Anti-HrB and anti-hrb revisited.
BACKGROUND
Since their description in the 1970s, anti-Hr(B) (antibody against a high-prevalence Rh antigen) and anti-hr(B) (anti-e-like antibody) are still a subject of debate about representing two aspects of a global immune response or being two independent antibodies.


METHODS
The aim of this study was to evaluate the immune response against the antigens of Rh system of 30 individuals presenting a hr(B)(RH31)- phenotype. Genomic analysis of RH genes was performed in all individuals.


RESULTS
Among the 30 individuals, 27 had a Hr(B)(RH34)- phenotype. No immunization against Rh antigens was found in 16 individuals. Three individuals made anti-D only, whereas six individuals made anti-Hr(B) (four with anti-hr(B) and two without anti-hr(B)) and two individuals made anti-hr(B) without anti-Hr(B). Among the 30 individuals, three had a Hr(B)+ phenotype. No immunization against Rh antigens was found in one individual, whereas two individuals made anti-hr(B); the genomic analysis of selected individuals showed the presence of a (C)ce(s) haplotype, either Type 1 or Type 2, and a DIII Type 5 ce(s) haplotype, in the homozygous state, in compound heterozygosity with each other or in heterozygosity with a DcE haplotype. Genomic data were in accordance with serologic data.


CONCLUSIONS
Our data provide the evidence that anti-Hr(B) and anti-hr(B) are independent antibodies, defining two different specificities. These antibodies may be produced by individuals expressing variants of RhCE protein. Serologic and molecular data indicate that e antigen encoded by the (C)ce(s) haplotype is a partial antigen. In individuals carrying a (C)ce(s) haplotype, the risk and the type of alloimmunization to Rh antigens are related to the second Rh haplotype.
Pham
Bach-Nga
BN
Institut National de la Transfusion Sanguine, CNRGS-INSERM U665, Paris, France. bnpham@ints.fr
Peyrard
Thierry
T
Tourret
Séverine
S
Beolet
Marylise
M
Many
Hélène
H
Juszczak
Geneviève
G
Roussel
Michèle
M
Kappler-Gratias
Sandrine
S
Rouger
Philippe
P
Le Pennec
Pierre-Yves
PY
D005091:Exons / Q000235:genetics; D005260:Female; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007518:Isoantibodies / Q000097:blood* / Q000276:immunology; D008297:Male; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System / Q000097:blood* / Q000235:genetics* / Q000276:immunology
D007518:Isoantibodies; C066468:RHCE protein, human; D012204:Rh-Hr Blood-Group System