Abstract: Objective To assess the miss detection rate (MDR) and frequency of the D variant among RhD negativeblood donors in Taiyuan. Methods From January 2013 to December 2021, 6 287 RhD negativeblood samples, initially screened, were collected. These samples were further confirmed using the tube antiglobulin test or microcolumn gel card method. RhD genotyping was done on the 17 specimens which showed discrepancies with previous testresults or the manufacturer's specifications for the primary screening reagent. By analyzing the number of D variant donors, blood donations and missed detections, the theoretical MDR and frequency of D variant were calculated in the RhD negativeblood samples from the primary screening. Results Between January 2013 and December 2021, the detection rate of D variant in the 6 287 RhD negative samples (including repeat donors) by preliminary screening was 5.36%（337/6 287）. Statistical analysis of 59 D variant blood donors who donated more than once revealed that theoretically, 5.37% of D variants were missed. Considering the MDR, the theoretical frequency of D variant in the RhD negative population from the preliminary screening was 7.68%. Conclusion Some D variant blood donors were missed in the conventional test. The theoretical MDR and frequency of D variant in the RhD negative samples by primary screening align more closely with the actual situation.

Key words: RhD negative, D variant, D variant miss detection rate, Repeat blood donor