[Immunochemical analysis of lectin receptors in the structure of trophoblastic beta 1-glycoprotein and pregnancy-associated alpha 2-glycoprotein]

Trophoblastic beta-glycoprotein (TBG), pregnancy-associated alpha 2-glycoprotein (AGP) and alpha-fetoprotein (AFP) bind to concanavalin A, phytohemagglutinin P and pea lectin. Lentil lectin interacts with TBG only, whereas peanut lectin and castor bean lectin are characterized by affinity to AGP. Hence, TBG, AGP and AFP contain the following carbohydrate components: alpha-D-mannose, alpha-D-glucose, N-acetyl-D-glucosamine and N-acetyl-D-galactosamine. In addition, AGP contains beta-D-galactose.

The disappearance rate of Schwangerschaftsprotein 1 in normal and pathological pregnancies

In six women with a normal vaginal delivery at term, in 12 women who had a suction curettage between 6 and 12 weeks gestation and in eight women with an ectopic pregnancy, the post-partum or the post-surgery decline in radioimmunoassayable SP1 was faster during the first 24 h after surgery or delivery than later, so that two half-lives were calculated. The first 'half-life' of about 20 h (0-24 h after delivery or surgery) was of the same order of magnitude in all groups studied and corresponded well to previously published values. The mean second 'half-life' (greater than 24 h after delivery or surgery) was significantly longer in term (72.2 h) and in ectopic pregnancies (64.1 h) than in first trimester pregnancies (45.5 h). These results might indicate that the metabolism of SP1 either changes during pregnancy or that the changing SP1 beta/SP1 alpha ratio during pregnancy markedly influences the levels of SP1 as measured by radioimmunoassay.

[Relation between the spatial structure and antigenic activity of trophoblast-specific beta1-glycoprotein]

Temperature- and pH-dependence of spatial structure of a native trophoblast-specific beta-glycoprotein (TSG), its desialated and deglycosylated derivatives, as well as of a fragment obtained by partial acid hydrolysis on the temperature and pH variations has been studied using CD and UV spectroscopy. Within the range 45-50 degrees C a conformational transition of the protein moiety of TSG, leading to partially reversible alterations in tertiary and secondary structures of this glycoprotein after cooling the solution to 20 degrees C has been found out. The results of spectral studies of the spatial structure of the TSG protein component have been compared with the data on antigen activity of native, temperature- and pH-denaturated, desialated, and deglycosilated TSG. It has been concluded that the protein moiety of TSG consists mainly of beta-structures; the greater part of antigen determinants of TSG is topographic and belongs to the protein component of TSG, and only 15% of antigen determinants are not connected with TSG's spatial structure.

An immunohistochemical study of intracranial germ cell tumours

Histologically verified intracranial tumours, mainly germ cell tumours of the pineal and suprasellar regions, were studied immunohistochemically using anti-serum of alpha fetoprotein (AFP), human chorionic gonadotropin (HCG), carcinoembryonic antigen (CEA), human placental lactogen (HPL), pregnancy specific beta-1 glycoprotein (SP-1), glial fibrillary acidic protein (GFAP), S-100 and neuron specific enolase (NSE). In germinomas, HCG positive cells were occasionally demonstrated in cells presenting as syncytiotrophoblastic giant cells (STGC), and GFAP and S-100 positive cells were found in the surrounding gliotic lesions. Teratomas were positive for CEA in their epithelial components. Endodermal sinus tumours were positive for AFP, choriocarcinomas for HCG and SP-1, and embryonal carcinomas for AFP, HCG and SP-1. HCG and SP-1 positive cells were demonstrated in STGC. As for the relationship between serum AFP level and tissue localization, many cases presenting a serum AFP level exceeding 220 ng/ml were positive for AFP in tumour tissue.

