Alpha-fetoprotein Assay Research Articles

Hepatocellular carcinoma in liver cirrhosis. A prospective study.

From January 1984 to December 1991 we carried out a prospective surveillance of the development of hepatocellular carcinoma (HCC) in 200 cirrhotic patients, monitored from the first histologic diagnosis of cirrhosis. Real-time ultrasonography (US) and serum alpha-fetoprotein (AFP) assays were performed every 3-6 months. During this period we detected HCC in 38 patients. The overall cumulative incidence of HCC in the 8 years was 41%, with a yearly incidence of 5.1%. Eighteen of 38 patients (48%) had a tumor < 5 cm in diameter. AFP reached diagnostic levels (> 500 ng/ml) in eight cases only (21%). Patients with initial AFP values > 20 ng/ml developed HCC more frequently than patients with values < or = 20 ng/ml; the percentage of HCC was statistically higher (p < 0.01) in patients in Child's B and C than in Child's A class. A periodic follow-up, using US and AFP, is suggested for the early diagnosis of HCC in cirrhotic patients.

Antenatal care for the normal patient

Screening protocols for low-risk obstetric patients are used to identify those at risk for adverse perinatal outcome. Gestational diabetes screening is best performed by administering 50 g of glucose in the nonfasting state, with plasma glucose values above 140 mg/dL at 1 hour considered abnormal. Assay of maternal serum alpha-fetoprotein is primarily used to identify pregnancies at risk for neural tube defects and other structural anomalies. However, an elevated value may also identify patients at increased risk for a number of abnormal pregnancy outcomes, even when the fetus is free from defects. Patients who have previously had a cesarean section are now strongly encouraged to undergo a trial of labor and to attempt a vaginal birth. Such a course is not without risk, and catastrophic complications can develop. Careful patient selection, appropriate counseling, and close management are necessary in this situation.

Ovarian Germ Cell Malignancies; The Yale University Experience

Abstract Eighty-one patients with ovarian germ cell malignancies (immature teratoma 29, dysgerminoma 26, endodermal sinus tumors 15, mixed germ cell tumor 8, other 3) seen or consulted on at Yale University over a 15 year period are presented. Initial therapy was successful in 70 of 81 (86.4%) patients and 75 (92.6%) are currently alive and disease free. Early stage dysgerminomas may be safely treated with surgery whereas advanced disease is exquisitely sensitive to vincristine, actinomycin D, and cyclophosphamide (VAC) therapy. Early stage immature teratoma is uniformly successfully treated with short-term VAC whereas advanced disease requires longer treatment. Early stage endodermal sinus tumor (EST) and mixed germ cell tumors may be effectively treated with VAC or platinum-based therapy but advanced disease should be treated with paltinum-based regimens. Serial alpha fetoprotein assays should determine duration of therapy in tumors containing EST elements. Conservative surgery to preserve reproductive function is appropriate for all patients with early stage ovarian germ cell malignancies and selected patients with advanced disease.

Reporting Cumulative Results Provides Precise Quality Control for Alpha-Fetoprotein Assays

Reporting Cumulative Results Provides Precise Quality Control for Alpha-Fetoprotein Assays

Ovarian germ cell malignancies: The Yale University experience

Eighty-one patients with ovarian germ cell malignancies (immature teratoma 29, dysgerminoma 26, endodermal sinus tumors 15, mixed germ cell tumor 8, other 3) seen or consulted on at Yale University over a 15 year period are presented. Initial therapy was successful in 70 of 81 (86.4%) patients and 75 (92.6%) are currently alive and disease free. Early stage dysgerminomas may be safely treated with surgery whereas advanced disease is exquisitely sensitive to vincristine, actinomycin D, and cyclophosphamide (VAC) therapy. Early stage immature teratoma is uniformly successfully treated with short-term VAC whereas advanced disease requires longer treatment. Early stage endodermal sinus tumor (EST) and mixed germ cell tumors may be effectively treated with VAC or platinum-based therapy but advanced disease should be treated with paltinum-based regimens. Serial alpha fetoprotein assays should determine duration of therapy in tumors containing EST elements. Conservative surgery to preserve reproductive function is appropriate for all patients with early stage ovarian germ cell malignancies and selected patients with advanced disease.

