Alpha-feto-protein during development and in disease

LEDGF is a new growth factor in fetal serum

Fetal serum supports the immortal growth of mammalian cell lines in culture while adult serum leads to the terminal differentiation and death of cells in culture. Many of the proteins in fetal serum that support the indefinite division and growth of cancerous cell lines remain obscure. The peptides and proteins of fetal versus adult serum were analyzed by liquid chromatography, nano electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS). Three batches of fetal serum contained the Alpha Fetoprotein marker while adult serum batches did not. Insulin (INS), and insulin-like growth factor (ILGF), fibroblast growth factor (FGF), epidermal growth factor (EGF) and platelet derived growth factor (PDGF) were increased in fetal serum. New fetal growth factors including MEGF, HDGFRP and PSIP1 and soluble growth receptors such as TNFR, EGFR, NTRK2 and THRA were discovered. Addition of insulin or the homeotic transcription factor PSIP1, also referred to as Lens Epithelium Derived Growth Factor (LEDGF), partially restored the rounded phenotype of rapidly dividing cells but was not as effective as fetal serum. Thus, a new growth factor in fetal serum, LEDGF/PSIP1, was directly observed by tandem mass spectrometry and confirmed by add back experiments to cell culture media alongside insulin.

AFP peptide (AFPep) as a potential growth factor for prostate cancer

Prostate cancer is the most common cancer among men in the USA. A peptide derived from the active site of alpha-fetoprotein (AFP), known as AFPep, has been shown to be efficacious in inhibiting breast cancer growth. The role of this derived peptide AFPep in the development of prostate cancer has yet to be studied. To investigate the role of AFPep on prostate cancer, we used the PC-3 and DU-145 cell lines. We found that through key anti-apoptosis and pro-proliferation molecules, AFPep enhances the proliferation of DU-145 prostate cancer cells. The anti-proliferative molecules p18, p21, and p27, along with the pro-apoptotic molecules Fas and Bax, were all down-regulated in DU-145 cell lines treated with AFPep. Conversely, AFPep was not found to have a proliferative effect on the PC-3 prostate cancer cell line. This finding suggests the effects of AFPep to be cell line-specific in prostate cancer. Further investigation into the effects of AFPep could lead to new areas of treating prostate cancer.

Peptide-Based Vaccines for Hepatocellular Carcinoma: A Review of Recent Advances

Primary liver cancer is the sixth most commonly diagnosed cancer and the third leading cause of cancer-related deaths worldwide. After surgery, up to 70% of patients experience relapses. The current first-line therapy for advanced cases of hepatocellular carcinoma (HCC) comprises sorafenib and lenvatinib administered as single-drug therapies. Regorafenib, cabozantinib, and ramucirumab are administered as second-line therapies. Recently, it has been reported that using the immune checkpoint inhibitors atezolizumab (anti-PDL1 antibody) and bevacizumab (anti-VEGF antibody) leads to longer overall survival of unresectable cases, when compared with the use of sorafenib. The role of cancer immunity against HCC has attracted the attention of clinicians. In this review, we describe our phase I/II clinical trials of peptide vaccines targeting GPC3 in HCC and discuss the potential of peptide vaccines targeting common cancer antigens that are highly expressed in HCC, such as WT-I, AFP, ROBO1, and FOXM1. Further, we introduce recent cancer vaccines targeting neoantigens, which have attracted attention in recent times, as well as present our preclinical studies, the results of which might aid to initiate a neoantigen vaccine clinical trial, which would be the first of its kind in Japan.

Deficits in Prenatal Serine Biosynthesis Underlie the Mitochondrial Dysfunction Associated with the Autism-Linked FMR1 Gene

Fifty-five to two hundred CGG repeats (called a premutation, or PM) in the 5′-UTR of the FMR1 gene are generally unstable, often expanding to a full mutation (>200) in one generation through maternal inheritance, leading to fragile X syndrome, a condition associated with autism and other intellectual disabilities. To uncover the early mechanisms of pathogenesis, we performed metabolomics and proteomics on amniotic fluids from PM carriers, pregnant with male fetuses, who had undergone amniocentesis for fragile X prenatal diagnosis. The prenatal metabolic footprint identified mitochondrial deficits, which were further validated by using internal and external cohorts. Deficits in the anaplerosis of the Krebs cycle were noted at the level of serine biosynthesis, which was confirmed by rescuing the mitochondrial dysfunction in the carriers’ umbilical cord fibroblasts using alpha-ketoglutarate precursors. Maternal administration of serine and its precursors has the potential to decrease the risk of developing energy shortages associated with mitochondrial dysfunction and linked comorbidities.

