 23 of 26 (88%), 12 of 14 (85%), and 1 of 6 (16%) of the patients, respectively. IXG11, 23H7, and IIIE5 interacted weakly with the skin of seven of eight non-cancer patients. McAb 15G5 was found to bind strongly to tumor lesions, to the respective uninvolved skin in four of five Kaposi's sarcoma patients, and also to skin and connective tissues of muscle from non-cancer patients. The mode of interaction was morphologically different for each McAb. It is suggested that McAbs IXG11, 23H7 and IIIE5 identify markers whose expression is markedly increased in Kaposi's sarcoma lesions as compared with uninvolved skin of the same patients. These markers may serve as immunologic probes for the investigation of this neoplastic process.

Soft tissue sarcomas of the extremity

In 1955, in a series of abstracts entitled "A Half Century of Effort to Control Cancer," Pack and Ariel wrote, "in each individual case, there is a constant battle of judgement between the wisdom of more radical amputation and the need for preservation of that important functional part." This dilemma remains with us today. In his paper on the histogenesis of tumors, Stout, relating to the philosophy of treatment, wrote that "the best chance of curing malignant tumors of the soft tissues lies in the hands of the therapist who makes the first attempt." Pack's words are as true today as they were in 1955, and although limb salvage is possible for many patients with soft tissue sarcomas, preservation of an extremity at the risk of patient survival is not a feasible option. Most efforts at less than amputative surgery must entail multimodality therapy. Although there are some reports of success with single-agent therapy, such as surgery alone, the majority of successful, nonamputative series include surgery with radiation and/or chemotherapy. It must be emphasized that an extremely important aspect of the treatment of these patients is the judgment and evaluation by the primary physician. Therefore it is extremely important that the primary physician be familiar with the many factors involved in prognosis, both in terms of local control and of systemic illness, in order for the patient to be informed of treatment options. If this is not possible, the patient should be referred to a center that is involved in active research protocols or treatments. Although rare, the soft tissue sarcomas remain among the most difficult to treat, even though over the years there has been significant progress in diagnosis, classification, and successful local control. Patient survival is based on a multitude of factors that include the histogenesis of the tumor, its grade, size, anatomical location, the surgical procedure performed, the use of preoperative or postoperative radiation, and the clinical stage of the disease--whether it is primary or metastatic. In time, it is probable that additional factors will be found.

An enzyme-linked immunosorbent assay (ELISA) for the detection of monoclonal antibodies recognizing surface antigens expressed on viable cells

A solid-phase enzyme-linked immunosorbent assay (ELISA) has been developed for detecting monoclonal antibodies binding to surface antigens expressed on viable adherent cells of tumor cell lines. This assay utilizes a sheep anti-mouse IgG to which a beta-galactosidase is linked. It is highly sensitive and permits quantification of IgG monoclonal antibody levels. In studies of monoclonal antibodies prepared against human tumors, the ELISA assay revealed the presence of antigens which were not seen using acetone-fixed cell immunofluorescence methods. This assay is safe, rapid, low cost, and gives reproducible quantitative results. As such it should prove useful to laboratories engaged in the study of antigens expressed on cell membranes.

Choice and specificity of complement in complement fixation assay

This study examines the relative activity of various complement sources in a variety of antigen-antibody (Ag-Ab) complement fixation assay systems. Studied were Ag-Ab systems of cytomegalovirus, adenovirus, Pneumococcus, Coccidiodes, and guinea pig kidney. Ab titers in each system were determined by microcomplement fixation assay using two batches of titrated rabbit, monkey, cat, dog, human cord, human adult, and guinea pig sera as complement sources. Assay sensitivity and Ab titers proved to be strongly related to the complement sources. There was considerable variation in the ability of Ag-Ab complexes to bind the complement of each of the species tested. Guinea pig, rabbit, and monkey sera gave comparable titers in four of the five Ag-Ab systems tested. Cat serum complement was able to detect anti-adenovirus and anti-Pneumococcus reactivity only. Human adult, human cord, and dog sera exhibited anti-complementary activity. The study emphasizes the importance of complement source in determining both the specificity and sensitivity of complement fixation assays in a given Ag-Ab system.