The use of hCG and other pregnancy proteins in the diagnosis of ectopic pregnancy

Early diagnosis of ectopic pregnancy has been greatly improved by three diagnostic advances: the development of rapid and highly sensitive pregnancy tests, advances in ultrasound examination, and laparoscopy. The estimation of hCG is clinically superior to the measurement of any other pregnancy protein or biochemical parameter. If an hCG test has a sensitivity of 25 IU/1, then 90-100% of ectopic pregnancies will give a positive result. But, the hCG test cannot distinguish between intrauterine and ectopic pregnancy, and here ultrasonic examination and laparoscopy are routine diagnostic measures to identify the site of trophoblastic activity. If highly sensitive hCG tests are used routinely, they may detect small amounts of hCG so early in ectopic pregnancy that the tubal swelling is missed, or hCG may be reminiscent from trophoblastic activity of a previous regressing intrauterine or ectopic pregnancy. The lesson we learn from such cases is that a patient with an elevated hCG level in whom an intrauterine pregnancy has been excluded should be carefully followed-up as long as hCG remains elevated because of the possibility of an early ectopic pregnancy.

Placental proteins in peripheral blood and tissues of ectopic pregnancies

Circulating human chorionic gonadotrophin (hCG), Schwangerschaftsprotein 1 (SP-1) and pregnancy-associated plasma protein A (PAPP-A) were examined in 10 women with ectopic gestation in relation to distribution and intensity of staining for these molecules using immunohistochemical techniques applied to matched trophoblastic and decidualized endometrial tissues. All 10 women revealed strong staining for hCG and SP-1 in the syncytiotrophoblast, which was apparently unrelated to maternal levels of hCG and SP-1, levels being less than the 10th centile of the normal range in 9/10 and 7/10 women, respectively. By contrast maternal PAPP-A levels seemed to correlate with the intensity and the distribution of staining for PAPP-A. Circulating PAPP-A was undetectable (less than 5 mIU/l) in 4 patients, and below the 10th centile in the remaining 6. Using immunohistochemical techniques hCG, SP-1 and PAPP-A could not be demonstrated in any of the decidualized endometrial tissues studied.

Immunolocalization of alpha and beta chains of human chorionic gonadotropin, placental lactogen and pregnancy-specific beta-glycoprotein in term placenta by a touch preparation method

Touch preparations of human placenta yield cells retaining antigenic reactivity to immunoperoxidase stains for alpha and beta chains of human chorionic gonadotropin, placental lactogen, and pregnancy-specific beta glycoprotein. This method is a rapid and simple alternative to conventional frozen and paraffin-embedded sections for detection of placental peptides.

Immunosuppressive properties of pregnancy serum on the mixed lymphocyte reaction

The human fetus may escape immunological attack because of serum factors which have immunomodulatory influence on maternal cellular effector responses. Paired peripheral and retroplacental sera were shown to inhibit the allogenic mixed lymphocyte reaction (MLR) used as an in-vitro model of cell-mediated immunity. There was no correlation between the suppressive effect of the peripheral and retroplacental sera and the serum concentrations of four pregnancy-related proteins (alpha-fetoprotein, pregnancy-associated alpha 2 glycoprotein, pregnancy-associated plasma protein A and Schwangerschaftsprotein 1) to which immunosuppressive properties have been ascribed, but there was a negative correlation between peripheral AFP and MLR inhibition (r = -0.62, P less than 0.001). Hence, the factor or factors responsible for suppressing the MLR are not those investigated in the present study.

Pregnancy-specific beta 1-glycoprotein in serum in monoclonal gammopathies: relationship with serum beta 2-microglobulin, and cellular origin