Alterations of Circulating Biomarkers During Late Term Pregnancy Complications in the Horse Part II: Steroid Hormones and Alpha-Fetoprotein

Preterm labor and/or abortion causes considerable economic impact on the equine industry. Unfortunately, few experimental models exist for the induction of various pregnancy-related complications, and therefore extrapolations are made from the experimental model for ascending placentits, although inferences may be minimal. Certain steroid hormones (progestogens, estrogens) and fetal proteins (alpha-fetoprotein; AFP) might improve the diagnostics for abnormal pregnancy, but the utility of these markers in the field is unknown. To assess this, thoroughbred mares (n = 702) were bled weekly beginning in December 2013 until parturition/abortion. Following parturition, fetal membranes were assessed histopathologically and classified as either ascending placentitis (n = 6), focal mucoid placentitis (n = 6), idiopathic abortion (n = 6) or no disease (n = 20). Weekly serum samples were analyzed for concentrations of progesterone, estradiol-17β, and AFP. Samples were analyzed retrospectively from the week of parturition/abortion in addition to the preceding four weeks. For both ascending and focal mucoid placentitis, a significant increase in progesterone and AFP was noted, alongside a significant decrease in estradiol-17β and the ratio of estradiol-17β to progesterone in comparison to controls. In contrast, idiopathic abortions experienced a decrease in progesterone concentrations alongside an increase in AFP, and this was only noted in the week preceding parturition/abortion. In conclusion, spontaneous placental infection in the horse altered both endocrine and feto-secretory markers in maternal circulation, while minimal changes were noted preceding noninfectious idiopathic abortion. Additionally, this is the first study to report an alteration in steroid hormones and AFP during the disease process of focal mucoid placentitis, the etiology of which includes Nocardioform placentitis.

Regulation of CCl4-induced liver cirrhosis by hepatically differentiated human dental pulp stem cells

Liver transplantation is the most effective treatment for treating liver cirrhosis. However, a limited number of donors, graft rejection, and other complications can undermine transplant success. It is considered that cell transplantation is an alternative approach of liver transplantation. We previously developed a protocol for hepatic differentiation of cluster of differentiation 117+ stem cells isolated from human exfoliated deciduous tooth pulp (SHEDs) under hydrogen sulfide exposure. These cells showed excellent hepatic function. Here, we investigated whether hepatocyte-like cell transplantation is effective for treating carbon tetrachloride (CCl₄)-induced liver cirrhosis. SHEDs were hepatically differentiated, which was confirmed via immunological analyses and albumin concentration determination in the medium. Rats were intraperitoneally injected with CCl₄ for and the differentiated cells were injected into rat spleen. Histopathological and immunohistochemical analyses were performed. Liver functions were serologically and pathologically determined. Quantitative real-time-polymerase chain reaction was implemented to clarify the treatment procedure of liver cirrhosis. In vitro-differentiated hepatocyte-like cells were positive for all examined hepatic markers. SHED-derived hepatocyte transplantation eliminated liver fibrosis and restored liver structure in rats. Liver immunohistochemical analyses showed the presence of human-specific hepatic markers, i.e., a large amount of human hepatic cells were very active in the liver and spleen. Serological tests revealed significant liver function recovery in the transplantation group. Expression of genes promoting fibrosis increased after cirrhosis induction but was suppressed after transplantation. Our results suggest that xenotransplantation of hepatocyte-like cells of human origin can treat cirrhosis. Moreover, cell-based therapy of chronic liver conditions may be an effective option.

Novel scores combining AFP with non-invasive markers for prediction of liver fibrosis in chronic hepatitis C patients

