['To assess whether cellular HIV-1 DNA prior to highly active antiretroviral therapy (HAART) initiation predicts its outcome.', 'Patients included all 51 hemophiliacs of the Greek component of the Multicenter Hemophilia Cohort Study who had initiated HAART and for whom cryopreserved lymphocyte samples before HAART initiation were available. Cellular HIV-1 DNA quantification was performed by a molecular beacon-based real-time PCR assay in multiple samples per patient with a median (interquartile range) follow-up of 76 (45-102) weeks.', 'The median (range) baseline HIV-1 DNA load was 297 (< 10 to 3468) copies per 1 x 10(6) peripheral blood mononuclear cells. Baseline HIV-1 DNA load did not predict initial virological response (VR). None of the patients with initial VR and baseline HIV-1 DNA load at or below the median experienced a subsequent virological rebound, while the cumulative probability of virological rebound by week 104 was 55% among those with HIV-1 DNA load greater than the median (P < 0.008). Cellular HIV-1 DNA load was the only parameter associated with sustained virological response as shown by univariate or multivariate analyses [adjusted odds ratio (95% confidence interval) 0.197 (0.048-0.801) per 1 log10 increase in DNA copies, P = 0.023].'] Does cellular HIV-1 DNA load predict HIV-RNA rebound and the outcome of highly active antiretroviral therapy?