Neurocognitive disturbances assoc. with acute infectious mononucleosis, Ross River fever and Q Fever

[Firestormm]

Brain Behav Immun. 2013 Nov 7.

Neurocognitive disturbances associated with acute infectious mononucleosis, Ross River fever and Q fever: A preliminary investigation of inflammatory and genetic correlates.

Cvejic E, Lemon J, Hickie IB, Lloyd AR, Vollmer-Conna U.

Source: School of Psychiatry, University of New South Wales, Australia.

Abstract
Disturbances in neurocognitive performance are a core feature of the acute sickness response to infection; however the underlying mechanisms remain unclear.

The current study used a computerised battery to assess neurocognitive functioning in subjects enrolled in the Dubbo Infection Outcomes Study (n=107) - a prospective cohort of subjects followed from documented acute infection with Epstein Barr virus, Ross River virus, or Coxiella burnetii until recovery.

Subjects were assessed when ill, and a subset again after complete recovery. Associations between sickness-related cognitive disturbances and single nucleotide polymorphisms (SNPs) in cytokine (interleukin [IL]-6, IL-10, tumor necrosis factor-α and interferon-γ) and neurobehavioral genes (serotonin transporter and catechol-O-methyltransferase) were explored.

During acute infection, subjects exhibited slower matching-to-sample responses (p=0.03), poorer working memory capacity (p=0.014), mental planning (p=0.045), and dual attention task performance (p=0.02), and required longer to complete discordant Stroop trials (p=0.01) compared to recovery.

Objective impairments correlated significantly with self-reported symptoms (p<0.05) as well as levels of the inflammation marker, C-reactive protein (p=0.001).

Linear regression analysis identified an association between neurocognitive disturbance during acute illness and functional polymorphisms in inflammatory cytokine genes. Specifically, the high cytokine producing G allele of the IL-6-174G/C SNP was associated with poorer neurocognitive performance when subjects were ill (p = 0.027).

These findings confirm that acute infection impacts on neurocognitive performance, manifesting as slowed responses and impaired performance on complex tasks requiring higher-order functioning which has important real-world implications.

The data provide the first preliminary evidence for a role of a genetic predisposition to more intense inflammatory responses in objective neurocognitive disturbances during acute infections. These associations require replication in a larger sample size.

 

[Valentijn]

It looks like they're talking about rs1800795, which 23andMe does test for (though it doesn't show up under the IL6 gene). I've got the rarer CC genotype, which should be somewhat protective based on that study, but it certainly didn't help me at all It would be interesting to see how big the impact of the SNP was, especially compared to the other variables mentioned.