A new biosensor for noninvasive determination of fetal RHD status in maternal blood of RhD negative pregnant women.

Ebru Dündar Yenilmez,Abdullah Tuli,Umut Kökbaş,Levent Kayrın,Kezban Kartlaşmış,Colette Kanellopoulos-Langevin

doi:10.1371/journal.pone.0197855

Abstract

Prenatal detection of the fetal RHD status can be useful in the management of RhD incompatibility to identify fetuses at risk of hemolytic disease. Hemolytic disease causes morbidity and mortality of the fetus in the neonatal period. The routine use of antenatal and postnatal anti-D prophylaxis has reduced the incidence of hemolytic disease of the fetus and newborn. This study describe the detection of fetal RhD antigens in blood of RhD negative pregnant women using a nanopolymer coated electrochemical biosensor for medical diagnosis. Cell free fetal DNA in maternal plasma was also used to genotyping fetal RHD status using multiplex real-time PCR. Twenty-six RhD negative pregnant women in different gestational ages were included in the study. RhD positive fetal antibodies detected with a developed biosensor in maternal blood of RhD negative mothers. The electrochemical measurements were performed on a PalmSens potentiostat, and corundum ceramic based screen printed gold electrode combined with the reference Ag/AgCl electrode, and the auxiliary Au/Pd (98/2%) electrode. Fetal RHD genotyping performed using fluorescence-based multiplex real-time PCR exons 5 and 7 of the RHD gene. The fetal RHD status of 26 RhD negative cases were detected 21 as RhD positive and 5 as RhD negative with electrochemical biosensor. Fetal RHD status confirmed with extracted fetal DNA in maternal plasma using multiplex real-time PCR RHD genotyping and by serological test after delivery. The new method for fetal RhD detection in early pregnancy is useful and can be carry out rapidly in clinical diagnosis. Using automated biosensors are reproducible, quick and results can be generated within a few minutes compared to noninvasive fetal RHD genotyping from maternal plasma with real-time PCR-based techniques. We suggest the biosensor techniques could become an alternative part of fetal RHD genotyping from maternal plasma as a prenatal screening in the management of RhD incompatibility.

Highlights

The cause of Rhesus hemolytic disease (RhD) of the RhD positive fetus of RhD negative pregnant women is the maternal IgG antibodies produced against the RhD antigen of the fetal erythrocytes
This study showed a biosensor design, which detects RhD status of the fetus in the early stage of pregnancy in RhD negative pregnant women blood
Impedence measurements were applied to characterize the electrochemical properties of the biosensor surface

Summary

Introduction

The cause of Rhesus hemolytic disease (RhD) of the RhD positive fetus of RhD negative pregnant women is the maternal IgG antibodies produced against the RhD antigen of the fetal erythrocytes. This situation has the significant cause of morbidity and mortality for the fetus. Cell-free fetal DNA (cffDNA) discovered from plasma of pregnant women by Lo et al in 1997 has been used for the noninvasive detection of fetal RhD status [7,8,9], which has the potential to avoid antenatal anti-RhD prophylaxis in RhD negative women [5, 10,11,12]. Many obstetricians accept fetal RhD status detection using circulating cffDNA from maternal plasma or serum. [13,14,15,16,17,18]

Objectives

Methods

Results

Conclusion