Pregnancy-specific beta 1-glycoprotein (SP1) was assayed by particle-counting immunoassay in serum from 86 healthy blood donors and 236 patients with various types of gammopathy. A concentration of 1 microgram/L was taken as the upper normal limit. Abnormally high values were found in one of 10 patients with monoclonal gammopathy of undetermined significance, in 65% of 152 patients with multiple myeloma, in 84% of 64 patients with Waldenström's macroglobulinemia, and in seven of 10 patients with monoclonal gammopathies associated with other myeloproliferative disorders. In a study of 90 myeloma patients, the SP1 value correlated (p less than 0.001) with the concentration of beta 2-microglobulin in serum, a value which had been corrected for possible renal dysfunction, but not with the concentration of the monoclonal component. SP1 was detected by direct immunofluorescence in myeloma cells of bone-marrow smears from six of 10 patients with myelomatosis. These six patients had serum SP1 values greater than 1 microgram/L, whereas the four patients with fluorescence-negative myeloma cells had SP1 values less than 1 microgram/L.

New placental proteins: chemistry, physiology and clinical use

In the past decade, several new placental proteins have been isolated and studied. The 'pregnancy-specific' beta 1-glycoprotein (SP1) is a major placental product with unusual physicochemical properties that has been extensively investigated, but its biological function remains uncertain. Pregnancy-associated plasma protein A (PAPP-A), a glycoprotein of mol. wt 400,000, has effects in vitro on the coagulation and complement cascades, probably by its properties of protease inhibition. Placental protein 5 (PP5) may be involved in the coagulation and fibrinolytic systems, and in follicle maturation and semen liquefaction. 'Placental protein 12' (PP12) is not a product of the placenta at all; it appears to be produced in the female genital tract under the influence of progesterone and may also be produced by proliferating liver cells. Further study may reveal new roles for these placental proteins beyond their traditional roles as tumour markers.

Immunohistochemical location of HPL, SP1 and beta-HCG in normal placentas of varying gestational age

Sixty-four placentas at various gestational ages were examined by immunohistochemical stains for HPL, SP1 and beta-HCG according to a modified PAP method (Sternberger 1970). Syncytiotrophoblast cell layer was identified as the main site of synthesis. Extravillous immunohistochemical reactions for HPL and SP1 (but not for beta-HCG) were found in X-cells of the basal plate and in the intervillous trophoblast islands. These cell types would thus seem to be derived from trophoblast. Hofbauer-cells of villous connective tissue stained specifically for beta-HCG apparently because of HCG phagocytosis. The intensity of staining for HPL, SP1 and beta-HCG was evaluated semiquantitatively in the syncytiotrophoblast cell layer at various gestational weeks. The maximum of staining for beta-HCG was found in the uniform syncytiotrophoblast layer of immature intermediate villi in early pregnancy (7-14 weeks), HPL and SP1 had their peak of staining reaction at 32-36 weeks of gestation. Increasing maturation results in a subspecialisation of the villous surface: epithelial plates (allowing feto maternal exchange) and nucleated portions of syncytiotrophoblast (which are the main site of hormone production and endocrine activity).

Complement activation, circulating protease inhibitors and pregnancy-associated proteins in severe pre-eclampsia

Circulating protease inhibitors, pregnancy-associated proteins and the split product of complement factor 3 (C3d) were measured in 14 women with severe pre-eclampsia and their matched controls. Only the mean levels of antithrombin III were observed to be significantly lower in pre-eclampsia (P less than 0.02).

Gastric choriocarcinoma; an immunohistochemical study

A case is reported of primary gastric choriocarcinoma occurring in a 73-year-old man, associated with a high serum level of beta hCG. Both primary and lymph node metastases contained exclusively cyto and syncytiotrophoblastic elements. Immunohistochemical localization of chorionic gonadotropin (hCG), placental lactogen (hPL) and pregnancy-specific glycoprotein (SP 1) is described in relation to cytotrophoblastic differentiation. An intramucosal focus of adenocarcinoma supports the hypothesis of the origin of choriocarcinoma from usual gastric cancer.

