Antenatal Rh prophylaxis is unnecessary for "Asia type" DEL women.
BACKGROUND
Generally Rh-negative patients need to be transfused with Rh-negative red blood cells. For pregnant women carrying Rh-positive fetus, the antenatal anti-D detection and Rh immunoglobulin prophylaxis are required worldwide. In East Asia, a RhD variant, termed "Asia type" DEL, was found in approximately 30% of apparent Rh-negative individuals. The antigenic and molecular properties of the DEL were previously defined. Few data discuss whether DEL could be immunized by D antigen clinically although DEL was reported arousing alloimmunization to true Rh-negative patients.


METHODS
To determine whether the DEL variant can be immunized to the D antigen, we retrospectively evaluated 104 Rh-negative pregnancies with allo-anti-D antibodies, and we also tracked 199 consecutive apparent Rh-negative pregnant women, with a history of gestations or parturitions but not subject to anti-D gamma-globulin prophylaxis, for evidence of allo-anti-D. The DEL variant was first excluded by ccee phenotypes and then identified through PCR analysis or sequencing.


RESULTS
In the retrospective study, we expected to find 30 DEL variants, yet none of the anti-D alloimmunized women were DEL-positive. And in the second group, none of 44 DEL-positive women versus 38 of 155 (24.5%) true Rh-negative women (those excluding DEL) formed allo-anti-D.


CONCLUSIONS
The data indicate that the "Asia type" DEL variant does not appear at risk of alloimmunization to the D antigen. It strongly suggests that the antenatal Rh immune globulin prophylaxis is unnecessary for DEL women. Furthermore, it implicates that the "Asia type" DEL may be deemed Rh-positive safely for clinical transfusion therapy.
Shenzhen Institute of Transfusion Medicine, Shenzhen Blood Center, Meigang Street, Nigang West Road, Futian, Shenzhen 518035, China. cpshaos@hotmail.com
Chao-Peng
CP
Shao
Hua
H
Xu
Qun
Q
Xu
Guo-Dong
GD
Sun
Jian-Ping
JP
Li
Bo-Wei
BW
Zhang
Xiao-Hua
XH
Liang
Zhong
Z
Liu
Ying
Y
Zhou
Dan
D
Li
Nai-Bao
NB
Zhuang
D000328:Adult; D001787:Blood Group Incompatibility / Q000517:prevention & control*; D002681:China; D005260:Female; D006801:Humans; D008875:Middle Aged; D011247:Pregnancy; D011250:Pregnancy Complications, Hematologic / Q000517:prevention & control*; D011446:Prospective Studies; D012189:Retrospective Studies; D012204:Rh-Hr Blood-Group System / Q000145:classification; D018029:Rho(D) Immune Globulin / Q000627:therapeutic use*; D055815:Young Adult
D012204:Rh-Hr Blood-Group System; D018029:Rho(D) Immune Globulin; C026410:Rho(D) antigen