Association of apolipoprotein E4 to the number of cerebral microbleeds in patients recovered from COVID-19

ABSTRACT

Background: COVID-19 has been associated with cerebral microbleeds (CMB). Previously, an association of ApoE4 with COVID-19 severity and CMBs in autopsy was found. In this study, we investigated if carrying the Apoe4 allele relates to the number of CMBs in magnetic resonance imaging (MRI) in patients recovered from COVID-19. Material(s) and Method(s) Adult patients recovered from COVID-19 and a control group without a history of COVID-19 was recruited. Exclusion criteria were major neurologic disease, developmental disability or pregnancy. The participants underwent brain MRI 6 months after infection, and a blinded neuroradiologist analyzed the findings. ApoE was genotyped using a microarray. Statistical analysis was performed using the statistical software R. A negative binomial model was chosen based on the distribution of CMBs. Result(s) Of the 216 subjects that underwent MRI, 168 consented to genetic testing, additionally 2 patients were excluded due to extensive CMBs and 1 due to diffuse axonal injury. We included 113 COVID-19 patients (49 ICU-treated, 29 ward-treated and 35 home-isolated) and 52 controls. The most prevalent comorbidities were hypertension, asthma and diabetes. CMBs was found in 47 subjects, with the number of CMBs ranging from 0 to 26. The ApoeE4 allele was carried by 37%, equally distributed among the groups. After adjustment, age (aRR = 1.06, p = 0.007) and COVID-19 (aRR = 2.59, p = 0.038) were independently associated with CMBs. The ApoE4 allele (aRR = 2.16, p = 0.07, CI = 0.94-5.10) was not significant. Conclusion(s) Age and previous COVID-19, but not possession of the ApoeE4 allele, were independently associated with the number of CMBs.