Immunohistochemical localization of two endometrial proteins in the early days of human pregnancy

Insulin-like growth factor binding protein-1 (IGFBP-1) [also known as placental protein 12(PP12)] and placental protein 14 (PP14) have been identified by specific immunostaining in early pregnancy specimens obtained 13-35 days of gestation. PP12 was evident in a discrete number of stromal decidual cells at the deciduotrophoblastic interface and under the endometrial surface epithelium. These cells did not have the rounded appearance of classic decidual cells but most often displayed cytoplasmic expansions. Staining for PP14 was strictly localized to the glandular epithelium of the endometrium. Implantation of the conceptus may be an important mechanism in the early expression of PP12 but not PP14.

Circulating levels of placental protein 14 in ectopic pregnancy

OBJECTIVE

To determine circulating levels of placental protein 14 (PP14) in complications of early pregnancy.

DESIGN

Biochemical monitoring of women presenting with vaginal bleeding and/or abdominal pain.

SETTING

An emergency gynaecological ultrasound clinic in a London teaching hospital.

SUBJECTS

Venous blood samples were obtained from 67 women with normal pregnancy (n = 9), ectopic pregnancy (n = 26) and failed intrauterine pregnancy (n = 32). This group included anembryonic pregnancy (n = 18), missed miscarriage (n = 2), spontaneous miscarriage of a previously demonstrated live fetus (n = 6), incomplete miscarriage (n = 4), complete miscarriage (n = 1) and molar pregnancy (n = 1).

MAIN OUTCOME MEASURES

Serum PP14 levels in the group of women with a failed intrauterine pregnancy in relation to the normal range for PP14.

RESULTS

Eighty-one percent of women who miscarried spontaneously had normal serum PP14 levels; 81% of women with ectopic pregnancy had depressed (< 5th centile) serum PP14 levels.

CONCLUSION

Measurements of PP14 may be useful in distinguishing spontaneous miscarriage from ectopic pregnancy, but not in the management of threatened miscarriage.

Characterisation of the differential expression of marker antigens by normal and malignant endometrial epithelium

In order to examine the production of marker proteins, a reproducible method has been established for culturing purified epithelial cells from normal and malignant endometrium. We have examined the differential expression of secretory proteins using immunohistochemistry in frozen tissue sections, immunocytochemistry in cell cultures derived from the same specimens and protein assays on the culture supernatants. Placental protein 14 (PP14) was produced by normal premenopausal epithelium but not by the post-menopausal or malignant endometrial epithelium. In contrast, placental alkaline phosphatase (PLAP) was produced by endometrial cancers and the endometrial adenocarcinoma-derived cell line Ishikawa, but not by the normal endometrial epithelium. Other markers such as CA-125, which was produced by both normal and malignant endometrium but not by the cell line, and human chorionic gonadotrophin (beta-hCG), which was produced by Ishikawa cells but not by any of the fresh tissues, were less cancer specific. Placental alkaline phosphatase is a direct product of endometrial cancers that can be readily assayed in serum using this two-site assay to test its clinical usefulness in monitoring patients at risk for endometrial cancer.

Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein A, markers for fetal Down syndrome at 8-14 weeks

Maternal serum levels of human chorionic gonadotrophin and its subunits (intact, alpha, and free beta h CG) and pregnancy-associated plasma protein A (PAPP-A) were measured in 279 women between 8 and 14 weeks' gestation. This group included 23 pregnancies in which the fetus had Down syndrome (DS), diagnosed either at birth or during the second trimester (n = 17) or from chorionic villus sampling (CVS) (n = 6). Normal medians were determined from the 258 apparently normal pregnancies. The median levels of intact hCG (1.4 MOM) and free beta hCG (2.1 MOM) were significantly raised, whereas the median level of PAPP-A (0.39 MOM) was significantly lower in the DS pregnancies when compared with the control group. Levels of alpha hCG were similar in both the control and the DS pregnancies. Analysis of samples taken prior to 14 weeks' gestation demonstrated that only PAPP-A (0.34 MOM) was significantly altered in DS pregnancies. However, after the exclusion of DS cases diagnosed at CVS, the median intact hCG (1.56 MOM), free beta hCG (2.27 MOM), and alpha hCG (1.8 MOM) were all raised in DS pregnancies. This emphasizes the problem of the interpretation of biochemical markers when DS cases are diagnosed at CVS.

