Increased plasma levels of soluble TNF-alpha receptors in bipolar disorder patients

  • Izabela Barbosa, Laboratory of Immunopharmachology, Institute of Biological Sciences and School of Medicine, Federal University of Minas Gerais, Brazil
  • Rodrigo Huguet, Laboratory of Immunopharmachology, Institute of Biological Sciences and School of Medicine, Federal University of Minas Gerais, Brazil
  • Vanessa Mendonca, Laboratory of Immunopharmachology, Institute of Biological Sciences and School of Medicine, Federal University of Minas Gerais, Brazil
  • Lirlandia de Sousa, Section of Clinical Pathology, Coltec, Federal University of Minas Gerais, Brazil
  • Fernando Neves, Federal University of Minas Gerais, Brazil
  • Moises Bauer, Laboratory of Cellular and Molecular Immunology, Pontifical Catholic University of Rio Grande do Sul, Brazil
  • Antonio Teixeira, Federal University of Minas Gerais, Brazil

Background and objectives: Bipolar disorder (BD) has been associated with a proinflammatory state in which TNF-α seems to play a pivotal role. The aim of our study was to evaluate the plasma levels of TNF-α and its soluble receptors (sTNFR1 and sTNFR2) in BD patients in comparison with control subjects. Methods: We evaluated 53 BD patients (34 in mania and 19 in euthymia) and 21 age and gender-matched controls. All subjects were assessed by the Mini-International Neuropsychiatry Interview. Patients were also evaluated with the Young Mania Rating Scale and the Hamilton Depression Rating Scale. The plasma levels of TNF-α, sTNFR1 and sTNFR2 were measured by ELISA. Results: Plasma levels of TNF-α were not significantly different between groups. BD patients present higher plasma levels of sTNFR1 and STNFR2 when compared to controls. This increase was particularly relevant in BD patients in mania. The use of mood stabilizing agents or other psychotropic drug, the presence of clinical and psychiatric comorbidities did not influence the plasma levels of the molecules measured. Plasma levels of sTNFR1 and sTNFR2 correlated with BD duration. Conclusions: Our results reinforce the involvement of inflammatory mechanisms in the BD. Moreover, this inflammatory response seems to be enhanced in episodes of mania and later stages of the disease.