Interleukin dynamics during cognitive stress in patients with chronic cerebral ischemia

Abstract

Neuroimmune interactions represent a highly dynamic mechanism for the regulation of cognitive function in chronic cerebral ischemia (CCI). The aim of this study was to investigate changes in salivary proinflammatory cytokines IL1β and IL6 and anti-inflammatory IL10 in patients with CCI (mean age 65.4 ± 9.1 years) before and after cognitive tests. After cognitive tests, the levels of salivary IL1β and IL6 were significantly elevated by 101.6 ± 19.1 pg/ml (n = 74) and 32.8 ± 6.1 pg/ml (n = 74), respectively. Using one-way ANOVA ana non-parametric statistical methods, we were able to demonstrate associations between changes in salivary interleukins and cognitive performance. In the group of patients with a significant increase in IL1β, some cognitive parameters were lower than in the group with negative or zero dynamics of this cytokine: The patients made more mistakes in the subtraction test (F = 11.5; n = 63; p = 0.001) and performed worse in the Luria test (F = 6.8; n = 65; p = 0.01). For IL6, Spearman's rank correlation coefficient for the number of mistakes in the subtraction test was positive and differed significantly from 0 (R = 0.26; n = 62; p = 0.042). The group with positive IL10 dynamics performed better in N-back test (F = 5.2; n = 67; p = 0.03) and made fewer mistakes in the subtraction test (F = 6.8; n = 63; p = 0.01) in comparison with patients who demonstrated negative IL10 dynamics. Good performance in other cognitive tests was not correlated with interleukin dynamics. The article also discusses possible mechanisms underlying interleukin effects on cognitive function in patients with CCI and applications of the obtained data.