Serum levels of alpha-fetoprotein (AFP) were reported to increase in patients with significant or advanced hepatic fibrosis. Combination of non-invasive tests decreases the use of liver biopsy in large proportion of chronic HCV patients. The aim of the study was to compare and combine AFP with commonly used non-invasive fibrosis tests in novel scores for prediction of different stages of hepatic fibrosis. Six hundred and fifty two treatment naïve chronic hepatitis C patients were enrolled. Demographic data, basic pre-treatment laboratory tests including complete blood count (CBC), liver biochemical profile and renal functions test, international normalized ratio (INR) in addition to AFP, liver stiffness measurement (LSM) by Fibroscan and liver biopsies were retrospectively analyzed. AST to Platelet Ratio Index (APRI) and FIB-4 scores were calculated. Different predictive models using multivariate logistic regression analysis were generated and presented in equations (scores) composed of a combination of AFP, LSM plus FIB-4/APRI scores. AFP was correlating significantly with LSM, FIB-4, and APRI scores. Areas under receiver operating characteristic curves (AUROCs) for predicting significant hepatic fibrosis, advanced hepatic fibrosis, and cirrhosis were 0.897, 0.931, and 0.955, respectively, for equations (scores) containing AFP, LSM, and FIB-4. AUROCs for predicting significant hepatic fibrosis, advanced hepatic fibrosis and cirrhosis were 0.897, 0.929, and 0.959, respectively, for equations (scores) containing AFP, LSM, and APRI. The study shows that combining AFP to serum biomarkers and LSM increases their diagnostic performance for prediction of different stages of liver fibrosis.

Amniotic fluid embolism complicating medical termination of pregnancy

BACKGROUND

Amniotic fluid embolism is always a severe complication and generally occurs during labour or immediately after childbirth.

CLINICAL FEATURES

We report the case of a patient falling victim to amniotic fluid embolism after the medical termination of her pregnancy at 24 weeks of amenorrhea following the discovery of a teratoma-carrying foetus. The amniotic fluid embolism diagnosis was strongly suspected in the face of the sudden onset of severe arterial hypotension, hypoxic respiratory distress, a coma state and disseminated intravascular coagulopathy immediately after the delivery. Additional tests were conducted to support the diagnosis: cytological testing of a peripheral venous sample and maternal broncho-alveolar lavage fluid, dosing of tryptase and alpha-fetoprotein levels as well as screening for insulin-like growth factor binding protein 1.

CONCLUSION

Amniotic fluid embolism is a rare and difficult diagnosis, especially in unconventional settings, yet it can be facilitated by screening for amniotic markers and tryptase.

Sialoblastoma: A literature review from 1966-2011

Sialoblastoma is a rare congenital tumour of the salivary glands arising mainly from the parotid gland. It is usually diagnosed at birth or shortly thereafter with a significant variability in histological appearance and clinical course. In extensive search of PubMed indexed journals, we got 46 cases of "sialobalstoma/embryoma/congenital basal adenoma", with one case was of German literature and three additional cases of adult sialobalstoma. This article has extensively reviewed the clinical, histopathological and immunohistochemical features, Magnetic resonance imaging (MRI) and Computerized Tomography (CT) findings, treatment and prognosis.

The Amazing Power of Cancer Cells to Recapitulate Extraembryonic Functions: The Cuckoo's Tricks

Inflammation is implicated in tumor development, invasion, and metastasis. Hence, it has been suggested that common cellular and molecular mechanisms are activated in wound repair and in cancer development. In addition, it has been previously proposed that the inflammatory response, which is associated with the wound healing process, could recapitulate ontogeny through the reexpression of the extraembryonic, that is, amniotic and vitelline, functions in the interstitial space of the injured tissue. If so, the use of inflammation by the cancer-initiating cell can also be supported in the ability to reacquire extraembryonic functional axes for tumor development, invasion, and metastasis. Thus, the diverse components of the tumor microenvironment could represent the overlapping reexpression of amniotic and vitelline functions. These functions would favor a gastrulation-like process, that is, the creation of a reactive stroma in which fibrogenesis and angiogenesis stand out.

High Alpha-Fetoprotein Persistence after Orchiectomy. On a Case of Uncommon Etiology

Background

The following report describes a case of inherited elevation of alpha-fetoprotein (AFP) in a young male suspected for testicular cancer. AFP shows very high values during fetal life. After birth the synthesis of AFP decreases dramatically, and only trace amounts are detected in the adult. From this age on, serum AFP can rise above normal in some diseases, e.g. liver disorders, and in some kind of tumors. A condition in which persistent high levels of AFP are found, named Hereditary Persistence of AFP [HPAFP), was first reported in 1983 by Ferguson-Smith, and then recorded in the literature only on eleven occasions till 2004. The occurrence of HPAFP may be underestimated. HPAFP can be easily confirmed by testing AFP levels in blood-related family members.