Hormone replacement therapy by the transdermal administration of oestradiol and norethisterone

The objective was to assess the efficacy and acceptability of a new transdermal norethisterone device as part of a hormone replacement therapy (HRT) regimen. The design was an open prospective clinical assessment for 6 months. The setting was the Academic Unit of Obstetrics and Gynaecology, Royal London Hospital, Whitechapel, London. Eighteen patients of confirmed menopausal status were recruited. Therapy consisted of continuous application of Estraderm TTS 50 (Ciba Laboratories) for a 28-day period, with the additional application of two norethisterone acetate patches in the last 12 days of this period. This schedule was repeated for six cycles. The main outcome measures were symptom and menstrual data--haematological indices, hepatic and renal function; lipid parameters; endometrial biopsy. The results showed a significant improvement in the patients' symptoms of hot flushes and sweating (P = 0.03). Of the 15 women who completed at least 6 months of medication, withdrawal vaginal bleeding was established at regular intervals in 9. One patient had a local irritant reaction to the patch. There were no significant changes observed in haematological indices, hepatic and renal function. There was a slight but not statistically significant decrease in the HDL cholesterol fraction when the patient was in the norethisterone phase of the cycle, but no change was observed between the beginning and end of the study. Histological examination of the endometrial biopsies showed features of secretory activity in 56% of samples after 6 months. There was no evidence of hyperplasia, pre-malignant or malignant changes in the remaining biopsies.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum CA 125 in a pregnancy generated by ovum donation

Serum CA 125 was measured by radioimmunoassay during the first trimester at intervals of 2 weeks in a woman with Turner's syndrome, who conceived following ovum donation from a healthy anonymous donor. Serum CA 125 concentrations were lower than or at the 10th percentile of the normal range. These findings imply that CA 125 may be secreted from the ovary in the first trimester, or produced at another site in response to stimuli from the ovary.

Regulation of corpus luteum function

The effects have been studied of different ovulation induction regimens [either clomiphene citrate or buserelin in combination with human menopausal gonadotrophin (HMG)] on the circulating concentrations of progesterone, oestradiol, relaxin and human chorionic gonadotrophin (HCG) during the first trimester of pregnancy. Ovulation induction with clomiphene resulted in elevated concentrations of gonadotrophins in both phases of the cycle, while during ovulation induction with buserelin, gonadotrophin concentrations were elevated in the follicular phase only. The concentrations of all corpus luteum products were greater in clomiphene pregnancies compared with spontaneous pregnancies, but only oestradiol and relaxin concentrations were greater in clomiphene pregnancies compared with buserelin pregnancies. The concentrations of HCG were significantly reduced in clomiphene pregnancies compared to natural pregnancies. Relaxin concentrations were significantly higher from 7 weeks gestation in buserelin compared with spontaneous pregnancies, while progesterone, oestradiol and HCG concentrations were not consistently different. Consistent associations were found between relaxin and HCG concentrations in spontaneous pregnancies and between the concentrations of relaxin and both progesterone and oestradiol in pregnancies achieved after ovulation induction.(ABSTRACT TRUNCATED AT 250 WORDS)

Reduced circulating placental protein concentrations during the first trimester are associated with preterm labour and low birth weight

Serum concentrations of human chorionic gonadotrophin (HCG), Schwangerschaftsprotein 1 (SP-1), pregnancy-associated plasma protein A (PAPP-A), progesterone and oestradiol were measured at weekly intervals between the fifth (embryo transfer plus 3 weeks) and 13th week of gestation during the first trimester of pregnancies achieved following in-vitro fertilization (IVF) and embryo transfer in a group of women who delivered before (n = 8) or at term (n = 52). Those women who had a preterm delivery had significantly lower concentrations of PAPP-A (weeks 7-13; P = 0.0001-0.028) and SP-1 (weeks 6-8 and 10-12; P = 0.004-0.04). After correction of birth weight for sex and gestational age at delivery, preterm delivery was found not to be associated with growth retardation. However, comparison of the circulating concentrations of the substances analysed in mothers who delivered babies of < 85% of the 50th centile of the normal range of birth weight for a given gestational age and sex, with those who delivered babies of > 85% revealed that the concentrations of HCG (P = 0.012-0.04 on weeks 6-9) and SP-1 (P = 0.003-0.03 on weeks 7, 9-13) were significantly lower in the former group. Weak, inconsistent associations were found between the circulating concentrations of HCG, SP-1 and PAPP-A and both corrected birth weight and gestational age at delivery. Thus, both the gestational age at delivery and low birth weight may be related to impaired placental development/function during the first trimester.

Serum PAPP-A measurements in first-trimester screening for Down syndrome

Serum PAPP-A measurements taken from 254 women in the first trimester are reported. Eleven chromosomal abnormalities were detected. The mean serum PAPP-A levels in cases of Down syndrome were 0.44 MOM at 9 weeks gestation, 0.15 MOM at 10 weeks, and 0.29 MOM at 11 weeks. The PAPP-A level at 10 weeks was below those of pregnancies which aborted spontaneously. At 11 weeks, the pregnancies with Down syndrome recorded the lowest PAPP-A levels at that gestation. On this small sample, offering chorionic villus sampling to women with singleton pregnancies and a PAPP-A level below 0.3 MOM (approximately 6.5 per cent of this at-risk group) would have detected all the Down syndrome fetuses at 10 weeks and 50 per cent at 11 weeks without selecting those cases destined to abort. This suggests that serum PAPP-A should continue to be investigated as a potential first-trimester screening test for Down syndrome.

