Screening of RHD fetal genotype in RhD negative women.

OBJECTIVE: In the Czech Republic in all women within a first trimester screening a laboratory testing for RhD blood group from the peripheral blood should be performed. The aim of the screening is to diagnose RhD negative pregnant women, who may be at risk of developing RhD alloimmunization if the fetus is RhD positive. Currently, the prevention of RhD alloimmunization is carried out regardless of the knowledge of RHD fetal status. Already at the beginning of pregnancy it is possible to determine the RHD genotype of the fetus non-invasively due to cell free fetal DNA circulating in maternal peripheral blood detection. The issue of screening examination of fetal RHD genotype is solved worldwide. In some European countries, the examination is routinely established and thus contributes to the optimization of prenatal care for RhD negative pregnant women, immunoglobulin administration is targeted only in pregnancies with RhD positive fetus. The aim of our study is to evaluate clinical and laboratory effectiveness of fetal RHD genotype screening in RhD negative women by TaqMan Real-time PCR method. Designe: Prospective cohort study. SETTING: Obstetrics and Gynecology Clinic of the Faculty of Medicine University Palacky and the University Hospital Olomouc; Institute of Medical Genetics of the Faculty of Medicine UP and the University Hospital Olomouc; Transfusion Department of the University Hospital Olomouc; Institute of Biophysics of the Faculty of Medicine UP Olomouc. MATERIAL AND METHODS: In 2011-2015 at the University Hospital Olomouc 337 examinations of RHD fetal genotype were performed in pregnant women in first and second trimester and evaluated by TaqMan Real-time PCR, followed by verification of the newborn RHD genotype. RESULTS: Methodology of fetal RHD genotype examination is accurate, reliable and useful in clinical practice. The sensitivity was 97.8%. The specificity was 98.7%. When assessing the effectiveness of the introduction of non- -invasive fetal RHD genotype screening in RhD negative women, it is necessary to assess the medical, organizational and economic aspects. More consistent prevention of RhD alloimmunization in the cases actually indicated may reduce the incidence of RhD alloimmunization. CONCLUSION: From the medical point of view the RHD genotype determination in all RhD negative women at the beginning of pregnancy seems effective. It allows to diagnose about 40% of pregnancies with RhD negative fetuses that do not require administration of IgG anti-D. IgG anti-D should be administered only in indicated cases. Determination of fetal RHD genotype by using TaqMan Real-time PCR is useful in clinical practice.

The effectiveness of KEL and RHCE fetal genotype assessment in alloimmunized women by minisequencing.

OBJECTIVE: To evaluate the effectiveness of the fetal KEL and RHCE genotype assessment in alloimmunized pregnant women by minisequencing. DESIGN: Prospective cohort study. SETTING: Obstetrics and Gynecology Clinic of the Faculty of Medicine UP and the University Hospital Olomouc; Institute of Medical Genetics of the Faculty of Medicine UP and the University Hospital Olomouc; Transfusion Department of the University Hospital Olomouc; Institute of Biophysics of the Faculty of Medicine UP Olomouc. SUBJECT AND METHOD: In the years 2001-2019, 366 samples of pregnant women in the first and second trimester were assessed KEL (n = 327) or RHCE (n = 39) genotype from the free fetal DNA circulating in the peripheral blood by minisequencing. The genotype of the fetus was verified from the buccal smear of the newborn. RESULTS: The KEL genotype was assessed in 327 women (the presence of a variant of the KEL1 alele, which corresponds to the presence of the erythrocyte antigen “K“. The analysis failed in 2 cases (2/327), 16 heterozygote women (KEL1/KEL2) were excluded and in the case of 309 homozygote women (KEL2/KEL2) the fetal KEL genotype was assessed. In the case of 95.8% of the fetuses (296/309) and 95.5% of the newborns (295/309), the KEL2/KEL2 genotype was assessed. In the case of 4.2 % of the fetuses (13/309) and 4.5% of the newborns (14/309), the KEL1/KEL2 genotype was assessed. The sensitivity was 92.86%. The specificity was 100%. The RHCE genotype was assessed in 39 women. In the case of 22 women, the presence of a variant of the RHCE gene, which corresponds to the presence of the erythrocyte antigen “C“/“c“, was assessed. 5 heterozygote women (C/c) were excluded. In the case of 11 homozygote women (C/C), the RHCE genotype was assessed. In the case of 64% (7/11) of the fetuses and newborns, the C/c genotype was assessed, in the case of 36% (4/11) the C/C genotype was assessed. In the case of 6 homozygote women (c/c), the RHCE genotype was assessed. In the case of 67% (4/6) of the fetuses and newborns, the C/c genotype was assessed, in the case of 33% (2/6) the c/c genotype was assessed. The sensitivity and specificity were 100%. In the case of 17 women, the presence of the variant of the RHCE gene, which corresponds to the presence of the erythrocyte antigen “E“/“e“, was assessed. 1 heterozygote woman (E/e) was excluded. In the case of 16 homozygote women (e/e), the RHCE genotype was assessed. In the case of 75% (12/16) of the fetuses and newborns, the e/e genotype was assessed, in the case of 25% (4/16) the E/e genotype was assessed. The sensitivity and specificity were 100%. CONCLUSION: The minisequencing method using the capillary electrophoresis enabled a reliable detection of the fetal KEL and RHCE genotype from the peripheral blood of pregnant women.

