CD4 and chronic obstructive pulmonary disease: The baseline numbers of sub-CD68+ and both epi- and sub-CD8+ cells were significantly higher (P = .002-.039, Fig 2, B and C, and Fig 3, E, Table II), whereas those of sub-CD4+ and CD20+ cells were significantly lower (P = .014-.041, Fig 2, D and E, Table II) in smokers and subjects with COPD compared with the baseline of nonsmokers.