scholarly journals Comparison of Different Blood Collection, Sample Matrix, and Immunoassay Methods in a Prenatal Screening Setting

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jeroen L. A. Pennings ◽  
Jacqueline E. Siljee ◽  
Sandra Imholz ◽  
Sylwia Kuc ◽  
Annemieke de Vries ◽  
...  
Keyword(s):  
Prenatal Screening ◽  
Protein A ◽  
Correlation Coefficients ◽  
First Trimester ◽  
Dried Blood Spots ◽  
Maternal Blood ◽  
Blood Collection ◽  
Antibody Microarray ◽  
Sample Matrix ◽  
Finger Prick

We compared how measurements of pregnancy-associated plasma protein A (PAPP-A) and the free beta subunit of human chorionic gonadotropin (fβ-hCG) in maternal blood are influenced by different methods for blood collection, sample matrix, and immunoassay platform. Serum and dried blood spots (DBS) were obtained by venipuncture and by finger prick of 19 pregnant women. PAPP-A and fβ-hCG from serum and from DBS were measured by conventional indirect immunoassay on an AutoDELFIA platform and by antibody microarray. We compared methods based on the recoveries for both markers as well as marker levels correlations across samples. All method comparisons showed high correlations for both marker concentrations. Recovery levels of PAPP-A from DBS were 30% lower, while those of fβ-hCG from DBS were 50% higher compared to conventional venipuncture serum. The recoveries were not affected by blood collection or immunoassay method. The high correlation coefficients for both markers indicate that DBS from finger prick can be used reliably in a prenatal screening setting, as a less costly and minimally invasive alternative for venipuncture serum, with great logistical advantages. Additionally, the use of antibody arrays will allow for extending the number of first trimester screening markers on maternal and fetal health.

scholarly journals First-trimester Screening: An Overview

2005 ◽  
Vol 53 (3) ◽  
pp. 281-283 ◽  
Author(s):  
Bernd Eiben ◽  
Ralf Glaubitz
Keyword(s):  
Prenatal Screening ◽  
Heart Defects ◽  
Protein A ◽  
Nasal Bone ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Maternal Blood ◽  
Chromosomal Anomalies ◽  
Detection Rates ◽  
Trimester Screening

An improvement in prenatal screening for chromosomal defects has been achieved by combining sonography and biochemical markers. Analyzing markers taken from maternal blood such as pregnancy-associated plasma protein A and free β-human chorionic gonadotropin in combination with the ultrasound marker nuchal translucency provides detection rates of 90% for the most important chromosomal anomalies. In addition, nuchal translucency is a marker for severe heart defects. This report discusses the potential of new markers such as the nasal bone.

scholarly journals False Positive Values of Biomarkers of Prenatal Screening on Chromosomopathy as Indicators of a Risky Pregnancy

2011 ◽  
Vol 30 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Jasmina Durković ◽  
Luka Anđelić ◽  
Bojana Mandić ◽  
Denis Lazar
Keyword(s):  
Genetic Screening ◽  
False Positive ◽  
Prenatal Screening ◽  
Protein A ◽  
First Trimester ◽  
Maternal Serum ◽  
Fetal Hypoxia ◽  
Beta Hcg ◽  
First Trimester Of Pregnancy ◽  
Fetal Karyotype

False Positive Values of Biomarkers of Prenatal Screening on Chromosomopathy as Indicators of a Risky PregnancyGenetic screening on chromosomopathy has been performed on 2000 pregnant women in their first trimester of pregnancy by determining Pregnancy associated plasma protein-A and free-beta HCG biomarkers in maternal serum. After obtaining a normal fetal karyotype, the pathological values of the biomarkers have been correlated with other pregnancy disorders, and the possible causes of the positive genetic screening have been tested. 340 false positive biomarkers (17%) have been detected. The increased free-beta HCG (48.24%) had a significant influence. A significant correlation (p > 0.01) between the increased free-beta HCG and bleeding during pregnancy has been established. Complications occurred in 78.52% pregnancies with pathological biomarkers, MISSed in 13.82%, miscarriages in 10.88%, induced pregnancy terminations caused by fetal anomalies in 8.82% and births with disturbed fetal vitality in 45%. The research results have shown a significant correlation (p > 0.01) between the increased value of the free-beta HCG biomarkers and fetal hypoxia. The false positive genetic screening, caused by the increased free-beta HCG, can indicate placental dysfunction and fetal vitality disruption.

