[Comparison of Inflammatory Biomarkers Between Bipolar Disorder I Patients and Control Subjects]

Inflammatory changes have been described in different affective episodes, as well as in the euthymic phase of Bipolar I Disease. These changes have been proposed as possible peripheral markers of the disease. For this reason well-designed studies are needed to explore this hypothesis.

Quantify and compare the serum levels of interleukins (IL) and tumour necrosis factor (TNF) in bipolar I patients and healthy subjects, including the comparison between the affective episodes of the disease.

Cross-sectional study including 41 bipolar I patients and 11 healthy control subjects. Serum levels of IL-1B, IL-RA, IL-2, IL-4, IL-6, IL-7, IL-8, IL-10, IL-12, and TNF were measured during the euthymic, depressive, and manic phases and were compared with the serum levels of the healthy subjects.

Manic phase patients had low education and high number of hospitalisations. Depressive phase patients showed high number of depressive episodes throughout life. No statistically significant differences were found in IL and TNF levels between bipolar I patients and healthy controls, or between the bipolar I subgroups (euthymic, manic and depressive states). An increase in the size of the sample is necessary in future studies, in order to enhance the statistical value of the results, and explore the inflammatory hypothesis of the bipolar disease.