Systemic cytokines related to cognitive function 6-9 months and 12-15 months after SARS- CoV-2 infection

Abstract Background. Cognitive symptoms persisting beyond the acute phase of COVID-19 infection are commonly described for up to 1 year after infection. The relationship between cognitive performance, in particular episodic memory processes observed chronically after infection, and cytokine levels in the acute phase of COVID-19 has not yet been identified in humans. Aim. Determine whether the levels of cytokines IL1β, IL-6 and TNFα secreted in the acute phase of SARS-CoV-2 infection are associated and predict verbal and visuospatial episodic memory performance in humans 6 to 9 months and 12 to 15 months post-infection. Method. The associations and predictive value of the concentration of cytokines measured in acute phase (IL-1β, IL-6, TNFα) from plasma samples of N = 33 hospitalised COVID-19 patients (mean age 61 years, 39–78, 65% in intensive care) in relation to their verbal and visuospatial episodic memory performance measured at 6–9 months and 12–15 months post-infection were analyzed. To do this, we used Spearman correlations and generalised linear mixed models. Results. IL-1β levels were associated with verbal episodic memory total recall scores 6–9 months post-infection. At 12–15 months post-infection IL-1β predicted verbal episodic memory scores and IL-6 predicted visuo-perceptive process. Conclusion. This study demonstrated that the severity of inflammatory reaction at acute phase of SARS-CoV-2 infection predicts verbal episodic memory performance in the long-term post-infection.