Initial clinical evaluation of an immunoradiometric assay for CA 19-9 using the NCI serum bank.

More than 1,600 coded sera obtained from blood donors and the NCI/Mayo Clinic Serum Bank were analyzed with an improved immunoradiometric assay for the carbohydrate antigenic determinant, CA 19-9. Results indicated that CA 19-9 is elevated in a large fraction of sera (67%) from patients with advanced adenocarcinomas of the upper gastrointestinal (GI) tract, including those with pancreatic, hepatobiliary and gastric carcinomas. Several of these sera had CA 19-9 exceeding 300,000 U/ml. A smaller fraction (18%) of patients with carcinomas of the large bowel had elevated serum CA 19-9 levels, the majority among patients with metastatic disease. In contrast, none of the healthy donors from the serum bank and only 4 of 1,023 of the blood donor specimens (0.4%) had CA 19-9 levels greater than or equal to 40 U/ml. Three of 235 sera (1.3%) from benign disease patients had levels of CA 19-9 in excess of 40 U/ml. These data suggest that the improved CA 19-9 immunoradiometric assay may have clinical utility as a diagnostic adjunct for adenocarcinoma of the upper GI tract and that the assay also may have some value in monitoring patients with advancing colorectal carcinoma, particularly in combination with CEA determinations. Rigorous prospective clinical trials will be necessary to verify these hypotheses.

Pleomorphism among murine tissue-associated gp70s.

The gp70s isolated from normal mouse tissues by radioimmune precipitation and SDS-polyacrylamide gel electrophoresis (SDS-PAGE) were shown to be highly pleomorphic. Their apparent molecular weights calculated from SDS-PAGE ranged from 75000 for thymus gp70 to 65000 for epididymal secretion gp70. Differences in the Mr of tissue-associated gp70s were confirmed by double-label co-electrophoresis studies. In addition, a high degree of primary structural pleomorphism among tissue-associated gp70s was demonstrated using two-dimensional tryptic peptide fingerprint analysis. These studies showed that most of the conserved peptides of tissue-associated gp70s were also common to xenotropic murine leukaemia virus (MuLV) gp70s. Thus, tissue-associated gp70s are probably encoded by endogenous xenotropic MuLV env genes or gene fragments. Tissue-associated gp70s also showed a very high level of primary structural pleomorphism. These phenomena were observed for gp70s derived from the tissues of several strains of mice. Tissue-associated gp70 pleomorphism may arise as a consequence of at least two simultaneously operating mechanisms. First, the expression of pleomorphic forms of gp70s on murine tissues may be regulated by mechanisms that also determine the differentiated state of the tissues. Second, endogenous xenotropic env genes may be modified by recombinational or mutational events among these genes, or among cellular genes that regulate the expression of endogenous proviral genes.

Radioimmunometric assay for a monoclonal antibody-defined tumor marker, CA 19-9.

We describe a solid-phase radioimmunometric sandwich assay for a new tumor marker defined by a monoclonal antibody (19-9). This antibody reacts with a carbohydrate antigenic determinant (CA 19-9) found at low concentrations in sera from healthy individuals but frequently increased in sera from patients with adenocarcinomas. The assay is sensitive and simple to perform. It requires duplicate 100-microL samples and may be performed in 6 h. The concentration of CA 19-9 in samples is determined by reference to a standard curve, which is essentially linear from 0 to 120 arbitrary units/mL. The average CV is approximately 10% in the range of 5.8 to 120 units/mL. The minimum detectable dose is 1.4 units/mL and analytical recovery of CA 19-9 is 97.6 to 100.6%. The average concentration of CA 19-9 in sera from 1020 healthy individuals was 8.4 (SD 7.4) units/mL; only 0.6% of such sera had concentrations greater than 37 units/mL. The assay has high specificity (98.5%), even among patients with benign diseases, and has high sensitivity (up to 79%) for patients with gastrointestinal adenocarcinomas, especially those of the pancreas.

Interaction of alcohol and zinc in fetal dysmorphogenesis.

The interaction of low doses of alcohol and marginal zinc deficiency during gestation was studied in pregnant mice and their fetuses. The combination of the two agents at subteratogenic doses was related to increased external and internal defects. Pregnant mice fed a diet containing 10 micrograms/g zinc were orally dosed with 2.0 micrograms/g of 50% ethanol for 18 days of pregnancy. Fetuses from these dams presented with more fetal defects than fetuses from control dams. Analysis of maternal livers showed a significant effect of alcohol on liver magnesium and zinc. Changes in fetal heart zinc levels were the only significant tissue effect of alcohol in the fetus.

Zinc status of pregnant alcoholic women: a determinant of fetal outcome.

The zinc status of 25 alcoholic and 25 non-alcoholic pregnant women was measured and correlated with fetal outcome. The volume index of alcohol consumption and the Michigan Alcoholic Screening Test were used to define alcoholic women. The alcoholic women had significantly lower plasma-zinc levels that the non-alcoholic women (50.7 versus 72.2 micrograms/dl). Fetal cord-plasma zinc levels were also lower in the offspring of alcoholic women (65.5 versus 81.3 micrograms/dl). Manifestation of fetal dysmorphogenesis appears to relate to zinc status.

