Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2015 Sep-Oct;37(5):316-9.
doi: 10.1016/j.bjhh.2015.07.002. Epub 2015 Jul 29.

Frequency of Wr(a) antigen and anti-Wr(a) in Brazilian blood donors

Janaína Guilhem Muniz  1 , Carine Prisco Arnoni  2 , Diana Gazito  2 , Rosangela de Medeiros Person  2 , Tatiana Aparecida de Paula Vendrame  2 , Flavia Roche Moreira Latini  2 , Lilian Castilho  3
Affiliations

Frequency of Wr(a) antigen and anti-Wr(a) in Brazilian blood donors

Janaína Guilhem Muniz et al. Rev Bras Hematol Hemoter. 2015 Sep-Oct.

Abstract

Background: Wr(a) is a low-incidence antigen, which is antithetical to the high prevalence red blood cell antigen, Wr(b). Anti-Wr(a) is a naturally occurring antibody that is found in approximately 1-2% of blood donors. The aim of this study was to determine the frequency of Wr(a) and anti-Wr(a) in Brazilian blood donors.

Methods: A total of 1662 Brazilian blood donors were molecularly analyzed using the SNaPshot methodology to determine the WR*A/B alleles and to predict the frequency of the Wr(a) antigen. To detect the anti-Wr(a), samples from 1049 blood donors were analyzed using a gel test with Wr(a+) red blood cells. The serum was treated with dithiothreitol (DTT) to determine the immunoglobulin classes. Immunoglobulin (Ig)-G isotype classification was performed in a gel test using the IgG1/IgG3 card. A monocyte monolayer assay was employed to predict the clinical significance of IgG anti-Wr(a).

Results: Of the 1662 donors, only one sample had the DI*02.03 allele in heterozygous predicting the Wr(a+b+) phenotype. Anti-Wr(a) was detected in 34 (3.24%) samples, 64.7% in females and 35.3% in males. Regarding the immunoglobulin class, eight (23.5%) cases of anti-Wr(a) were classified as IgG and 26 (76.5%) as IgM. Of the eight cases of IgG anti-Wr(a), four were IgG1, two were IgG3 and three anti-Wr(a) were not IgG3 or IgG1, and thus probably IgG2 or IgG4. The results of the monocyte monolayer assay showed that IgG anti-Wr(a) might be of clinical significance.

Conclusion: This study shows a very low frequency (0.06%) of the Wr(a) antigen in Brazilian blood donors. Additionally, it shows that the frequency of anti-Wr(a) in this population is higher than previously reported.

Keywords: Allele frequency; Anti-Wr(a); Diego blood group; Wr(a) antigen.

PubMed Disclaimer

Figures

Figure 1
Figure 1
GeneMapper electropherogram of representative SNaPshot fragment in the analysis of the Wr(a+) donor.
Figure 2
Figure 2
Monocyte monolayer assay slides (1000×). (A) Negative control and (B) Monocyte monolayer assay with anti-Wra.
See this image and copyright information in PMC

References

    1. Reid M.E., Lomas-Francis C., Olsson M.L. Third Edition. Academic Press; Elsevier: 2012. The blood group antigen facts book.
    1. Bruce L.J., Ring S.M., Anstee D.J., Reid M.E., Wilkinson S., Tanner M.J. Changes in the blood group Wright antigens are associated with a mutation at amino acid 658 in human erythrocyte band 3: a site of interaction between band 3 and glycophorin A under certain conditions. Blood. 1995;85(2):541–547. - PubMed
    1. Daniels G. 2nd ed. Blackwell Science; Bristol: 2002. Human blood groups.
    1. Wallis J.P., Hedley G.P., Charlton D., Parker P.C., Scott Y., Chapman C.E. The incidence of anti-Wra and Wra antigen in blood donors and hospital patients. Transfus Med. 1996;6(4):361–364. - PubMed
    1. Garratty G. Screening for RBC antibodies-what should we expect from antibody detection RBCs. Immunohematology. 2002;18(3):71–77. - PubMed

LinkOut - more resources