Maternal serum soluble fms-like tyrosine kinase-1 at 12, 22, 32 and 36 weeks' gestation in screening for pre-eclampsia

OBJECTIVE

To examine the distribution of maternal serum soluble fms-like tyrosine kinase-1 (sFlt-1) at 12, 22, 32 and 36 weeks' gestation in singleton pregnancies that develop pre-eclampsia (PE) and examine the performance of this biomarker in screening for PE.

METHODS

Serum sFlt-1 was measured in 7066 cases at 11-13 weeks, 8079 cases at 19-24 weeks, 8472 at 30-34 weeks and 4043 at 35-37 weeks. Bayes' theorem was used to combine the a-priori risk from maternal characteristics and medical history with serum levels of sFlt-1. The performance of screening for PE in women requiring delivery < 32, between 32 + 0 and 36 + 6 and ≥ 37 weeks' gestation was estimated.

RESULTS

In pregnancies that developed PE, serum sFlt-1 was increased and the separation in multiples of the median (MoM) values from normal was greater with earlier, compared to later, gestational age at which delivery for PE became necessary. In pregnancies that developed PE, the slope of the regression lines of sFlt-1 MoM with gestational age at delivery increased with advancing gestational age at screening. Measurement of sFlt-1 at 11-13 weeks did not improve the prediction of PE achieved by maternal factors alone, sFlt-1 at 19-24 weeks improved the prediction of PE delivering < 37 weeks but not for PE delivering ≥ 37 weeks, sFlt-1 at 30-34 weeks improved the prediction of PE delivering < 37 and PE delivering ≥ 37 weeks and sFlt-1 at 35-37 weeks improved the prediction of PE delivering ≥ 37 weeks. The detection rates (DRs), at a false-positive rate (FPR) of 10%, of PE delivering < 32 weeks were 52% and 65% with screening at 12 and 22 weeks, respectively. The DRs for PE delivering between 32 + 0 and 36 + 6 weeks were 44%, 44% and 93% with screening at 12, 22 and 32 weeks. The DR for PE delivering ≥ 37 weeks were 37%, 37%, 52% and 69% with screening at 12, 22, 32 and 36 weeks, respectively.

CONCLUSIONS

The performance of combined screening with maternal factors, medical history and serum sFlt-1 is superior for detection of early, compared to late, PE and improves with advancing gestational age at screening. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Prediction of small-for-gestational-age neonates: screening by maternal biochemical markers at 30-34 weeks

OBJECTIVE

To investigate the potential value of serum placental growth factor (PlGF), soluble fms-like tyrosine kinase-1 (sFlt-1), pregnancy-associated plasma protein-A (PAPP-A), free β-human chorionic gonadotropin (β-hCG) and α-fetoprotein (AFP) at 30-34 weeks' gestation in the prediction of delivery of small-for-gestational-age (SGA) neonates, in the absence of pre-eclampsia (PE).

METHODS

This was a screening study in singleton pregnancies at 30-34 weeks' gestation, including 490 that delivered SGA neonates and 9360 cases that were unaffected by SGA, PE or gestational hypertension (normal outcome). Multivariable logistic regression analysis was used to determine if screening by serum PlGF, sFlt-1, PAPP-A, free β-hCG and AFP, individually or in combination, improved the prediction of SGA neonates provided by screening with maternal characteristics and medical history (maternal factors), and estimated fetal weight (EFW) from fetal head circumference, abdominal circumference and femur length.

RESULTS

Compared to the normal group, the mean log10 multiples of the median (MoM) values of PlGF and AFP were significantly lower and the mean log10 MoM values of sFlt-1 and free β-hCG were significantly higher in the SGA group with a birth weight < 5(th) percentile (SGA < 5(th)) delivering < 5 weeks following assessment. The best model for prediction of SGA was provided by a combination of maternal factors, EFW and serum PlGF. Such combined screening, predicted, at a 10% false-positive rate, 85%, 93% and 92% of SGA neonates delivering < 5 weeks following assessment with birth weight < 10(th), < 5(th) and < 3(rd) percentiles, respectively; the respective detection rates of combined screening for SGA neonates delivering ≥ 5 weeks following assessment were 57%, 64% and 71%.

CONCLUSION

Combined screening by maternal factors, EFW and serum PlGF at 30-34 weeks' gestation can identify a high proportion of pregnancies that subsequently deliver SGA neonates.

Prediction of small-for-gestational-age neonates: screening by placental growth factor and soluble fms-like tyrosine kinase-1 at 35-37 weeks

OBJECTIVE

To investigate the potential value of maternal serum placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) at 35-37 weeks' gestation in the prediction of delivery of small-for-gestational-age (SGA) neonates, in the absence of pre-eclampsia (PE).

METHODS

This was a screening study in singleton pregnancies at 35-37 weeks, including 158 that delivered SGA neonates with birth weight < 5(th) percentile and 3701 cases unaffected by SGA, PE or gestational hypertension. Multivariable logistic regression analysis was used to determine if measuring serum levels of PlGF and sFlt-1 improved the prediction of delivery of SGA neonates provided by screening with maternal characteristics and medical history (maternal factors), and estimated fetal weight (EFW) from fetal head circumference, abdominal circumference and femur length.

RESULTS

Compared to the normal group, the median PlGF multiples of the median (MoM) was significantly lower and the median sFlt-1 MoM was significantly higher in the SGA group. Combined screening by maternal factors and EFW at 35-37 weeks predicted, at 10% false-positive rate (FPR), 90%, 92% and 94% of SGA neonates with birth weight < 10(th), < 5(th) and < 3(rd) percentiles, respectively, delivering < 2 weeks following assessment; the respective values for SGA delivering ≥ 37 weeks were 66%, 73% and 80%. When PlGF and sFlt-1 were added to a model that combines maternal factors and EFW, sFlt-1 did not remain as a significant independent predictor of SGA < 5(th). Combined screening by maternal factors, EFW and serum PlGF, predicted, at a 10% FPR, 88%, 96% and 94% of SGA neonates with birth weight < 10(th), < 5(th) and < 3(rd) percentiles, respectively, delivering < 2 weeks following assessment and the respective values for SGA delivering ≥ 37 weeks were 64%, 75% and 80%.

CONCLUSION

sFlt-1 does not provide significant independent prediction of SGA, in the absence of PE, in addition to combined testing by maternal factors and fetal biometry at 35-37 weeks; whilst the addition of PlGF alone marginally improves the performance of screening.

Granulomatous amebic encephalitis in a multivisceral transplant recipient

A 40-year-old man with multivisceral allograft developed acutely right-sided numbness 9 months after transplantation. Cranial magnetic resonance imaging (MRI) showed a small left parietal lesion, and cerebrospinal fluid analysis was unremarkable. Stereotactic brain biopsy was non-diagnostic. The patient continued to deteriorate, developed cerebral edema and died at 13 days after the onset of symptoms. Unexpectedly, autopsy demonstrated acanthamebic encephalitis. This case highlights diagnostic difficulties encountered with amebic encephalitis and expands the spectrum of opportunistic central nervous system (CNS) infections in solid and visceral organ transplant recipients.