Zhang 2020a.

Study characteristics
Methods	Trial design: case series Type of publication: novel report in Chest journal Setting: hospitals in China Recruitment period: 30 January‐17 March 2020 Country: China  Language: English  Number of centres: 4 Trial registration number: NR (case series)  Date of trial registration: NR
Participants	Age: 31‐73 years  participant 1: 69; participant 2: 55; participant 3: 73; participant 4: 31 Gender: 2 male, 2 female participant 1: F; participant 2: M; participant 3: M; participant 4:  F Ethnicity: not stated Number of participants (recruited/allocated/evaluated): 4 Severity of disease: critical  Comorbidities: hypertension (participants 1 and 3), COPD (participant 2), chronic kidney impairment (participant 3), pregnancy (participant 4) Inclusion criteria: NR Exclusion criteria: NR Additional diagnoses: participant 1: bacterial pneumonia, fungal pneumonia, pneumorrhagia, ARDS, septic shock participant 2: ARDS participant 3: ARDS, renal failure, fungal pneumonia, multiple organ failure, septic shock, pneumorrhagia, cystorrhagia, GI bleeding, pneumothorax participant 4: ARDS, septic shock, multiple organ failure, cardiac failure, newborn death due to asphyxia, bacterial infection Previous treatments (e.g. experimental drug therapies, oxygen therapy, ventilation) participant 1: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha), antibacterial therapy, antifungal therapy, supportive care, IVIG, albumin, zadaxin, mechanical ventilation participant 2: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha 2a), noninvasive mechanical ventilation/high‐flow nasal cannula, corticosteroids (methylprednisolone)  participant 3: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha 2b, oseltamivir, ribavirin), mechanical ventilation, renal replacement therapy, antifungal therapy (caspofungin, voriconazole), venovenous ECMO participant 4: antiviral therapy (lopinavir‐ritonavir, ribavirin), mechanical ventilation, renal replacement therapy, antibacterial therapy (imipenem, vancomycin), caesarean section, venovenous ECMO
Interventions	CP therapy or hyperimmune immunoglobulin therapy: CP  Details of CP: Type of plasma: prepared from recovered patients, no other information provided Volume: 200‐2400 mL  participant 1: 900 mL  participant 2: 200 mL  participant 3: 2400 mL  participant 4: 300 mL  Number of doses: 1‐8 doses  participant 1: 3 doses (200 mL, 400 mL, 300 mL each)  participant 2: 1 dose  participant 3: 8 doses (each dose not stated) participant 4: 1 dose  Antibody test and antibody‐titre: NR Pathogen inactivated or not: NR RT‐PCR tested: NR Details of donors:  Gender: NR HLA and HNA antibody‐negative: NR Severity of disease: NR Timing from recovery from disease: NR RT‐PCR tested: NR Treatment details, including time of plasma therapy (e.g. early stage of disease): days 11‐41 admission participant 1: days 19, 29, 30 admission  participant 2: day 11 admission participant 3: day 15, 23, 27, 30, 32, 34, 38, 41 admission participant 4: day 19 admission For studies including a control group: comparator (type): none (not applicable)  Concomitant therapy:  participant 1: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha), antibacterial therapy, antifungal therapy, supportive care, IVIG, albumin, zadaxin, mechanical ventilation participant 2: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha 2a), noninvasive mechanical ventilation/high‐flow nasal cannula, corticosteroids (methylprednisolone)  participant 3: antiviral therapy (arbidol, lopinavir‐ritonavir, interferon alpha 2b, oseltamivir, ribavirin), mechanical ventilation, renal replacement therapy, antifungal therapy (caspofungin, voriconazole), venovenous ECMO participant 4: antiviral therapy (lopinavir‐ritonavir, ribavirin), mechanical ventilation, renal replacement therapy, antibacterial therapy (imipenem, vancomycin), caesarean section, venovenous ECMO Duration of follow‐up: up to 51 days  Treatment cross‐overs: none Compliance with assigned treatment: good (all compliant)
Outcomes	Primary study outcome: NR Primary review outcomes All‐cause mortality at hospital discharge:  reported Time to death: not applicable Secondary review outcomes Number of participants with grade 3 and grade 4 AEs, including potential relationship between intervention and adverse reaction (e.g. TRALI, transfusion‐transmitted infection, TACO, TAD, acute transfusion reactions): none Number of participants with SAEs: none Improvement of clinical symptoms, assessed through need for respiratory support at up to 7 days; 8‐15 days; 16‐30 days: yes (extubation date reported), 15 days post‐first plasma infusion (participant 1) and 22 days post‐first plasma infusion (participant 4), participant 2 already off respiratory support prior to plasma infusion, participant 3 remained in ICU up to the time of report writing 30‐day and 90‐day mortality: NR (all alive) Admission on the ICU: all in ICU at baseline  Length of stay on the ICU: NR  Time to discharge from hospital: 3 participants, 1  remained in ICU up to the time of report writing QoL‐ NR Additional study outcomes: viral load, antibody (ELISA), chest imaging results
Notes	Sponsor/funding: NR COIs: none disclosed Other: NR