Characteristics of alveolar lumen–LA interfaces
| Parameters | Never smokers | Smokers w/o COPD | GOLD I COPD | GOLD II–III COPD | GOLD IV COPD | Overall p value* |
|---|---|---|---|---|---|---|
| LAs with alveolar interfaces, % | ||||||
| BRALT | 50 (0–100) | 50 (0–100) | 100 (100–100) | 100 (100–100) | 100 (0–100) | 0.205 |
| VALT | NA | 100 (100–100) | 100 (100–100) | 100 (0–100) | 100 (83–100) | 0.427 |
| ALT | 100 (100–100) | 100 (100–100) | 100 (100–100) | 100 (75–100) | 100 (100–100) | 0.615 |
| Simple squamous epithelium, % of total alveolar interface | ||||||
| BRALT | 97 (93–100) | 80 (80–80) | 100 (100–100) | 67 (9–100) | 55 (37–73) | 0.077 |
| VALT | NA | 74 (74–74) | 51 (0–100) | 73 (57–100) | 63 (0–84) | 0.655 |
| ALT | 100 (84–100) | 71 (53–89) | 61 (10–70) | 77 (40–89) | 81 (56–97) | 0.126 |
| Simple cuboidal epithelium, % of total alveolar interface | ||||||
| BRALT | 3 (0–7) | 20 (20–20) | 0 | 17 (0–91) | 26 (13–41) | 0.115 |
| VALT | NA | 26 (26–26) | 49 (0–100) | 25 (0–43) | 20 (13–100) | 0.724 |
| ALT | 0 (0–16) | 29 (11–47) | 39 (30–90) | 23 (11–60) | 13 (2–36) | >0.050 |
| Columnar epithelium, % of total alveolar interface | ||||||
| BRALT | 0 | 0 | 0 | 0 (0–65) | 17 (0–40) | 0.097 |
| VALT | NA | 0 | 0 | 0 (0–6) | 6 (0–68) | 0.141 |
| ALT | 0 | 0 | 0 | 0 | 1 (0–34) | 0.089 |
| Number of langerin+ DCs per mm2 of LA | ||||||
| All LAs | 87 (19–262) | 50 (31–128) | 141 (90–262) | 113 (0–203) | 147 (85–228) | 0.225 |
| BRALT | 38 (37–104) | 0 | 151 (141–161) | 94 (0–218) | 130 (108–254) | 0.036 |
| VALT | NA | 70 (31–190) | 174 (61–288) | 179 (27–232) | 145 (96–409) | 0.508 |
| ALT | 182 (102–262) | 100 (99–101) | 168 (155–182) | 79 (0–203) | 126 (15–181) | 0.256 |
| Number of langerin+ DCs per mm of total alveolar interface | ||||||
| All LAs | 0 | 0.14 (0–2.36) | 2.96 (0–5.27) | 2.11 (0–5.76) | 3.10 (1.08–4.77) | 0.031 |
| BRALT | 0 | NA | 0.83 (0–1.67) | 0 (0–3.39) | 3.03 (0.95–5.16) | 0.061 |
| VALT | NA | 0 (0–3.82) | 5.11 (3.21–7.02) | 8.56 (0–11.86) | 4.18 (1.03–8.22) | 0.411 |
| ALT | 0 | 0.84 (0.28–1.40) | 1.87 (0–3.74) | 1.57 (0–9.19) | 1.70 (0–4.78) | 0.349 |
| Number of langerin+ DCs per mm of simple squamous interface | ||||||
| BRALT | 0 | NA | 0.54 (0–1.07) | 0 (0–3.46) | 0.74 (0–3.96) | 0.382 |
| VALT | NA | 0 | 0.24 (0–0.47) | 0 (0–6.81) | 0 (0–2.86) | 0.592 |
| ALT | 0 | 0 | 3.01 (0–6.01) | 0 (0–6.45) | 1.16 (0–4.93) | 0.429 |
| Number of langerin+ DCs per mm of simple cuboidal interface | ||||||
| BRALT | 0 | NA | 1.89 (0–3.78) | 0 (0–6.52) | 1.70 (0–6.29) | 0.211 |
| VALT | NA | 0 (0–5.89) | 9.78 (5.81–13.74) | 5.66 (0–26.06) | 6.85 (0–15.71) | 0.523 |
| ALT | 0 | 4.64 (4.18–5.09) | 0 | 3.05 (0–13.70) | 0.72 (0–7.97) | 0.183 |
| Number of langerin+ DCs per mm of columnar interface | ||||||
| All LAs | NA | NA | NA | 5.26 (3.97–6.56) | 2.10 (0–9.48) | 0.178 |
| BRALT | NA | NA | NA | 2.98 (0–5.95) | 3.44 (0–7.13) | 1.000 |
| VALT | NA | NA | NA | 9.84 (0–19.69) | 2.94 (0–24.83) | 1.000 |
| ALT | NA | NA | NA | 0 | 0 (0–7.12) | 0.422 |
Values are median (range).
*Kruskal–Wallis test for differences between groups or Mann–Whitney test for comparisons between two groups.
ALT, alveolar-only lymphoid tissue; BRALT, small airway/bronchiolar-associated lymphoid tissue; COPD, chronic obstructive pulmonary disease; DC, dendritic cell; GOLD, Global Initiative for Chronic Obstructive Lung Disease; LA, lymphoid aggregate; NA, not available; VALT, vascular-associated lymphoid tissue.