Glial activation among individuals with neurological post-acute sequelae of coronavirus disease 2019: A positron emission tomography study of brain fog using [F]-FEPPA.

BACKGROUND

This study examined the regional distribution of glial activation in essential workers with neurological post-acute sequelae of coronavirus disease 2019 (COVID-19) infections (N-PASC).

METHODS

We injected ≤185 MBq of [F]-FEPPA as an intravenous bolus and positron-emission tomography over 2 h. To measure distribution volume (V) we recruited 24 essential workers (14 N-PASC, 10 Never-COVID-19 Controls, of whom 22 successfully placed arterial lines). Individuals with low binding affinity were excluded from this study, and V was adjusted for translocator protein genotype. Analyses that passed the false discovery rate are reported.

RESULTS

Participants at midlife survived mild to moderate COVID-19 without hospitalization but reported onset of post-acute sequelae of COVID-19 (PASC) for, on average, 22 months before undergoing neuroimaging. Hippocampal V was higher (V = 1.70, 95% C.I. = [1.30-2.21], p = 0.001) in participants with persistent brain fog after COVID-19, reflecting an increase of 10.58 mL/cm in V (area under the receiver-operating curve, AUC = 0.95 [0.85-1.00]). At a cutoff of 10.6, sensitivity/specificity/accuracy were 0.88/0.93/0.91.

CONCLUSION

The results from this study imply that neuroimmune response is a distinct and identifiable characteristic of brain fog after COVID-19. Results suggest that [F]-FEPPA could be used to support N-PASC diagnosis.