Addition of N-terminal pro-B natriuretic peptide to soluble fms-like tyrosine kinase-1/placental growth factor ratio > 38 improves prediction of pre-eclampsia requiring delivery within 1 week: a longitudinal cohort study.

OBJECTIVE: Short-term prediction of pre-eclampsia (PE) using the soluble fms-like tyrosine kinase-1 (sFlt-1)/placental growth factor (PlGF) ratio is characterized by frequent false-positive results. As such, no treatment can be recommended to test-positive patients and multiple measurements are often required. The aim of this study was to evaluate the effectiveness of N-terminal pro-B natriuretic peptide (NT-proBNP), uric acid and the sFlt-1/PlGF ratio for prediction of delivery with PE within 1 week in singleton pregnancies with suspected PE and sFlt-1/PlGF ratio > 38. METHODS: This was a longitudinal prospective cohort study of singleton pregnancies presenting at 24 + 0 to 36 + 6 weeks of gestation with clinically suspected PE and sFlt-1/PlGF ratio > 38, enrolled between January 2015 and June 2017. Multiple samples per patient were allowed but were restricted to one sample per gestational week. From 495 enrolled patients, 270 blood samples from 134 patients were ultimately analyzed. By using generalized estimating equations (GEE), the best-fit model was selected for prediction of delivery with PE within 1 week. The predictive value of this model was then assessed using area under the paired-ROC curve (AUC) analysis. RESULTS: The best-fit model included the sFlt-1/PlGF ratio, NT-proBNP and the gestational week at the time of the measurement. This combined model was compared with the GEE model based on the sFlt-1/PlGF ratio and the gestational week at the time of the measurement (reduced model). The AUC for the combined model was 0.845 (95% CI, 0.787-0.896), which was significantly greater (P = 0.011) than that of the reduced model (0.786 (95% CI, 0.722-0.844)). CONCLUSION: The addition of NT-proBNP assessment improves the short-term prediction of delivery as a result of PE compared with sFlt-1/PlGF ratio alone, when the sFlt-1/PlGF ratio is > 38. This finding should be considered in future research on the assessment of short-term risk of delivery as a result of PE. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

sFlt-1/PlGF for prediction of early-onset pre-eclampsia: STEPS (Study of Early Pre-eclampsia in Spain).

OBJECTIVE: A high ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) has been linked to pre-eclampsia (PE). We evaluated the sFlt-1/PlGF ratio as a predictive marker for early-onset PE in women at risk of PE. METHODS: This prospective, Spanish, multicenter study included pregnant women with a risk factor for PE, including intrauterine growth restriction, PE, eclampsia or hemolysis, elevated liver enzymes and low platelet count syndrome in previous pregnancy, pregestational diabetes or abnormal uterine artery Doppler. The primary objective was to show that the sFlt-1/PlGF ratio at 20, 24 and 28 weeks' gestation was predictive of early-onset PE (< 34 + 0 weeks). Serum sFlt-1 and PlGF were measured at 20, 24 and 28 weeks. Multivariate logistic regression was used to develop a predictive model. RESULTS: A total of 819 women were enrolled, of which 729 were suitable for analysis. Of these, 78 (10.7%) women developed PE (24 early onset and 54 late onset). Median sFlt-1/PlGF ratio at 20, 24 and 28 weeks was 6.3 (interquartile range (IQR), 4.1-9.3), 4.0 (IQR, 2.6-6.3) and 3.3 (IQR, 2.0-5.9), respectively, for women who did not develop PE (controls); 14.5 (IQR, 5.5-43.7), 18.4 (IQR, 8.2-57.9) and 51.9 (IQR, 11.5-145.6) for women with early-onset PE; and 6.7 (IQR, 4.6-9.9), 4.7 (IQR, 2.8-7.2) and 6.0 (IQR, 3.8-10.5) for women with late-onset PE. Compared with early-onset PE, the sFlt-1/PlGF ratio was significantly lower in controls (P < 0.001 at each timepoint) and in women with chronic hypertension (P < 0.001 at each timepoint), gestational hypertension (P < 0.001 at each timepoint) and late-onset PE (P < 0.001 at each timepoint). A prediction model for early-onset PE was developed, which included the sFlt-1/PlGF ratio plus mean arterial pressure, being parous and previous PE, with areas under the receiver-operating characteristics curves of 0.86 (95% CI, 0.77-0.95), 0.91 (95% CI, 0.85-0.97) and 0.93 (95% CI, 0.86-0.99) at 20, 24 and 28 weeks, respectively, and was superior to models using the sFlt-1/PlGF ratio alone or uterine artery mean pulsatility index. CONCLUSIONS: The sFlt-1/PlGF ratio can improve prediction of early-onset PE for women at risk of this condition. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

N-terminal pro-brain natriuretic peptide as a potential non-invasive marker of cardiac transplantation rejection.

