CCL11 and GDF11 Levels in Drug-Naive Young Adults with Bipolar Disorder

Abstract

Bipolar disorder (BD) is a chronic and often progressive illness that has a significant impact on quality of life and functioning. Pharmacological treatments are not effective for all patients, emphasizing the need to better understand the pathophysiology of the disorder. It is well known that patients with BD present with increased levels of inflammatory markers during mood episodes and often exhibit chronic low grade inflammation, implicating the immune system in the etiology of the disorder. Furthermore, patients with BD show deficits in neurotrophic factors suggesting that alterations in neurogenesis may precipitate clinical features. Recent evidence indicates that accelerated aging processes may underlie the pathophysiological changes observed in BD, implicating biomarkers related to aging. The chemokine C-C motif chemokine 11 (CCL11) and the cytokine growth differentiation factor 11 (GDF11) have been identified as proteins that increase and decrease with age, respectively. As such, this thesis presents research examining serum levels of these proteins in drug-naive young adults with BD and a matched healthy control group. We analyzed serum levels of CCL11 and GDF11 using enzyme linked immunosorbent assay (ELISA). Our results indicate that serum levels of CCL11 and GDF11 do not differ between the BD group and the healthy control group, however CCL11 levels were elevated in males and in individuals with tobacco abuse/dependence when considering the entire sample. Our results suggest that serum levels of these proteins do not differ between drug-naive young adults with BD and healthy controls, but that alterations may be due to demographic and lifestyle factors. Small sample size and low power should be considered when interpreting these results.