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Abstract

Blood Center/Blood Hospital-Based Donor Center

Oral Abstract - Blood Safety Evaluation

OA4-AM24-ST-27 - Prevalence of Anti-HBs In Anti-HBc Only Reactive Blood Donors – Implications For A Strategy To Mitigate Donor Deferral And Donation Discard

Saturday, October 19, 2024

1:45 PM - 2:45 PM

Location: 362

CE: Zero

Presenting Author(s)

GO

Guillermo Orjuela, MD, MS (he/him/his)

Medical Director LATAM
Abbott, Distrito Capital de Bogota, Colombia

Disclosure(s): Abbott: Full-time/Part-time Employee or Owner (Ongoing), Stock Shareholder (self-managed) (Ongoing)

PDF

Disclosure(s):

Guillermo Orjuela, MD, MS: Abbott: Full-time/Part-time Employee or Owner (Ongoing), Stock Shareholder (self-managed) (Ongoing)

Background/Case Studies: Anti-HBc detection is one of the primary causes of serology-mediated exclusion of donors and donations. False reactive, but also non-infectious true positive anti-HBc donors, could be reinstated after further testing, reducing the proportion of discarded donations and donor deferrals. An alternative algorithm for HBV screening in blood donors was successfully introduced in Japan, whereby some anti-HBc reactive donors can be eligible to donate depending on results of anti-HBs titers and HBV-DNA detection, maintaining the level of safety of the blood supply. This study aimed to assess the prevalence and distribution of anti-HBs titers among anti-HBc reactive, HBV-NAT negative donors at one regional blood center in Brazil.

Study

Design/Methods: From January to December 2022, HBsAg and HBV-NAT (MP6) negative blood donors with anti-HBc reactive or inconclusive results were invited to return to the blood center for medical counselling and further testing. A second sample was taken and re-tested for anti-HBc using the same screening assay (Alinity s, Abbott) and anti-HBs titers were quantified in persistently reactive samples using the Abbott Architect assay. Individuals with high anti-HBs titers (>200mUI/mL) were categorized as not infectious. Demographic information from this population was also captured.

Results/Findings:

A total of 126,409 donations were analyzed during 2022. The reactive rate for anti-HBc was 0.88%. During the timeframe of the study, 847 anti-HBc(+), HBsAg(-) and HBV NAT(-) blood donors returned to the blood center for further testing. Anti-HBc was persistently reactive in 649 (76.6%, 95%CI 73.7-79.4) of these samples, which ultimately underwent anti-HBs quantification. Anti-HBs titers were < 10UI/mL in 130 (20.0%, 95%CI 17.1-23.3) donors, >10-200UI/mL in 123 (19.0%, 95%CI 16.1-22.2) and >200mUI/mL in 396 (61.0%, 95%CI 57.2-64.7). Not infectious individuals were mainly men (59.9%) from the metropolitan region (44%), with a median age of 44 years (IQR=13). In this subgroup, the mean anti-HBs titer was significantly higher in women than men (866.57 UI/mL vs 772.70 UI/mL, p< 0.01).

Conclusions:

Approximately 23% of anti-HBc only reactive donors were likely false positives and could be reinstated for future donations. Among probable true anti-HBc donors without HBV-NAT, more than 60% had anti-HBs titers above a safety threshold of 200mUI/mL, making them optimal candidates for an acceptance or re-entry program, ideally coupled with ID-NAT. Taking together, these strategies could potentially reduce anti-HBc related discards and donor deferrals by almost 70% in this population.