COVID-19 convalescent plasma: interim recommendations from the AABB.
Cohn CS., Estcourt L., Grossman BJ., Pagano MB., Allen ES., Bloch EM., Casadevall A., Devine DV., Dunbar NM., Foroutan F., Gniadek TJ., Goel R., Gorlin J., Joyner MJ., Metcalf RA., Raval JS., Rice TW., Shaz BH., Vassallo RR., Winters JL., Beaudoin G., Tobian AAR.
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.