Establishment and application of a new method for the detection of drug antibodies by flow cytometry.

Background: The drug antibodies can seriously affect the efficacy of the drug and/or destroy red blood cells (RBCs). In severe cases, the drug antibodies may lead to hemolytic anemia, ineffective transfusion, and even life-threatening conditions. However, current methods for detecting drug-induced antibodies present several limitations: cumbersome operational workflows, time-consuming processes, suboptimal sensitivity for low-titer antibodies, and ease of disturbance by autoantibodies and erythrocyte alloantibodies. Therefore, there is an urgent need for a drug antibody detection method with operational simplicity, ultrahigh sensitivity, and interference resistance.

Methods: Blood samples were collected from patients with drug-induced immune hemolytic anemia (DIIHA). Based on the established assay protocol, nine reaction systems were prepared and sequentially analyzed by flow cytometry. The results of flow cytometry were used to determine the presence or absence of drug antibodies, identify the specific type of drug antibody, and assess the antibody titer.

Results: Different drug antibodies, including ceftriaxone, cefoperazone, and amoxicillin, were identified in all six patients with DIIHA. Upon discontinuation of the implicated antibiotics, the efficacy of blood transfusions in those six patients showed significant improvement.

Conclusions: This approach offers several advantages, including ease of operation, rapid detection time, high specificity and sensitivity, and excellent interference resistance. This new approach will be suitable for determining drug antibodies in clinical laboratories.