Invalid Nucleic Acid Test Results May Limit Deceased Donor Organ Utilization

BACKGROUND: Nucleic acid testing (NAT) is essential for detecting transmissible viral infections in deceased organ donors and guiding safe organ allocation. However, invalid discriminatory NAT (dNAT) results may lead to unnecessary donor exclusion and reduced organ availability. METHODS: We performed a retrospective analysis of HIV-1/2, HBV, and HCV NAT results from deceased organ donors in the United States. Donor specimens were tested at eleven laboratories using FDA-approved donor screening assays. Donor serologic results and organ utilization outcomes were reviewed to evaluate the clinical impact of invalid dNAT results. RESULTS: Invalid dNAT results occurred in 0.027% of donor cases (n = 27), predominantly in cases suggestive of HCV infection (n = 22). Although infrequent, these cases had a disproportionate impact on organ utilization. Serologic findings frequently supported true infection despite unresolved NAT results. Repeat testing did not resolve these cases and extended result reporting times by a median of 22 h. In 30% of cases (n = 6) in which organ utilization was available, organs were not transplanted, reflecting uncertainty in infectious risk assessment. CONCLUSION: Although rare, invalid dNAT results have clinical and operational consequences, contributing to delays, conservative donor classification, and reduced organ utilization. These findings highlight the need for standardized reporting of invalid results and access to rapid alternative confirmatory testing to support informed clinical decision-making and reduce unnecessary organ discard.