TY - JOUR

T1 - Non-Invasive Fetal K Status Prediction

T2 - 7 Years of Experience

AU - Rieneck, Klaus

AU - Clausen, Frederik Banch

AU - Bergholt, Thomas

AU - Nørgaard, Lone Nikoline

AU - Dziegiel, Morten Hanefeld

N1 - Publisher Copyright: © 2022 The Author(s). Published by S. Karger AG, Basel.

PY - 2022

Y1 - 2022

N2 - Introduction: In the Kell blood group system, the K and k antigens are the clinically most important ones. Maternal anti-K IgG antibodies can lead to the demise of a K-positive fetus in early pregnancy. Intervention can save the fetus. Prenatal K status prediction of the fetus in early pregnancy is desirable and gives a good basis for pregnancy risk management. We present the results from 7 years of clinical experience in predicting fetal K status as well as some theoretical considerations relevant for design of the assay and evaluation of results. Methods: Blood was collected from 43 women, all immunized against K, at a mean gestational age of 18 weeks (range 10-38). A total of 56 consecutive samples were tested. The KEL∗01.01/KEL∗02 single nucleotide variant that determines K status was amplified from maternal plasma DNA by PCR without allele specificity. The PCR product was sequenced by NGS technology, and the number of sequenced KEL∗01.01 and KEL∗02 reads were counted. Prediction of the fetal K status was based on this count and was compared with the serologically determined K status of the newborns. Results: All fetal K predictions were in accordance with postnatal serology where available (n = 34), using our current data analysis. Conclusion: We have developed an NGS-based method for the non-invasive prediction of fetal K status. This approach requires special considerations in terms of primer design, stringent preanalytical sample handling, and careful analytical procedures. We analyzed samples starting at GA 10 weeks and demonstrated the correct prediction of fetal K status. This assay enables timely clinical intervention in pregnancies at risk of hemolytic disease of the fetus and newborn caused by maternal anti-K IgG antibodies.

AB - Introduction: In the Kell blood group system, the K and k antigens are the clinically most important ones. Maternal anti-K IgG antibodies can lead to the demise of a K-positive fetus in early pregnancy. Intervention can save the fetus. Prenatal K status prediction of the fetus in early pregnancy is desirable and gives a good basis for pregnancy risk management. We present the results from 7 years of clinical experience in predicting fetal K status as well as some theoretical considerations relevant for design of the assay and evaluation of results. Methods: Blood was collected from 43 women, all immunized against K, at a mean gestational age of 18 weeks (range 10-38). A total of 56 consecutive samples were tested. The KEL∗01.01/KEL∗02 single nucleotide variant that determines K status was amplified from maternal plasma DNA by PCR without allele specificity. The PCR product was sequenced by NGS technology, and the number of sequenced KEL∗01.01 and KEL∗02 reads were counted. Prediction of the fetal K status was based on this count and was compared with the serologically determined K status of the newborns. Results: All fetal K predictions were in accordance with postnatal serology where available (n = 34), using our current data analysis. Conclusion: We have developed an NGS-based method for the non-invasive prediction of fetal K status. This approach requires special considerations in terms of primer design, stringent preanalytical sample handling, and careful analytical procedures. We analyzed samples starting at GA 10 weeks and demonstrated the correct prediction of fetal K status. This assay enables timely clinical intervention in pregnancies at risk of hemolytic disease of the fetus and newborn caused by maternal anti-K IgG antibodies.

KW - Cell-free DNA

KW - Genotyping

KW - Hemolytic disease of the fetus and newborn

KW - Kell blood group

KW - Next-generation sequencing

KW - Non-invasive prediction

KW - Prenatal diagnosis

U2 - 10.1159/000521604

DO - 10.1159/000521604

M3 - Journal article

C2 - 36159959

AN - SCOPUS:85124538576

VL - 49

SP - 240

EP - 249

JO - Transfusion Medicine and Hemotherapy

JF - Transfusion Medicine and Hemotherapy

SN - 1660-3796

ER -