Optimization of the antibody identification interval in a high‐volume transfusion centre

BACKGROUND AND OBJECTIVES: No established standards currently exist regarding the optimal interval for repeating antibody identification. Considering both transfusion safety and resource constraints, this study aimed to investigate the feasibility of extending the interval between antibody identification tests in a high-volume transfusion setting. MATERIALS AND METHODS: We retrospectively reviewed 153,526 records over a 7-year period in which antibody identification was repeated at 7-day intervals under current practice. Cases with autoantibodies, non-specific antibodies, drug-related antibodies, passive anti-D from Rhesus immunoglobulin (RhIG) or unidentified antibodies were excluded. Time intervals to newly detected antibodies (0-7, 8-14, 15-21 and 22-30 days) were analysed in transfused patients with at least one pre-existing antibody. RESULTS: A total of 5806 antibodies were detected from 4835 patients (3.15%). Of these, 217 antibodies were detected in 155 patients (3.21%) who were known to previously possess at least one antibody. Antibody development was most frequently detected at 8-14 days post transfusion (16 cases, 35.56%), followed by 22-30 days (14 cases, 31.11%), 15-21 days (10 cases, 22.22%) and 0-7 days (5 cases, 11.11%). The median time to new antibody detection was 15.5 days (interquartile range, 10-26 days). CONCLUSION: This study proposes an optimal interval for antibody identification in settings with a high prevalence of transfusion-dependent patients and resource constraints. A 14-day interval has the potential to reduce personnel workload and costs while maintaining transfusion safety.