[Application of the concetrations ratio of soluble receptor tyrosine kinase type 1, and placental growth factor for short-term prediction and diagnosis of preeclampsia]. / Vyuzití pomeru koncentrací solubilního receptoru tyrozinkinázového typu 1 a placentárního rustového faktoru pro krátkodobou predikci a diagnostiku preeklampsie.

OBJECTIVE: Bring a comprehensive overview of the available information about applications of the concetration ratio of soluble receptor tyrosine kinase type 1 (sFlt-1), and placental growth factor for short-term prediction and diagnosis of preeclampsia. DESIGN: Overview study. SETTINGS: Department of Midwifery, Faculty of Health Sciences, Olomouc; Department of Clinical Biochemistry, University Hospital Olomouc; Department of Obstetrics and Gynecology, University Hospital Olomouc; Department of Obstetrics and Gynecology, 2nd Faculty of Medicine, Charles University in Prague and Motol University Hospital. METHODS: Analysis of literary sources and databases Ovid, Medline (2001-2016). CONCLUSION: Preeclampsia is a multisystem disease with not fully understood etiology. This disease occurs in 2-5% of pregnant women. Preeclampsia is one of the main causes of global maternal and perinatal morbidity and mortality. It manifests itself as a newborn hypertension and proteinuria after 20 weeks of pregnancy in previously normotensive women. The only effective treatment is the delivery of the child. Diagnosis of preeclampsia comprises measuring blood pressure and proteinuria. These indicators have low diagnostic sensitivity and specificity. In preeclampsia, there is a decrease of serum levels of placental growth factor (PlGF). Soluble receptor tyrosine kinase type 1 (sFlt-1) is an antagonist of PlGF. Increased levels of sFlt-1 in proportion to the reduced level of PlGF are associated with an increased risk of preeclampsia. The sFlt-1/PlGF ratio can be a better predictive marker in the diagnosis of pre-eclampsia after 20 weeks of gestation.

[Spontaneous antepartal RhD alloimmunization]. / Spontánní antepartální RhD aloimunizace.

AIM OF THE STUDY: Assess the incidence of spontaneous antepartal RhD alloimmunization in RhD negative pregnant women with an RhD positive fetus. DESIGN: Clinical study. SETTING: Department of Obstetrics and Gynecology, Medical School and University Hospital Olomouc. METHODS: A total of 906 RhD negative women with an RhD positive fetus and without the presence of anti-Dalloantibodies at the beginning of pregnancy were examined. Always it was a singleton pregnancy, RhD blood group of the pregnant women was assessed in the 1st trimester of pregnancy, RhD status of the fetus was determined after delivery. Screening for irregular antierythrocyte antibodies was performed in all women in the 1st trimester of pregnancy, at 28-32 weeks gestation and immediately prior to delivery at 38-42 weeks gestation. Screening for irregular antierythrocyte antibodies was performed also at 6 months following delivery in all cases of positive antibodies before delivery. Antibody screening was performed using the indirect antiglobulin (LISS/NAT) and enzyme (papain) test with their subsequent identification using a panel of reference erythrocytes by column agglutination method Dia-Med. After delivery, the volume of fetomaternal hemorrhage was assesed in all RhD negative women and RhD alloimmunization prophylaxis was performed by administering the necessary IgG anti-D dose; none of the women were administered IgG anti-D antepartally. RESULTS: During screening for irregular antierythrocyte antibodies at 28-32 weeks gestation, anti-D alloantibodies were diagnosed in 0.2% of the women (2/906); immediately prior to the delivery at 38-42 weeks gestation, anti-D alloantibodies were diagnosed in 2.3% of the women (21/906) and repeatedly even at 6 months following delivery (21/157). In 82.7% of the women (749/906), examination at 6 months following delivery was not performed, therefore in these women spontaneous antepartal RhD alloimmunization cannot reliably be ruled out. Alloimmunization may not be diagnosed yet at term of delivery. If anti-D alloantibodies were not present prior to the delivery, these women were all administered IgG anti-D in a dose of at least 125 µg after delivery. CONCLUSION: In RhD negative women with an RhD positive fetus, the incidence of spontaneous antepartal RhD alloimmunization was at least 2.3%. Most cases may theoretically be prevented by prophylactic administration of 250 µg of IgG anti-D to all RhD negative women at 28 weeks gestation.