[Study on the effect of direct anti-human globulin test positive strength on patients' red blood cell transfusion]

Objective: To investigate the effect of direct antiglobulin test (DAT) positive strength on the clinical effect of red blood cell transfusion. Methods: The clinical data was collected on blood transfusion compatibility test and clinical transfusion of patients who underwent DAT testing from January 2015 to March 2019 in the Department of Blood Transfusion, Beijing Shijitan Hospital affiliated to Capital Medical University. A retrospective cohort study method was used to analyze the correlation between the DAT positive strength and the blood match results, irregular antibody test results, bilirubin value after blood transfusion, and red blood cell transfusion effect. Results: According to the blood matching test results, the minor cross-matching results were significantly correlated with the DAT strength (r=0.58, P<0.01). The DAT strength of the antibody-screening positive patients was greater (χ(2)=126.810, P<0.01). DAT-positive strength influences the direct bilirubin, the higher the DAT-positive strength, the higher the direct bilirubin concentration of the patients (χ(2)=32.069, P<0.01). DAT-positive strength also had an effect on patients' total bilirubin value (χ(2)=17.981, P=0.001). From the effect of red blood cell transfusion, patients with a DAT positive strength of 0.5 had a lower effective rate of transfusion (28.6%). The remaining DAT strength had no relation to the effect of red blood cell transfusion, and the efficiency of blood transfusion in patients with different DAT-positive strengths (1, 2, 3, 4) was 57.0%, 60.1%, 65.6% and 60.0%, respectively. With the same DAT strength, the patient's transfusion efficiency was higher (χ(2)=41.071, P=0.009). Conclusion: Different DAT-positive strengths are correlated with the patient's minor cross-match results and bilirubin content, while the effect of red blood cell transfusion has no significant correlation with DAT-positive strength. However, with the increase of DAT positive strength, patients are more likely to have irregular antibodies.