Role of Therapeutic Plasmapheresis in SARS-CoV-2 Induced Cytokine Release Syndrome: A Retrospective Cohort Study on COVID-19 Patients.

Background: Cytokine release syndrome (CRS) significantly contributes to the pathophysiology and progression of COVID-19. It is speculated that therapeutic plasma exchange (TPE) can dampen CRS via elimination of pathogenic cytokines.

Objectives: The study is intended to compare the outcomes of COVID-19 patients with CRS treated with TPE and standard care (SC) to their counterparts receiving SC alone.

Methodology: A retrospective cohort study of severe COVID-19 confirmed patients presenting with CRS and admitted to the medical ICU was conducted between March and August 2021. Using case-control (CC) matching 1:1, 162 patients were selected and divided into two equal groups. The primary outcome was 28-day in-hospital survival analysis in severe COVID-19 patients with CRS. However, secondary outcomes included the effect of plasmapheresis on inflammatory markers, the need for mechanical ventilation, the rate of extubation, and the duration of survival.

Results: After CC matching, the study cohort had a mean age of 55.41 (range 56.41±11.56 in TP+SC and 54.42±8.94 in SC alone; p=0.22). There were 25.95% males and 74.05% females in both groups. The mean time from first day of illness to hospitalization was 6.53±2.18 days. The majority of patients with CRS had comorbid conditions (75.9%). Diabetes mellitus was the most common comorbidity (40.1%), followed by hypertension (25.3%), and chronic kidney disease (21%). Notable reduction in some inflammatory markers (D-dimers, LDH, CRP and serum ferritin) (p<0.0001) was observed in the group that received TPE+SC. Moreover, the patients in the plasmapheresis plus standard care group required relatively less mechanical ventilation as compared to the group receiving SC alone (46.9% vs 58.1%, respectively; p>0.05). The rate of extubation in the TP+SC group vs SC alone was 60.5% vs 44.7%, respectively (p>0.05). Similarly, the mortality percentages in both groups were 19.8% and 24.7%, respectively.

Conclusion: For this particular group of matched patients with COVID-19-induced CRS, TPE+SC was linked with relatively better overall survival, early extubation, and earlier discharge compared to SC alone. As these results were not statistically significant, multi-centered randomized control trials are needed to further elaborate the role of therapeutic plasmapheresis in COVID-19 induced CRS.