Pregnancy-specific parameters in early pregnancies after in vitro fertilization: prediction of the course of pregnancy

The plasma concentrations of the beta subunit of human chorionic gonadotropin (beta-hCG), pregnancy-specific glycoprotein, and progesterone were measured in 37 pregnancies after in vitro fertilization. Twenty-one pregnancies ended with delivery, 9 as clinical abortions, and 7 as biochemical abortions. To predict the pregnancy outcome as early as possible, we designed a prediction graph by calculating a "cutoff line" using discriminant analysis and prediction bands up to 95% probability. This prediction graph can help in the estimation of the probability of pregnancy outcome with satisfactory reliability by determination of beta-hCG only.

Trophoblastic proteins as tumor markers in nonseminomatous germ cell tumors

In order to examine the relative usefulness of measurements of oncoplacental proteins as tumor markers in patients with nonseminomatous germ cell tumors, the authors measured alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), pregnancy-specific beta 1-glycoprotein (SP1), human placental lactogen (hPL), and placental cystine aminopeptidase (oxytocinase, CAP) in serial blood samples obtained from 26 men with these neoplasms. HCG and AFP were each elevated in 62% of the patients and both were elevated in 38%. SP1 and hPL were increased in 31% and 12%, respectively. None of the patients had elevated CAP activity. Serum hCG and SP1 concentrations were strongly correlated (r = 0.78, P less than 0.001). No patient had an elevated SP1 without a concomitant elevation in serum hCG. Serial measurements of hCG and SP1 indicated that they were concordant in five of the eight patients in whom both were elevated, and AFP and hCG were concordant in only one half of the ten patients in whom both markers were elevated. The number of patients with hPL elevations were too few for meaningful comparison of this marker with the others. These results indicate that measurements of SP1, hPL, and CAP do not provide additional useful information over that obtained from measurements of hCG and AFP in patients with nonseminomatous germ cell tumors.

Inguinal sweat gland carcinoma with choriocarcinomatous differentiation

An inguinal sweat gland carcinoma is described including the unusual occurrence of alpha hCG. The alpha hCG was demonstrated in the tumor presenting choriocarcinomatous differentiation and undifferentiated polygonal cells in ordinary tumor nests. beta hCG and SP-1 were weakly and sporadically demonstrated in a small area of the tumor presenting choriocarcinomatous differentiation. On the other hand, hPL and histochemical reaction of placental type alkaline phosphatase were not observed in the choriocarcinomatous and undifferentiated tumor cells. CEA was observed in both ordinary sweat gland carcinoma nests and choriocarcinomatous differentiated regions. In the ordinary tumor nests, enzyme histochemical reactions of phosphorylase and SDH were positive. And S 100 protein was sporadically demonstrated. In spite of chemotherapy and radiotherapy, the patient died after a short duration of the disease.

Estimation of gestational age by last menstrual period, by ultrasound scan and by SP1 concentration: comparisons with date of delivery

The date of delivery in 62 normal pregnant women was predicted by last menstrual period, by ultrasound scan and by the serum concentration of Schwangerschaftsprotein 1 (SP1). It was found that SP1 concentration in the first trimester gave as reliable an indication of when labour would occur as did the last menstrual period or ultrasound scan.

Gestational trophoblastic diseases: the ratio of choriogonadotropin to specific pregnancy protein, hCG/SP1, provides useful diagnostic and prognostic evidence

Serum levels of human chorionic gonadotropin (hCG), specific pregnancy protein (SP1), and hPL were measured in 675 samples from women with uneventful pregnancy, and serially from the time of presentation in 125 patients with hydatidiform mole (HM), 43 with invasive mole (IM), and 34 with choriocarcinoma (CC). In HM serum levels of hCG and SP1 declined steadily from presentation to remission; when gestational age at the time of molar evacuation was shorter than 11 weeks, hCG declined to the normal range later than SP1 (57% patients), and when the age was longer--at the same rate as SP1 (26% patients) or earlier (17% patients). Serum levels of either marker were higher in IM than in HM and tended to increase, and in CC were either lower or higher than in IM. Treatment was followed by parallel decline of either marker, although SP1 declined to the normal range later than hCG in 12% of patients with IM and in 10% with CC. The hCG/SP1 ratios in normal pregnancy declined exponentially between the beginning and 23rd week of gestation and stayed level thereafter. The ratios calculated for the gestational age at the time of initial evacuation of the uterus or delivery were close to those of normal pregnancy in 80%, slightly increased in 20% of patients with spontaneously regressing HM, and markedly increased in 70% of patients with IM and in 74% of patients with CC. The ratios tended to increase during chemotherapy. An increase in the hCG/SP1 ratio seemed to be a characteristic sign of malignant change when compared with this ratio in normal pregnancy and hydatidiform mole. Determination of SP1 for monitoring therapy seemed redundant, and hPL assay was useful for discrimination between relapse and pregnancy.

