s / Drug and Alcohol Dependence 146 (2015) e202–e284 e227 for these projections in context-induced reinstatement of heroin seeking. Financial support: NIDA/IRP. http://dx.doi.org/10.1016/j.drugalcdep.2014.09.083 The effect of high stress on T-cell protein expression in chronic drug users: HIV implications Nawal Boukli, Sheila Lopez, Madeline Rodriguez, Eddy Rios Microbiology and Immunology, Universidad Central Del Caribe, Bayamon, United States Aims: Stress anddrugusemaywork in synergy toaffect immune response. We aim to (1) group chronic poly drug users (PDU) according to psychological, physiological and immunological characteristics, and (2) examine stress impact on plasma cytokine profile and protein expression of T-lymphocytes from HIV+ and HIV− PDUs. Methods: In non-PDU HIV−HCV− controls (n=10) and PDU samples (n=47; 20% female, age 18–35 years), stresswasmeasured by the PERI and cortisol/DHEA quantification. Cellular immune response has been evaluated by CD4/CD8 quantification. Protein expression alterations were detected through proteomics. Results: HIV−HCV− (18), HIV+HCV− (7), HIV−HCV+ (13), HIV+HCV+ (9) and non PDU HIV−HCV− control group (10). PERI scale scores were related to low and high cortisol levels. Immunologically, among 18 HIV−HCV− PDU 100% had >410 CD4 cell counts/ l; 5 of 7 HIV+HCV− PDU had high CD4 counts; all 10 non-PDU HIV−HCV− had normal CD4 cell counts. The proteomic data identified proteins showing altered expression mainly in oxidative stress, proteolytic and glycolytic enzymes, inhibitors and structural proteins in the group of PDU+ with high stress as compared to those with low stress values. Conclusions: Our findings allowed the identification of several proteinmarkers candidates for early diagnostic and/or treatment of PDU under stress. Further, the scientific processes implemented to stratify PDU+ and PDU− users according to physiological, immunological and psychologicalmeasurements are important to correlate with the protein profile of the participant groups. This will contribute to the deeper understanding of the effect of stress in the PDU and underlying mechanisms for drug of abuse prevention. Financial support: Supported by NCRR (5G12RR003035), NIMHHD (8G12MD007583), NIDA (2R24DA013335; R25DA030310). http://dx.doi.org/10.1016/j.drugalcdep.2014.09.084 Early initiation of alcohol and illicit drug use: Associations with psychopathology among inpatient substance users Nadia Bounoua, Bina Ali, Aaron Lim, William Lechner, Julia M. Shadur, J.W. Felton, L. MacPherson, C.W. Lejuez University of Maryland, College Park, College Park,