Hepatocellular carcinoma in Italian patients with cirrhosis.

Patients with cirrhosis of the liver are recognized as being at risk for hepatocellular carcinoma. The magnitude of the risk, the natural history of this disease, and the possibilities for detecting potentially curable tumors in patients in the Western world are unknown. To address these questions, we examined 447 Italian patients with well-compensated cirrhosis (which was of viral origin in 62 percent of them) from 1985 through 1990, performing serum alpha-fetoprotein assays and real-time ultrasonography every 3 to 12 months. Hepatocellular carcinoma was found in 30 patients (7 percent) at base line and in another 29 patients (7 percent of 417 patients free of tumor at base line) during follow-up periods averaging 33 months (range, 1 to 48). The cumulative hazard of the development of hepatocellular carcinoma during follow-up was higher among patients with persistently elevated serum alpha-fetoprotein levels (12 with tumors among 42 with such levels) than among those with fluctuating levels (11 among 82) or those with consistently normal levels (6 among 255). Only 17 patients had potentially operable tumors. The proportion of potentially operable tumors among those detected during follow-up was significantly lower than the proportion at enrollment (4 of 29 vs. 13 of 30, P = 0.027). The survival at one year of the 12 patients who underwent surgery was 67 percent, and the tumor-recurrence rate was 60 percent. Outcome was not appreciably different for the five patients who refused surgery. In the West, as in Asia, patients with cirrhosis of the liver are at substantial risk for hepatocellular carcinoma, with a yearly incidence rate of 3 percent. Our screening program did not appreciably increase the rate of detection of potentially curable tumors.

Pediatric HBsAg Chronic Liver Disease and Adult Asymptomatic Carrier Status

Unlike adults (greater than 60% of cases), it is rare to find the chronic hepatitis B virus (HBV) carrier status with normal transaminases among children. The aim of this study was to investigate whether this status would depend on the duration of HBV infection, that is, whether chronic hepatitis in childhood would lead to the asymptomatic carrier status in later life. We reexamined all of our patients with chronic HBV infection of greater than 10 years' duration and with histologically documented chronic hepatitis during childhood. This was a group of 36 adolescents and young adults. All subjects were screened for tumor using alpha-fetoprotein assay and hepatic ultrasound. Eight patients with cirrhosis underwent esophageal fiberoptic endoscopy. All patients were in good general condition, with no clinical signs of liver failure. Only two patients had abnormal transaminase levels, both of whom had evidence of delta infection. All but one patient became anti-HBe positive. Five cases had HBsAg clearance. (Seventy-one percent of patients were HBeAg positive and 14% anti-HBe positive at the onset of the disease.) Hepatic ultrasound revealed no tumors in any of the subjects, and fiberoptic endoscopy demonstrated no esophageal varices. This study suggests that (a) chronic hepatitis and asymptomatic carrier status may be subsequent stages of the B virus infection; and (b) chronic hepatitis in childhood is generally benign and may evolve into an asymptomatic carrier status. The main problem with the chronic carrier status is probably the increased risk of hepatocellular carcinoma.

α–Fetoprotein in the Woodchuck Model of Hepadnavirus Infection and Disease: Immunochemical Analysis of Woodchuck α–Fetoprotein and Measurement in Serum by Quantitative Monoclonal Radioimmunoassay