Methods

An elevated serum AFP (about 20 μg/mL) was found in a 27–year-old white man with an unremarkable medical history, who was concerned to have left testicular cancer. By our examination, his left testis was markedly reduced in size. β-HCG, LDH, and liver function were normal. Surgical inguinal exploration with testis and spermatic cord excision was carried out. Postoperative repeated AFP levels remained persistently elevated, in the range from 20 to 30 μg/mL. Careful evaluation for occult cancer showed no abnormality. Histology showed necrotic tissue and could not make a reliable diagnosis. A literature search was done using PubMed by key word “alpha-fetoprotein” and “elevation”. Thinking of a hereditary trait, we decided to screen patient's blood-related family members.

Results

AFP was found to be elevated in another four out of six relatives within three generations, unrelated to any disease. This pedigree was consistent with an autosomal dominant inheritance pattern.

Conclusions

HPAFP could mislead the physician. Failure to recognize HPAFP can lead to unsuitable treatments. The existence of this clinically benign condition needs to be considered in both children and adults with unexplained and persistent elevation of AFP, e.g. those diagnosed or suspected for germ cell tumor.

Proteins secreted by embryonic stem cells activate cardiomyocytes through ligand binding pathways

Human embryonic stem cells (hESC) underlie embryogenesis but paracrine signals associated with the process are unknown. This study was designed to 1) profile native proteins secreted by undifferentiated hESC and 2) determine their biological effects on primary neonatal cardiomyocytes. We utilized multi-analyte, immunochemical assays to characterize media conditioned by undifferentiated hESC versus unconditioned media. Expression profiling was performed on cardiomyocytes subjected to these different media conditions and altered transcripts were mapped to critical pathways. Thirty-two of 109 proteins were significantly elevated in conditioned media ranging in concentration from thrombospondin (57.2+/-5.0 ng/ml) to nerve growth factor (7.4+/-1.2pg/ml) and comprising chemokines, cytokines, growth factors, and proteins involved in cell adhesion and extracellular matrix remodeling. Conditioned media induced karyokinesis, cytokinesis and proliferation in mono- and binucleate cardiomyocytes. Pathway analysis revealed comprehensive activation of the ROCK 1 and 2 G-protein coupled receptor (GPCR) pathway associated with cytokinesis, and the RAS/RAF/MEK/ERK receptor tyrosine kinase (RTK) and JAK/STAT-cytokine pathway involved in cell cycle progression. These results provide a partial database of proteins secreted by pluripotent hESC that potentiate cell division in cardiomyocytes via a paracrine mechanism suggesting a potential role for these stem cell factors in cardiogenesis and cardiac repair.

The effects of mouse alpha-fetoprotein on T-cell-dependent and T-cell-independent immune responses in vitro

Mouse alpha-fetoprotein (AFP) suppressed the specific antibody response to the T-cell-dependent antigen sheep erythrocytes (SRBC) and the phytohemagglutinin- and concanavalin-A-stimulated DNA synthesis of purified T lymphocytes but failed to inhibit the T-cell-independent antibody response to dinitrophenyl-substituted Ficoll (DNP-Ficoll) and the lipopolysaccharide-stimulated polyclonal B-cell antibody synthesis. Mouse amniotic fluid (MAF) suppressed antibody responses to both T-cell-dependent and T-cell-independent antigens; however, the effects could be differentiated since dialysis of the MAF removed most of the suppressive effect on the DNP-Ficoll response but did not diminish the inhibitory action on the anti-SRBC response. The results indicate that AFP suppresses certain T-lymphocyte functions in vitro and does not act by directly inhibiting B-cell functions.

Early occurrence of hepatocellular carcinoma in biliary atresia treated by liver transplantation

A case of liver transplantation for HCC complicating BA in an eight-month old infant is reported. HCC in BA is extremely rare. Screening of AFP and ultrasonographic examination should be performed regularly in patients with secondary biliary cirrhosis for early detection of HCC.

Congenital sialoblastoma (embryoma) associated with premature centromere division and high level of alpha-fetoprotein

Sialoblastoma is a rare, locally aggressive, and potentially malignant perinatal salivary tumor that predominantly affects the parotid glands. To date, 29 cases of sialoblastoma have been reported. We report a further case of sialoblastoma diagnosed at 37 weeks of gestation presenting with novel findings that are the premature centromere division and a high level of alpha-fetoprotein.