Corpus luteum failure in ectopic pregnancy

The endocrinology of ectopic pregnancy was studied in order to investigate the origin of the discordance in the circulating amounts of human chorionic gonadotrophin (HCG) and those of oestradiol and progesterone. Serial maternal blood samples were obtained at 4-9 weeks gestation from 93 patients who became pregnant following in-vitro fertilization and embryo transfer including 10 ectopic, 21 anembryonic and 62 normal singleton pregnancies. The samples were analysed for HCG, Schwangerschaft protein-1 (SP-1), pregnancy-associated plasma protein-A (PAPP-A), progesterone and oestradiol. In ectopic pregnancies, concentrations of all substances analysed were significantly reduced compared to singleton pregnancies from 5 weeks gestation (P < 0.05-0.001) but they were not significantly different from those of anembryonic pregnancies. In ectopic pregnancies, associations were found between the concentration of both HCG and SP-1 and those of progesterone and oestradiol. No associations were found between PAPP-A and any other substances analysed. This may be due to insensitivity of the PAPP-A assay; alternatively PAPP-A concentrations may be differentially reduced in ectopic pregnancy. These findings suggest that progesterone and oestradiol are derived from the corpus luteum in early ectopic pregnancy but that the corpus luteum fails rapidly and the dominant source of both hormones becomes the trophoblast as early as 5 weeks.

Interactions between the embryo and corpus luteum

A total of 102 patients who had become pregnant following in-vitro fertilization (IVF) and embryo transfer were studied at weekly intervals between 4 and 14 weeks gestation. The pregnancies were classified as follows: (i) normal singleton, n = 52; (ii) normal twin, n = 24; (iii) heterotopic, n = 4 (weeks 4-8 only); and (iv) anembryonic with a viable intra-uterine singleton, n = 22. The serum concentrations of human chorionic gonadotrophin (hCG), Schwangerschaft protein-1 (SP-1) and pregnancy-associated plasma protein-A (PAPP-A), oestradiol and progesterone were measured. The mean serum concentrations of HCG, SP-1 and PAPP-A were significantly less in heterotopic than in singleton, singleton/anembryonic or twin pregnancies (P < 0.01-0.05), while those of progesterone and oestradiol were not different at any time. There were no significant differences between the serum concentrations of any of the substances analysed in singleton/anembryonic and singleton pregnancies, but the concentrations of all the substances analysed were significantly greater in twin pregnancies from as early as 7 weeks (P < 0.01-0.05). These data show that in heterotopic pregnancies trophoblast function is reduced, as suggested by the lower concentrations of the placental proteins. Despite this the concentrations of oestradiol and progesterone, derived predominantly from the corpus luteum between 4 and 8 weeks, are equivalent to those found in twin pregnancies, and greater than those found in singleton and singleton/anembryonic pregnancies. These findings support the notion that although HCG may rescue the corpus luteum it does not subsequently have a direct effect on its function, and suggest that the embryo may influence corpus luteum function.

Evidence for the in-vitro de-novo synthesis of immunoglobulin and a previously undescribed 17 kDa protein (TEP-2) by the mucosa of the fallopian tube

De-novo synthesis and secretion of proteins by short-term explants of matched Fallopian tube mucosa and endometrium were studied using radiolabelled L-[35S]methionine and [3H]glucosamine. To compare directly each anatomical site of the Fallopian tube and endometrium from the same source, newly synthesized proteins were separated on one-dimensional polyacrylamide gel electrophoresis and examined by auto-radiography. De-novo synthesis of two protein bands provisionally designated as tubal epithelial protein 1 (TEP-1) and tubal epithelial protein 2 (TEP-2), was observed in explants of the Fallopian tube mucosa obtained from each anatomical site throughout the ovarian cycle (n = 20). TEP-2 was not apparent in tubal mucosa obtained from post-menopausal women (n = 5). De-novo synthesis of TEP-1 and TEP-2 was not apparent in autoradiographs of radiolabelled proteins from short-term explants of endometrium. From the autoradiographs the molecular mass of TEP-1 and TEP-2 was calculated to be 25 kDa and 17 kDa, respectively. Incorporation of glucosamine into newly synthesized protein occurred in TEP-2 but not TEP-1. TEP-1 was observed to be immunochemically identical to immunoglobulin kappa light chains.

