The flow cytometry profile of BAL T cells recovered from a representative HIV-infected patient with lymphocytic alveolitis (case #5) and an uninfected control subject. Main results of BAL analysis of case #5 are summarized in the legend of Fig 3. The profile of CD5, CD28, and CD152 molecules (panels A, B, C, J, K, and L), activation markers (panels D, E, F, M, N, and O), and cytoplasmic cytokines (panels G, H, I, P, Q, and R) was determined as reported in the Materials and Methods section. A consistent pattern of expression of costimulatory molecules and cytoplasmic cytokines was seen in all HIV-infected patients with lymphocytic alveolitis.