Depression Correlates with Increased Plasma Levels of Inflammatory Cytokines and a Dysregulated Oxidant/Antioxidant Balance in HIV-1-Infected Subjects Undergoing Antiretroviral Therapy

Abstract

OBJECTIVE: Depression is the most common psychiatric diagnosis in the HIV/AIDS population and represents a risk factor for disease progression. Since HIV-1 infection is characterized by immunologic and metabolic disturbances, we want to study the effects of depression on different components related to pro-inflammatory and oxidative stress markers. We hypothesize that depression will lead to increased pro-inflammatory cytokine levels and altered antioxidant/oxidant balance.METHODS: We included males and females who were ≥21 years of age, whose HIV-1 sero-status was confirmed by Western Blot, and who were currently undergoing antiretroviral treatment. Patients completed the participation consent form, a socio-demographic survey, and the Patient Health Questionnaire-9 (PHQ-9) for depression assessment. We isolated the plasma from participants' blood samples for viral load analysis (RT-PCR), T-cell counts (flow cytometry), and hematological parameters. A cytokine magnetic bead panel was used to measure interleukin-15 (IL-15), interferon gamma-induced protein 10 (IP-10), IL-12 and granulocyte colony-stimulating factor (G-CSF) levels. We also performed assays to determine the antioxidant activity of superoxide dismutase (SOD) and catalase and to measure the lipid peroxidation levels using malondialdehyde (MDA) and 8-isoprostane assays. Statistical comparisons and correlations at 5% level of significance were determined.RESULTS: Our results show that subjects with mild/moderate to severe depression as assessed by PHQ-9 had a significantly decreased adherence to anti-retroviral treatment. Subjects with depression also had significantly lower levels of white blood cells (WBC) and platelets (PLT) than did the non-depressed group. The HIV(+) subjects with depression had increased levels of IL-15, IP-10, IL-12 p40/p70 and G-CSF compared to their non-depressed counterparts. The latter had increased MDA and 8-isoprostane levels.CONCLUSIONS: Our results suggest that HIV(+) subjects with depressive symptoms have higher levels of inflammation and altered oxidant/antioxidant balance. Although the groups were small, this study strengthens the hypothesis that alterations in cytokines are associated with the mechanisms underlying depression symptoms.