TABLE 1.
Baseline characteristics of study participants in the control group
| Recovered COVID-19 | Never COVID-19 | p-value | |
|---|---|---|---|
| Participants | 4 | 5 | |
| Age, years | 48 (32–61) | 26 (24–65) | 1.00 |
| Male | 2 (50) | 2 (40) | 1.00 |
| BMI kg·m−2 | 25.6 (21.9–287.7) | 22.9 (22.4–24.6) | 0.71 |
| Cigarette smoking status | 0.17 | ||
| Former | 2 (50) | 0 (0) | |
| Never | 2 (50) | 5 (100) | |
| Cannabis smoking status | 1.00 | ||
| Current | 1 (25) | 1 (20) | |
| Never | 3 (75) | 4 (80) | |
| E-cigarette smoking status | 1.00 | ||
| Current | 0 (0) | 1 (20) | |
| Never | 4 (100) | 4 (80) | |
| SGRQ | 3.1 (1.9–4.9) | 1 (0.8–5.7) | 0.54 |
| Symptoms | 2.6 (0–6) | 6.7 (5.7–23.2) | 0.26 |
| Activity | 9.2 (4.7–13.7) | 0 (0–0) | 0.23 |
| Impact | 0 (0–0) | 0 (0–0) | 0.50 |
| Pulmonary function testing | |||
| FVC L | 4.1 (3.9–4.4) | 3.9 (3.8–4.8) | 0.90 |
| FVC % predicted | 122.2 (113.4–127.5) | 116.5 (106.6–122.3) | 0.39 |
| FEV1 L | 3.5 (3.3–3.8) | 3.4 (3–4.2) | 1.00 |
| FEV1 % predicted | 123.1 (117.5–125.4) | 116.9 (104.6–117.7) | 0.11 |
| FEV1/FVC % | 80.8 (80.3–83.9) | 81 (78.4–86.9) | 0.66 |
| DLCO % predicted | 108.2 (105.3–111.6) | 108.1 (99.4–112.2) | 0.71 |
| Blood cell counts | |||
| White blood cells ×109 cells·L−1 | 5.2 (4.9–5.5) | 4.5 (3.9–4.6) | 0.11 |
| Neutrophils % | 58.3 (54.6–61.8) | 55.7 (46.8–57.1) | 0.71 |
| Lymphocytes % | 29.7 (28–31.3) | 34.9 (34.6–36.5) | 0.18 |
| Monocytes % | 4.5 (4.1–5.2) | 4.3 (4.2–4.4) | 0.90 |
| Eosinophils % | 3.1 (1.8–4.6) | 2 (1.9–2.5) | 1.00 |
| Basophils % | 0.5 (0.4–0.5) | 0.7 (0.6–1) | 0.10 |
| BAL differential cell count# | |||
| Macrophage % | 90 (82.3–94.8) | 79 (77–91) | 0.54 |
| Lymphocytes % | 8.5 (5–14) | 8 (4–16) | 1.00 |
| Neutrophils % | 1.5 (0.8–3) | 5 (2–5) | 0.39 |
| Eosinophils % | 0 (0–0.3) | 0 (0–0) | 0.37 |
Data are presented as n, median (interquartile range) or n (%), unless otherwise stated. COVID-19: coronavirus disease 2019; BMI: body mass index; SGRQ: St George's Respiratory Questionnaire; FVC: forced vital capacity; FEV1: forced expiratory volume in 1 s; DLCO: diffusion capacity for carbon monoxide; BAL: bronchoalveolar lavage. #: the percentages of each type of leukocyte present in the BAL fluid.