Clinical significance of cigarette smoking and dust exposure in pulmonary alveolar proteinosis: a Korean national survey

Table 1 Baseline Characteristics of the patients diagnosed with PAP between 1993 and 2014 in Korea (n = 78)

Variables^a	N = 78
Classification
Idiopathic	75 (96.2)
Secondary	3 (3.8)
Age (median years [IQR])	47.5 (42.5–59)
Male	47 (60.3)
Smoking status (n = 73)
Never-smoker	34 (46.6)
Ex-smoker	18 (24.6)
Current smoker	21 (28.8)
Symptoms
Symptomatic	62 (79.5)
Asymptomatic	16 (20.5)
Disease severity score^b (n = 65)
1	9 (13.8)
2	33 (50.8)
3	16 (24.6)
4	4 (6.2)
5	3 (4.6)
Presence of dust exposure (n = 71)	34 (47.9)
Extent of radiologic involvement
Diffuse bilateral lung involvement	32 (41.0)
Chest CT pattern (n = 50)
Ground glass opacity (GGO) only	18 (36.0)
GGO + crazy paving appearance	32 (64.0)
FVC % predicted	81.1 ± 16.6
DL_CO % predicted	69.5 ± 25.2
PaO₂ mm Hg	79.1 ± 24.7
D(A-a)O₂ mm Hg	28.1 ± 15.2
Hb g/dL	14.1 ± 2.3
LDH U/L	419.3 ± 180.7
CEA ng/mL	7.0 ± 7.8
Follow-up days (median [IQR])	677 (214–1588)

IQR interquartile range, FVC forced vital capacity, DL _CO diffusing capacity of the lung for carbon monoxide, Hb hemoglobin, LDH lactate dehydrogenase, CEA carcinoembryonic antigen
^aParametric data are shown as means (± standard deviation) and nonparametric data as medians and interquartile ranges (IQRs). Dichotomous or discontinuous variables are presented as numbers (%)
^bData on arterial blood gas analyses could not be obtained in 13 patients. The categories of score ranged from DSS 1 to DSS 5 as described previously¹⁷; DSS 1 = no symptoms and PaO₂ ≥ 70 mmHg, DSS 2 = symptomatic and PaO₂ ≥ 70 mmHg, DSS 3 = 60 mmHg ≤ PaO₂ < 70 mmHg, DSS 4 = 50 mmHg ≤ PaO₂ < 60 mmHg, DSS 5 = PaO₂ < 50 mmHg

ISSN: 1471-2466