IL-36 is Closely Related to Neutrophilic Inflammation in Chronic Obstructive Pulmonary Disease

Figures & data

Table 1 Characteristics of COPD Patients and Control Subjects

	Control Subjects	Patients with COPD	p value
Sex (M/F)	12/8	55/15	p > 0.05
Age (years)	63.1 ± 9.6	67.4 ± 8.0	p > 0.05
BMI	25.6 ± 2.5	24.6 ± 4.4	p > 0.05
Smoking-status (NS/S)	14/6	54/16	p > 0.05
FEV1 (%predicted)	108.4 ± 12.9	48.3 ± 19.2	p < 0.0001
FEV1/FVC (%)	80.1 ± 6.8	46.3 ± 12.7	p < 0.0001
Neutrophils counts (*10^9)	2.7 (2.2–3.7)	5.9 (4.0–7.6)	p < 0.0001
Neutrophils (%)	0.55 (0.47–0.65)	0.75 (0.64–0.83)	p < 0.0001
Eosinophils counts (*10^9)	0.16 (0.083–0.25)	0.046 (0.00–0.18)	p < 0.01
Eosinophils (%)	0.027 (0.021–0.039)	0.008 (0.00–0.030)	p < 0.01

Notes: FEV1 (%predicted): the ratio of forced expiratory volume in the first second to the predicted forced expiratory volume; FEV1/FVC: the ratio of forced expiratory volume in the first second to forced vital capacity. Data are presented as the mean ±SD or median (IQR).

Table 2 Primers for qRT-PCR

Genes	Primers (5′–3′)
Homo-IL-36α
Forward	ATCGGGTGTGGGTTCTTCAG
Reverse	GGTCCCCGACTTTAGCACAC
Homo-IL-36β
Forward	TGGGTAGAAAGAAGTGGAAGAGTT
Reverse	TGGTCCGCATGGATGAGAAA
Homo-IL-36γ
Forward	CGGAGCAGTCACAGTGTATGA
Reverse	CTAGTTCTGGGCCTGCGGT
Homo-GAPDH
Forward	GCACCGTCAAGGCTGAGAAC
Reverse	TGGTGAAGACGCCAGTGGA

Figure 1 IL-36 was highly expressed in patients with COPD and was related to the severity of COPD. The levels of the IL-36α (A), IL-36β (B), and IL-36γ (C) in the serum of patients with COPD were measured using the ELISA kit. The number of samples in each group was as follows, GOLD 1 (n = 6), GOLD 2 (n = 20), GOLD 3 (n = 20), GOLD 4 (n=9), Control (n = 15). Data were pooled from at least 3 independent experiments and are presented as the mean ±SD. *p < 0.05, **p < 0.01.

Figure 2 IL-36 was highly expressed in patients with COPD and was related to the severity of COPD. The mRNA levels and significant differences in IL-36α (A), IL-36β (B), and IL-36γ (C) in PBMCs of patients with COPD were determined by PCR. The number of samples in each group was as follows, GOLD 1 (n = 6), GOLD 2 (n = 20), GOLD 3 (n = 20), GOLD 4 (n=9), Control (n = 15). Data were pooled from at least 3 independent experiments and are presented as the mean ±SD. *p < 0.05, **p < 0.01.

Figure 3 In COPD, IL-36 was closely related to neutrophils. (A–C) Correlation analysis of IL-36 and neutrophils in the COPD group. (D–F) Correlation analysis of IL-36 and eosinophils in the COPD group. (G–I) Correlation analysis of IL-36 and the lung functions in the COPD group.

Figure 4 For control subjects, the IL-36 levels were not related to the number of inflammatory cells. (A–C) Correlation analysis of IL-36 and neutrophils in the control group. (D–F) Correlation analysis of IL-36 and eosinophils in the control group.