Comparison of multiple assays for detecting human antibodies directed against surface antigens on normal and malignant human tissue culture cells

Four separate assays of human antibody reactivity to four separate normal and malignant human tissue culture cell lines from two patients have been evaluated using a single highly-reactive allogeneic serum. The visual and end-point cytolysis assay and the 51Chromium release assay were equally sensitive in measuring complement mediated antibody cytoxicity and both were far more sensitive than a trypan blue dye exclusion assay. The assay of antibody reactivity by hemadsorption technique was about 10 times more sensitive than any of the cytotoxicity assays. This latter assay measures only IgG antibody however. These assays showed that cell lines from different patients may differ greatly in 'reactivity' to an allogeneic serum and emphasized the importance of utilizing tumor and normal cells from the same patient when using tissue culture cells to search for tumor specific reactivity. These observations emphasize the importance of utilizing multiple assays against paired normal and malignant cells from the same patient to be certain of the specificity and magnitude of the measured antibody.

Growing human sarcomas in culture

Efforts to establish human soft tissue and bone sarcomas in long-term cultures are described. Of 49 attempts 22 (45%) were successful, yielding cells that proliferated in vitro for 6 months or longer. Infrequent medium changes, maintenance of pH in physiologic range and avoidance of early trypsinization all appear to be important for survival of explanted cells and their initial growth under culture conditions. Cytologic criteria can be used to confirm that cells in established lines derive from malignant mesenchymal cells present in the tumors of origin.

Fetal antigens in retinoblastoma

Plasma carcinoembryonic antigen (CEA) and alpha fetoprotein (AFP) levels were studied in five patients with retinoblastoma. CEA and AFP were found elevated in four of five patients prior to therapy. Following enucleation and/or radiation therapy, the elevated values were significantly lowered. This preliminary study suggests that CEA and AFP levels may be of value in the diagnosis of retinoblastoma, and that serial CEA levels may be useful in evaluation of retinoblastoma patients after treatment.

Immunologic approaches to the diagnosis of cancer

A variety of immunologic approaches can be applied to the diagnosis of human cancer, and these have the potential advantages of specificity and sensitivity. Many tumor distinctive markers have been detected in the circulation of cancer patients. Cancer patients frequently have detectably depressed immune competence, but also have cell-mediated and humoral immune reactivity against tumor-associated antigens. Radiolabeling of specific antibodies may allow localization in vivo of tumors. With each of these potential immunodiagnostic approaches, it is necessary to systematically evaluate the assays and determine their value for specific clinical applications.

[Carcinofetal antigens. III. Further carcinofetal antigens (author's transl)]

The occurrance and significance of important carcinofetal antigens other than AFP and CEA are reported. These included the alpha 2 H-protein which is produced in the liver and increases in serum of patients with various tumors, the fetal sulphoglycoprotein antigen FSA from the gastric juice of patients with gastric cancer, the carcinoplacental alkaline phosphatase (REGAN-isoenzyme)which is found in the serum of patients suffering from e.g. bronchogenic, mammary, urogenital and gastrointestinal carcinomas, the beta-S-fetoprotein which is most likely to be identical with C-reactive protein, gamma-fetoprotein, the carcinofetal antigen in glial tumors (CFGA); ectopic production of placental hormones like human gonadotropin, placental lactogen, plasminogen-activators; leukemia-associated antigens. Furthermore, some other less known carcinofetal antigens are mentioned.

Tumor-specific cell-mediated immunity in household contacts of cancer patients

Patients with osteogenic sarcoma (and related tumors), hypernephroma, and breast carcinoma, and their household contacts were tested for tumor-specific cell-mediated immunity against these tumors with the use of a short-term chromium-51 release assay. This assay, reproducible over many months and well-correlated with the clinical course of the patients, was used to demonstrate that household contacts of patients with osteogenic sarcoma and breast carcinoma have specific immunity against the tumor type with which they have been in contact. In both types of tumors, the range of cytotoxicity values produced by lymphocytes from the household contacts was significantly higher than that of the normal population. The incidence of immunity was much higher in household contacts of patients with breast carcinoma than in those of patients with osteogenic sarcoma. Immunity was found with equal frequency in men and women, as well as in genetically and nongenetically related household contacts (guardians, adopted children, spouses). Immunity against hypernephroma was not demonstrated in either patients with hypernephroma or their household contacts.