HLA-DQB1*0201 phenotype and severe primary RhD immunization

Abstract

Purpose of Investigation: Although post-delivery administration of anti-D immunoglobulin (anti-D Ig) and antenatal prophylaxis the residual prevalence of RH alloimmunization is due to an incomplete application of the guidelines or to clinical conditions that foster mechanisms of immunization. Materials and Methods: The authors report a case of devastating RhD alloimmunization in a secundipara, group 0 Rh negative, without potentially immunizing events. Results: Anti-D antibodies were screened at 6/2 and at 13/4 weeks and were found negative. Fetal echocardiography at 25/0 weeks showed dilated right cardiac sections and a mild pericardial effusion. Titer of anti-D antibodies was (1:1024) with negative Kleihauer-Betke. At 27/0 weeks she had an increase of anti-D antibody titer (1:8192), peak systolic velocity in the middle cerebral artery suggested severe fetal anemia. A positive HLA-DQB1 allele *0201 was found, and she gave birth to an infant with severe immune-mediated hemolysis (HB: 3.8 g/dl) who was discharged 62 days after birth due to perinatal complications. Conclusion: HLA-DQB1*0201 phenotyping can improve the surveillance and treatment of non-sensitized D negative patients.