Epidemiological characteristics, outcome analysis, and management strategies for DAT-positive blood donors
10.13303/j.cjbt.issn.1004-549x.2026.03.008
- VernacularTitle:献血者DAT阳性的流行病学特征、转归分析及管理策略
- Author:
Shiyu YIN
1
;
Zhihua XU
1
;
Xueqin GENG
1
;
Zhuan LIU
1
;
Hongliang HUANG
1
Author Information
1. Yancheng Blood Center, Yancheng 224005, China
- Publication Type:Journal Article
- Keywords:
blood donors;
direct antiglobulin test (DAT);
red blood cell;
follow-up;
management strategies
- From:
Chinese Journal of Blood Transfusion
2026;39(3):360-366
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To investigate the epidemiological characteristics, outcome patterns, and management strategies for blood donors with a positive direct antiglobulin test (DAT). Methods: A retrospective analysis was conducted on donation data from 808 386 donors from 2013 to 2023, focusing on those whose blood was discarded due to DAT positivity. Follow-up was performed on 125 DAT-positive donors, and 98 blood samples were collected. The samples were re-tested for DAT, DAT typing (IgG/C3d), and unexpected antibody screening using both the tube method and the microcolumn gel method. Results: Epidemiological characteristics: Retrospective data revealed 147 DAT-positive blood donors, yielding a positivity rate of 1/5 500. The DAT positivity rate using the tube method was 0.118‰ (49/416 893), lower than that of the microcolumn gel method at 0.25‰ (98/391 493). Among DAT-positive individuals, 44.2% (65/147) exhibited agglutination intensity<2+. Outcome analysis: The proportion of donors with positive DAT test results that converted to negative was 54.1% (53/98), with a conversion interval ranging from 8 to 117 months (mean 49.9 months). All donors in the negative conversion group had a previous DAT intensity<2+, whereas 95.6% (43/45) of the non-negative conversion group had intensity ≥2+ (P<0.001). Unexpected antibodies (anti-E, anti-M, etc.) were detected in 18 cases. Methodological differences: Review of results revealed 35 cases positive by both the DAT tube assay and microcolumn gel method. An additional 10 cases were positive by only one method: 5 were positive only by the tube assay, and 5 were positive only by the microcolumn gel method. Clinical validation: Among 14 DAT-positive donors who became negative and donated blood again, the clinical infusion efficacy of red blood cell products could be assessed in 10 cases, with 9 cases demonstrating effective infusion. Conclusion: Some DAT-positive blood donors may naturally convert to negative status, with the intensity of previous test results potentially serving as a key predictive factor for conversion. It is recommended to employ a combined approach of tube-based and microcolumn gel-based methods for retesting, concurrently screening for irregular antibodies. A tentative tiered management strategy is proposed: individuals with DAT intensity <2+ should be deferred for 12 months before retesting, while those with ≥2+ intensity should be permanently deferred.