BACKGROUND: Transplantation is the main palliative treatment for patients with heart failure. Clinical signs of cardiac rejection can be very non-specific or even absent. Thus, successful management relies on early diagnosis, ideally before the onset of clinical features of cardiac dysfunction. Although endomyocardial biopsy (EMB) is the reference diagnostic method, several non-invasive methods have been proposed to reduce the number of EMB performed during the follow-up of the transplanted patient. The aim of the present work was to study the potential relationship between rejection and serum concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) as well as cardiac troponin T (cTnT) in post-transplantation patients. METHODS: Twenty-three consecutive orthotopic heart transplantation recipients with a mean age of 51 years (range 22-66) were prospectively recruited from the cardiac transplantation programme at the Hospital Universitario Central de Asturias. Serum NT-proBNP and cTnT were measured during the follow-up of these patients (ranging from 9-13 months post-transplantation) and compared with the results of EMB. RESULTS: Serum NT-proBNP concentrations progressively decrease during the first year post-transplantation, reaching concentrations slightly higher than the reference values. NT-proBNP concentrations increase significantly in those patients with a rejection episode graded >or=3A on the basis of the EMB (P<0.001, Mann-Whitney U-test). No relation between cTnT and rejection was observed. CONCLUSIONS: The potential of NT-proBNP as a non-invasive marker of transplantation rejection shows promising results, since NT-proBNP concentrations increase whenever a significant rejection event takes place in the first year of follow-up.

Reducción de la prevalencia de los defectos de cierre del tubo neural mediante un programa regional de cribado con alfafetoproteína en suero materno / Reduction in the prevalence of neural tube closure defects through a regional screening programe with alpha-fetoprotein in maternal serum

Objetivo: Optimación de un programa regional de cribado con alfafetoproteína sérica materna con objeto de que la prevalencia de los defectos de cierre del tubo neural en el Principado de Asturias sea próxima a cero.Sujetos y métodos: Las participantes han sido gestantes pertenecientes a las diferentes áreas de salud del Principado de Asturias independientemente de su procedencia, sanidad pública o privada. Se estudiaron a 63.163 embarazadas en 11 años. Todas las técnicas bioquímicas se realizaron en el Laboratorio de Bioquímica del Hospital San Agustín.Resultados: Se ha conseguido optimizar el programa de cribado con alfafetoproteína en suero materno con porcentajes muy bajos de falsos positivos y amniocentesis realizadas, el 1,9 y el 0,5 por ciento, respectivamente. Se ha observado que las anencefalias presentan valores de alfafetoproteína en suero materno significativamente más elevados que las espinas bífidas abiertas, y se ha conseguido disminuir la prevalencia de este tipo de malformaciones en el Principado de Asturias de una media de 1,3 a prácticamente cero.Conclusiones: La puesta en funcionamiento de un programa de estas características requiere un equipo multidisciplinario para que los resultados obtenidos sean satisfactorios. Después de varios años de desarrollo los resultados obtenidos han convencido a los obstetras y médicos generalistas de la utilidad de incorporar dicho programa al protocolo del embarazo. Este programa ha servido, además, para obtener un conocimiento exhaustivo de este tipo de malformaciones en el Principado de Asturias. (AU)

Utilidad de la alfafetoproteína sérica materna como parámetro de riesgo del embarazo / Utility of maternal serum alpha-fetoprotein as a risk marker of the pregnancy

Objetivos: Demostrar que las embarazadas con valores elevados, sin justificación aparente, de alfafetoproteína sérica tienen un riesgo mayor de resultados perinatales adversos.Sujetos y métodos: Se estudiaron 43.424 gestantes desde el segundo trimestre del embarazo hasta el parto. Se calculó el riesgo relativo entre los valores de alfafetoproteína en suero materno (AFPSM) y los resultados perinatales siguientes: partos pretérminos, muertes fetales anterior y posterior a la semana 28 de gestación, y recién nacidos con bajo peso.Resultados: Se estudió la influencia de las concentraciones de AFPSM sobre 4 resultados perinatales adversos, observándose en todos ellos una diferencia significativa entre el grupo de gestantes considerado control (AFPSM 2,5 MDM). Se observó un mayor riesgo relativo en las gestantes con muerte fetal anterior a la semana 28 de gestación.Conclusiones: Se ha comprobado que existe una relación entre los valores elevados de AFPSM y el riesgo de un resultado perinatal adverso. Sin embargo, la AFPSM no se puede considerar un marcador de cribado adecuado, por su baja sensibilidad, para seleccionar gestantes con un riesgo elevado de un resultado adverso. (AU)

Optimization of nucleated red blood cell (NRBC) recovery from maternal blood collected using both layers of a double density gradient.

