Inflammatory Markers in the Staging of Bipolar Disorder: A Systematic Review of the Literature.

ABSTRACT

BACKGROUND: Previous studies suggest that inflammatory molecules play an important role in the pathophysiology of Bipolar Disorder (BD). The evidence suggests that BD may present a progressive course. Therefore there are theories that postulate the relationship between progression and stages of the disease with distinct peripheral biomarkers. OBJECTIVE: The aim of this study was to carry out a systematic review of the literature of studies about the association between peripheral inflammatory markers and clinical variables related with staging in BD patients. METHODS: We conducted a systematic review using electronic databases PubMed, SciELO, LiLACS and PsycINFO. Keywords were divided into inflammatory markers and, BD and staging. Studies involving euthymic BD patients, studies evaluating peripheral biomarkers and studies correlating these with clinical variables related to neuroprogression or stage of BD were included. RESULTS: We present and discuss the methods and findings of ten articles. The inflammatory markers were measured with different techniques and show some contradictories results. The TNF superfamily and inflammatory cytokines may have a relationship with the neuroprogression of the disease. CONCLUSIONS: This study suggests that TNF and ILs could play a role in neuroprogression. However, longitudinal studies are needed to clarify the relationship between factors associated with neuroprogression.