Immunosuppression as a risk factor for COVID-19: a meta-analysis

Background: While immunosuppression poses a theoretical increase in the risk of COVID-19, the nature of this relationship is yet to be ascertained. Aims: To determine whether immunosuppressed patients are at higher risk of COVID-19 to help inform the management of patients receiving immunosuppressant therapies during the pandemic. Methods: We performed a random-effects meta-analysis of data from studies that reported on the prevalence of immunosuppression among patient cohorts with COVID-19. Results: Sixty full-text publications were identified. In total, six individual studies were included in the final analysis, contributing a total of 10 049 patients with COVID-19 disease. The prevalence of immunosuppressed patients among the study cohorts with COVID-19 ranged from 0.126% to 1.357%. In the pooled cohort a total of 64/10 049 (0.637%) patients with COVID-19 disease was immunosuppressed. Observed to expected ratios were used to compare the prevalence of immunosuppression in cohorts with confirmed COVID-19 disease to the background prevalence of immunosuppression in the general community. The observed to expected ratio of immunosuppression among patients with COVID-19 illness, relative to the general community, was 0.12 (95% confidence interval: 0.05–0.27). Conclusions: Compared to the general population, immunosuppressed patients were not at significantly increased risk of COVID-19 infection. This finding provides support for current expert consensus statements, which have recommended the continuation of immunosuppressant therapy in the absence of COVID-19.