The isolation of fetal nucleated red blood cells (NRBC) from maternal blood represents a promising approach to non-invasive prenatal diagnosis. However, the number of fetal NRBC in maternal circulation is quite low and therefore difficult to isolate. An enrichment procedure in which both layers from a double density 1.077/1.107 g/ml gradient are collected was optimized, followed by MACS selection using non-commercial monoclonal antibodies. The influence of the delay in processing maternal blood on the NRBC distribution in both interfaces of the gradient was also studied in cord blood and peripheral maternal blood samples. A significant increase in the number of NRBC isolated from maternal blood was achieved by collecting both layers of the double density gradient compared with the previous protocol in which only the lower layer was recovered. Cord blood samples showed significant differences in the number of NRBC recovered when processed at 24 instead of within 3 h. This effect was also observed in the number of NRBC collected only from the upper layer of peripheral maternal blood samples. Therefore, in order to minimize the target cell losses, it is advisable to process the maternal blood samples as soon as possible.

Células fetales en sangre materna: estado actual y perspectivas futuras / Fetal cells in maternal blood: Present and future

Los métodos diagnósticos están evolucionando de manera vertiginosa hacia técnicas mínimamente invasivas. En el campo del diagnóstico prenatal, se está dedicando gran esfuerzo para encontrar alternativas no invasivas para la obtención de tejido fetal, lo que permitiría ofrecer ese diagnóstico prenatal a todas las gestantes, y no sólo a aquellas con alto riesgo de portar un feto aneuploide. El hallazgo de células fetales en la circulación materna y las aplicaciones diagnósticas que se han descrito recientemente, hacen este objetivo cada vez más alcanzable. Se revisan los trabajos más relevantes publicados hasta el momento sobre el aislamiento de células fetales de sangre materna, destacando los motivos por los que los eritroblastos han sido elegidos, casi unánimemente, como célula fetal diana, así como los principales métodos de separación, enriquecimiento y análisis desarrollados o adaptados para este fin. Por último, se muestra cuáles son las perspectivas de la futura aplicación clínica de toda esta investigación (AU)

Development, characterization, and use of monoclonal antibodies made to antigens expressed on the surface of fetal nucleated red blood cells.

BACKGROUND: Current methods for obtaining fetal cells for prenatal diagnosis are invasive and carry a small (0.5-1.0%) but definite risk of miscarriage. An attractive alternative would be isolation of fetal cells from peripheral maternal blood using antibodies with high specificity and avidity. METHODS: To generate antibodies, we purified nucleated red blood cells (NRBCs) from fetal livers and used them as the immunogen to generate monoclonal antibodies (mAbs) directed against surface antigens. RESULTS: The four antibodies recognized at least two conformationally sensitive epitopes of the transferrin receptor. Isolation of NRBCs from 252 maternal blood samples using these antibodies in magnetic activated cell sorting after an initial density gradient centrifugation yielded 0-419 NRBCs per 25 mL of maternal blood. One antibody, 2B7.4, not only isolated the highest number of NRBCs (>10 in 90% of the samples) but also isolated these NRBCs in 78 consecutive maternal samples. CONCLUSION: Antibody 2B7.4 shows promise for the isolation of NRBCs from maternal blood and should allow studies concerning the source of these cells, fetal vs maternal, and the factors controlling their prevalence.

Maternal serum alpha-fetoprotein screening for neural tube defects. Report of a program with more than 30000 screened pregnancies.

Maternal serum alphafetoprotein (MSAFP) screening has been set up in Asturias, in the north of Spain, in 1987 in order to make possible the prenatal diagnosis of neural tube defects (NTD) to overall pregnancy population. This large study shows the high sensitivity and specificity of MSAFP screening when it is done with absolute control of all variables such as gestational age, pregnant woman's weight, diabetes, etc. On the other hand, this study also shows a poor sensitivity second level ultrasound for the early diagnosis of NTD in the presence of spina bifidas with no bulge. We have also observed that the incidence of NTD in Asturias remained constant in the last six years, around 1.5-1.6 per 1000 pregnancies. However, due to MSAFP screening, there has been a decline in the prevalence of children born with these defects. We conclude that MSAFP screening is the best tool to identify and reduce NTD in our Region (Spain).

