Successful transfusion care for a patient with the Rhesus -D- phenotype and antibodies against Rh17 and two additional alloantibodies

D--phenotype due to RHD-RHCE hybrid transcript in a case of severe haemolytic disease of newborn with anti-Rh 17(Hrₒ) antibodies

BACKGROUND

D antigen is one among the most immunogenic antigens and is the most common cause of Haemolytic Disease of Fetus and Newborn (HDFN). The D-phenotype is a rare Rh variant in which none of the RhCE antigens are expressed on the red cell surface. Individuals having D-phenotype are capable of producing a rare alloantibody named as anti-Rh17(Hrₒ) in response to pregnancy or transfusion and has the potential to react with C/c and E/e antigens causing severe haemolytic transfusion reaction (HTR) and haemolytic disease of fetus and newborn (HDFN).

CASE REPORT

We have encountered a case of severe HDFN with an accidental discovery of D- phenotype of the mother with anti-Rh-17 antibodies. D- phenotype has been confirmed with molecular typing along with genotyping of all family members.

CONCLUSION

Rare phenotypes like D- individuals especially if allo-immunised are of great concern at times of transfusion requirements. Hence, proper identification of these individuals are important to contribute them to the rare donor pool and to adopt adequate patient blood management strategies.

The Outcome of Hemolytic Disease of the Fetus and Newborn Caused by Anti-Rh17 Antibody: Analysis of Three Cases and Review of the Literature

Background

Anti-Rh17 is a rare red blood cell (RBC) antibody to high-frequency antigens that may cause severe hemolytic disease of the fetus and newborn (HDFN). Despite the rarity of HDFN caused by Anti-Rh17, this antibody was reported in many different populations. Emergency transfusions, especially exchange transfusions, present a huge problem if no compatible RBCs of phenotype D- are available.

Methods

Here we report obstetrical histories of three women and describe their pregnancies complicated by anti-Rh17 antibodies. We summarized published cases of pregnancies complicated by anti-Rh17 and reviewed transfusion treatment and outcomes. Additionally, a simplified flowchart for the management of such pregnancies is proposed.

Results

Four pregnancies were affected by severe HDFN, and three of them ended with perinatal death. In the fourth case, the baby was born hydropic and icteric and the condition was rapidly deteriorating. Emergency exchange transfusion was performed with incompatible O-negative RBC units in AB-negative plasma. The baby was discharged on the 14th day in good health. In the available literature, 15 women and 22 pregnancies were reported, 20 of them developed severe HDFN. According to the data, intrauterine transfusion for treatment of HDFN was the most common form of treatment with the donation of the mother's blood. Different options for exchange transfusion were described, including incompatible RBCs.

Conclusion

In more than 90% of described pregnancies of HDFN caused by anti-Rh17 antibody, transfusion treatment was required. Therefore, RBC from D- phenotype has to be available. According to published data, in emergent circumstances when maternal and blood from donor with phenotype D- is not available, incompatible exchange transfusion is a better choice than delaying transfusion when it is necessary. It is of essential importance that pregnancies with high risk of HDFN due to anti-Rh17 are managed by a multidisciplinary team (transfusion medicine specialist, obstetrician, neonatologist) in a highly specialized tertiary institution.

Sensitization to multiple rh antigens by transfusion of random donor platelet concentrates in a -D- phenotype patient

The -D- phenotype is a rare Rh phenotype that strongly expresses D antigen without C, c, E, or e antigens. In -D- phenotype individuals, anti-Rh17 (Hr_o) is commonly found if there is a history of pregnancy or transfusion with red blood cells (RBCs) that express C, c, E, or e antigens. We report the first case of a -D- phenotype patient with multiple Rh antibodies including anti-Rh17 who had a history of two occasions of transfusion with eight random donor platelet concentrates two and six years ago. We found that a trivial amount of RBCs in the platelet components was able to trigger sensitization to RBC antigens, especially the highly immunogenic and clinically significant Rh antigens, including C, c, E, e or CcEe polypeptides. To avoid unnecessary sensitization and to minimize the risk of hemolytic transfusion reactions in patients with this rare Rh phenotype, a modified strategy for pretransfusion screenings needs to be discussed in the field of transfusion medicine.