Serological analysis of anti-K and anti-Wra detected in patient treated with daratumumab: a case report / 中国输血杂志

【Objective】 To investigate the reasonable serological detection method by analyzing the characteristics of anti-K and anti-Wra from a patient who received treatment with daratumumab. 【Methods】 Unexpected antibody screening and identification were performed by saline method, polybrene, cardioagglutinin, dithiothreitol (DTT) treatment, trypsin treatment and papain treatment in the patient's plasma and acid elution solution. Heat elution test was detected after absorbing patient serum with K antigen negative red blood cells. The characteristics of antibodies were analyzed and their titer was continuously detected. Cross matching was performed after excluding interference of daratumumab. 【Results】 Anti-K and anti-Wra were detected in saline and polybrene in the patient's plasma. The patient's elution solution contained daratumumab. DTT or trypsin treatment excluded interference of daratumumab but papain treatment did not. DTT treatment destroyed K antigen and missed the detection of IgG antibodies in the Kell system. Trypsin treatment did not affect K antigen and can detect IgG antibodies of Kell system(anti-k)in the serum of the patient treated with daratumumab. Anti K was IgM and the titer was 4 by saline method and it decreased to no agglutination in room temperature after 39 days. Anti-Wra was IgG and the titer by polybrene method was 4, and it decreased to 1 after 39 days. After 76 days, neither anti-K nor anti-Wra could be detected. Transfusions of K and Wra antigen negative red blood cells were safe and effective. 【Conclusion】 DTT treatment can exclude interference of daratumumab, but attention should be paid to missed detection of anti-K. To avoid interference of daratumumab and identify unexpected antibody, multiple methods such as DTT treatment, polybrene and trypsin treatment in combination are recommended.

Antigen profile and antibody frequency of Wra in voluntary blood donors in Shaanxi province, containing 2 clinical cases of anti-Wra identification / 中国输血杂志

【Objective】 To understand the antigen profile and antibody frequency of Wra in voluntary blood donors in Shaanxi province. 【Methods】 Wra antigen and antibody screening as well as blood group typing and antibody identification were performed by serological tests and confirmed by genetic testing. 【Results】 The incidence of Wra antigen in 7 490 voluntary blood donors was 0.013%(1/7 490), and the frequency of anti-Wra in 729 voluntary blood donors was 0.823%(6/729). 【Conclusion】 This study explored the polymorphism of Wra antigen and antibodies in blood donors, which is informative in the risk assessment of blood transfusion and the screening and identification of respective antibodies.

Frequency of Wra antigen and anti-Wra in Brazilian blood donors

BACKGROUND: Wra is a low-incidence antigen, which is antithetical to the high prevalence red blood cell antigen, Wrb. Anti-Wra 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 Wra and anti-Wra 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 Wra antigen. To detect the anti-Wra, 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-Wra.RESULTS: Of the 1662 donors, only one sample had the DI*02.03 allele in heterozygous predicting the Wr(a+b+) phenotype. Anti-Wra 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-Wra were classified as IgG and 26 (76.5%) as IgM. Of the eight cases of IgG anti-Wra, four were IgG1, two were IgG3 and three anti-Wra were not IgG3 or IgG1, and thus probably IgG2 or IgG4. The results of the monocyte monolayer assay showed that IgG anti-Wra might be of clinical significance.CONCLUSION: This study shows a very low frequency (0.06%) of the Wra antigen in Brazilian blood donors. Additionally, it shows that the frequency of anti-Wra in this population is higher than previously reported.

First case of Anti-Wra antibody in Korea / 대한수혈학회지

Authors found anti-Wra antibody in a 44-year-old female patient with uterine myoma for the first time in Korea. Since anti-Wright antibodies have been implicated in hemolytic transfusion reactions and hemolytic disease of the newborn, Wra positive cells should be included in the antibody screening panel in Korea.