Individual longitudinal evolution before and after CPT. Individual longitudinal evolution of temperature (A), inflammation biomarkers [CRP (B), ferritin (C), IL-6 (D)], and SARS-CoV-2 RT-PCR (E) and viral load assessed using ddPCR (F). (D) IL-6 was assessed in 5 patients at days −5 and +7, considering days 0 and +1 the days of CPT. (F) ddPCR was assessed in 9 patients with a sensitivity threshold of 1.17 log (copies per milliliter), represented by the dashed line. (G) Lymphocyte immunophenotyping (T, natural killer [NK], and B lymphocytes) at baseline was assessed by flow cytometric analysis. The expression of CD3, CD19, and CD16/CD56 was used to quantify T cells, B cells, and natural killer cells, respectively. (H) Quantification of peripheral SARS-CoV-2–specific T lymphocytes in 3 patients (P1, P2, and P3) prior to plasma transfusion. Results are expressed as the number of spot-forming cells (SFC) per million circulating CD3⁺ T lymphocytes. CFX1, positive control peptide pool; COV-S1, Spike glycoprotein S1; COV-S2, Spike glycoprotein S2; NCAP, nucleoprotein; PHA, phytohemagglutinin A (positive control mitogen); VME1, membrane protein.