Relationship between HIV-1 viral load and continued drug use in untreated infected injection drug users

The role of continued drug use in development of AIDS has been investigated , using mainly CD4(+) cells as outcome variable. The objective of this stud y was to verify whether continued drug use can influence HIV-1 plasma viral load. We used cross-sectional enrolment data of the HIV-infected IDUs coho rt study Manif 2000 (October 1995-October 1996), recruiting patients in hos pital departments of Marseilles, Nice and Paris suburbs. To minimize biases due to differential access to health care, only patients receiving outpati ent care for at least 2 years but with no intiretroviral treatment were sel ected for analysis (n = 108). Available information regarding clinical and laboratory information from medical records and clinical examination as wel l as drug use and HIV-related risk practices were obtained by, a face-to-fa ce and a self-administered questionnaire. Patients denying recent heroin in jection were cross-validated by a serological assay to detect morphine. For ty-two patients (39%) reported recent heroin injection; among those denying recent use (n = 66), eight (positive for serum morphine assay) were re-cla ssified as IDUs. A difference of 0.35 log in viral load was observed betwee n active and ex-ID Us which increases (0.6 log, p = 0.03) in those who have been using drugs for 10 years or more. This result persisted when adjusted for CD4(+) counts, clinical stage or years since diagnosis. Continued drug use may have a significant but limited impact on HIV viral load only ill p atients with a longer history of drug use. Consequences of persisting drug use on long-term progression to AIDS has to be investigated further.