Increased Serologic Reactivity with Automated CMIA Testing and Its Implications for Deceased Donor Eligibility Determination in the United States

Background In the United States, the use of Food & Drug Administration (FDA)-licensed, approved, or cleared tests is required for infectious disease screening and determining the eligibility of deceased donors for all Human Cells, Tissues, and Cellular and Tissue-Based Products (HCT/Ps). With the discontinuation of two manual enzyme-linked immunoassay (EIA) tests, automated Chemiluminescent Microparticle Immunoassay (CMIA) technology was introduced as the primary alternative. This study compares serologic reactivity rates between manual EIA and automated CMIA methods. Methods Serology testing was performed on blood specimens from deceased tissue and cornea donors using either manual EIA assays or automated CMIA platforms. A retrospective analysis of approximately 140,000 donors was conducted to evaluate assay-specific reactive rates. Concordance between serology and Nucleic Acid Testing (NAT) results was also assessed. Results Reactive rates for HBsAg, HIV-1/2 antibodies, and HTLV-I/II antibodies increased following the transition to CMIA-based testing compared to manual EIA methods. However, these increases were not associated with a corresponding rise in NAT reactive results, indicating a potential increase in false-positive or non-viremic results. Conclusions Automated testing offers improved quality control and reduces variability associated with manual techniques. However, the shift to CMIA assays resulted in a higher number of reactive serology results, leading to increased donor ineligibility despite negative NAT results. The data presented here highlights the potential impact on donor deferral rates for tissue and cornea donors due to assay platform changes.