Exploration of the Serological Characteristics of Patients with Positive Direct Antiglobulin Test

doi:10.3969/j.issn.1004-5775.2025.17.019

Abstract：Objective: To explore the serological characteristics of patients with positive direct antiglobulin test. Methods: A total of 92 patients diagnosed with positive direct antiglobulin test and clinically diagnosed with autoimmune hemolytic anemia at the First Affiliated Hospital of Henan University of Science and Technology from August 2022 to February 2024 were selected as the study subjects. All patients underwent direct antiglobulin test, antibody identification, and cross-matching tests. The agglutination intensity of the direct antiglobulin test was analyzed, and the classification of direct antiglobulin test, blood group identification results, and cross-matching test results of all patients were analyzed. Results: Among the 92 patients, 29 had weak agglutination, 27 had 1+, 34 had 2+, and 2 had 3+. Among the 92 patients, 47 had IgG + C3d type, 28 had pure IgG type, and 17 had pure C3d type. Among the 92 patients with positive direct antiglobulin test, 71 had ABO blood group incompatibility between forward and reverse typing, and 57 had red cell and serum agglutination. Among the 92 patients with positive direct antiglobulin test, 76 had incompatible cross-matching, 29 of whom were due to cold antibodies, 15 due to cold agglutinin titer above 1:256, and 32 due to cold agglutinin titer above 1:128. Conclusion: For patients with positive direct antiglobulin test, while performing direct antiglobulin typing, it is also necessary to conduct allogeneic antibody identification tests, and select appropriate blood according to the test results. When performing blood group identification for patients with positive direct antiglobulin test, cold antibody absorption test, ether elution test, etc., can be used to improve the compatibility rate of cross-matching.