The flow cytometry profile of AM recovered from a representative HIV-infected patient with lymphocytic alveolitis (case #5) and an uninfected control subject. BAL analysis revealed the presence of a P. carinii pneumonia; 34% of BAL cells were lymphocytes, as determined by morphological evaluation and the CD4/CD8 ratio was 0.03. The profile of CD72, CD80, and CD86 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 observed in all HIV-infected patients with lymphocytic alveolitis.