CD68 and chronic obstructive pulmonary disease: In subjects with COPD on day 7 postinfection, the numbers of sub-CD68+ and CD4+ cells were associated with peak nasal lavage virus load (r = 0.54 and 0.66, P = .027 and .007, respectively, Fig E1, A and B); sub-CD20+ cells correlated with peak sputum virus load (r = 0.57, P = .028, Fig E1, C); sub-CD8+ cells correlated with BAL virus load (r = 0.88, P = .013, Fig E1, D).