Fig. 2

The numbers of peripheral blood monocytes are significantly increased in severe COPD patients. The total number of blood monocytes (a), and the numbers of classical monocytes (b), intermediate monocytes (c) and non-classical monocytes (d) cells are presented. The percentages of classical monocytes and non-classical monocytes are also presented. The percentages of each population were determined relative to the total number of monocytes, and data are presented for the classical (e), non-classical (f), and intermediate (g) monocyte sub-populations. Data are presented as box plots with the mean (red line) and median (black line). The box delineates the interquartile range, and the vertical line represents the interquartile range. * = p < 0.05 and ** = p < 0.01 relative to the normal