Table 1.
Patient characteristics and the data of serum and BALF levels of SP-A and SP-D
| IPF | SAR | HS | ||
|---|---|---|---|---|
| N | 36 | 18 | 20 | |
| Sex (male: female) | 18:8 | 8:10 P = 0.073 | 17:3 P = 0.339 | P = 0.004 |
| Age (years old) | 67.6 ± 8.0 | 53.7 ± 16.2 P < 0.001 | 28.2 ± 6.3 P < 0.001 | P < 0.001 |
| Smoking status (current: ex-: never smoker) | 7: 20: 9 | 4: 8: 6 P = 0.528 | 8: 0: 12 P < 0.001 | P < 0.001 |
| BALF recovery (%) | 51.7 ± 16.5 | 57.9 ± 12.5 P = 0.513 | 66.1 ± 22.4 P = 0.001 | P = 0.002 |
| Serum SP-A level (ng/ml) | 84.5 (55.5 – 115.8) | 33.3 (26.1 – 52.0) P < 0.001 | - | |
| Serum SP-D level (ng/ml) | 272.0 (172.0 – 441.8) | 75.0 (48.8 – 97.3) P < 0.001 | - | |
| BALF SP-A level (ng/ml) | 1275.0 (581.0 – 2672.5) | 1600.0 (972.0 – 3220.0) | 1978.0 (1380.0 – 3749.0) | P = 0.245 |
| BALF SP-D level (ng/ml) | 379.0 (223.8 – 570.8) | 704.5 (389.3 – 967.5) P = 0.003 | 667.0 (391.0 – 1219.0) P = 0.003 | P < 0.001 |
| BALF/serum ratio of SP-A levels | 19.1 (6.9 – 41.6) | 51.2 (18.5 – 103.8) P = 0.01 | - | |
| BALF/serum ratio of SP-D levels | 1.3 (0.7 – 2.4) | 7.8 (4.7 – 20.1) P < 0.001 | - |
The data of age and the BALF recovery rate with symmetric distribution are presented as mean ± standard deviation. Sex and the smoking status were evaluated by the chi-square test. The other data show asymmetric distribution, which is presented as a median (interquartile range). P values below each data value were calculated using the Mann–Whitney U–test to compare with the IPF group. P values in the rightmost column were calculated using the Kruskal–Wallis test to analyze the distribution of data among the three groups. SP-A, surfactant protein A; SP-D, surfactant protein D; BALF, bronchoalveolar lavage fluid; HS, healthy subjects; IPF, idiopathic pulmonary fibrosis patients; SAR, sarcoidosis patients.