Woodchuck hepatitis virus infection of the eastern woodchuck represents a useful model for the study of hepatitis B virus infection and disease in humans, including hepatocellular carcinoma. In man, hepatocellular carcinoma is frequently detected and monitored using assays for serum alpha-fetoprotein. To study the relationship between alpha-fetoprotein and woodchuck hepatitis virus-induced hepatocellular carcinoma in the woodchuck model, we produced a monoclonal antibody to woodchuck alpha-fetoprotein and used biophysical and immunochemical methods to demonstrate its specificity and affinity (7 x 10(8) L/mol) for woodchuck alpha-fetoprotein. A competition radioimmunoassay was then developed and standardized for measuring serum alpha-fetoprotein concentrations. In the radioimmunoassay system, woodchuck alpha-fetoprotein was detected between 20 ng/ml (20% to 25% inhibition) and 8,500 ng/ml (97% to 98% inhibition). Elevated serum alpha-fetoprotein concentrations (450 to 452,000 ng/ml) were measured in 21 of 23 woodchucks in the advanced stages of woodchuck hepatitis virus-induced hepatocellular carcinoma. Serum alpha-fetoprotein was elevated above normal (greater than or equal to 450 ng/ml) as early as 3 to 11 mo before terminal hepatocellular carcinoma in 11 of 16 of the woodchuck hepatitis virus-carrier woodchucks. In a pilot study, serum alpha-fetoprotein became markedly elevated above normal in woodchuck hepatitis virus-carrier woodchucks that developed hepatocellular carcinoma but not in serologically recovered or uninfected woodchucks (i.e., without hepatocellular carcinoma). Thus, alpha-fetoprotein may provide a useful noninvasive marker in the woodchuck model for detecting and monitoring woodchuck hepatitis virus-induced hepatocellular carcinoma from earlier stages.

Screening antisera for subtype specificity based on immunoblotting of lectin-affinity electrophoresis: Application toward alpha-fetoprotein subfractions

We adapted a method for evaluating monoclonal antibody specificity toward isoforms and examined 29 alpha-fetoprotein (AFP) antibodies from Hybritech. These antibodies were separated by affinity electrophoresis on agarose-containing erythroagglutinating phytohemagglutinin (PHA-E) followed by immunoblotting onto nitrocellulose. Under these conditions, AFP separates into four subfractions: NR (nonreactive with PHA-E), WR (reactive weakly), RS2 (strongly reactive), and RS1 (very strongly reactive). When polyclonal goat anti-AFP control was used as the test antibody, the distribution of amniotic fluid AFP was approximately 50%, 31%, 12%, and 7% for NR, WR, RS2, and RS1, respectively. The distribution for these same bands from the serum of a patient with hepatocellular carcinoma was 39%, 31%, 30%, and 0%; from the serum of a patient with embryonal carcinoma, it was 29%, 38%, 0%, and 33%, respectively. Twenty-six monoclonal antibodies, including the two used in the Hybritech Tandem-E assay for AFP, showed similar distribution, while the remaining three antibodies showed no reactivity to any of the AFP antigens in this system. Although we were not able to demonstrate any specificity of these antisera toward any single AFP isoform, use of this affinity electrophoresis system provides a model for studying isoform specificity of other AFP antibodies and other antibody-antigen systems.

Circulating antibodies to mouse monoclonal immunoglobulins caused false-positive results in a two-site assay for alpha-fetoprotein.

Journal Article Circulating antibodies to mouse monoclonal immunoglobulins caused false-positive results in a two-site assay for alpha-fetoprotein. Get access N Dahlmann, N Dahlmann Search for other works by this author on: Oxford Academic Google Scholar F Bidlingmaier F Bidlingmaier Search for other works by this author on: Oxford Academic Google Scholar Clinical Chemistry, Volume 35, Issue 12, 1 December 1989, Page 2339, https://doi.org/10.1093/clinchem/35.12.2339 Published: 01 December 1989

Chemiluminescent enzyme immunoassay of alpha-fetoprotein based on an adamantyl dioxetane phenyl phosphate substrate.

We have evaluated a new chemiluminescent substrate for the alkaline phosphatase (EC 3.1.3.1) label used in a Hybritech Tandem-E immunoassay of alpha-fetoprotein (AFP). The new substrate, adamantyl 1,2-dioxetane phenyl phosphate (AMPPD), emits light at 477 nm when acted upon by the enzyme. Detection limits for AFP with this method were 33 ng/L (mean of 20 replicates of the zero standard + 2 SD) and 470 ng/L (twice background). Between-batch CVs ranged from 4.31% to 9.60% for AFP in the range 29.1-132.0 micrograms/L. Comparison of results for 49 specimens assayed with use of the chemiluminescent kit and a colorimetric version of the AFP assay gave statistical values as follows: slope = 0.88, intercept = 4.19, and r = 0.94.