The stability of free-β human chorionic gonadotrophin and pregnancy-associated plasma protein-A in first trimester dried blood spots

2011 ◽  
Vol 31 (3) ◽  
pp. 293-298 ◽  
Author(s):  
Nicholas J. Cowans ◽  
Anastasia Stamatopoulou ◽  
Paivi Liitti ◽  
Mikko Suonpaa ◽  
Kevin Spencer
Keyword(s):  
Plasma Protein ◽  
Protein A ◽  
First Trimester ◽  
Dried Blood Spots ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Blood Spots ◽  
The Stability

scholarly journals Evaluation of a Dried Blood Spot Assay to Measure Prenatal Screening Markers Pregnancy-Associated Plasma Protein A and Free β-Subunit of Human Chorionic Gonadotropin

2013 ◽  
Vol 59 (6) ◽  
pp. 968-975 ◽  
Author(s):  
Nicholas J Cowans ◽  
Mikko Suonpaa ◽  
Heikki Kouru ◽  
David Wright ◽  
Kevin Spencer
Keyword(s):  
Relative Humidity ◽  
Chorionic Gonadotropin ◽  
Human Chorionic Gonadotropin ◽  
Prenatal Screening ◽  
Protein A ◽  
First Trimester ◽  
Β Subunit ◽  
Drying Process ◽  
Serum Assay ◽  
Blood Spot

BACKGROUND First-trimester prenatal screening for aneuploidy by use of dried blood spots (DBSs) may offer practical benefits in settings where the instability of intact human chorionic gonadotropin (hCG) is problematic. We evaluated a DBS pregnancy-associated plasma protein A (PAPP-A) and free β-subunit of hCG (free hCGβ) dual assay and compared it to serum screening. METHODS Hematocrit-corrected DBS PAPP-A and free-hCGβ concentrations were measured and compared with serum concentrations in 252 first-trimester samples. Serum intact hCG was also measured and, with serum free hCGβ, was used to fit a model to predict serum-equivalent DBS free-hCGβ concentrations. In a separate experiment, we investigated the effects of temperature and relative humidity during the blood spot drying process. RESULTS The DBS assay for PAPP-A performed similarly to the serum assay, whereas free-hCGβ DBS measurements were consistently higher than in serum. Purifying blood spots of intact hCG suggested that the free-hCGβ DBS assay is measuring a composite of free hCGβ and additional β-subunits from intact hCG. The drying experiment showed that increased temperature and relative humidity during the drying process resulted in increased free hCGβ and reduced PAPP-A. CONCLUSIONS Despite measuring additional free hCGβ compared to the serum assay, DBS analysis has a role in first-trimester combined screening for trisomy 21.

The influence of different sample collection types on the levels of markers used for Down's syndrome screening as measured by the Kryptor Immunosassay system

2003 ◽  
Vol 40 (2) ◽  
pp. 166-168 ◽  
Author(s):  
Kevin Spencer
Keyword(s):  
Processing Time ◽  
Point Of Care ◽  
Protein A ◽  
First Trimester ◽  
Maternal Serum ◽  
Blood Collection ◽  
Chromosomal Anomalies ◽  
Sample Collection ◽  
Edta Plasma ◽  
Β Hcg

Background: In a rapid point-of-care screening programme for chromosomal anomalies, analysis of biochemical markers in maternal blood can now be accomplished in a rapid time frame (less than 20 min). The need to leave whole blood samples some 10 min for coagulation and a further 5 min for centrifugation adds additional processing time. Methods: The possibilities for reducing this processing time were investigated using various anticoagulated blood collection systems and the Kryptor analytical platform. Plasma levels of α-fetoprotein (AFP), pregnancy-associated plasma protein-A (PAPP-A) and free human chronic gonadotrophin β-subunit (β-hCG) were compared with those in maternal serum. Results: From the mean results from ten patients it was shown that use of heparin plasma resulted in a statistically significant reduction in levels of PAPP-A and that EDTA plasma reduced the levels of PAPP-A dramatically. For AFP, levels in citrated plasma and EDTA plasma were also significantly reduced, whereas levels of free β-hCG were not affected. Conclusion: Use of alternative sample types for PAPP-A is not possible. The sample of choice for first trimester screening using the Kryptor platform is maternal serum.