IgA-CK-BB complex with CK-MB electrophoretic mobility can lead to erroneous diagnosis of acute myocardial infarction.

This patient, on admission, presented with a tentative diagnosis of myocardial infarction: the electrocardiogram showed a nonspecific ST-segment and T-wave abnormalities, and total creatine kinase (CK; EC 2.7.3.2) activity was slightly increased (238 U/L). However, a high electrophoretic value for CK-MB (50% of total CK activity) and the electrophoretic pattern of lactate dehydrogenase (EC 1.1.1.27) isoenzymes ruled out myocardial infarction. The isoenzyme migrating as CK-MB was found later to contain no immunologically normal CK-M subunits, and it was bound to IgA. A mixture of the patient's serum and a human serum control containing all CK isoenzymes showed altered electrophoretic mobility only for CK-BB, indicating that the patient's serum contained antibodies to the B unit of CK. Elution from a Sephadex G-200 column showed that the peak at which most of the anodic CK was eluted corresponded to a molecular mass of approximately 200 kDa. Evidently this atypical isoenzyme was an IgA-CK-BB complex. Because this macro CK type 1 can mimic CK-MB, it may therefore be a source of confusion.

Influence of air pollution on extrinsic childhood asthma.

A crossed comparative study was done with 248 extrinsic asthmatic children living either in polluted or non-polluted areas (mean emission per year of sedimentary material greater than or less than 300 mg/m2/day, respectively) to establish the influence of air pollution on childhood extrinsic asthma. The mean number of wheezing crises per year was significantly higher for the children living in polluted areas (10.4 versus 7.69). In addition, incidence of severe asthma (types II, III, and IV) in children living in polluted areas was markedly increased whereas the slight form of asthma (type I) was more frequent in children living in non-polluted areas. No correlation, however, between the wheezing episodes and levels of atmospheric contaminants (fumes and SO2) was detected when a group of 84 extrinsic asthmatic children living in polluted areas was studied longitudinally for a year. The data indicate that air pollution, as an isolated agent, plays a transient role in the appearance of wheezing episodes in subjects with extrinsic asthma. Results also suggest that the air pollution may potentiate wheezing episodes via alternative mechanisms.

Characterization of receptors for insulin and insulin-like growth factor-1 on FRTL-5 thyroid cells.

FRTL-5 rat thyroid cells have receptors for both insulin and IGF-I which can be distinguished in binding studies. The ability of TSH to regulate each in an antiparallel manner is atypical. If these receptors are shown to have independent as well as coordinate activities, studies of the mechanisms of their receptor cross-talk in these cells will be relevant to understanding IGF-I and insulin receptors in other tissues.

Serum levels of total IgE in non-allergic children. Influence of genetic and environmental factors.

The purpose of this study was to establish the range of total serum IgE in a healthy population lacking personal and family history of allergy, as well as the influence of genetic factors (family history of allergy), environmental factors (degree of air pollution), age, and sex on the serum IgE levels. Using a commercial enzyme immunoassay (Phadezym IgE Prist) the mean serum level of IgE was determined in 363 non-atopic children from 0 to 12 years of age. The geometric mean of serum IgE increased according to age, indicating a positive correlation between both. Higher mean values of serum IgE were found for children with a family history of allergy, than for children without (27.82 and 14.49 U/ml respectively). The percentage of variation due to age was about 94.5% in children with no family history of allergy. The mean value of serum IgE increased with the degree of air pollution in the living area (15.49 U/ml in non-polluted areas, 20.78 U/ml in very polluted areas). However, the influence of air pollution was smaller than the influence of family history on the mean values of serum IgE. The mean value of serum IgE was not modified by sex.

Abnormal electrophoretic mobility of creatine kinase isoenzyme in serum of an otherwise healthy person.

We describe the abnormal electrophoretic mobility of a creatine kinase isoenzyme in the serum of an apparently healthy individual. In agarose gel electrophoresis this isoenzyme migrates more toward the cathode than does the MM isoenzyme. It is more resistant to heat and more strongly inhibited by urea than the normal MM isoenzyme. We performed gel filtration, on a Sephadex G-200 column, of the patient's serum and observed two distinct isoenzymes with different relative molecular masses; a normal isoenzyme of 80,000 daltons and another abnormal one of 240,000 daltons. We performed serum immunoelectrophoresis but did not observe any immune complex formation involving the abnormal isoenzyme.