The human cervical cancer oncogene protein is a biomarker for human hepatocellular carcinoma

Human cervical cancer oncogene (HCCR) was identified and appeared to function as a negative regulator of p53 gene. The objective of this study was to validate HCCR expression as a candidate marker for human hepatocellular carcinoma. HCCR epitope was identified as Y(355)LGTRR(360). According to immunofluorescence study, HCCR was predominantly localized in the plasma membrane and cytoplasm of hepatocellular carcinoma. HCCR proteins were overexpressed in the tumorous compared with the nontumorous cirrhosis tissues. However, HCCR was not detected in normal liver tissue. Concentration of HCCR protein in the serum was measured in a total of 570 subjects, and comparisons were made to alpha-fetoprotein. Serological studies revealed 78.2% sensitivity of HCCR (cutoff value, 15 microg/ml), which was significantly higher than 64.6% of alpha-fetoprotein (P = 0.0098) and 95.7% specificity for hepatocellular carcinoma. Forty of 52 (76.9%) patients with carcinoma negative for alpha-fetoprotein showed positive values for HCCR. A positive rate of 69.2% in carcinoma patients with tumor sizes <2 cm was found to be a higher rate than measurement of alpha-fetoprotein. Furthermore, HCCR expression was also detected in liver cirrhosis at an intermediate level between carcinoma and normal groups, which gave 88.1% sensitivity and 79.0% specificity using 8 microg/ml as a cutoff value. In summary, the HCCR assay may have an advantage over the alpha-fetoprotein assay in that it is elevated according to disease progression from liver cirrhosis to carcinoma, and it is more frequently positive in patients with early, small hepatocellular carcinoma.

Hereditary persistence of alpha-fetoprotein is due to both proximal and distal hepatocyte nuclear factor-1 site mutations

BACKGROUND AND AIMS

The molecular mechanism of hereditary persistence of alpha-fetoprotein (HPAFP) has been previously described in a large Scottish family, consisting of a -119G>A substitution in the distal hepatocyte nuclear factor 1 (HNF-1) binding site of the alpha-fetoprotein (AFP) gene promoter. We report here the molecular mechanisms of HPAFP in 2 new unrelated families.

METHODS

Family 1 was of Bengali origin, and family 2 was Italian. Four of 5 subjects (family 1) and 3 of 9 (family 2) showed HPAFP. The AFP gene promoter was studied in all available family members.

RESULTS

All subjects with high AFP levels had mutated promoter sequences. Family 1 showed the reported -119G>A substitution. Family 2 showed -55C>A and -65C>T substitutions in the proximal putative HNF-1 binding region of the promoter. The -55C>A mutation increased the similarity of the proximal HNF-1 binding region to a consensus binding region. Gel shift assays confirmed its increased affinity toward HNF-1, and transfection experiments revealed an increased level of gene transcription. The -65C>T substitution theoretically created a CCAAT box. However, gel shift and transfection experiments failed to show any biological effect of this substitution that is associated with the -55C>A mutation.

CONCLUSIONS

Two different mutations localized in either HNF-1 binding sites of the AFP gene promoter may result in HPAFP. This highlights the importance of HNF-1 in AFP gene expression. Unexplained persistent AFP should lead to family study and/or AFP gene promoter sequencing to avoid inappropriate explorations and treatment decisions.

Fetuin in human bone marrow: detection in foetal tissue and patients with mastocytosis

Fetuin, a foetal protein of unknown function, has been shown to be expressed in both the immune and nervous systems, especially during development. Here, we show for the first time, that fetuin is abundantly present in many cells of the foetal human bone marrow, but is restricted to cells of the monocytic lineage in the adult. Fetuin's immunoreactivity increased considerably in adult human bone marrow in some pathological conditions, particularly in mastocytosis and was also increased in bone marrows in some cases of acute leukaemias, especially in acute myeloid leukaemia. This increase in the presence of fetuin in neoplastic bone marrows is not reflected by an increased level of circulating fetuin. This last observation contradicts earlier suggestions that fetuin is specifically reduced in cancer patients. A consistent increase in fetuin immunoreactivity in bone marrow of most cases of mastocytosis, as demonstrated in this paper, could become a useful tool in the diagnosis of this disease.