Clinical value of pregnancy-specific beta 1-glycoprotein (SP1) and beta-hCG determination in serum in suspected ectopic pregnancy

We compared the clinical value of pregnancy-specific beta 1-glycoprotein (SP1) determination in serum by means of a highly sensitive enzyme-linked immunosorbent assay (ELISA) versus that of beta human chorionic gonadotropin (beta-hCG) determination in suspected ectopic pregnancy. The study comprised 58 women admitted consecutively with suspected ectopic pregnancy but without signs warranting immediate surgical intervention. Both SP1 and beta-hCG were found in 11 patients with ectopic pregnancy and in 8 patients with early intra-uterine pregnancy, whereas beta-hCG was detected in 4 and SP1 in 7 of 8 women with a recent abortion. Of 31 women presenting a non-pregnant condition, 2 were positive for both SP1 and beta-hCG. The measurement of SP1 in serum thus appears to be an alternative to beta-hCG measurement when ectopic pregnancy is suspected.

Serum lactoferrin and C-reactive protein in mother and newborn after preterm rupture of membranes

Eleven of 15 serum lactoferrin (S-LF) values and all 16 C-reactive protein (CRP) values were significantly elevated in cases of premature rupture of the amniotic membranes (PROM). There was no correlation between values of C-reactive protein and lactoferrin in either mothers or their newborn. The difference in C-reactive protein between mothers and their newborn was significant, but this was not the case with serum lactoferrin. This suggest that there is no transplacental transfer of C-reactive protein, even in preterm rupture of the membranes, and this is probably also the case with lactoferrin.

Comparison of the concentration of schwangerschaftsprotein 1 (SP1) in the serum and urine of pregnant women

Schwangerschaftsprotein 1 (SP1) values in serum and urine were compared. The first appearance of the protein in urine happens 9-17 days after the first SP1-positive serum, i.e., about 9 days after the first missed period. Urinary SP1 values up to 6 weeks after LMP do not correlate with gestational age as do serum values, but towards the end of the first trimester this correlation becomes almost as good as the one obtained with serum. The urinary SP1 concentration of SP1 fluctuates around 2.3% of the serum concentration throughout pregnancy.

Tumor marker expression in breast carcinomas and relationship to prognosis. An immunohistochemical study

A collaborative immunohistochemical study was carried out to examine the expression and prognostic significance of tumor markers in a retrospective series of 233 invasive breast carcinomas. The patterns of tumor marker expression in 94 patients with short remission duration (recurrence within five years) were compared with 50 patients with intermediate (at five to ten years) and 89 patients with long (no recurrence at ten years or longer) remission durations. The antigens examined were carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), placental lactogen, alpha-lactalbumin, and pregnancy-specific beta-1 glycoprotein. Carcino-embryonic antigen was the most frequently expressed antigen, whereas HCG was demonstrated least frequently. Also, the ABH isoantigen status was examined using monoclonal antibodies; isoantigen expression was observed in a subset of breast carcinomas, contrary to previous reports of total deletion in breast cancer. Two of the markers, CEA and HCG, were examined by both laboratories, each with two different antisera and also with both PAP and ABC immunohistochemical technics. Meticulous efforts were taken to provide quality control and ensure reproducibility of results. These included the use of serial sections of duplicate pathologic material by both institutions, standardization of experimental conditions and interpretation criteria, double-blind evaluation of exchanged slides, and use of standardized data sheets to record staining extent and intensity. No significant disagreements were observed between data obtained through the different approaches. The steps that were taken to minimize interobserver and interinstitutional differences in this study are presented as a model for collaborative immunohistochemical studies. The expression of tumor markers, alone or in combination, was not found to bear any significant relationship to prognostic indicators, such as the likelihood of recurrence, interval before recurrence, or presence of metastasis.

