TABLE 1

Baseline characteristics

Characteristics of CHP cohort^#	No IS^¶	IS⁺	p-value
Age years	65.1±10	61.1±12	0.07
Male	19 (50%)	34 (37%)	0.16
Caucasian race/ethnicity	31 (82%)	80 (86%)	0.52
BMI kg·m⁻²	33.0±9	32.6±9	0.83
Ever-smoker	20 (53%)	54 (58%)	0.57
Antigen exposure^§
Avian	19 (50%)	42 (45%)	0.61
Mould	11 (29%)	28 (30%)	0.90
Hot tub	1 (3%)	2 (2%)	0.99
Unknown	11 (29%)	29 (31%)	0.80
Gastro-oesophageal reflux	20 (53%)	58 (62%)	0.30
Crackles	28 (73%)	85 (91%)	0.008
Clubbing	3 (8%)	26 (28%)	0.012
TLC^ƒ % predicted	79.7±19	69.0±17	0.002
FVC^## % predicted	73.3±19	60.0±17	<0.001
D_LCO^¶¶ % predicted	69.2±23	47.2±22	<0.001
Oxygen therapy	9 (24%)	66 (71%)	<0.001
ANA seropositivity	11 (31%)	26 (29%)	0.78
HRCT features
HRCT fibrosis score	117.8±10	125.9±18	0.01
Mosaic attenuation	31 (82%)	81 (87%)	0.42
Ground-glass opacities	33 (87%)	86 (93%)	0.31
Honeycombing	14 (37%)	42 (45%)	0.38
Histopathological features
SLB obtained	18 (47%)	62 (67%)	0.04
Poorly formed granulomas	11 (61%)	41 (66%)	0.69
Honeycombing with UIP pattern	7 (39%)	29 (47%)	0.55
Follow-up time months	43±30	38±27	0.37

Data are presented as mean±sd or n (%). CHP: chronic hypersensitivity pneumonitis; IS: immunosuppressive therapy; BMI: body mass index; TLC: total lung capacity; FVC: forced vital capacity; D_LCO: diffusing capacity of the lung for carbon monoxide; ANA: antinuclear antibody; HRCT: high-resolution computed tomography; SLB: surgical lung biopsy; UIP: usual interstitial pneumonia. ^#: n=131. ^¶: n=38. ⁺: n=93. ^§: a historical assessment of environmental antigen exposures (avian, mould, hot tub and unknown) is performed for all patients in the University of Chicago interstitial lung disease registry, regardless of referring diagnosis; the presence of antibodies to serum precipitins supported the diagnosis but was not a requirement; ANA was evaluated in 125 patients, threshold used for seropositive titre ≥1:320. ^ƒ: exception for patients, n=127. ^##: exception for patients, n=130. ^¶¶: exception for patients, n=116.