Hereditary persistence of alpha-fetoprotein. Case report and review of the literature

Persistently elevated alpha-fetoprotein (AFP) levels of 24 to 30 micrograms/ml (normal < 10 micrograms/ml) were found in a 38-year-old healthy man. Subsequently, AFP was found to be elevated in another five out of 13 family members within three generations. The pedigree is consistent with an autosomal dominant inheritance pattern. No discernible disease and no functional abnormality appears to be associated with this clinically benign disorder which has been recorded in the literature on four occasions to date. The reported AFP levels in these other cases ranged from 18 to 198 micrograms/ml. Physiologically, AFP is mainly produced in the liver and the yolk sac of human fetuses more than four weeks old, with peak values of up to 4 mg/ml at 12 to 16 weeks of gestation. After birth, AFP levels usually fall, within eight to 12 months, to a very low concentration of < 10 micrograms/ml and persist at low levels throughout life. However, AFP levels can rise above normal in both children and adults in distinct conditions and diseases which will be discussed. Hereditary persistence of alpha-fetoprotein (HPAFP) should be considered in both children and adults with unexplained and persistent elevation of AFP e.g., those screened for hepatocellular carcinoma or diagnosed for germ cell tumor. It should also be recognized in AFP screening for neural tube defects or Down's syndrome during pregnancy. Hereditary persistence of AFP can be easily confirmed by analyzing AFP levels in family members.

Downregulation of phorbol 12-myristate 13-acetate-induced tumor necrosis factor-alpha and interleukin-1 beta production and gene expression in human monocytic cells by human alpha-fetoprotein

We previously identified a specific receptor of alpha-fetoprotein (AFP) on human monocytes. Although AFP alters many immune cell functions, the effect of AFP on monocyte cytokine production is unknown. Because tumor necrosis factor--alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) are important cytokines in immunoregulation, we investigated whether AFP could modulate TNF-alpha and IL-1 beta production in U937, a human monocytic cell line. Our results showed that U937 cells secreted TNF-alpha and IL-1 beta in response to either phorbyl 12-myristate 13-acetate (PMA) or IFN-gamma + LPS. In contrast, AFP significantly suppressed PMA-induced TNF-alpha and IL-1 beta production by U937 cells in a time and dose dependent fashion. Pretreatment of U937 cells with AFP resulted in maximal inhibition of PMA-stimulated TNF-alpha and IL-1 beta production by 58% and 67% respectively. AFP also inhibited interferon-gamma plus lipopolysaccharide (IFN-gamma + LPS)-induced TNF-alpha and IL-1 beta production. Furthermore, Northern blot analysis showed that AFP suppressed PMA-mediated TNF-alpha and IL-1 beta messenger RNA (mRNA) expression. PMA-induced prostaglandin E2 (PGE2) production by U937 cells was enhanced by AFP. Pretreatment with indomethacin, a cyclooxygenase inhibitor, reversed AFP-inhibited TNF-alpha production by 78%. Thus, we conclude that AFP downregulates TNF-alpha and IL-1 beta production via a PGE2-dependent mechanism.

Management strategies for mares at risk for periparturient complications

Perinatal death accounts for a large percentage of foal mortality. The most serious threats to perinatal survival remain septicemia, hypoxia, and dysmaturity. Topics discussed in this article include biochemical indices of fetoplacental function and evaluation and management of the high-risk mare.

Plasma protein levels in normal human fetuses: 13 to 41 weeks' gestation

OBJECTIVES

To establish reference ranges for the levels of alpha-fetoprotein, albumin, prealbumin (transthyretin) alpha-1-antitrypsin, transferrin, ceruloplasmin and total protein in the plasma of normal human fetuses and newborn babies.

DESIGN

Prospective study of individual normal cases to fulfil objectives.

SETTING

Pathology laboratories of the University of Edinburgh and the biochemistry laboratories of the University of Keele.

SUBJECTS

Twenty-two normal fetuses 13 to 22 weeks of gestation and 66 babies born between 24 and 41 weeks gestation.

RESULTS

Albumin is the predominant plasma protein throughout gestation. The levels of alpha-fetoprotein and prealbumin fell significantly with increasing gestation, whereas the concentrations of the other proteins studied increased. The ratios of individual proteins to total protein demonstrated similar trends.

CONCLUSIONS

This study provides developmental profiles of normal human fetal plasma proteins to serve as possible reference data for abnormal fetuses. Declining levels of prealbumin (transthyretin) were unexpected and suggest a functional role for this protein in early pregnancy.

