Table 1.
Baseline Characteristics by SP-A Tertile*
| Characteristics | Overall (n = 82) | Lowest Tertile (n = 28) | Middle Tertile (n = 27) | Highest Tertile (n = 27) | p Value† |
|---|---|---|---|---|---|
| Age at biopsy, yr | 62 (10) | 61 (13) | 62 (9) | 62 (8) | 0.93 |
| Male gender, No. (%) | 51 (62) | 18 (64) | 17 (63) | 16 (59) | 0.92 |
| Race and ethnicity | |||||
| White | 74 | 24 | 25 | 25 | 0.32 |
| Hispanic | 6 | 4 | 1 | 1 | |
| Black | 1 | 0 | 1 | 0 | |
| Asian | 1 | 0 | 0 | 1 | |
| Smoking status | |||||
| Never-smoker | 31 | 8 | 13 | 10 | 0.28 |
| Former smoker | 40 | 17 | 12 | 11 | |
| Current smoker | 11 | 3 | 2 | 6 | |
| Duration of symptoms, mo | 34 | 31 | 36 | 36 | 0.75 |
| Immunosuppressive therapy, No. of patients treated (%) | 47 (57) | 18 (64) | 15 (56) | 14 (52) | 0.63 |
| Baseline pulmonary function tests | |||||
| FVC, % predicted | 64 (18) | 64 (18) | 60 (16) | 68 (18) | 0.25 |
| FEV1, % predicted | 74 (19) | 76 (23) | 70 (18) | 77 (15) | 0.31 |
| Total lung capacity, % predicted | 75 (16) | 75 (15) | 73 (17) | 78 (17) | 0.45 |
| Dlco, % predicted | 54 (16) | 58 (18) | 53 (12) | 50 (17) | 0.15 |
| Baseline oxygen saturation, % | 95 (3) | 95 (3) | 95 (3) | 95 (3) | 0.78 |
| Baseline alveolar-arterial oxygen gradient‡ | 21 (9–36) | 15 (7–27) | 21 (13–36) | 31 (10–42) | 0.12 |
| Baseline BAL fluid neutrophils,‡ % | 6 (3–13) | 6 (4–11) | 3 (2–12) | 11 (2–18) | 0.41 |
*Values are given as the mean (SD), No., or median (interquartile range), unless otherwise indicated. Lowest tertile, ≥ 80.4 ng/mL; middle tertile, 81 to 123 ng/mL; highest tertile, > 123 ng/mL.
†p Values are for comparison among the three subgroups, using χ2 test, Fisher exact test, or analysis of variance, where appropriate.
‡Data were not normally distributed. A Kruskal-Wallis test was performed.