The Effect of Chronic Immunosuppression on the Severity and Outcomes of COVID-19 ICU Patients

Abstract

Rationale: There is currently limited and conflicting data regarding the effect of immunosuppression on severity and outcomes of Coronavirus Disease 2019 (COVID-19). Mortality rates of solid organ transplant recipients hospitalized with COVID-19 range as widely as 5-67%. Some of these reports therefore seem to suggest that immunosuppressed patients have a similar mortality when compared to non-immunosuppressed patients. Also, there is limited data on the incidence of bacterial and fungal superinfections in these critically ill COVID-19 patients who are immunosuppressed. Our study aims to understand the impact of immunosuppression on the clinical course and outcomes of COVID-19 patients admitted to our intensive care units (ICUs). Methods: This study is a retrospective analysis of all adult patients with COVID-related acute respiratory distress syndrome (ARDS) admitted to the ICUs of a quaternary care hospital between 03/01/2020 and 05/31/2020. Patients on chronic immunosuppressive medications were identified. Demographic and clinical characteristics, inflammatory markers at the time of ICU admission and clinical outcomes of these patients were compared and analyzed with patients who were not immunosuppressed. Means, medians and categorical variables were compared using t-test, Mann-Whitney U-test and Fisher's exact test, respectively. P-value of <0.05 was taken to be statistically significant. Results:Of the 210 patients admitted to our ICUs with COVID-related Acute Respiratory Distress Syndrome, 23 (11%) were taking immunosuppressant medications before they were admitted to our unit. 11 patients had a history of organ transplantation (Liver: 4, Kidney: 4, Heart: 2 and Stem cell transplantation: 1). There was no statistically significant difference between the two groups in terms of demographics, comorbidities, severity as indicated by inflammatory markers and outcomes such as death, acute kidney injury (AKI) requiring dialysis, and bacterial or fungal superinfection. Conclusion: Our study seems to imply that there is no significant difference in the severity and outcomes of the immunosuppressed patients who were admitted to our ICUs. Our study did show an increased incidence of mortality (52.17% vs. 44.02%) and an increased rate of positive sterile fluid cultures (34.78% vs. 25.13%) in these immunosuppressed patients but the difference was not statistically significant. It is possible that an increased sample size may have revealed statistically significant differences. Therefore, larger studies are needed to determine if immunosuppression impacts the outcome of critically ill COVID-19 patients.