献血者DAT阳性的流行病学特征、转归分析及管理策略OA

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 dona-tion data from 808 386 donors from 2013 to 2023,focusing on those whose blood was discarded due to DAT positivity.Fol-low-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 agglutina-tion 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 in-tensity≥2+(P<0.001).Unexpected antibodies(anti-E,anti-M,etc.)were detected in 18 cases.Methodological differ-ences: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 microcol-umn 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 infu-sion.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 retest-ing,while those with≥2+intensity should be permanently deferred.