Increased serum IL-17 and decreased serum IL-10 and IL-35 levels correlate with the progression of COPD

Figures & data

Table 1 Clinical data of included patients (75 cases)

Items	Groups	COPD group (n, %)	Control group (n, %)
Gender	Male	47 (62.7)	15 (50)
	Female	28 (37.3)	15 (50)
Age (years)	<70	33 (44)	16 (53.3)
	≧70	42 (56)	14 (46.7)
Smoking status	Yes	39 (52)	11 (36.7)
	No	36 (48)	19 (63.3)
GOLD classification	1	7 (9.3)
	2	13 (17.3)
	3	29 (38.7)
	4	26 (34.7)
Scores of mMRC	2	12 (16)
	3	31 (41.3)
	4	32 (42.7)
Clinical history (years)	<10	25 (33.3)
	≧10<20	21 (28)
	≧20	29 (38.7)

Notes: GOLD-1, the predicted FEV₁ percentage is ≥80%; GOLD-2, the predicted FEV₁ percentage is ≥50%, but <80%; GOLD-3, the predicted FEV₁ percentage is ≥30%, but <50%; and GOLD-4, the predicted FEV₁ percentage is <30%.

Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; GOLD, Global initiative for chronic Obstructive Lung Disease; mMRC, modified British Medical Research Council for dyspnea scale for symptom classification of COPD.

Table 2 Correlations between clinical features and the serum levels of IL-17, IL-10, and IL-35 in patients with stable COPD (N=75)

Parameter	Group	n	Level of IL-17			Level of IL-10			Level of IL-35
			(M±SD, pg/mL)	Statistical value	P-value	(M±SD, pg/mL)	Statistical value	P-value	(M±SD, pg/mL)	Statistical value	P-value
Resources	Healthy control	30	40.77±16.07	−8.80	<0.001	320.63±33.46	14.81	<0.001	353.61±57.12	17.30	<0.001
	Stable COPD	75	69.31±14.57			188.34±44.05			169.28±45.83
Gender	Male	47	70.71±15.89	1.077	0.285	187.97±45.29	−2.75	0.071	164.08±46.09	−1.27	0.207
	Female	28	66.97±11.95			205.74±36.37			177.99±45.03
Age (years)	<70	33	65.41±16.40	−2.10	0.039	206.14±46.96	3.30	0.001	191.84±46.51	4.17	<0.001
	≧70	42	72.38±12.31			174.35±36.41			151.55±31.76
Smoking	Yes	39	72.00±15.58	1.68	0.096	172.51±45.68	−3.47	0.001	158.12±48.8	−2.25	0.027
	No	36	66.39±12.99			205.48±35.43			181.36±39.72
GOLD grade	1	7	42.07±8.36	64.84	<0.001	267.86±25.76	74.61	<0.001	252.41±22.13	136.33	<0.001
	2	13	55.28±8.74			220.39±17.38			212.69±17.19
	3	29	71.61±6.34*			194.24±15.80*			172.67±11.82*
	4	26	81.09±8.35*			144.32±28.27*			121.40±23.51*
mMRC score	2	12	48.28±10.74	31.95	<0.001	247.05±32.76	24.31	<0.001	236.48±27.38	38.66	<0.001
	3	31	69.13±10.93**			189.05±30.17			172.76±32.42**
	4	32	77.37±10.59**			165.63±38.77**			169.27±45.89**
Clinical history (years)	<10	25	58.89±16.35	16.86	<0.001	221.75±39.79	20.31	<0.001	203.32±37.21	27.63	<0.001
	≧10<20	21	69.41±9.81			188.18±33.32			178.08±30.07
	≧20	29	78.22±9.18***			159.64±33.60***			133.39±46.89***

Notes: For IL-17: *, GOLD grades 3 and 4 compared with GOLD grades 1 and 2; **, mMRC scores of 3 and 4 compared with mMRC score of 2; ***, a clinical history of ≥20 years compared with a history of <10 years. For IL-10: *, GOLD grades 3 and 4 compared with GOLD grades 1 and 2; **, mMRC score of 4 compared with mMRC scores of 3 and 2; ***, a clinical history of ≥20 years compared with a history of <10 years. For IL-35: *, GOLD grades 3 and 4 compared with GOLD grades 1 and 2; **, mMRC scores of 4 and 3 compared with mMRC score of 2; ***, a clinical history of ≥20 years compared with a history of <20 years.

Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global initiative for chronic Obstructive Lung Disease; IL, interleukin; mMRC, modified British Medical Research Council.

Figure 1 Correlation between clinical factors and the serum level of IL-17 in patients with stable COPD.

Notes: (A) The expression of serum IL-17 was upregulated in patients with stable COPD compared with those in the control group (P<0.001). (B) Increased serum IL-17 level positively correlated with the age of patients (P=0.039). (C) Serum IL-17 expression did not correlate with the smoking status of patients (P=0.096). (D) The serum level of IL-17 in patients with GOLD-3 and -4 was higher than that in patients with GOLD-1 and -2 (*P<0.001). (E) Patients with mMRC scores of 3 and 4 showed higher serum levels of IL-17 compared with those with mMRC score of 2 (*P<0.001). (F) Patients with a long clinical history displayed a higher expression of serum IL-17 than those with a short history (*P<0.001).
Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global initiative for chronic obstructive Lung Disease; IL, interleukin; mMRC, modified British Medical Research Council.

Figure 2 Correlation between clinical factors and the serum level of IL-10 in patients with stable COPD.

Notes: (A) Patients with stable COPD showed lower levels of serum IL-10 than those in the control group (P<0.001). (B) Decreased IL-10 negatively correlated with the age of patients (P=0.001). (C) Decreased IL-10 negatively correlated with the smoking status of patients (P=0.001). (D) Patients with GOLD-3 and -4 showed lower levels of serum IL-10 than those with GOLD-1 and -2 (*P<0.001). (E) Serum level of IL-10 in patients with mMRC score of 4 was lower than in those with mMRC scores of 2 and 3 (*P<0.001). (F) Patients with longer clinical history displayed a lower expression of serum IL-10 than those with a short history (*P<0.001).
Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global initiative for chronic Obstructive Lung Disease; IL, interleukin; mMRC, modified British Medical Research Council.

Figure 3 Correlation between clinical factors and the serum level of IL-35 in patients with stable COPD.

Notes: (A) A lower level of serum IL-35 was observed in patients with stable COPD compared with those in the control group (P<0.001). (B) The upregulation of serum IL-35 negatively correlated with the age of patients (P<0.001). (C) The upregulation of serum IL-35 negatively correlated with the smoking status of patients (P=0.027). (D) Patients with GOLD-3 and -4 showed lower levels of serum IL-35 than those with GOLD-1 and -2 (*P<0.001). (E) Patients with mMRC scores of 3 and 4 showed lower levels of serum IL-35 than those with mMRC score of 2 (*P<0.001). (F) Patients with a long clinical history displayed a lower expression of serum IL-35 than those with a short history (*P<0.001).
Abbreviations: COPD, chronic obstructive pulmonary disease; GOLD, Global initiative for chronic Obstructive Lung Disease; IL, interleukin; mMRC, modified British Medical Research Council.

Table 3 Linear correlation analysis of important indicators (N=75)

Items	Linear correlation analysis of continuous variables
	Correlations		Variance analysis			Coefficients
	Pearson’s correlation	P-value	Adjusted square	F-value	P-value	Regression coefficient	T-value	P-value	95% CI	Equation
IL-17 and IL-10	−0.717	<0.001	0.51	77.25	<0.001	−2.17	−19.39	<0.001	−2.658 to −1.676	^Y=338−2.17X
IL-17 and IL-35	−0.765	<0.001	0.58	103.27	<0.001	−2.41	−20.03	<0.001	−2.880 to −1.937	^Y=336−2.41X
IL-10 and IL-35	0.775	<0.001	0.59	109.53	<0.001	0.81	10.46	<0.001	0.653–0.961	^Y=17+0.807X
IL-17 and FEV1/FVC	−0.789	<0.001	0.62	120.46	<0.001	−0.008	−10.976	<0.001	−0.009 to −0.006	^Y=−0.969−0.008X
IL-17 and FEV1% predicted	−0.847	<0.001	0.71	185.35	<0.001	−0.011	−13.61	<0.001	−0.013 to −0.010	^Y=−1.217−0.011X
IL-10 and FEV1/FVC	0.778	<0.001	0.601	112.29	<0.001	0.003	10.597	<0.001	0.002–0.003	^Y=−0.035+0.003X
IL-10 and FEV1% predicted	0.815	<0.001	0.659	143.98	<0.001	0.004	12.000	<0.001	0.003–0.004	^Y=−0.244+0.004X
IL-35 and FEV1/FVC	0.834	<0.001	0.692	166.68	<0.001	0.003	12.922	<0.001	0.002–0.003	^Y=−0.001+0.003X
IL-35 and FEV1% predicted	0.869	<0.001	0.751	224.21	<0.001	0.004	14.976	<0.001	0.003–0.004	^Y=−0.19+0.004X

Abbreviations: FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; IL, interleukin.

Figure 4 Correlation between the serum levels of IL-17, IL-10, and IL-35 in patients with stable COPD.

Notes: (A) Histogram of serum IL-17 and IL-10 shows that the normalized residuals belonged to normal distribution (P>0.05). (B) The P–P plot suggests that scatter points derived from IL-17 and IL-10 had normal distribution (P<0.05). (C) The dependent variable is approximately linear with the standardized predictive value, which indicates that IL-17 and IL-10 had a negative linear correlation (P<0.001). (D) The vast majority of normalized residuals did not exceed 3, suggesting no abnormal values of IL-17 and IL-10 were found. (E) Histogram of IL-17 and IL-35 shows that the normalized residuals belonged to normal distribution (P>0.05). (F) The P–P plot suggests that scatter points derived from IL-17 and IL-35 showed a normal distribution (P<0.05). (G) The dependent variable is approximately linear with the standardized predictive value, which indicates that IL-17 and IL-35 had a negative linear correlation (P<0.001). (H) The vast majority of normalized residuals did not exceed 3, suggesting no abnormal values of IL-17 and IL-35 were found. (I) Histogram of IL-10 and IL-35 shows that the normalized residuals had normal distribution (P>0.05). (J) The P–P plot suggests that scatter points derived from IL-10 and IL-35 had normal distribution (P<0.05). (K) The dependent variable is approximately linear with the standardized predictive value, which indicates that IL-10 and IL-35 had a positive linear correlation (P<0.001). (L) The vast majority of normalized residuals did not exceed 3, suggesting no abnormal values of IL-10 and IL-35 were found.
Abbreviations: COPD, chronic obstructive pulmonary disease; IL, interleukin.

Figure 5 Correlation between the serum levels of IL-17, IL-10, and IL-35 and pulmonary function in patients with stable COPD.

Notes: (A) Histogram of serum IL-17 and FEV₁/FVC suggests that these variables had a characteristic of normal distribution (P>0.05). (B) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-17 and FEV₁/FVC of patients had a negative linear correlation (P<0.001). (C) Histogram of serum IL-17 and FEV₁% predicted suggests that these variables had a characteristic of normal distribution (P>0.05). (D) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-17 and FEV₁% predicted of patients had a negative linear correlation (P<0.001). (E) Histogram of serum IL-10 and FEV₁/FVC suggests that these variables had a characteristic of normal distribution (P>0.05). (F) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-10 and FEV₁/FVC of patients had a negative linear correlation (P<0.001). (G) Histogram of serum IL-10 and FEV₁% predicted suggests that these variables had a characteristic of normal distribution (P>0.05). (H) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-10 and FEV₁% predicted of patients had a negative linear correlation (P<0.001). (I) Histogram of serum IL-35 and FEV₁/FVC suggests that these variables had a characteristic of normal distribution (P>0.05). (J) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-35 and FEV₁/FVC of patients had a negative linear correlation (P<0.001). (K) Histogram of serum IL-35 and FEV₁% predicted suggests that these variables had a characteristic of normal distribution (P>0.05). (L) The dependent variable is approximately linear with the standardized predictive value, which indicates that serum IL-35 and FEV₁% predicted of patients had a negative linear correlation (P<0.001).
Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; IL, interleukin.