Developmental profile of plasma proteins in human fetal cerebrospinal fluid and blood

Total protein, alphafetoprotein, albumin, prealbumin, alpha-1-antitrypsin, transferrin and ceruloplasmin levels were measured in samples of human fetal and neonatal cerebrospinal fluid (CSF) (97 cases), obtained between 12 and 41 weeks of gestation. In 39 of these cases (13 to 40 weeks gestation) plasma was also available for comparative analysis. CSF was collected from lateral ventricles in the first half of gestation and from the lumbar region in the second. Since these CSF samples were obtained from different sites, the protein levels in the lateral ventricle (early) samples could not be compared directly with those in the lumbar (later) samples. However, the mean protein levels in the lumbar samples were lower than those in the ventricular samples, which is in accord with the decline in CSF protein levels described in maturing animal fetuses. Despite a wide scatter of results, particularly in the first half of gestation, significant decline in the level of CSF alphafetoprotein was demonstrated during both first and second halves of gestation, and of albumin and prealbumin in the second half. No sex differences were found except for ceruloplasmin in lumbar CSF later in gestation, when males had higher levels than females. In fetal plasma, protein levels increased with increasing gestation apart from alphafetoprotein and prealbumin which both declined progressively. CSF/plasma ratios were dissimilar for different proteins, and changed with increasing gestation. These findings support the concept that the human fetal blood brain barrier matures early.

Isolation and characterization of a distinct immunoregulatory isoform of alpha-fetoprotein produced by the normal fetus

In this report, we examine the functional significance of the molecular microheterogeneity of alpha-fetoprotein (AFP). In doing so, we have taken the direct approach of purifying the naturally occurring isomeric forms of fetal-derived AFP using a preparative anion exchange column linked to an automated fast protein liquid chromatography (FPLC) system followed by parallel testing of each isolated molecular variant for in vitro immunoregulatory activity. The data obtained demonstrate the presence of seven distinct variants of AFP as defined by their retention volumes on FPLC elution profiles, by their pIs on analytical IEF gels, and by Western blot analysis. Molecular mass determination by SDS-PAGE showed each isomer to be equivalent in size to 69,000-dalton native unfractionated AFP molecules. All the immunosuppressive activity of AFP was localized to a single variant representing only 6% of the total composition of native AFP. The immunoregulating isomer termed AFP-1 was the least acidic of the seven isolated variants with a pI of 5.1 and displayed a sialic acid content of 1 mol/mol of protein. The inhibitory activity of AFP-1 could be readily measured on T cell-dependent antibody synthesis, Con A-induced stimulation of Lyt-1+23- thymocyte DNA synthesis, and lymphokine-activated NK cell activity. All other isomers were without effect in these test systems. The immunosuppressive AFP-1 isomer also displayed the strongest growth-promoting influence on cultured bone marrow lymphocytes. There was no correlation between functional activity and degree of expression of sialic acid residues on the AFP molecules. These findings demonstrate that the immunoregulating function of AFP is confined to a distinct and relatively small subpopulation of native AFP molecules and should therefore contribute to the resolution of outstanding questions regarding the structure/function relationship of this onco-fetal glycoprotein.

alpha-Fetoprotein and albumin gene expression in brain and other tissues of fetal and adult rats

Quantitative measurement of messenger RNA (mRNA) for alpha-fetoprotein (AFP) and albumin in developing rat liver and in different fetal and adult tissues reveals a close correlation between the previously determined rate of protein synthesis and mRNA levels. mRNA for AFP and albumin exists in fetal intestine, lung, liver and kidney whereas there are no such transcripts in fetal brain or heart. There are no mRNA transcripts for AFP in any adult organs other than the liver. The lack of mRNA AFP in fetal brain tissue indicates that the AFP found in fetal brain cells is absorbed from the serum. This finding supports the hypothesis that AFP may serve as a carrier protein to deliver bound molecules, such as non-esterified fatty acids, to brain cells at a specific time during development.

alpha-Fetoprotein: relationship between maternal serum and amniotic fluid levels

Levels of alpha-fetoprotein were determined in 297 paired samples of maternal serum and amniotic fluid from patients with normal pregnancies at 16 to 17 completed weeks of gestation. Gestational ages were determined by menstrual history and ultrasonography, and the assays for alpha-fetoprotein were performed by a single reference laboratory. The results of the study failed to demonstrate any statistical relationship between the concentrations of alpha-fetoprotein in these two fluid compartments (r = 0.006). This finding was confirmed when the results at 16 and 17 weeks were analyzed individually. These findings indicate that amniotic fluid levels of alpha-fetoprotein cannot be predicted by those levels determined in maternal serum, and that simple diffusion is an inadequate explanation for the transfer of alpha-fetoprotein from amniotic fluid to maternal serum. The lack of correlation also emphasizes that the sensitivity and specificity of maternal serum alpha-fetoprotein screening for neural tube defects must continue to be based upon the detection rates in large population studies and the determination of "normal" values by reference laboratories.