Concomitant secretion of Schwangerschaftsprotein 1 and human chorionic gonadotrophin following conception

Daily measurements of serum oestradiol, progesterone, Schwangerschaftsprotein 1 (SP1) and hCG were made in 13 menstrual cycles during which conception occurred. The assays were continued until 21 d after ovulation. SP1 was detected in maternal blood 8-14 d after ovulation and hCG 9-13 d after ovulation. We conclude that these two proteins are secreted simultaneously but independently by the syncytiotrophoblast.

[New developments in the area of markers in diagnosis and monitoring of ovarian cancer]

The diagnostic and prognostic prediction of ovarian carcinoma can be substantially improved by combining serological markers synchronized with radiological and morphological methods. The validity of the following markers was investigated in a prospective trial between 1977 and 1983: CEA, TPA, SP-1, SP-3, alpha-1-antitrypsin, alpha-2-macroglobulin, c-reactive protein. The results were correlated with those of the CA 12-5 determination. Pre-operatively, ovarian carcinoma was indicated by CA 12-5 (93.7%), sialyl transferase (65.6%), TPA (53.1%), CEA (28.1%). These markers would appear suitable to control the clinical course.

The immunohistochemical localization of pregnancy-specific beta 1-glycoprotein in postimplantation rat trophoblast

Pregnancy-specific beta 1-glycoprotein (SP1) was identified by peroxidase-antiperoxidase (PAP) immunohistochemistry in the placenta of inbred strains of rat between 10 and 21 days of gestation. SP1 was located predominantly in basal zone trophoblast and in intravascular trophoblast of decidual vessels, but it was absent from labyrinthine trophoblast. No perivascular cells were identified by SP1 staining, but occasional clusters of interstitial trophoblast stained for SP1. The results suggest that basal and labyrinthine trophoblast are functionally different.

Serum concentration of placental proteins in non-pregnant and pregnant subjects

Chorionic gonadotrophin (hCG) and Schwangerschaftsprotein 1 (SP1) were measured in 35 menstrual cycles in 20 women. During the follicular phase, 3 samples were positive for hCG and two of these were also positive for SP1. All these positives occurred on the day of ovulation or immediately before. In the luteal phase 25 specimens showed both hCG and SP1 and two showed only SP1, the positive results occurring 3-15 days after ovulation. The placental proteins were also measured in a further eight women who became pregnant. The pattern in these was quite different. The first positives were detected 8 days after ovulation and by 12 days all the subjects were positive for both proteins. Thereafter both proteins increased sharply in concentration. A group of 139 subjects who, on biological grounds, could not have conceived, showed no positive results.

Monitoring of postimplantation embryo viability following successful in vitro fertilization and embryo transfer by measurement of placental proteins

