Convalescent plasma treatment is associated with lower mortality and better outcomes in high risk COVID-19 patients – propensity score matched case-control study

Tworek, Adam; Jaroń, Krzysztof; Uszyńska-Kałuża, Beata; Rydzewski, Andrzej; Gil, Robert; Deptała, Andrzej; Franek, Edward; Wójtowicz, Rafał; Życińska, Katarzyna; Walecka, Irena; Cicha, Małgorzata; Wierzba, Waldemar; Zaczyński, Artur; Król, Zbigniew J.; Rydzewska, Grażyna

Objective The aim of the study was to investigate efficacy and safety of convalescent plasma (CP) transfusion in a group of high-risk COVID-19 patients. Methods This prospective study included 204 patients from a single tertiary-care hospital, hospitalized with COVID-19, of whom 102 were treated with CP administration and standard care (PG) and 102 others who received standard care only (CG). The CG was selected from 336 hospitalized patients using the propensity score matching (PSM) technique using age, MEWS score, and comorbidities. The primary outcome was mortality rate; secondary outcomes were the requirement of ventilator, length of ventilator need, length of intensive care unit (ICU) stay, and length of overall hospital confinement. Additionally, parameters predicting death in COVID-19 patients were identified. Results Findings confirmed a significantly lower mortality rate in the PG versus the CG (13.7% vs. 34.3 %, p=0.001) and a significant difference in cumulative incidence of death between the two groups (p <0.001). CP treatment was associated to lower risk of death (OR =0.25 CI 95 [0.06; 0.91], p =0.041). There were no significant differences in ICU stay, ventilator time, and hospitalization time between the two groups. Conclusions A significantly lower mortality rate was observed in the group of patients treated with CP. Age, presence of cardiac insufficiency, active cancer, requirement of ventilator, and length of hospitalization were significantly increasing the risk of death in both groups. Our study shows, that CP brings better outcomes when administrated in the earlier stage of high-risk COVID-19 disease.