. 2021 Jan 13;22:14. doi: 10.1186/s12931-020-01609-4

Table 3.

Correlation between percentage of IL-4-expressing Th2 cells, and demographic characteristics and key features of COPD

	Intracellular IL-4	Secreted IL-4
Age (years)^a	p = 0.57	p = 0.49
	r = − 0.11	r = 0.14
Sex (male/female)^b	p = 0.42	p = 0.68
Smoking (pack years)^a	p = 0.95	r = 0.32
	r = 0.01	r = 0.20
Smoking (ex-smokers vs current-smokers)^b	p = 0.70	p = 0.06
Chronic bronchitis (yes/no)^b	p = 0.25	p = 0.16
Dyspnea scale (mMRC)^a	p = 0.83	p = 0.18
	r = 0.04	r = − 0.26
FEV₁ (%)^a	p = 0.66	p = 0.19
	r = − 0.08	r = − 0.25
FVC (%)^a	p = 0.76	p = 0.34
	r = 0.06	r = − 0.19
FEV₁/FVC (%)^a	p = 0.25	p = 0.51
	r = − 0.21	r = − 0.13
RV (%)^a	p = 0.07	p = 0.71
	r = 0.32	r = 0.07
TCL (%)^a	p = 0.11	p = 0.53
	r = 0.30	r = 0.02
RV/TCL (%)^a	p = 0.56	p = 0.49
	r = 0.11	r = 0.02
Emphysema (yes/no)^b	p = 0.44	p = 0.88
Emphysema score^a	p = 0.40	p = 0.48
	r = 0.16	r = 0.14
Eosinophils (%)^a	p = 0.14	p = 0.17
	r = − 0.28	r = 0.26
Eosinophils (total count)^a	p = 0.52	p = 0.71
	r = − 0.12	r = 0.07
Exacerbations (n per year)^a	p = 0.82	p = 0.46
	r = 0.04	r = − 0.15
ICS (yes/no)^b	p = 0.27	p = 0.50

mMRC modified Medical Research Council, FEV₁ forced expiratory volume in one second, FVC forced vital capacity, RV residual volume, ICS inhaled corticosteroid

^aQuantitative data were evaluated by Spearman correlation test (p and r values)

^bQualitative data were evaluated by Mann and Whitney test (p values only)