scholarly journals Potential of Dried Blood Self-Sampling for CyclosporineC2Monitoring in Transplant Outpatients

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Alexander Benedikt Leichtle ◽  
Uta Ceglarek ◽  
Helmut Witzigmann ◽  
Gábor Gäbel ◽  
Joachim Thiery ◽  
...  
Keyword(s):  
Therapeutic Drug Monitoring ◽  
Venous Blood ◽  
Dried Blood Spots ◽  
Capillary Blood ◽  
Blood Sampling ◽  
Therapeutic Drug ◽  
Blood Collection ◽  
Blood Samples ◽  
Drug Levels ◽  
Finger Prick

Background. Close therapeutic drug monitoring of Cyclosporine (CsA) in transplant outpatients is a favourable procedure to maintain the long-term blood drug levels within their respective narrow therapeutic ranges. Compared to basal levels (C0), CsA peak levels (C2) are more predictive for transplant rejection. However, the application ofC2levels is hampered by the precise time of blood sampling and the need of qualified personnel. Therefore, we evaluated a newC2self-obtained blood sampling in transplant outpatients using dried capillary and venous blood samples and compared the CsA levels, stability, and clinical practicability of the different procedures.Methods. 55 solid organ transplant recipients were instructed to use single-handed sampling of each 50μL capillary blood and dried blood spots by finger prick using standard finger prick devices. We used standardized EDTA-coated capillary blood collection systems and standardized filter paper WS 903. CsA was determined by LC-MS/MS. The patients and technicians also answered a questionnaire on the procedure and sample quality.Results. TheC0andC2levels from capillary blood collection systems (C0[ng/mL]:114.5±44.5;C2:578.2±222.2) and capillary dried blood (C0[ng/mL]:175.4±137.7;C2:743.1±368.1) significantly(P<.01)correlated with the drug levels of the venous blood samples (C0[ng/mL]:97.8±37.4;C2:511.2±201.5). The correlation atC0wasρcap.-ven.= 0.749, andρdried blood-ven= 0.432; atC2:  ρcap.-ven.= 0.861 andρdried blood-ven= 0.711. The patients preferred the dried blood sampling because of the more simple and less painful procedure. Additionally, the sample quality of self-obtained dried blood spots for LC-MS/MS analytics was superior to the respective capillary blood samples.Conclusions.C2self-obtained dried blood sampling can easily be performed by transplant outpatients and is therefore suitable and cost-effective for close therapeutic drug monitoring.

scholarly journals Prenatal Screening Markers for Down Syndrome: Sensitivity, Specificity, Positive and Negative Expected Value Method

2018 ◽  
Vol 37 (1) ◽  
pp. 62-66
Author(s):  
Jasmina Durković ◽  
Milan Ubavić ◽  
Milica Durković ◽  
Tibor Kis
Keyword(s):  
Down Syndrome ◽  
Biochemical Markers ◽  
Trisomy 21 ◽  
Prenatal Screening ◽  
Protein A ◽  
First Trimester ◽  
Expected Value ◽  
Maternal Serum ◽  
Beta Hcg ◽  
Sensitivity Specificity

