Molecular HPA genotyping by microarray in B razilian blood donors

• Published in: Transfusion (Philadelphia, Pa.) Vol. 54; no. 2; pp. 405 - 411
• Main Authors: Conti, Fabiana, Bertrand, Gerald, Dezan, Marcia, Costa, Thiago, Aravechia, Maria, Mota, Mariza, Castilho, Lilian, Kaplan, Cécile, Kutner, José
• Format: Journal Article
• Language: English
• Published: 01-02-2014
• ISSN: 0041-1132; 1537-2995
• DOI: 10.1111/trf.12272

Background
H
uman platelet antigens (
HPA
) polymorphisms may cause
HPA
alloimmunization, platelet (PLT) refractoriness, fetomaternal alloimmune thrombocytopenia, and posttransfusion purpura. Characterized by significant racial admixture, the
B
razilian population might benefit from the knowledge about
HPA
frequency to guide decision‐making concerning PLT transfusion.
Study Design and Methods
HPA
frequencies were determined in 158
DNA
samples from
B
razilian blood donors by microarray for
HPA
‐1 to ‐9, ‐11, and ‐15. A
HPA
‐2 discrepancy was solved by polymerase chain reaction with sequence‐specific primers (
PCR‐SSP
) and sequencing.
Results
While
a
alleles were predominant for
HPA
‐1 to ‐9 and ‐11,
b
alleles were absent for
HPA
‐6, ‐7, ‐8, and ‐11.
HPA
‐3 and
HPA
‐15 had a higher prevalence of
ab
genotypes. One case of
HPA
‐
4ab
and two cases of
HPA
‐
9abw
were detected, the latter not previously described in
B
razilian blood donors. One sample was not interpretable for
HPA
‐2 due to a
GPIb
468
C
>
G
mutation; this donor was characterized as
HPA
‐2
ab
by
PCR‐SSP
and sequencing.
Conclusion
Allele frequencies were comparable to those described in other
B
razilian studies. Rare
HPA
‐9 alleles were described in
B
razilians for the first time. A mutation near the
HPA
‐2 polymorphism suggests that complementary methods might be necessary in specific cases. PLT genotyping by microarray proved to be fast, accurate, and reliable.