Maternal serum alpha-fetoprotein screening for neural tube defects. Report of a combined study in Germany and short overview on screening in populations with low birth prevalence of neural tube defects

The basis of maternal serum alpha-fetoprotein (AFP)-screening for neural tube defects is discussed. A report is given of a large scale screening study in the Federal Republic of Germany combining the experiences in Giessen and Hannover on over 50,000 pregnant women, about evenly distributed among both centers. Published and known forthcoming data from other low incidence populations, particularly of European countries, are reviewed briefly. The conclusion is reached that general screening could effectively be instituted and in the final result should also be cost-beneficial.

Tissue and plasma concentrations of pregnancy-associated plasma protein-A (PAPP-A): comparison with other fetoplacental products

Human placental lactogen (hPL), alpha fetoprotein (AFP), prolactin (PRL) and pregnancy-associated plasma protein-A (PAPP-A) were measured by radioimmunoassay in plasma, in homogenates of trophoblast, decidua, chorion, amnion and in amniotic fluid from 10 patients after non-complicated term delivery. Plasma samples and homogenates of trophoblast and decidua were also collected from 10 patients undergoing surgical termination of pregnancy between 7 and 12 weeks gestation. In addition, plasma and endometrial samples from 10 patients undergoing hysterectomy for other indications than malignancy were analysed for comparison. The highest tissue concentrations of hPL, AFP and PRL corresponded in each case to the known site of synthesis. For PAPP-A the highest concentration was found in maternal plasma at term [238.8 +/- 75.6 (SEM) micrograms/ml]. The highest tissue concentration was found at term in the decidua (57.0 +/- 2.0 micrograms/g), more than three times higher than that in the trophoblast (16.9 +/- 5.4 micrograms/g). The concentrations of PAPP-A in endometrial samples from non-pregnant women (1.9 +/- 0.6 micrograms/g) was 40 times higher than that in the corresponding plasma samples (0.05 +/- 0.02 microgram/ml). These observations point to the decidua as a possible source of PAPP-A.

Prenatal diagnosis--a compilation of diagnosed conditions

This article provides physicians with an up-to-date listing of 182 fetal conditions diagnosed prenatally. This information is presented in two key tables: the first an alphabetical listing of the conditions and the second a grouping of them according to disease categories. The latter table also presents the technique(s) used to establish the diagnosis, as well as pertinent references. Chromosomal abnormalities, diagnosed from amniotic fluid cell karyotypes, have not been individually tabulated in either table. Current techniques utilized for prenatal diagnosis are presented (see Comment).

Culture medium components modify the effects exerted by alpha-fetoprotein (AFP) on lymphocyte response

Incorporation of [methyl-3H]thymidine to DNA of lymphocytes cultured in the presence of various concentrations of alpha-fetoprotein (AFP) from human cord blood serum was investigated. It was found that AFP by itself does not exert mitogenic effects. In phytohemagglutinin (PHA) stimulated cultures it may inhibit DNA biosynthesis or exert augmentative effects on this process dependent on the composition of the culture medium.

Human alpha-fetoprotein/AFP/ I. Isolation of homogenous AFP from cord blood serum

The AFP from human cord blood was isolated by means of affinity chromatography with the use of antibodies as ligands and by gel filtration. The preliminary purification was achieved by affinity chromatography on CNBr-Sepharose 4B coupled with anti AFP-antibody. Further purification was obtained by the use of immunoadsorbent with anti-human serum protein antibodies. Final purification was achieved by gel filtration on Sephadex G-200. Homogeneity of the purified AFP was demonstrated by means of gel filtration, polyacrylamide gel electrophoresis, isoelectric focusing and immunoelectrophoresis.

Sixteen years' experience of counselling, diagnosis, and prenatal detection in one genetic centre: progress, results, and problems

The work of one Genetic Centre over 16 years, covering about 14 000 kinships, is described. The numbers registered in a year increased from an average of 477 in the early 1960s to 1612 in 1976/1977. The increase is largely, but not entirely, attributable to the advent of prenatal diagnosis, and an account is given of our experience with this. In 1916 patients who had a successful amniocentesis, results indicative of fetal abnormality were found in 4.3% and a balanced translocation was found in an additional 0.9%. Results indicative of fetal abnormality were found in 3.5% of mothers referred because of a maternal age of 40 or more, 3.9% referred because of a high risk of neural tube defect, and 19.3% referred because of a high risk of an inborn error of metabolism. A number of cases with difficult diagnostic problems are described.