SummaryBackground: Genetic screening for chromosomopathy is performed in the first trimester of pregnancy by determining fetal nuchal translucency (NT), and the pregnancy associated plasma protein-A (PAPP-A) and free human chorionic gonadotropin (free-beta HCG) biomarkers in maternal serum. Methods: We tested the sensitivity, specificity, positive and negative expected values of each marker with the aim of setting a model for prenatal screening readings. Statistical data treatment has been performed on a sample of 340 pregnant women with positive results of prenatal screening. Results: Sensitivity of PAPP-A was 0.6250 (probability 62.50%), free beta HCG 0.5893 (58.93%), NT 0.1785 (17.85%). Specificity of PAPP-A was 0.5106 (probability 51.06%), free beta HCG 0.5246 (52.46%), NT 0.9718 (97.18%). Positive expected value of PAPP-A was 0.2011 (probability 20.11%), free beta HCG 0.1964 (19.64%), NT 0.556 (55.56%). Negative expected value of PAPP-A was 0.8735 (probability 87.35%), free beta HCG 0.8662 (86.62%), NT 0.8571 (85.71%). The NT marker has a significantly higher specificity, which means that its normal value will significantly reduce the final risk of trisomy 21. The sensitivity of NT is much lower than that of biochemical markers, which means that a pathological value of NT does not have a significant influence on the final risk, i.e. the significantly higher sensitivity of biochemical markers will reduce the final risk of trisomy 21. Conclusion: The analyses stress the importance of using a software which has the possibility to separate the level of a biochemical risk by correlating PAPP-A and free beta HCG and, by adding the NT marker, calculate the level of a final risk of Down syndrome.

Trends in early prenatal screening for chromosomal abnormalities and congenital malformations in Russia in 2018

2020 ◽  
pp. 76-78
Author(s):  
Е.А. Калашникова ◽  
Е.Н. Андреева ◽  
П.А. Голошубов ◽  
Н.О. Одегова ◽  
Е.В. Юдина ◽  
...  
Keyword(s):  
Reference Values ◽  
Congenital Malformations ◽  
Prenatal Screening ◽  
Chromosomal Abnormalities ◽  
First Trimester ◽  
First Trimester Screening ◽  
Trimester Screening ◽  
Overall Effectiveness ◽  
Regions Of Russia

В ходе анализа результатов раннего пренатального скрининга (РПС) в России за 2018 г. (Аудит-2019) дана оценка качества мероприятий, общей эффективности и тенденций развития системы РПС в субъектах РФ посредством сравнения рассчитанных основных организационных, методологических и интегральных показателей с международными референтными значениями. In the course of analyzing the results of early prenatal combined first-trimester screening (FTS) in Russia for 2018 (Audit-2019) the assessment of the quality of measures, the overall effectiveness and trends in the development of the FTS system in the regions of Russia. They are presented by comparing the calculated main organizational, methodological and integral indicators with international reference values.

scholarly journals Comparison between Enzyme Immunoassays Performed on Samples of Dried Blood and Serum for Toxoplasmosis Prenatal Screening: Population-based Study

2021 ◽  
Vol 43 (05) ◽  
pp. 351-356
Author(s):  
Bárbara Araújo Marques ◽  
Ericka Vianna Machado Carellos ◽  
Vânia Maria Novato Silva ◽  
Fernando Henrique Pereira ◽  
Maria Regina Lage Guerra ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Prenatal Screening ◽  
Dried Blood Spots ◽  
Population Based ◽  
Minas Gerais ◽  
Immunoglobulin M ◽  
Screening Tests ◽  
Reference Test ◽  
Screening Programs ◽  
Blood Spots

Abstract Objective Most prenatal screening programs for toxoplasmosis use immunoassays in serum samples of pregnant women. Few studies assess the accuracy of screening tests in dried blood spots, which are of easy collection, storage, and transportation. The goals of the present study are to determine the performance and evaluate the agreement between an immunoassay of dried blood spots and a reference test in the serum of pregnant women from a population-based prenatal screening program for toxoplasmosis in Brazil. Methods A cross-sectional study was performed to compare the immunoassays Imunoscreen Toxoplasmose IgM and Imunoscreen Toxoplasmose IgG (Mbiolog Diagnósticos, Ltda., Contagem, Minas Gerais, Brazil)in dried blood spots with the enzyme-linked fluorescent assay (ELFA, BioMérieux S.A., Lyon, France) reference standard in the serum of pregnant women from Minas Gerais Congenital Toxoplasmosis Control Program. Results The dried blood spot test was able to discriminate positive and negative results of pregnant women when compared with the reference test, with an accuracy of 98.2% for immunoglobulin G (IgG), and of 95.8% for immunoglobulin M (IgM). Conclusion Dried blood samples are easy to collect, store, and transport, and they have a good performance, making this a promising method for prenatal toxoplasmosis screening programs in countries with continental dimensions, limited resources, and a high prevalence of toxoplasmosis, as is the case of Brazil.

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