Long-term serologic follow-up of blood donors with biologic false reactivity on an anti-human T-cell lymphotropic virus Types I and II chemiluminescent immunoassay and implications for donor management

BACKGROUND: This study reports the results of the long‐term serologic follow‐up of blood donors who gave an index biologic false‐reactive (BFR) result on an anti‐human T‐lymphotropic virus Types I and II (HTLV‐I and ‐II) chemiluminescent immunoassay (ChLIA). STUDY DESIGN AND METHODS: All allogeneic whole‐blood and apheresis donors who gave an index BFR result on a HTLV‐I and ‐II ChLIA between May 10, 1997, and December 31, 2004, were included in the study. Donors were followed up for an additional 2 years until December 31, 2006. RESULTS: A total of 332 donors gave an index BFR donation during the study period. Donors were divided into five groups based on results of donations subsequent to the index BFR donation: 89 (26.8%) donors gave only nonreactive donations subsequent to the index BFR result, 56 (16.9%) donors gave only BFR donations, 43 (13.0%) gave one or more subsequent BFR donations before giving only nonreactive donations, 59 (17.8%) donors gave intermittent BFR and nonreactive donations, and 85 (25.6%) donors gave no further donations during the study period. The estimated mean duration of biologic false reactivity from the time of the index BFR donation in donors who gave only a single BFR result was 7.0 (1.4‐42.75) months and 23.3 (4.1‐92.25) months in those donors who gave several BFR results before giving nonreactive donations. Modeling of the data indicated that notification and deferral of donors after two consecutive BFR donations would result in the deferral of 143 of 332 (43.1%) of donors with an index BFR result while allowing donors to give three BFR results would reduce the number of deferred donors to 74 of 332 (22.3%). CONCLUSION: The results of this study indicate that although biologic false reactivity is usually transient, the time for resolution is variable. Allowing donors to give two or three BFR results before notification and deferral is one strategy that would substantially reduce the number of donors requiring deferral.