Serum levels of pregnancy-associated plasma protein A (PAPP-A), human chorionic gonadotropin (hCG), and pregnancy-specific beta 1-glycoprotein (SP1) were measured in 21 women after successful in vitro fertilization and embryo transfer. Of the 21 pregnancies, 14, including 1 twin gestation, progressed successfully to term. The remaining seven, composed of tubal (n = 3), anembryonic (n = 1), and spontaneously aborted (n = 3) pregnancies, failed during the first half of pregnancy. Placental protein measurement was of no diagnostic value in the detection of anembryonic pregnancy. Similarly, measurement of hCG and SP1 could not readily distinguish tubal ectopic from normal intrauterine pregnancies. By contrast, the predictive value (38.9%) of a depressed PAPP-A level in conjunction with superior diagnostic sensitivity (70%) and relative risk factor (23.6) proved to be of greater diagnostic value in this potentially lethal condition. In the absence of ultrasonography, the biochemical diagnostic indices were comparable in the prediction of spontaneous abortion. However, in the presence of a live fetus, PAPP-A levels were consistently depressed (sensitivity, 91.7%) many weeks before pregnancy demise. The relative risk factor of depressed PAPP-A levels was 29 times greater than the risk associated with a depressed hCG level. These findings further demonstrate the potential diagnostic value of PAPP-A measurement for monitoring postimplantation embryo viability.

Development and characterization of monoclonal antibodies to pregnancy-specific beta 1-glycoprotein

Six monoclonal antibodies were developed to pregnancy-specific beta 1-glycoprotein (PS beta 1G). Studies of ascitic fluid antibodies by a double-antibody radioimmunoassay (RIA) included an evaluation of titers, dose-response parameters, and mass action properties. Four of the antibodies demonstrated moderate to high titers ranging from 1/40 000 to greater than 1/120 000, as determined by the specific binding of 125I-labeled PS beta 1G. In inhibition studies utilizing a standard containing known quantities of placental PS beta 1G, two of the antibodies (AR#11 and B#2) were highly sensitive and only slightly lower in this regard than a high affinity polyclonal antiserum. The binding affinities of AR#11 and B#2 monoclonals were greater than 10(9) mol-1 which underline their importance as potential clinical reagents for the RIA of PS beta 1G. The Scatchard plots, for several of the antibodies, were linear and in full agreement with a single order of binding sites predicted for specific monoclonal reagents. Immunodiffusion results provide preliminary evidence that at least three distinct determinants on PS beta 1G are recognized by a number of the monoclonal antibodies. Further studies on the fine specificities of the antibodies by solid-phase RIA, as well as a detailed evaluation of their clinical applications, are in progress.

Evidence for the presence of oncoplacental SP1-like protein in normal nonpregnant serum

To seek the pregnancy-specific beta 1-glycoprotein (SP1) in nonpregnant serum, normal human serum was applied to immunoadsorbent containing monoclonal anti-SP1 antibodies. SP1 eluted with 8 M urea was further analyzed by sodium dodecyl sulfate-gel electrophoresis and immunoblotting. A SP1-positive band with the same electrophoretic mobility as purified placental SP1 was found. The results suggest that serum from normal nonpregnant subjects contains material closely related to the placental protein SP1. The mean serum concentrations of SP1 were similar in men and women, ranging from 1.1-3.4 ng/ml.

Monitoring of postimplantation embryo viability by measurement of PAPP-A, SP1, and hCG

After successful in vitro fertilization and embryo transfer, chorionic gonadotropin, pregnancy-specific beta 1-glycoprotein, and pregnancy-associated plasma protein-A were measured in serum samples collected serially from 21 patients. While 14 pregnancies, including one twin pregnancy, progressed successfully to term, the remaining seven pregnancies failed during the first half of gestation. This latter group consisted of three tubally implanted, one anembryonic, and three spontaneously aborted pregnancies. Circulating levels of hCG, SP1, and PAPP-A in the patient with an anembryonic pregnancy were within normal limits. Similarly, 90.5% of the serum samples obtained from women with tubal pregnancies showed hCG levels within normal limits. By contrast, only two of these samples had detectable PAPP-A, of which only one was within normal limits. Of the samples obtained from the patients who spontaneously aborted, including one patient with normal ultrasonic findings up to 48 hours prior to the event, 85.7% had PAPP-A concentration below the 10th percentile, whereas only 16.7% of these samples showed depressed hCG levels. These data suggest that PAPP-A measurement has great clinical potential in the management of compromised early pregnancies.

