Human Chorionic Gonadotrophin Assay Research Articles

Signal amplification surface-enhanced Raman scattering immunosorbent assay of human chorionic gonadotrophin based on repeated enzyme biocatalytic precipitation

A novel surface-enhanced Raman scattering (SERS) immunoassay method based on tyramine signal amplification (TSA) technology triggering the formation of enzyme repeats on an enzyme-linked immunosorbent assay (ELISA) was designed for highly sensitive detection of human chorionic gonadotropin (hCG) using enzymatic biocatalytic precipitation toward o-phenylenediamine (OPD). Initially, a horseradish peroxidase (HRP)-labeled hCG antibody was fixed by the double antibody sandwich method, and then a tyramine-HRP conjugate was used to form HRP repeats by triggering the immobilized HRP on ELISA with the aid of H2O2. In the presence of the target hCG, the HRP repeats carried by the sandwich immune complex catalyzed the oxidation of OPD to produce product molecules with different structures, resulting in changes in the SERS fingerprint spectrum. The analytical performance of the SERS immunoassay was studied in detail using SERS spectral characterization. Under the optimum conditions, the immunosensor displayed a working range from 1 IU L-1 to 16 IU L-1 with a detection limit (LOD) of 0.17 IU L-1 relative to the target hCG. Compared to the traditional SERS immunosensor, a higher detection sensitivity can be obtained. Therefore, this work provides a new strategy for hCG detection and inspiration for the construction of sensitive and efficient immunosensors.

Signal Amplification Surface-Enhanced Raman Scattering Immunosorbent Assay of Human Chorionic Gonadotrophin Based on Repeated Enzyme Biocatalytic Precipitation

Signal Amplification Surface-Enhanced Raman Scattering Immunosorbent Assay of Human Chorionic Gonadotrophin Based on Repeated Enzyme Biocatalytic Precipitation

Human chorionic gonadotrophin assays to monitor GTD.

Hydatidiform mole (HM) occurs in 1:500-1000 pregnancies and are generally characterised as a benign proliferative disorder of chorionic villous trophoblast. HM belongs to the group of disorders, collectively known as gestational trophoblastic disease (GTD), which include invasive mole, choriocarcinoma, placental site trophoblastic tumour and epitheloid trophoblastic tumour. Patients with HM are at increased risk of developing these malignant forms and hence accurate diagnosis is very important for monitoring persistent diseases and informing correct patient management. In this review, we describe the current model for HM follow-up in the UK, with special emphasis on the in-house human chorionic gonadotrophin (hCG) radioimmunoassay (RIA) currently employed for monitoring women in our programme. We briefly discuss the structure, function and significance of hCG monitoring in GTD and the limitations and benefits of the current assays used for measuring oncology hCG. In particular, we describe the preliminary work evaluating a replacement antibody for the current gold-standard UK-RIA method.

Weekly intramuscular progesterone for luteal phase support in women receiving oocyte donation is associated with a decreased miscarriage rate.

To determine whether adding intramuscular to vaginal administration of progesterone reduces miscarriage rates compared with those of vaginal administration alone for luteal phase support in women receiving oocyte donation and to determine the best time to introduce intramuscular progesterone. Retrospective analysis of miscarriage rates in women receiving oocyte donation. Recipients underwent endometrial preparation by hormone replacement treatment. Vaginal progesterone alone or associated with intramuscular progesterone was used for luteal support. This study analysed 186 oocyte donation cycles from January 2016 to May 2018 with embryo transfer on Day 2 or 3 and vaginal progesterone administration: 106 embryo transfer cycles with vaginal progesterone alone, 29 with weekly intramuscular progesterone added once the human chorionic gonadotrophin (HCG) assay was positive, and 51 with weekly intramuscular progesterone added the evening of embryo transfer. The rates of positive HCG assays, biochemical pregnancies and clinical pregnancies did not differ between the treatment groups. The miscarriage rate was significantly lower when intramuscular progesterone began the evening of embryo transfer than with vaginal administration alone (16.7% versus 47.0%, respectively; P = 0.049 after Bonferroni correction). The live birth rate was higher when intramuscular progesterone began the evening of embryo transfer than with vaginal administration alone (37.3% versus 16.0%, respectively; P = 0.009 after Bonferroni correction). Adding intramuscular to vaginal progesterone administration appears to decrease the miscarriage rate and increase the live birth rate in oocyte donations. The initiation of intramuscular progesterone is most beneficial when it is introduced the evening of embryo transfer.

