RHCE variants inherited with altered RHD alleles in Brazilian blood donors.
BACKGROUND
The high homology and opposite orientation of RH genes promote rearrangements between them and generate a large number of RHD and RHCE variants which can be inherited together. Searching of RHD-CE genotypes predicting partial antigens in donors is of interest in order to find more closely matched donors for African descent patients. This study aimed to evaluate a molecular approach to search for RhCE variants in a cohort of individuals with altered expression of D antigen and determine the association of RH variant alleles in Brazilian blood donors.


METHODS
From 80,961 blood samples tested, 421 with atypical D typing results were studied. The samples were phenotyped for C, c, E, e antigens. Rh variants were identified using molecular techniques.


RESULTS
All 421 samples had altered RHD alleles, being 56·3% of them partial D. Among them, 94·9% presented variant RHCE*ce and the most common associations were: RHD*weak D type 4.2.2 with RHCE*ceAR; RHD*DAR linked to RHCE*ceVS.02; RHD*weak D type 4.0 linked to RHCE*ceVS.02 and RHCE*ce (c.48C, c.105T, c.733G, c.744C, c.1025T). Among the samples with RhCE variants, 10·6% predict partial c, partial e, hr(B) - and/or hr(S) - and 100% express low prevalence antigens.


CONCLUSIONS
Targeting individuals with altered expression of D antigen can be a good strategy for finding donors with RhCE variants. In our study 94·9% of the partial D samples revealed altered RHCE variant alleles and 5·7% of the samples with altered RHD allele predicted partial c, partial e and the lack of the high prevalence hr(B) and hr(S) antigens.
Technical scientific department Colsan - Associação Beneficente de Coleta de Sangue, São Paulo, SP, Brazil. carine.arnoni@colsan.org.br.
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Prisco Arnoni
Technical scientific department Colsan - Associação Beneficente de Coleta de Sangue, São Paulo, SP, Brazil.
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Guilhem Muniz
Technical scientific department Colsan - Associação Beneficente de Coleta de Sangue, São Paulo, SP, Brazil.
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de Paula Vendrame
Technical scientific department Colsan - Associação Beneficente de Coleta de Sangue, São Paulo, SP, Brazil.
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de Medeiros Person
Technical scientific department Colsan - Associação Beneficente de Coleta de Sangue, São Paulo, SP, Brazil.
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Roche Moreira Latini
Molecular Immunohematology Laboratory Hemocentro - Unicamp, Campinas, SP, Brazil.
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Castilho
D000483:Alleles; D001782:Blood Donors; D001938:Brazil; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D060005:Genotyping Techniques; D006801:Humans; D008297:Male; D012204:Rh-Hr Blood-Group System / Q000097:blood / Q000235:genetics
C066468:RHCE protein, human; D012204:Rh-Hr Blood-Group System; C026410:Rho(D) antigen
Rh variants; RhCE alleles; blood group genotyping; partial RhD