The pulmonary microenvironment can be HIV infected from the asymptomatic period of HIV infection and it has been demonstrated that HIV presence elicits a discrete virus-specific CTL immune response in the lungs. In this study we analyzed T cell subsets and compared the proportion of CD8+ T cells harboring HIV in the lung and in the circulation of HIV-seropositive patients with T cell alveolitis. Proviral load was assessed using the DNA-polymerase chain reaction technique on highly purified CD8+ T cells isolated from peripheral blood and bronchoalveolar lavage. The proviral load of pulmonary CD8+ T cells showed an upward trend with respect to corresponding samples isolated from the peripheral blood of the same patients.