Diagnostic validity of cervicovaginal human chorionic gonadotrophin at 26–36 weeks of gestation as a biochemical predictor of preterm birth

The aim of this study was to assess the diagnostic accuracy of qualitative and quantitative assay of human chorionic gonadotrophin (hCG) in cervicovaginal secretion as a biochemical predictor of preterm birth. A prospective study was conducted at Ain-Shams University Maternity Hospital, Cairo, Egypt. A total of 390 pregnant women were included in the statistical analysis: 90 women who presented with threatened preterm labor and 300 asymptomatic pregnant women with matched age, gestational age, bodyweight, parity and obstetric history. Qualitative and quantitative measurements of cervicovaginal fluid hCG at 26-36 weeks of gestation were performed to assess the risk for preterm birth. In women with threatened preterm labor (group 1) and asymptomatic pregnant women (group 2), preterm birth occurred in 35.6% and 9.3%, respectively. We analyzed predictive performances of qualitative and quantitative assay of hCG in cervicovaginal secretion, while combining group 1 and group 2. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of qualitative test, by the cut-off level of 25 mIU/mL, to predict preterm birth were 68.3%, 96.1%, 76.9%, 94.3% and 91.8%, respectively; those of quantitative test, by the cut-off level of 34.5 mIU/mL, were 100%, 98.5%, 92.3%, 100% and 98.7%, respectively. Both the qualitative and quantitative assessment of cervicovaginal fluid hCG at 26-36 weeks of gestation were valuable in the prediction of occurrence of preterm birth in the women who presented with threatened preterm labor as well as in the asymptomatic pregnant population.

Ectopic Pregnancy

Ectopic pregnancy (EP) continues to be the number one cause of maternal deaths in the first trimester of pregnancy. Over the past 30 years, several key developments including accurate and rapid serum human chorionic gonadotrophin assays, the introduction of high-resolution transvaginal probes and more recently tertiary hospital Early Pregnancy Units have changed the management of EPs. Early transvaginal ultrasound diagnosis of EP not only potentially decreases mortality and surgical intervention rates, but also promotes modern management options including expectant or medical management. The aim of this review is to demonstrate that transvaginal ultrasound is the new 'gold standard' diagnostic tool of choice for all forms of EP.

Diagnosis of ectopic pregnancy

Ectopic pregnancy (EP) accounts for 1–2% of pregnancies and represents a major event in a woman’s reproductive lifetime. EP can be due to either contraceptive or reproductive failure and complicates infertility treatment. EP must be diagnosed early to simplify the treatment strategy, which must always be directed towards optimizing subsequent fertility. Epidemiologic findings indicate that a history of tubal disease and smoking are the principal risk factors of EPs considered to be reproductive (rather than contraceptive) failures. A risk scale to determine the probability of EP for any given patient was constructed by adding together the attributable risks for different EP risk factors. The diagnostic strategy uses abdominal and transvaginal ultrasound and human chorionic gonadotrophin assays. Progesterone assays are useful only for determining the activity of the pregnancy but do not help to identify its site. In the future, a proteomic approach or better knowledge of the multiple human chorionic gonado...