Serum PAPP-A levels are depressed in women with fetal Down syndrome in early pregnancy

The value of maternal serum pregnancy-associated plasma protein (PAPP)-A in screening for Down syndrome in early pregnancy was assessed using stored samples. Seventeen cases of Down syndrome and 66 unaffected control pregnancies were studied. The median PAPP-A level in the cases was 0.42 multiples of the expected value in controls (p < 0.0001). Eleven cases (65 per cent) had levels less than half the expected value compared with only six controls (9 per cent). A commercial assay kit is now needed so that prospective screening with this marker can begin.

First-trimester maternal serum Schwangerschafts protein 1 (SP1) in pregnancies associated with chromosomal anomalies

The relationship between first-trimester maternal serum Schwangerschafts protein 1 (SP1) and the karyotype of the pregnancy was examined in 692 women who underwent chorionic villus biopsy at 6-12 weeks. There were 30 pregnancies with abnormal karyotypes, consisting of 14 Down's syndrome (DS), eight trisomy 18, and eight other anomalies, two of which were mosaics. The normal ranges and medians for gestation were defined from the 662 cases in which the karyotype was normal. The median SP1 (0.5 MOM) of the abnormal group was significantly lower than that of the normal group (1.0 MOM). This relationship was maintained for the DS pregnancies (0.4 MOM) and for anomalies other than trisomy 18 (0.43 MOM) but not trisomy 18 (1.1 MOM). It is possible that the use of SP1 as a screening test for chromosome anomalies in the first trimester could have a 43 per cent detection rate for a 5 per cent false-positive rate.

In-vitro synthesis of total protein and placental protein PP14 by the fallopian tube mucosa: variation in relation to anatomical site, the ovarian cycle and the menopause

De-novo synthesis and secretion of protein by short term explants of mucosa from each anatomical section of the Fallopian tube and endometrium of pre-menopausal (n = 25) and tubal mucosa of post-menopausal (n = 5) women were studied by demonstration of incorporation of radiolabelled L-[35S]methionine and one-dimensional SDS-polyacrylamide gel electrophoresis. A consistent finding in 25 pre-menopausal women was the presence of a 25 kDa protein band synthesized by tissue obtained throughout the ovarian cycle. Western blotting demonstrated that this protein band contained placental protein 14 (PP14)-like immunoreactivity in the proliferative (n = 2) and luteal phase (n = 2) of the ovarian cycle. To determine if there is quantitative variation in total protein and PP14 synthesis and secretion during the ovarian cycle, the total quantities of protein and PP14 synthesized were determined by Coomassie Brilliant Blue staining and radioimmunoassay respectively. Analysis of the results of total protein assay revealed statistically significant differences in relation to the anatomical origin of the study tissue (P < 0.01), the stage of the ovarian cycle (P < 0.04) and the manner in which each anatomical site varied during the ovarian cycle (P < 0.01), the endometrium being significantly different from the Fallopian tube. When the data for PP14 synthesized by the Fallopian tube mucosa were analysed, these effects were not seen. PP14 was not detected in the culture media of Fallopian tube mucosa obtained from post-menopausal women.

Prevalence screening for ovarian cancer in postmenopausal women by CA 125 measurement and ultrasonography

OBJECTIVE

To assess the performance of the sequential combination of serum CA 125 measurement and ultrasonography in screening for ovarian cancer.

DESIGN

The serum CA 125 concentration of each subject was determined and those with a concentration > or = 30 U/ml were recalled for abdominal ultrasonography. If ultrasonography gave abnormal results surgical investigation was arranged. Volunteers were followed up by annual postal questionnaire.

SETTING

General practice, occupational health departments, ovarian cancer screening clinic.

SUBJECTS

22,000 women volunteers who were postmenopausal and aged over 45 years.

MAIN OUTCOME MEASURES

Apparent sensitivity, specificity, positive predictive value, years of cancer detected.

RESULTS

41 women had a positive screening result and were investigated surgically. 11 had ovarian cancer (true positive result) and 30 had other disorders or no abnormality (false positive result). Of the 21,959 volunteers with a negative screening result, eight subsequently presented clinically with ovarian cancer (false negative result) and 21,951 had not developed ovarian cancer during follow up (apparent true negative result). The screening protocol achieved a specificity of 99.9%, a positive predictive value of 26.8%, and an apparent sensitivity of 78.6% and 57.9% at one year and two year follow up respectively. The estimated number of years of cancer detected by the prevalence screen was 1.4 years.

CONCLUSIONS

This screening protocol is highly specific for ovarian cancer and can detect a substantial proportion of cases at a preclinical stage. Further investigation is required to determine the effect of the screening protocol on the ratio of early to late stage disease detected and on mortality from ovarian cancer.