Hepatocarcinoma in a Child: A Clinical and Experimental Study

An inoperable hepatocarcinoma in a 2-year-old female was treated with chemotherapy. Regression of the tumour allowed complete surgical excision. The tumour was successfully xenografted into athymic rats. Growth of tumour was monitored by external measurement and plasma alphafetoprotein (AFP) assays. AFP levels meanwhile in the patient fell from 2 x 10(6) international units/ml preoperatively to 10 units/ml post-operatively. The value of AFP as a tumour marker in hepatic tumours and the availability of xenograft material for experimentation enabled the measurement of plasma AFP levels as well as assessing the tumour mass.

Multiple fluorescence labeling with europium chelators. Application to time-resolved fluoroimmunoassays.

Multiple fluorescence labeling with conventional probes like fluorescein, to improve the detection limit of labeled reactants, is not usually successful because of fluorescence quenching. In contrast, we found that the europium chelator 4,7-bis(chlorosulfophenyl)-1,10-phenanthroline-2,9-dicarboxylic acid (BCPDA) can be incorporated into proteins at very high molar ratios. Working with thyroglobulin as a model protein, we found that when 160 BCPDA molecules are incorporated into one thyroglobulin molecule, the fluorescence emitted by the labeled protein in the presence of excess Eu3+, is equivalent to that emitted by approximately 900 molecules of unconjugated BCPDA:Eu3+ complexes. We took advantage of the lack of any quenching effects and of the enhancement observed with the multiply labeled protein, to develop a universal reagent system consisting of (a) streptavidin covalently coupled to BCPDA labeled thyroglobulin and (b) excess Eu3+. With this approach, streptavidin is heavily labeled through thyroglobulin and retains its full biotin binding activity. We used the reagent to develop a highly sensitive time-resolved heterogeneous immunofluorometric assay of alpha-fetoprotein (AFP) in serum, using monoclonal antibodies. One antibody is immobilized in white microtitration wells (solid-phase) and the other is biotinylated. We demonstrate that this assay, using the newly developed reagent, is 25-fold more sensitive than the one using directly BCPDA labeled antibody and 5-fold more sensitive than an assay that uses BCPDA-labeled streptavidin. The detection limit of the assay with the new reagent was down to 60 amol of AFP per well. We conclude that multiple fluorescence labeling with europium chelators is an effective method of extending the sensitivity of currently used fluorescence immunoassay procedures.

Histologic markers in primary and metastatic tumors of the liver

To investigate the value of different tissue markers in the histologic diagnosis of hepatic tumors, we performed immunoperoxidase stains for alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), carcinoembryonic antigen (CEA), and an erythropoiesis-associated antigen (ERY-1) on formalin-fixed, paraffin-embedded samples from 107 primary and metastatic tumors of the liver. AFP was present in 17% of the hepatocellular carcinomas, in 7% of the metastatic carcinomas, and in none of the cholangiocarcinomas. AAT was present in 41% of the hepatocellular carcinomas, in 37% of the cholangiocarcinomas, and in 50% to 70% of the metastatic carcinomas of the liver. Intracytoplasmic CEA was found in 75% of the cholangiocarcinomas, in 92% to 100% of the metastatic carcinomas, and in only one of the mixed hepatocellular-cholangiocarcinomas. ERY-1 was present in 89% of the hepatocellular carcinomas, whereas none of the cholangiocarcinomas or metastatic carcinomas stained for this marker. We conclude that immunohistochemical assays for AFP and AAT are of limited value in the differential diagnosis of hepatic tumors. However, immunohistochemical stains for ERY-1 and CEA can be valuable in differentiating hepatocellular carcinomas from metastatic tumors.

Use of patients' data to control alpha-fetoprotein assays when screening for neural tube defects.

Use of patients' data to control alpha-fetoprotein assays when screening for neural tube defects.

Prospective prenatal screening for fetal abnormalities using a quantitative immunoassay for acetylcholinesterase.

An immunoassay based on a monoclonal antibody specific for acetylcholinesterase (AChE) was used prospectively over a two year period to screen second trimester amniotic fluids for fetal abnormalities. All 26 cases of spina bifida, three of which had normal alphafetoprotein (AFP) concentrations and ultrasound scans, were detected by the immunoassay. Four clear fluids, with abnormal AFP concentrations, had normal AChE titres and yielded normal outcomes. Some difficulties were encountered with both the AChE immunoassay and polyacrylamide gel testing when amniotic fluids were contaminated with old blood. However, the quantitative nature of the AChE immunoassay and its independence of operator experience make it an ideal adjunct to AFP assay for routine screening of amniotic fluids.