High-dose hook effect in six automated human chorionic gonadotrophin assays

The high-dose hook effect is a well-known phenomenon of two-site immunoassays including those for human chorionic gonadotrophin (hCG). We investigated the occurrence of a high-dose hook effect in six routinely available hCG assays using a sample with a total hCG concentration of approximately 3,600,000 IU/L. Dilutions of a sample with high hCG concentration were analysed using six common methods: Advia Centaur, Immulite 2000, Dimension RxL, Unicel DxI 800, Roche E170 and Abbott Architect. The measured concentrations and corresponding assay signals were obtained for each method. Performance was compared with manufacturer claims. Four of the tested platforms demonstrated a clear high-dose hook effect, while the other methods showed no hook effect at the highest level tested. Our results indicate that the hook effect may occur in some hCG assays, although the risk of reporting falsely low results was in most cases at higher concentrations than those indicated in manufacturers' product information. Assay design plays a major role in its occurrence. Laboratories should be aware of the assay limitations in this regard.

Treatments for gestational trophoblastic disease

Gestational trophoblastic disease (GTD) is a relatively rare but important group of benign and malignant disorders that affect women of child-bearing potential. Most cases are now diagnosed earlier than previously owing to advances in our knowledge of the disease and accuracy of ultrasonography, combined with the high analytical sensitivity of human chorionic gonadotrophin assays, although occasionally patients with metastases present at a late stage with life-threatening complications. Early diagnosis and referral to a specialist center for further management is vital so that patients can receive the optimal standard of care. Patients can be grouped into high- and low-risk categories using well-established prognostic scoring systems, enabling the minimum appropriate treatment to be recommended. Chemotherapy regimens for the disease are now well established, so that for the vast majority, GTD is a curable condition, and patients can be reassured that fertility is normally preserved. Regular follow-up by h...

Place du dosage sérique de l’HCG dans la surveillance des tumeurs testiculaires séminomateuses non sécrétantes

Human chorionic gonadotrophin (HCG) is secreted by 10 to 20% of seminomas. The authors evaluated variations of serum total HCG levels in patients with normal baseline levels for the surveillance of treated testicular seminomas in order to determine the value of assay of this tumour marker in the follow-up of testicular seminoma. Retrospective study from January 1988 to March 2007, including 95 cases of operated testicular cancer, including 28 seminomas, 25 of which did not secrete HCG (baseline total HCG less than 15 IU/L). Patients were reviewed periodically: every three months for one year, every six months during the second year, then annually, comprising of clinical examination, CT examination and assay of tumour markers (HCG, LDH and AFP). Mean follow-up was 77.5 months (range: 6-120). Twenty-five patients had a total HCG level less than 15 IU/L three months after orchidectomy. Serum HCG remained stable at less than 15 IU/L in all patients with a follow-up of more than three years. Two patients developed non-regional lymph node recurrence with no modification of the serum HCG level. All treated non-HCG-secreting seminomas with or without recurrence had stable and normal HCG levels throughout follow-up, which raises the question of the value of HCG assay in the follow-up of these patients following histological confirmation of the diagnosis.

An immunonanogold resonance scattering spectral probe for rapid assay of human chorionic gonadotrophin

BackgroundSeveral assays for human chorionic gonadotrophin (hCG) such as radioimmunoassay and fluorescence immunoassays were reported. So far, there was no report about the immunonanogold resonance scattering spectral (ING-RSS) assay based on the immunoreaction and resonance scattering (RS) effect. MethodsThree ING-RSS probes for hCG were prepared, using nanogold in size of 8, 10, 13 nm to label rabbit hCG antiserum (anti-hCG). ResultsIn citric acid–Na2HPO4 buffer solution and in the presence of polyethylene glycol (PEG)6000, the immunoreaction between hCG and nanogold-labeled anti-hCG took place, the immunonanogold-complex was formed and deposited. The decreased intensity ΔIRS for the nanogold in sizes of 8, 10, 13 nm was proportional to hCG concentration in the ranges of 40–10000, 40–10000 and 40–8000 mIU/ml, with the detection limits of 19.4, 15.1 and 13.6 mIU/ml, respectively. The hCG in urine samples were assayed by the ING-RSS assay, and by immunospectrophotometry. The results of both assays showed a close correlation. ConclusionThis assay has simplicity, sensitivity and good selectivity for quantitative determination of hCG.

