Table 2.

Comparisons of immune factors.

Immune factor	LC (n = 262)	ILD (n = 220)	Normal (n = 57)	P value
CRP (mg/L)	3.34 ± 5.07	1.83 ± 3.14	0.23 ± 0.34	<0.001
CER (g/L)	0.35 ± 0.10	0.31 ± 0.25	0.25 ± 0.04	<0.001
RF (IU/mL)	18.58 ± 43.47	55.46 ± 83.80	6.23 ± 2.03	<0.001
C3 (g/L)	0.97 ± 0.25	1.04 ± 0.26	1.70 ± 0.29	<0.001
C4 (g/L)	0.21 ± 0.09	0.24 ± 0.09g	0.27 ± 0.24	<0.001
IgG (g/L)	13.42 ± 7.56	14.38 ± 5.98	8.63 ± 1.55	<0.001
IgA (g/L)	2.81 ± 1.57	2.78 ± 1.53	2.58 ± 1.00	0.96
IgM (g/L)	1.22 ± 0.72	1.32 ± 0.96	1.17 ± 0.59	0.77

Data expressed as mean ± standard deviation and differences between groups analyzed by Kruskal–Wallis test. P < 0.05 was considered significant. LC: lung cancer, ILD: interstitial lung disease, Normal: healthy individuals, CRP: C-reactive protein, CER: ceruloplasmin, RF: rheumatoid factor.