S‐100 protein and neuron‐specific enolase in amniotic fluid as markers of abdominal wall and neural tube defects in the fetus

The aim of this study was to determine whether there is increased leakage of neuron-specific enolase (NSE) and S-100 protein into amniotic fluid in pregnancies with neural tube defects, since both these proteins are produced by neural tissue, and to compare the value of these substances for detecting such defects with that of the more conventional techniques of alpha-fetoprotein (AFP) and acetylcholinesterase (AChE) gel electrophoresis. Amniotic samples from 25 mid-pregnancies (15-17 weeks' gestation) with neural tube defects (14 with open spina bifida and 11 with anencephaly) and from seven mid-pregnancies with abdominal wall defects were compared with a control material consisting of 80 amniotic fluid samples from 80 consecutive mid-pregnancy amniocenteses, with normal karyotypes and AFP concentrations. All of the above cases of abnormalities were primarily detected through increased AFP levels in the amniotic fluid. Amniotic fluid samples from 13 pregnancies with fetuses with autosomal chromosomal abnormalities and seven amniotic fluid samples contaminated with blood were also included in the investigation. It is concluded from the results that the conventional AFP assay combined with AChE gel electrophoresis is the best method for screening amniotic fluid for neural tube defects and defects of the abdominal wall. Neither NSE nor S-100 assay alone proved to be superior for the detection of these cases in mid-trimester amniotic fluid. The S-100 assay, however, could give additional information in cases where AChE gel electrophoresis is not decisive; for example, in samples contaminated with blood.

Time-resolved immunofluorometric assay for alpha-fetoprotein in dried-blood samples collected on filter paper.

Time-resolved immunofluorometric assay for alpha-fetoprotein in dried-blood samples collected on filter paper.

Mass screening of primary hepatocellular carcinoma by alpha‐fetoprotein in a rural area of Taiwan – a dried blood spot method

A prospective survey of primary hepatocellular carcinoma (PHC) was conducted in a rural area of Taiwan using a two-site enzyme immunoassay for alpha-fetoprotein (AFP) in dried blood samples collected on filter paper. Of 1894 men over 40 years of age who were tested, 20 (1%) had AFP levels of greater than 20 ng/ml of blood on screening. Nineteen of these men received ultrasound examinations, and small PHCs were detected in 4 (21%). The remaining 15 cases had other types of hepatobiliary tract diseases, and 6 (40%) were also serum HBsAg positive. They should all be closely followed up by AFP determination and ultrasound examination of the liver. In contrast to the low resection rate of PHC in symptomatic patients who were admitted through the outpatient clinic during the period of this survey, the four cases with small PHC discovered by AFP screening had their tumors successfully removed (5/57 vs. 4/4, p less than 0.005). Our preliminary results showed that this method is a simple, sensitive and convenient assay for AFP and may be used as a first-line screening test in mass population surveillance programs for PHC, particularly in areas where PHC is highly prevalent.

Measurement of placental alkaline phosphatase in maternal plasma as an indicator of subsequent low birthweight outcome

Placental alkaline phosphatase (P-ALP) was measured by a specific monoclonal antibody-based immunoassay in plasma samples of 117 women who subsequently were delivered of an infant of birthweight less than 2.5 kg. P-ALP values greater than twice the normal median were found in 32% of maternal plasma samples from low birthweight cases in one series and in 35% in another series, while in normal outcome controls the corresponding value was 8%. The differences were highly significant. The proportion of low birthweight cases with elevated maternal P-ALP values appears to be very similar between 15 and 34 weeks gestation. At 16-18 weeks gestation there is a significant positive correlation (r = 0.40) between P-ALP and maternal plasma alpha-fetoprotein (AFP) values in low birthweight cases. The use of P-ALP assay in combination with AFP assay appears to improve the detection of pregnancies with subsequent low birthweight outcome.