ABSTRACT
BACKGROUND: Brain injury is a medical emergency that needs to be diagnosed and treated promptly. Several proteins have been studied as biomarkers of this medical condition. The aims of this study were to: 1) evaluate the selectivity and precision of a commercial ELISA kit for neurofilament medium polypeptide (NFM) protein; and 2) evaluate the concentration in cerebrospinal fluid (CSF) and serum of healthy individuals and patients with brain damage. METHODS: An ELISA from Elabscience was used. The selectivity was evaluated using size-exclusion chromatography and mass spectrometry. Intra- and inter-batch coefficients of variation (CV) were also studied. Fifty-one CSF samples from 36 age-matched patients with hemorrhagic stroke (HS) (n=30), ischemic stroke (IS) (n=11) and healthy individuals (n=10) were assayed. In addition, serum samples from healthy volunteers (n=47), 68 serum samples from seven patients with HS, 106 serum samples from 12 patients with traumatic brain injury (TBI) and 68 serum samples from 68 patients with mild traumatic brain injury (mTBI) were also analyzed. RESULTS: NFM was identified in the chromatographic fraction with highest immunoreactivity. The intra- and inter-batch CVs were ≤10% and ≤13%, respectively. The CSF-NFM concentration in HS was significantly higher (p<0.0001) than in IS and controls. Serum NFM concentration ranged from 0.26 to 8.57 ng/mL in healthy individuals (median=2.29), from 0.97 to 42.4 ng/mL in HS (median=10.8) and from 3.48 to 45.4 ng/mL in TBI (median=14.7). Finally, 44% of patients with mTBI had increased NFM concentration, with significantly higher levels (p=0.01) in patients with polytrauma. CONCLUSIONS: To our knowledge this is the first study describing increased NFM levels in CSF and serum from patients with brain damage.
Subject(s)
Brain Injuries/blood , Brain Injuries/cerebrospinal fluid , Neurofilament Proteins/blood , Neurofilament Proteins/cerebrospinal fluid , Adult , Biomarkers/blood , Case-Control Studies , Enzyme-Linked Immunosorbent Assay , Female , Humans , Male , Middle Aged , Reproducibility of Results , Stroke/blood , Stroke/cerebrospinal fluidABSTRACT
OBJECTIVE: To evaluate the population parameters applied to the calculation of risk for Down syndrome (DS) in the first trimester screening (FTS) and the comparison of performance obtained including or excluding maternal age from the mathematical algorithm. METHODS: Three different calculation engines for prenatal risk of DS were developed on the basis of the population parameters from the Serum, Urine and Ultrasound Screening Study, the Fetal Medicine Foundation, and a combination of both of them. These calculators were evaluated in 14,645 first trimester pregnant women, including 59 DS affected fetuses, comparing their performance with that obtained by our commercial software Elipse® (Perkin Elmer Life and Analytical Sciences, Turku, Finland). Advanced first trimester screening (AFS) strategy was also analyzed, and a hybrid strategy (FTS + AFS) was evaluated. RESULTS: By selecting population parameters from the Serum, Urine and Ultrasound Screening Study, the detection rate increased from 76% (Elipse) to 86% with a small increase in the false positive rate (FPR), from 3.3% to 3.7%, respectively. DS screening performance significantly improved by using the hybrid strategy (AFS in pregnant women under 35 years and FTS in pregnant women over 35 years), with a 92% detection rate (FPR: 3.9%). CONCLUSIONS: In the present study, a new hybrid screening strategy has been proposed to achieve DS detection rates higher than 90%, for a convenient <4% FPR.
Subject(s)
Down Syndrome/diagnosis , Down Syndrome/etiology , Models, Theoretical , Pregnancy Trimester, First , Prenatal Diagnosis/methods , Adolescent , Adult , Down Syndrome/diagnostic imaging , Down Syndrome/epidemiology , Female , Gestational Age , Humans , Mass Screening , Maternal Age , Middle Aged , Population , Pregnancy , Pregnancy Trimester, First/blood , Pregnancy Trimester, First/physiology , Pregnancy Trimester, First/urine , Risk Assessment , Risk Factors , Ultrasonography , Young AdultABSTRACT
BACKGROUND: Hemolytic disease of the fetus and newborn (HDN) is caused primarily by feto-maternal RhD incompatibility. Although all RhD negative pregnant women undergo routine antenatal RhD prophylaxis at 28 weeks of gestation, and following delivery if the newborn is RhD positive, HDN has not been eradicated. Here, we investigated fetal Rhesus D (RHD) genotype in maternal plasma during the first trimester of pregnancy in our area. METHODS: Plasma samples were obtained from 111 RhD negative pregnant women, between 9 and 13 weeks of gestation. DNA from maternal plasma containing cell-free fetal DNA (cffDNA) was analyzed by quantitative PCR (qPCR) to detect RHD exons 5 and 7. A beta-globin (HBB) sequence was quantified to estimate total DNA concentration. qPCR results were compared with newborn RhD determined in cord blood serum. The influence of several gestational parameters on DNA concentration was also analyzed. RESULTS: The specificity and sensitivity of the assay was 93% and 100%, respectively, with 97% diagnostic accuracy. Cell-free DNA concentrations during the first trimester of pregnancy were not affected by the gestational parameters studied (free-beta fraction of human chorionic gonadotropin and pregnancy-associated plasma protein A concentrations, fetal sex, materno-fetal ABO blood group incompatibility, maternal weight and gestational age). CONCLUSIONS: Non-invasive fetal RHD genotyping during the first trimester of pregnancy can be determined with a high specificity, thus representing a valuable tool for improving the management of RhD negative pregnant women. As a high percentage of pregnant women participate in the routine first trimester combined screening program for aneuploidies, the fetal RHD study could be of immediate implementation, since the same blood collection could be used.
