COOMBS TRỰC TIẾP DƯƠNG TÍNH Ở NGƯỜI HIẾN MÁU TOÀN PHẦN: TỶ LỆ, XU HƯỚNG VÀ KẾT QUẢ THEO DÕI TẠI BỆNH VIỆN TRUYỀN MÁU HUYẾT HỌC GIAI ĐOẠN 2020-2025

Abstract

Objective: To describe the prevalence, trends, and selected characteristics of blood donors with a positive Direct Antiglobulin Test (DAT) on packed red blood cell (PRBC) units prepared from whole blood donations at the Blood Transfusion and Hematology Hospital during 2020-2025.

Subjects and methods: A retrospective, cross-sectional descriptive analysis was conducted using internal follow up data. Data were collected at the Blood Transfusion and Hematology Hospital during 2020-2025. The analysis included blood donors whose whole blood derived PRBC units were recorded as DAT positive after confirmatory testing following hospital feedback reports. Follow up testing outcomes were analyzed among donors who returned for repeat testing and had documented repeat DAT results.

Results: Among 1.506.619 blood donation attendances, 1.169 DAT positive cases were recorded, corresponding to a prevalence of 0,078%. The prevalence of DAT positivity increased from 0,041% in 2020 to 0,090% in 2025, with a statistically significant trend (p<0,001). Among DAT positive cases, females accounted for 67,7%, donors aged under 30 years accounted for 42,3%, and blood group O accounted for 46,0%. A total of 469 donors returned for repeat DAT testing, of whom 244 remained DAT positive. Multivariable logistic regression among donors who returned for repeat testing showed that the 40-49 year age group and a repeat testing interval of 1-4 weeks were independently associated with persistent DAT positivity.

Conclusion: DAT positivity among blood donors was uncommon. However, it remains an important marker requiring ongoing monitoring to support donor safety management and transfusion safety. Repeat testing outcomes indicated that DAT positivity may persist in some cases, and earlier repeat testing was associated with a higher likelihood of persistent DAT positivity. Therefore, the timing of repeat testing should be considered when monitoring and interpreting repeat DAT results.