Cutaneous metastasis of gestational choriocarcinoma

A 40-year-old woman presented with subcutaneous masses on her chest wall, abnormal vaginal bleeding and an enlarged uterus. Chest X-ray and liver ultrasound revealed metastatic disease to these sites, respectively. A urine human chorionic gonadotrophin assay was positive. A biopsy of the chest wall lesion and endometrium revealed choriocarcinoma. Treatment with methotrexate, actinomycin-D and cyclophosphamide led to complete resolution of the disease on examination, X-ray and ultrasound scans. The urinary pregnancy test became negative.

Integrated first and second trimester screening for Down syndrome

Purposes: It is uncertain whether first trimester nuchal translucency is more effective than the well established second trimester serum screening for fetal Down syndrome or whether their combination works best. We report our data on a large multicenter non‐interventional trial in which all subjects underwent both first and second trimester screening to assess their relative efficacy.Methods: All women who attended the obstetric clinic before 15 weeks were recruited. An ultrasound examination was performed at 10–14 weeks to measure the nuchal translucency. The nuchal measurements were not acted upon unless the fetus showed gross features of hydrops fetalis. All women had serum alpha‐fetoprotein and human chorionic gonadotrophin assay at 15–20 weeks. The Down syndrome risk assigned by serum screening was disclosed and amniocentesis was offered if this assigned risk was at or >1:250 or if the women were 35 years and older. Efficacy of different combinations of screening were compared.Results: Between January 1997 and August 2000, 17590 women were recruited (19% was 35 years and older). After excluding subjects who miscarried, defaulted the serum test and other reasons, 16237 pregnancies were included in the final analysis. Of these, 35 pregnancies were affected by Down syndrome (2.2 cases per 1000 pregnancies). At a false‐positive rate of 5%, the detection rate of Down syndrome by nuchal translucency alone; nuchal translucency + age; serum human chorionic gonadotrophin, alpha‐fetoprotein + age and nuchal translucency + human chorionic gonadotrophin + alpha‐fetoprotein + age were 61, 69, 73 and 86%, respectively. Comparison of areas under the receiver‐operating characteristic curves showed statistically significant differences between these methods of screening.Conclusions: Integration of nuchal translucency and second trimester serum alpha‐fetoprotein and human chorionic gonadotrophin assay yielded the best screening efficacy for Down syndrome.

Flow immunoassay for detection of human chorionic gonadotrophin using a cation exchange resin packed capillary column

A human chorionic gonadotrophin (HCG) detection was carried out by the flow immunoassay system with a cation exchange resin packed capillary column (762 μm i.d.×10 cm length), that can be considered a miniaturised version of the previously reported system. The HCG and fluorescein isothiocyanate (FITC) conjugated immunoglobulin G (IgG) antibody complex was separated from free FITC conjugated IgG on the basis of differences in isoelectric points. The fluorescence intensity correlated linearly with concentrations of HCG in the range of 25–1500 mIU/ml. This simple technique permits the assay of HCG within 1.3 min. It was possible to reuse of free FITC conjugated IgG. This simple and rapid immunoassay method can be used for the continuous detection of HCG.

Highly sensitive immunological assays for human chorionic gonadotrophin and prostatic acid phosphatase using phenacyl phosphate as a chemiluminescent label

A highly sensitive assay for alkaline phosphatase (ALP) was developed using phenacyl phosphate as a substrate for chemiluminescent assays. This substrate is applied to two types of immunological assays based on ALP labelling, an assay for human chorionic gonadotrophin (hCG) in urine by a two-site immunometric assay and an assay for human prostatic acid phosphatase (PAP) adsorbed on a solid phase by an antibody. The results of the validation on these assays were good and detection limits were 15–40 times better than for conventional assays, viz. 6.25 × 10 −6 IU for hCG and 1.25 × 10 −18 mol PAP.

