Objectives: Splenectomy is a common surgical procedure, and splenectomized patients have shown to be severely more affected by certain infections than patients with a preserved splenic function. We investigated the risk of COVID-19 infection and subsequent hospitalisation and death in splenectomized patients.
Methods: We conducted a case-control study of all individuals with a microbiologically verified COVID-19 infection in Denmark through December 31, 2020. To each case, we matched three controls on age, sex, and region of residence. We examined the association between previous splenectomy and the risk of COVID-19 infection, hospitalisation, and death using a logistic regression model.
Results: We identified 165,623 individuals with a positive COVID-19 test and 493,300 matched controls. Mean age was 38 years. 130 and 422 splenectomies were performed in the COVID-19 positive individuals and controls, respectively. Splenectomized patients did not have a higher risk of COVID-19 infection than non-splenectomized patients (adjusted OR: 0.89; 95% CI: 0.73-1.08). Among COVID-19 positive individuals, splenectomized patients may have an increased risk of hospitalisation or death (adjusted OR for combined endpoint: 1.44; 95% CI: 0.79-2.61).
Conclusions: Splenectomized patients are not at an increased risk of COVID-19 infection, but they may have a higher risk of hospitalisation or death among COVID-19 positive individuals. This may be attributed to higher comorbidity levels.
Keywords: COVID-19; corona; immunology; splenectomy; splenic function.