Discussion
We report herein an observational cohort of immunosuppressed patients, mostly with HM (almost all with B lymphoid disease), infected by the Omicron subvariants BA.1 or BA.2, and treated with CCP. The 28-days OS for the whole cohort was 76% (CI = 65-84) without differences according to the type of immunosuppression whereas the severity of COVID-19 at the time of CCP infusion greatly impacts the outcome. Indeed patients with high flow oxygen had a poor outcome despite CCP infusion with 53 % 28-days OS.
Early in the pandemic, our team reported the interest of CCP in B-depleted patients such as patients with CLL or treated with rituximab11. Despite the efficacy of CCP in such patients our results are quite disappointing. Indeed, in the recent observational study from the EPICOVIDEHA registry, mortality rate among hospitalized HM patients infected with Omicron was 16.5% that reaches 23% 30-day mortality in patients with chronic lymphoid leukemia (CLL)10. Is to note that in our cohort, 32 % of patients needed high flow oxygen at the time of CCP infusion that could explain the mitigate response after CCP infusion. The beneficial effect of CCP was also described in patients with primary antibody deficiency with a clinical improvement and a decreasing of the viral load12. Concerning SOTR, few data are available with two relevant series of 10 and 13 patients reporting the feasibility of CCP with a mortality rate of 10 and 23% respectively linked to COVID-1913,14.
To date, the time of CCP infusion remains debated. While B-depleted patients with high oxygen need and treated with CCP had a poor outcome7, it could be interesting in similar patients with prolonged COVID-1911. Indeed, clinicians must distinguish patients with protracted disease as “smoldering COVID” from patients presenting with aggressive course. Besides the time between CCP infusion and the symptoms onset, the disease course should be informative and must be take into account in the decision to use CCP.
In a context of urgent need for therapeutic options when new SARS-CoV-2 variants emerge and escape current monoclonal antibodies, CCP remains an interesting treatment option for immunosuppressed patients whatever the underlying disease. Furthermore, some effort must be made to better anticipate disease course that should guide the timing of CCP infusion.