Background: Both early life stress (ELS) and substance abuse, especially cocaine, have robust effects on the inflammatory system. Considering the role of the tumor necrosis factor system in inflammatory signaling and its association with ELS, the aim of the study was to compare plasma levels of TNF-alpha, its soluble receptors and ligands during early abstinence of crack cocaine.
Methods: This study included 24 crack cocaine-dependent women with (CRACK-ELS) and 20 without (CRACK) a history of ELS. A healthy control group (HC), containing 25 participants, was included to provide reference values. The Childhood Trauma Questionnaire (CTQ) retrospectively assessed childhood maltreatment history of patients. Plasma levels of TNF-alpha, TNF-related weak inducer of apoptosis (TWEAK), TNF-related apoptosis-inducing ligand (TRAIL), soluble receptors TNFRI (sTNFRI) and TNFRII (sTNFRII) were assessed on the 18th day of treatment.
Results: The CRACK-ELS group had higher TNF-alpha and lower TWEAK levels compared to the CRACK and HC groups. sTNFRII was increased, but only in comparison with the crack cocaine group and the controls. TRAIL levels were slightly higher in the CRACK-ELS group, while no differences were found for sTNFRI levels. Also, TNF-alpha plasma level was positively predicted by abstinence severity and childhood maltreatment severity, and TWEAK was negatively predicted by childhood maltreatment severity.
Conclusions: This is the first study to evaluate the newly secreted tumor necrosis factor superfamily ligands, TWEAK and TRAIL, during crack cocaine abstinence, supporting the association between early life stress and peripheral pro-inflammatory levels.
Keywords: Child abuse; Cytokines; Inflammation; Substance-related disorders; TNF; TRAIL; TWEAK.
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