Anti-D in RhD Positive Patient: Auto Anti-D or Anti-LW?

Abstract

Anti-LW and anti-D can be indistinguishable. Therefore, it is important to differentiate them since anti-D is a clinically significant antibody. ICAM4 and RHD genes encode the Landsteiner-Wiener (LW) and RhD antigens, respectively. However, the LW antigens expression requires an interaction with Rh proteins. Hence, LW antigen is being express more strongly by RhD positive (RhD+) than RhD negative (RhD-) individuals. We describe a 51-year-old male with underlying multiple medical problems. His blood group was O RhD+ with Rh phenotype R₁r (DCe/dce). The patient had been receiving regular packed cells (PC) transfusion for anemia due to underlying chronic kidney disease. Immunohematology workup showed antibody identification positive for auto-control with anti-D specificity which suggestive for the presence of autoantibody (anti-D or anti-LW). Cross-matching revealed incompatibility with all RhD+ but compatible with RhD- PC. Further investigations should be done to differentiate these two antibodies. The laboratory approaches in order to differentiate anti-LW and anti-D will be discussed and highlighted.