Samuel O. Freedman

The preparation of purified carcinoembryonic antigen of the human digestive system from large quantities of tumor tissue.

Abstract A method is described for the preparation of the carcinoembryonic antigen (CEA) of the human digestive system from large quantities of metastatic tumor tissue. The purification process is far more rapid than that originally described, and results in a higher yield of CEA than that previously obtained. The procedure involves the sequential steps of extraction in perchloric acid, column chromatography on Sepharose 4B and Sephadex G-200, and preparative electrophoresis on Sephadex G-25. The final product shows a high degree of uniformity as determined by both physiochemical and immunochemical criteria.

Carcinoembryonic antigen (CEA) in clinical medicine. Historical perspectives, pitfalls and projections

Carcinoembryonic antigen (CEA) was first detected by the immunization of rabbits with human colon cancer extract. The techniques of antiserum absorption and immunologic tolerance were employed in an attempt to render the resulting antisera tumor‐specific. Using the procedures of precipitation and precipitin‐inhibition in gel media, hemagglutination, passive cutaneous anaphylaxis and immunofluorescence, CEA was identified exclusively in all cancers of gastrointestinal origin and fetal digestive organs in the first two trimesters of gestation. The subsequent development of radioimmunoassays for CEA has raised the question of the presence of this material, in very low concentrations, in other normal and diseased (cancerous and noncancerous) tissue, but the problem of cross‐reactivity within a family of closely related, but nonidentical, molecules remains to be resolved. CEA was initially purified by a sequence of steps involving extraction in perchloric acid, sieve chromatography, and preparative block electrophoresis. The molecule was characterized as a relatively heterogeneous acid glycoprotein with a molecular weight of approximately 200,000 and its carbohydrate (one‐half to two‐thirds of the molecule) and protein composition were determined. CEA was localized to the glycocalyx of the colon cancer cell and it was found that the CEA could be released from this site into the circulation of the cancer patient, where it could then be detected by means of radioimmunoassay. The clinical implications of this observation, as they have evolved over the past eight years, form the basis of the papers that constitute this supplement.

Response of lymphocytes from patients with gastrointestinal cancer to the carcinoembryonic antigen of the human digestive system

The carcinoembryonic antigen (CEA) of the human digestive system is a tumor‐specific constituent of all entodermally‐derived digestive organ cancers. It is, however, also found in fetal gut, pancreas, and liver in the first two trimesters of gestation. Hum oral antibodies to the CEA have been demonstrated in most patients with non‐met static gastrointestinal cancers but have no apparent relationship to the course of the disease. The present investigation was designed to study cell‐mediated immunity to the CEA. The test system employed was that of lymphocyte transformation upon in vitro exposure to the antigen. No significant response was obtained with lymphocytes from patients with gastrointestinal cancer, pregnant women, or normal individuals. Hence, with the test system employed, no evidence for a cell‐mediated immune reaction to the CEA was observed.

Ability of anti-brain heteroantisera to distinguish thymus-derived lymphocytes in various species☆

Abstract Anti-brain heteroantisera prepared in rabbits against mouse and dog brain tissues appear to distinguish T from B lymphocytes in homologous species, although some sensitivity of bone marrow cells to these antisera is also observed. Cross-reactivity of these antisera with heterologous thymus cells could not be demonstrated. The brain T lymphocyte antigen (BAθ) could not be detected in fetal mouse brain and was only present in neonatal dog brain in low concentration, increasing in concentration in a sigmoidal fashion with maturation. Rabbit antisera to human brain tissue (frontal lobe) did not have corresponding specificity for human thymus cells. Anti-mouse brain antisera are not immunosuppressive in allografted mice.

Carcinoembryonic antigen: Current clinical applications

For many years investigators have searched for a simple blood test that will easily detect the presence of malignancy in the human body. Various attempts have been made to utilize either biochemical or morphologic changes in blood samples as an indication of cancer. To date, none of these has been universally successful, and it is for this reason that there has been considerable recent interest in immunologic methods. Such methods for detecting foreign substances in tissue fluids have 2 major advantages over other techniques. The first is that they are exquisitely sensitive, i.e., one can detect nanogram quantities of a given material; and the second is the extreme specificity of most immunologic procedures. The studies to be described on carcinoma of the colon and digestive system have been carried out in our laboratory since 1963 in close collaboration with Drs. Phil Gold, John Krupey, David Thomson, and Michael Gold. The reason that carcinoma of the colon was selected for investigation was that it does not metastasize locally. In other words, if a primary carcinoma of the colon is resected surgically, there are no local metastases in the gut beyond 7 cm. distally or proximally to the lesion. This property enables the investigator to obtain normal control tissue from the same patient who harbors the malignancy. The object of our initial experiments was to demonstrate in primary cancers of the colon a substance that is antigenic and is not present in normal colon, diseased tissues, or any other type of tumor. Investigators have searched for so-called tumor-specific antigens for many years, but there have been several problems associated with these studies in humans. It is fairly easy to demonstrate tumor-specific antigens in animals when tumors are induced with viruses or chemical carcinogens. However, in the human situation there is the problem of confusion between tumor-specific antigens and individual-specific antigens. Every individual has a set of antigens or isoantigens of his own. Therefore, normal bowel from a second individual cannot be utilized as a satisfactory control tissue. An additional difficulty has been that in other studies

Endocrinopathy and IgA deficiency

Abstract Three cases of IgA deficiency occurring in association with endocrine hypofunction—Turners syndrome, hypothyroidism, and diabetes—are described. The significance of IgA deficiency associated with chromosome abnormalities are discussed in view of the present finding of IgA deficiency in a patient with Turners syndrome displaying a karyotype of 44 autosomes, X, isochromosome of the long arm of X.

The effect of the sequence of erythrocyte sensitization on the bis-diazotized benzidine hemagglutination reaction.

The BDB-hemagglutinating properties of six different antigen-antibody systems were studied. In each case two tests were performed in which the erythrocytes were sensitized by the addition of BDB either before or after the addition of the antigen It was found that in those systems where the antigenic determinants were protein in nature the two methods of sensitization gave rise to virtually identical titers. However, in the systems in which the antigens contained phenolic and/or carbohydrate determinant groups, markedly higher titers were obtained if the BDB was mixed with the erythrocytes before rather than after the addition of the antigenic material. It is suggested that the nonspecific adsorption of carbohydrate and phenolic groups onto red cell surfaces in the absence of BDB is the most likely explanation for this phenomenon. This dual method of BDB hemagglutinin has potential applications as a method of investigating the chemical nature of antigenic determinants of unknown composition.

Leukopenia, leukoagglutinins, and low IgM in a family with severe febrile illnesses.

Abstract A family is described in which the propositus and four of his ten siblings suffered severe virus-like illnesses. Leukopenia, leukoagglutinins and low IgM found in several family members were associated with a history of severe febrile illness. It is possible that the described abnormalities have pathogenic significance and possible mechanisms are discussed.

The isolation of the γ subunit of fetal hemoglobin (HbF) and its use in a radioimmunoassay for HbF

Abstract A method is described for the purification, from fetal hemoglobin (HbF), of the fetal specific globin chain (γ chain) in its native state. In the absence of α chain (the globin chain common to all adult human hemoglobins) γ chain, when used as an immunogen, is able to express its unique antigenicity. Here, a specific, high titer antiserum raised against γ chain has been used to establish a sensitive radioimmunoassay for HbF. This approach may be applicable to the measurement of other normal and abnormal hemoglobins.