Abstract: Objective To analyze the direct antiglobulin test (DAT) positive rate, demographic distribution, characteristics of irregular antibodies, and donation frequency among voluntary whole blood donors in Nanchong City from 2011 to 2025, providing a basis for donor health management and transfusion safety. Methods A retrospective analysis was conducted on DAT-positive voluntary whole blood donors in Nanchong City from January 1, 2011 to December 31, 2025. The DAT positive rate was calculated, differences between gender and age groups were compared, The types of irregular antibodies, agglutination intensity, and donation frequency were analyzed. Results Among 316 443 whole blood donations over 15 years, 395 were DAT positive (0.125%). The positive rate in females (0.182%) was significantly higher than that in males (0.074%) (P<0.001), with the highest rate observed in females aged 40~49 (0.374%) (P<0.001). The detection rate of irregular antibodies among DAT-positive donorls was 7.087%, predominantly autoantibodies (16 cases), with no significant difference between genders (P>0.05). Agglutination intensity was mainly 2+ (42.391%) and 1+ (29.348%), with only 3 female cases showing 4+ intensity. Among DAT positive individuals, first-time donors accounted for the largest proportion (45.316%), and the positive rate decreased with increasing donation frequency. Conclusion The DAT positive rate among voluntary whole blood donors in Nanchong area is relatively low, with higher rates in 40~49 years female group. Most DAT positive cases exhibit weak to moderate agglutination intensity. The detection rate of irregular antibodies in DAT positive individuals is higher than that in the general blood donor population. DAT positive status is most common among first-time blood donors. Enhanced screening and follow-up for DAT positivity in this population are recommended to safeguard donor health and clinical blood transfusion safety.

Key words: Voluntary blood donors, Direct antiglobulin test, Irregular antibodies