Placental proteins in the diagnosis and evaluation of the "elusive" early pregnancy

For many many years much time and effort has been invested to identify, purify, and quantify markers of significant reproductive events. The search for such markers has been recently intensified with the widespread acceptance of IVF and ET as a treatment regimen for the management of certain causes of infertility. Now it is possible to monitor ovarian folliculogenesis and time of ovulation, successful fertilization, and subsequent nidation and the ensuing pregnancy. Following successful fertilization and zygote development, EPF, a protein complex which suppresses in vitro lymphocyte rosette formation can be detected within 24 hours. Shortly after implantation hCG can be measured in the maternal circulation. The developing trophoblastic tissue continues to synthesize and secrete into the maternal circulation many varied proteins including SP1, PAPP-A, and PP5. To date hCG is the mainstay of rapid and early pregnancy diagnosis and is an accepted biochemical marker of successful implantation and trophoblastic activity. Combination of hCG and EPF measurement offers the clinician new insight into his infertile patient for now it is possible to monitor successful fertilization and implantation as separate independent events. Such diagnostic assays should also provide new insight into early embryo mortality rate at the pre- and postimplantation stage and hence indicate the selection pressures acting on an embryo. It is the application of these assays which has led to the definition of subclinical abortions and to the description of biochemical pregnancies. The value of these proteins for the management of compromised early pregnancies has to be more fully examined. Although the differentiation between a normal and abnormal pregnancy is more readily ascertained by serial sampling and analysis of the time taken for circulating levels to double (3). Preliminary data suggest the potential of EPF and PAPP-A measurement in such clinical conditions is enormous. Our studies suggest that PAPP-A, at present, is the only biochemical marker which can predict pregnancy abortion, even in the presence of normal ultrasound scans, many weeks prior to the event, thus implying a vital biological role for PAPP-A in normal pregnancy (52). Despite the need for more intensive evaluation of these early pregnancy indicators the search for that "demmed elusive" marker has more than "Those Frenchies" earnestly looking for him here and there.

Pregnancy-associated plasma protein A: a clinically significant predictor of early recurrence in stage II breast carcinoma

The primary tumors and metastases from 30 patients with stage II breast carcinoma treated with low- or standard-dose combination chemotherapy (cyclophosphamide, methotrexate, 5-fluorouracil) were studied by the immunoperoxidase technique for pregnancy-associated plasma protein A (PAPP-A), pregnancy-specific beta-1-glycoprotein (SP-1), and placental protein five (PP-5). In addition to immunostaining, 25 traditional clinicopathologic features were assessed with respect to early (at less than two years) recurrence. Of the 11 patients with early recurrences, nine (82 per cent) were PAPP-A-positive, while 16 of the 19 patients without early recurrences (84 per cent) were PAPP-A-negative (P less than 0.0005). None of the other clinicopathologic features correlated with early recurrence. Immunostaining for PAPP-A is thus a clinically significant predictor of early recurrence in patients with stage II breast carcinoma.

Particle-counting immunoassay (PACIA) of pregnancy-specific beta 1-glycoprotein, a possible marker of various malignancies and Crohn's ileitis

Pregnancy-specific beta 1-glycoprotein (SP1) was assayed by particle-counting immunoassay (PACIA) with a sensitivity of 1 microgram/L. In serum from 50 men, the SP1 concentration was less than 1 microgram/L, whereas three of the specimens from 46 nonpregnant women had values exceeding 1 microgram/L. In 29% of 950 consecutive patients' sera, SP1 concentrations exceeded 1 microgram/L--in sarcoma (six of six), in malignant hemopathies (101/127, 80%) such as myeloma (20/26, 92%) and acute myeloblastic leukemia (23/27, 90%), and in various other types of cancer (11/19, 58%) except for bronchial epithelioma, which did not lead to any significant increase of SP1 in the five patients examined. The concentration of SP1 was also frequently increased in patients with Crohn's ileitis (28/43, 65%) but not in patients with other inflammatory disorders.