Cupro-zinc superoxide dismutase: a possible biologic marker for alcoholism (studies in black patients).

Cupro-zinc superoxide dismutase (SOD-1) was measured by competition radioimmune assay of erythrocyte lysates of alcoholic and control subjects. Normal amounts of SOD-1 were found in the extract from control subjects (815 ng/mg Hb) and from white alcoholics (874 ng/mg Hb). However, the level of SOD-1 in lysates from black alcoholics (1033 ng/mg Hb) was significantly increased (p = 0.0001, rank sum test) compared with black and white controls. This increase was not related to any other observed hematologic disorder or to any historical, demographic, or laboratory value examined.

A radioimmune assay for human cupro-zinc superoxide dismutase and its application to erythrocytes.

A competition radioimmunoassay for human superoxide dismutase (SOD-1) is described. Radioiodinated SOD-1 is incubated with unlabeled competitor and limiting antibody, then immune complexes are isolated using Staphylococcus aureus. The assay is sensitive (detecting 5 ng enzyme) and reproducible. Average values for SOD-1 in lysates of erythrocytes from normal individuals is 854 +/- 100 ng/mg hemoglobin and that of patients with trisomy-21 is 1313 +/- 110 ng/mg hemoglobin.

Autologous immune responses to the major oncornavirus polypeptides in unmanipulated AKR/J mice.

The autologous immune response of AKR/J mice to the structural proteins of murine leukemia virus (MuLV) was examined. Immunoglobulins from the renal glomeruli were chemically eluted, separated from antigens, recovered, and tested for immunological reactivity against MuLV structural proteins. Analyzing immune precipitates obtained after mixing radiolabeled Tween-disrupted MuLV preparations with eluates from AKR/J mice on sodium dodecyl sulfategel electrophoresis, we found evidence of antibodies to the major classes of MuLV structural components: gp70, gp45, p30, and one or more proteins in the 10,000- to 15,000-dalton class. Using rate zonal centrifugation we confirmed that the eluates from AKR/J glomeruli contained antibody(s) that bound specifically to p30. These results indicate that AKR/J mice spontaneously mount immune responses against the major oncornavirus polypeptide antigens.

Immunopathogenicity and oncogenicity of murine leukemia viruses. II. Infection of mice and rats with Scripps leukemia virus.

The pathologic consequences of infection of newborn mice and rats with MuLV (Scripps leukemia virus--SLV) were observed. Serum MuLV p30 concentrations of most strains were elevated 20 to 100 times that of controls while MuLV gp70 levels were elevated only 1.1 to 14.8 times, probably reflecting in part the higher concentrations of gp70 in control sera but also indicating the lack of parallelism in regulation of synthesis of these two viral antigens. Infected mice of most strains developed immunologic diseases, including antinuclear antibody and glomerulonephritis, but not Coombs' antibodies. The nature and severity of the immunologic disease varied considerably, depending upon the genetic character of the host. Most infected animals developed lymphatic leukemias, but four strains showed partial to complete resistance to SLV oncogenesis: BALB/c (nude); C57 Bl/6; (NZB times NZW) F1, and (NZW times BALB/c) F1.

Immunopathogenicity and oncogenicity of murine leukemia viruses. I. Induction of immunologic disease and lymphoma in (BALB-c times NZB)F1 mice by Scripps leukemia virus.

This report clearly demonstrates that a systemic lupus erythematosus (SLE)-like syndrome and lymphoma can be induced in immunologically normal (BALB/c x NZB)F(1) mice by infection of neonates with a murine leukemia virus (MuLV) (Scripps leukemia virus [SLV] 60A) isolated from NZB lymphoblasts. SLV 60A was titered in vitro (XC test) and administered to newborn and adult (BALB/c x NZB)F(1) mice over six log(10) dilutions. Propagation of MuLV in the newborn recipients was indicated by greatly elevated serum Mu gs-1 levels which were proportional to the dose of virus given. The SLE-like syndrome was characterized by antinuclear antibodies (ANA) and immune complex-type glomerulonephritis. ANA production was related to the dose of virus and reached the highest levels at 8-16 wk. The incidence of glomerulonephritis was also correlated with the dose of virus and reached nearly 50% in the animals given the highest virus dose. Both titers of ANA and incidence of glomerulonephritis were greater in females than in males, although the amounts of Mu gs-1 in sera of both sexes were equal. The incidence of direct Coombs' positivity was not significantly affected by inoculation of this virus. The incidence and time of onset of thymocytic lymphoma were linearly related to the amount of virus inoculated. High serum Mu gs-1 levels predicted lymphoma development and reflected increases in the amount of infectious virus in the spleen. No induction of tumors, autoimmunity, or high serum Mu gs-1 levels followed administration of SLV 60A to 6-wk old (BALB/c x NZB)F(1) mice or inactivated 60A or active AKR virus to newborns.