Methods
We retrospectively analyzed the data from a nationwide, observational
and multicentric study based on the French CCP Early Access Program.
Between December 29th 2021 and March 16th 2022, 32 centers located in
France requested the use of CCP during the SARS-CoV-2 Omicron variant
wave. Due to underlying disease or treatment administered, patients with
hematological malignancy (HM), solid organ transplanted recipients
(SOTR) or those treated for autoimmune disease (AID) were considered
immunosuppressed and eligible for CCP early access program. Infection
with a B1 or BA.2 SARS-CoV-2 subvariants was documented on
nasopharyngeal swab. We considered a threshold of positivity for
anti-Spike antibodies of > 260 BAU/mL, as the ability of
vaccines to prevent severe forms of COVID-198. Every
patient was informed of the study protocol and none refused to
participate. Data was anonymized according to the French Law and ethical
clearance was obtained from the French Infectious Diseases Society
(CER-MIT 2022-0702).
We administered two consecutive transfusions of two ABO compatible high
titers convalescent plasma units (200-220 mL each) at days 0 and 1.
Transfused CCP were initially provided by pre-Omicron convalescent
vaccinated donors with very high anti-spike IgG ratio (> 9,
ELISA Euroimmun) to ensure anti-Omicron seroneutralization
ability9 and after mid-January 2022 by Omicron
convalescent vaccinated donors with high-anti spike IgG ratio
(> 6, ELISA Euroimmun). The primary outcome was the overall
survival (OS) at day 28 after plasma infusion (d28).