In vivo effects of methamphetamine on HIV-1 replication: A population-based study.

Although a number of in vitro studies have shown that methamphetamine (METH) can increase HIV-1 replication in human immune cells, a direct link between METH use and HIV-1 pathogenesis remains to be determined among HIV-1 patients. According to the status of METH use and HIV-1 infection, we enrolled participants and divided them into four groups: METH+HIV+, METH-HIV+, METH+HIV-, and METH-HIV-. HIV viral loads and HIV-1-related cellular factors were measured and compared among different groups. A total of 60 participants were enrolled into this study, 15 within each group. HIV viral loads in METH+HIV+ group were significantly higher than those in METH-HIV+ group, while CD4+ T cell counts had an inverse trend between the two groups (p<0.05). METH users or HIV-1 infected patients had lower CCR5+, CXCR4+ percentages in CD4+ T cells than METH-HIV- subjects (p<0.01). However, METH use had little effect on CD3 expression in PBMCs and the levels of MIP-1α, MIP-1β and IL-6 in PBMCs or plasma, which were increased by HIV-1 infection with or without METH. TLR-9 and IFN-α levels in PBMCs of METH users with or without HIV infection were higher than non-METH users (p<0.05). METH use is associated with higher viral loads and lower CD4+ T cell counts in HIV-infected individuals. This finding may be mediated by activation of innate immunity (TLR-9, IFN-α) by METH use.