The Presence of the Anti-D Alloantibody in the Plasma of a Pregnant Woman Initially Typed as RhD-Positive
Keywords:
RhD; anti-D immunoglobulin prophylaxis; pregnancyAbstract
Background: Although the general population can be classified as rhesus D (RhD)-positive or -negative, there are individuals whose RhD status is determined to be a D variant, i.e., the weak D, partial D or DEL phenotype. Through this case presentation we want to draw attention to the possibility of incorrect RhD serologic interpretation, which can lead to the omission of anti-D administration.
Methods: We present the case of a 27-year-old pregnant woman, initially serologically typed as RhD-positive, in the 31st week of gestation, who was diagnosed with the anti-D alloantibody in her second pregnancy.
Main findings: In the 34th week of gestation, the anti-D titer was 1:1 (a score of 7), in the 35th week it was 1:2 (a score of 18), in the 37th week it was 1:2 (a score of 15) and on the delivery day (39th week) it was 1:2 (a score of 16). Anti-D was eluted from the red blood cells of the newborn without requiring therapy. The RhD typing of the mother was conducted and determined to be partial D category IV type 4.
Principal conclusion: Partial D category IV type 4 can still cause a discrepancy between serologic typing and genotyping, increasing the incidence of anti-D alloimmunization.