<abstract xmlns="http://www.w3.org/1999/xhtml">

<p>The blocking of red blood cell (RBC) antigens occurs when potent maternal antibodies bind to antigens on fetal or neonatal RBCs, causing them to be negative when typed with human IgM antisera. This phenomenon is rare; when it does occur, the antibody is usually of a high titer. This reported finding is typically due to anti-D, with rare reports describing false-negative K phenotyping due to blocking by maternal anti-K. We report a case of a potent anti-K with a titer of 32 that blocked K antigens on neonatal RBCs, causing them to phenotype as K–. The neonate also had clinically significant anemia (i.e., hemolytic disease of the newborn) due to the anti-K.</p>
</abstract>

The blocking of red blood cell (RBC) antigens occurs when potent maternal antibodies bind to antigens on fetal or neonatal RBCs, causing them to be negative when typed with human IgM antisera. This phenomenon is rare; when it does occur, the antibody is usually of a high titer. This reported finding is typically due to anti-D, with rare reports describing false-negative K phenotyping due to blocking by maternal anti-K. We report a case of a potent anti-K with a titer of 32 that blocked K antigens on neonatal RBCs, causing them to phenotype as K–. The neonate also had clinically significant anemia (i.e., hemolytic disease of the newborn) due to the anti-K.

K antigens on neonatal red blood cells blocked by anti-K with titer of 32

Immunohematology

{"article-title":"K antigens on neonatal red blood cells blocked by anti-K with titer of 32"}

The blocking of red blood cell (RBC) antigens occurs when potent maternal antibodies bind to antigens on fetal or neonatal RBCs, causing them to be negative...

K antigens on neonatal red blood cells blocked by anti-K with titer of 32

Published Online: Feb 17, 2021

Page range: 54 - 57

DOI: https://doi.org/10.21307/immunohematology-2020-041

Keywords
HDFN, blocked antigen, maternal anti-K, titer

© 2020 J. Novoselac et al., published by Sciendo

K antigens on neonatal red blood cells blocked by anti-K with titer of 32

Published Online: Feb 17, 2021

Page range: 54 - 57

DOI: https://doi.org/10.21307/immunohematology-2020-041

KeywordsHDFN, blocked antigen, maternal anti-K, titer

© 2020 J. Novoselac et al., published by Sciendo

Keywords
HDFN, blocked antigen, maternal anti-K, titer