Rapid one step urine test for human chorionic gonadotrophin in evaluating suspected complications of early pregnancy.

To determine the ability of a sensitive one step urine test to detect human chorionic gonadotrophin in women with suspected complications of early pregnancy. Test on women presenting to accident and emergency department with gynaecological problems over six months. Results were validated using a quantitative assay for human chorionic gonadotrophin in serum and urine. Accident and emergency department and gynaecology wards of a university teaching hospital. 130 unselected women. Detection of human chorionic gonadotrophin by one step test, presence of ectopic pregnancy, and results of quantitative analysis of chorionic gonadotrophin in serum and urine. 79 women had a positive urine test result and 51 a negative result. All 12 women with ectopic pregnancy had a positive test result, although urinary concentration varied from 191 IU/l to 47,800 IU/l. Only one woman, who had a faintly positive result, was found not to be pregnant on subsequent examination. The sensitivity and negative predictive values of the urine test were 100% respectively. 33 women were sent home from the accident and emergency department with normal clinical findings after a negative urine test result. All these women had undetectable concentrations of chorionic gonadotrophin in matched samples of urine and serum. A simple, rapid one step test for chorionic gonadotrophin should be available for the initial evaluation of emergency gynaecological problems. The additional cost of the test is offset by not admitting those patients whose clinical findings are normal and who have a negative urine test result and by reducing the number of women requiring quantitative assays of chorionic gonadotrophin.

An assay for human chorionic gonadotrophin using the capillary fill immunosensor

Recently there has been much research effort directed towards the development of immunosensors. Optical technologies are currently proving very attractive for the construction of such sensors. The fluorescence capillary fill device (FCFD) has been designed to fulfil these needs. The development of an assay for human chorionic gonadotrophin (hCG) in the FCFD for a variety of body fluids (whole blood, serum, urine and saliva) demonstrates the versatility and assay performance of the device.

Endocrine changes in women conceiving during treatment with an LHRH agonist

We report on eight patients who conceived during pituitary desensitization with buserelin in the luteal phase of the menstrual cycle. Pregnancy was diagnosed between day 12 and 21 of buserelin administration. Analysis of serum luteinizing hormone on day 12 showed that pituitary desensitization occurred in conjunction with increasing production of ovarian steroid hormones. Serum concentrations of human chorionic gonadotrophin (HCG) were less than 10 IU/l on day 1 of buserelin administration for seven of the eight patients. The serum concentration of HCG on day 12 showed a median value of 722 IU/l (range 14.6-798 IU/l). Five of the eight patients were given HCG support (10,000 IU) following the diagnosis of pregnancy--three of these patients have ongoing pregnancies and the remaining two had blighted ova on scan. Of the remaining three patients, one had a singleton pregnancy which miscarried at 9 weeks, one had a blighted ovum on scan and bled per vagina shortly after this, and one bled per vagina prior to a scan being carried out. Our results show that pregnancy can occur during pituitary desensitization with buserelin, despite patients being counselled not to have unprotected intercourse in the cycle during which administration commences. An HCG assay on day 1 of buserelin administration is not helpful. Pregnancy should be suspected when ovarian steroid production persists despite complete pituitary down-regulation.

The use of an enzyme-linked immunosorbent assay for human chorionic gonadotrophin in gynaecological emergencies.

The use of an enzyme-linked immunosorbent assay for human chorionic gonadotrophin in gynaecological emergencies.

Ectopic pregnancy: Problems of diagnosis

SummaryThe hospital incidence and problems in the diagnosis of ectopic pregnancy have been assessed at Ealing Hospital. The ratio of ectopic pregnancy to total births over 28 weeks was 1: 73. Ectopic pregnancy was found in 48 patients, but 37 other patients needed either laparoscopy or laparotomy to exclude this diagnosis. β-Subunit human chorionic gonadotrophin assay might be useful in improving diagnostic accuracy.