Case Report: Blocking Anti-B

Recently, I had a case where the blocking antibody was not an anti-D, but rather an anti-B in a case of ABO hemolytic disease of the fetus/newborn HDFN.  The D typing result was weak but the D control in the gel was positive so the result was indeterminate.  DAT was 3+ IgG and anti-B was identified in the eluate (mother was antibody screen negative, regular elution panels (group O cells) were negative.  Some of the actual workup follows: