Table 1. Comparisons of clinical characteristics and eosinophil biomarkers between severe and nonsevere asthmatics.

Variables	Severe asthmatics (n = 235)	Non severe asthmatics (n = 898)	P value
Age (yr)	46.01 ± 13.93	42.69 ± 14.63	0.001
Sex (female, %)	62.6	61.9	0.848
Atopy (%)	54.4	54.9	0.885
Smoking history (current and ex-smoker, %)	57.4	45.9	0.023
Duration of asthma (yr)	8.04 ± 6.61	5.72 ± 10.56	< 0.0001
Chronic rhinosinusitis (%)	50.0	35.0	0.008
Nasal polyp (%)	41.7	28.0	0.007
Log (baseline FEV1)	1.83 ± 0.15	1.94 ± 0.12	< 0.0001
Log (methacholine PC20)	0.40 ± 0.67	0.53 ± 0.73	0.042
Log (total IgE)	2.27 ± 0.55	2.20 ± 0.64	0.248
Log (total eosinophil count)	2.53 ± 0.44	2.39 ± 0.47	0.002
Sputum eosinophil (%)	26.95 ± 35.59	22.11 ± 33.15	0.031
Sputum neutrophil (%)	56.62 ± 35.29	58.90 ± 33.84	0.558
Serum ECP (µg/L)	44.52 ± 45.95	31.99 ± 38.46	< 0.0001
Serum EDN (MBL) (ng/mL)	69.08 ± 42.40	58.46 ± 35.56	0.034
Serum EDN (K-EDN) (ng/mL)	157.75 ± 128.18	109.02 ± 104.12	0.001
Serum periostin (ng/mL)	91.56 ± 41.21	77.72 ± 38.56	0.001

Each value is presented as mean ± standard deviation or %.

FEV1, forced expiratory volume in 1 second; PC20, provocation concentration causing a 20% fall in FEV1; Log (total IgE), log-transformed serum total immunoglobulin E levels; Log (total eosinophil count), log-transformed total eosinophil count; ELISA, enzyme-linked immunosorbent assay; EDN, eosinophil-derived neurotoxin; Serum EDN (MBL), serum EDN levels measured by ELISA kit of MBL; Serum EDN (K-EDN), serum EDN levels measured by ELISA kit of K-EDN.