Abstract # 3081 Impaired cognition and fatigue; the role of sleep and neuroinflammation for non-specific symptoms in allergy

Allergy is associated with non-specific symptoms such as fatigue and impaired cognition. Allergic patients also report worse sleep compared to healthy controls. As part of a study where we investigated seasonal changes in the glial cell marker translocator protein (TSPO), we studied fatigue, sleep and cognitive functions in allergic patients, in relation to seasonal changes in the glial cell marker translocator protein (TSPO) as measured using positron emission tomography (PET). We examined 18 patients with severe seasonal allergy and 13 healthy subjects in and out of pollen season, using TSPO PET, subjective ratings of fatigue and sleepiness, objective and subjective sleep measures and a test-battery of cognitive tests (CANTAB). Allergic subjects had shorter total sleep time, regardless of season, compared to healthy controls. Subjects with allergy also reported worse sleep quality during pollen season, but had a higher percentage of deep sleep. These effects were paralleled by increased fatigue and sleepiness, as well as increased levels of IL-5 and TNF- α during pollen season, but were unrelated to brain TSPO levels. Allergic patients showed lower scores on intra-extra dimensional set shift during pollen season, indicating lower capacity in set-shifting and flexibility of attention. We speculate that impaired sleep, together with neuroinflammatory mechanisms, contribute to a sickness-like state in allergy, characterized by fatigue, and dysregulated exteroceptive – and potentially increased interoceptive – attention.