Recommendations Regarding Practical DEL Typing Strategies for Serologically D-Negative Asian Donors

• Published in: Transfusion medicine and hemotherapy 2020-02, Vol.47 (1), p.88-93
• Main Authors: Kim, Tae Yeul, Hong, Yun Ji, Kim, Mi Jung, Kim, Hyungsuk, Kim, Taek Soo, Park, Jeong Su, Park, Kyoung Un, Han, Kyou-Sup
• Format: Article
• Language: English
• Subjects: Research Article
• ISSN: 1660-3796; 1660-3818
• DOI: 10.1159/000500098

Background: DEL, the weakest D variant, is mistyped as D-negative by routine serological assays. Transfusion of red blood cells expressing the DEL phenotype has the potential to elicit anti-D alloimmunization in D-negative recipients. The goal of this study was to recommend DEL typing strategies for serologically D-negative Asian donors. Methods: RhCE phenotyping and the adsorption-elution test were performed on 674 serologically D-negative samples. RHD genotyping using real-time polymerase chain reaction and melting curve analysis were also undertaken to identify DEL alleles. Costs and turnaround time of RhCE phenotyping, the adsorption-elution test, and RHD genotyping were estimated. Results: Sensitivity and specificity of the adsorption-elution test for serologically D-negative samples were 94.9% (93/98) and 91.5% (527/576), respectively. C+ phenotypes were detected in all 98 samples with DEL alleles. Despite comparable costs, RHD genotyping was more accurate and rapid than the adsorption-elution test. Conclusions: Two practical DEL typing strategies using RhCE phenotyping as an initial screening method were recommended for serologically D-negative Asian donors. Compared with DEL typing using RHD genotyping, serological DEL typing using adsorption-elution test is predicted to increase the incidence of anti-D alloimmunization and decrease the D-negative donor pool without having any cost-competitiveness but can be used in laboratories where molecular methods are not applicable.