COVID-19 convalescent plasma: interim recommendations from the AABB.

BACKGROUND: COVID-19 convalescent plasma (CCP) has emerged as a potential treatment for COVID-19. However, efficacy data and recommendations for its use are limited. METHODS: AABB commissioned a panel of experts to develop interim recommendations based on limited data to guide use of this scarce resource. The panel performed a literature review using the search terms "COVID-19," "SARS-CoV-2" and "convalescent plasma." The interim recommendations reflect a consensus of expert opinion. INTERIM RECOMMENDATION 1: When making risk benefit decisions, one should consider the risk of CCP as comparable to standard (SARS-CoV-2 non-immune) plasma. INTERIM RECOMMENDATION 2: CCP is optimally effective when transfused as close to symptom onset as possible. CCP is unlikely to provide benefit for patients with late-stage disease or on mechanical ventilation. INTERIM RECOMMENDATION 3: The effectiveness of CCP is related to the antibody quantity within a unit; high-titer CCP is superior to low-titer CCP. A single high-titer unit should be sufficient for most patients. INTERIM RECOMMENDATION 4: If group B or group AB CCP is unavailable, transfusion of group A or group O CCP with low anti-A/B titer may be acceptable for group B and group AB patients. INTERIM RECOMMENDATION 5: Additional randomized controlled trial (RCT) data are needed to fully assess CCP efficacy and to identify which specific patient populations and unit characteristics might confer the greatest benefit. CONCLUSIONS: These interim recommendations are based on the best-available evidence at the time of writing. Additional data from on-going RCTs will lead to clinical practice guidelines in the future.