Table 2.
Total phospholipids and surfactant apoprotein concentration, phospholipid profiles, phosphatidylcholine molecular species, and adsorption properties of LA§
| ARDS | Control | |||
| T0 (<24 h) | T1 (3–5 d) | T2 (7–9 d) | ||
| Total Phospholipids [μg/ml] | 31.9 ± 5.0 | 24.3 ± 4.2 | 27.9 ± 5.1 | 35.9 ± 4.8 |
| Phospholipid-to-protein ratio | 0.043 ± 0.010 *** | 0.052 ± 0.021 | 0.109 ± 0.024 §§ | 0.461 ± 0.030 |
| PC [%] | 73.3 ± 2.0 ** | 72.4 ± 3.6 | 74.7 ± 2.2 | 81.3 ± 1.6 |
| PG [%] | 3.6 ± 0.9 *** | 2.8 ± 0.8 | 5.3 ± 0.7 § | 11.6 ± 1.1 |
| PS [%] | 6.5 ± 1.1 *** | 5.4 ± 0.9 | 6.1 ± 1.2 | 1.8 ± 0.7 |
| PI [%] | 5.3 ± 0.9 * | 5.3 ± 1.2 | 5.9 ± 1.3 | 2.5 ± 0.3 |
| PE [%] | 4.8 ± 1.0 * | 6.9 ± 1.6 | 3.3 ± 0.8 | 1.4 ± 0.4 |
| SPH [%] | 5.0 ± 0.7 *** | 5.6 ± 0.9 | 2.9 ± 0.7 § | 0.6 ± 0.3 |
| PC 16:0/16:0 | 26.81 ± 1.61 *** | 32.98 ± 2.36 § | 40.16 ± 1.89 §§§ | 60.65 ± 1.27 |
| PC 16:0/18:1 | 20.43 ± 1.71 *** | 15.37 ± 2.06 § | 12.57 ± 0.79 §§ | 9.68 ± 0.49 |
| PC 16:0/18:2 | 10.33 ± 0.80 *** | 10.00 ± 1.49 | 8.53 ± 0.55 § | 5.43 ± 0.31 |
| PC 16:0/16:1 | 7.76 ± 0.53 * | 6.46 ± 0.40 § | 9.79 ± 0.80 § | 4.84 ± 0.55 |
| PC 16:0/14:0 | 6.76 ± 1.50 | 6.39 ± 0.51 | 7.67 ± 1.44 | 7.18 ± 0.64 |
| PC 16:0/20:4 | 4.36 ± 0.46 ** | 2.63 ± 0.32 § | 2.30 ± 0.55 § | 1.95 ± 0.19 |
| PC 18:0/18:2 | 4.52 ± 0.47 * | 3.99 ± 0.39 | 2.98 ± 0.45 § | 1.54 ± 0.45 |
| PC 18:1/18/1 | 4.00 ± 0.23 | 3.70 ± 0.61 | 2.52 ± 0.22 § | 3.22 ± 0.39 |
| PC 18:0/18:1 | 2.67 ± 0.37 | 3.66 ± 0.52 § | 2.02 ± 0.18 | 2.14 ± 0.29 |
| SP-A [% PL] | 2.61 ± 0.32 ** | 3.07 ± 0.57 | 3.61 ± 0.27 § | 4.12 ± 0.09 |
| SP-B [% PL] | 2.29 ± 0.32 ** | 2.93 ± 0.43 | 2.94 ± 0.41 | 3.71 ± 0.32 |
| SP-C [% PL] | 1.19 ± 0.25 * | 1.34 ± 0.23 | 1.37 ± 0.26 | 2.28 ± 0.22 |
| SP-D [ng/ml] | 14.9 ± 2.9 | 18.8 ± 7.1 | 18.4 ± 5.8 | 14.2 ± 2.2 |
| γ ads [mN/m] | 39.0 ± 1.3 | 33.8 ± 4.7 | 33.2 ± 3.7 | 19.1 ± 0.9 |
§ All data represent mean ± standard error. Control = healthy volunteers; ARDS = acute respiratory distress syndrome. Phospholipid-to-protein ratio and phospholipid profiles were determined in bronchoalveolar lavage fluids (BALF). Each phospholipid class is depicted as percent of all phospholipids. All data are given as mean ± standard error. Definitions of abbreviations: PC = phosphatidylcholine; PG = phosphatidylglycerol; PS = phosphatidylserine; PI = phosphatidylinositol; PE = phosphatidylethanolamine; SPH = sphingomyelin. Values for lysophosphatidylcholine and cardiolipin were not given due to their low content in patients and controls. Phosphatidylcholine molecular species were determined in large surfactant aggregates (LA). Each molecular species is depicted as percent (mol/mol) of all molecular species. Molecular species with a relative content lower than 2% (14:0/14:0, 18:0/18:0, 16:0/22:6, 18:0/20:4, 18:1/18:2, 18:0/14:0) are not given. No significant statistical difference in these molecular species between ARDS at T0 and healthy controls and ARDS at T0 and T1 or T2, respectively, was observed. All data are given as mean ± standard error. Definitions of abbreviations: 14:0 = myristic acid; 16:0 = palmitic acid; 16:1 = palmitoleic acid; 18:0 = stearic acid; 18:1 = oleic acid; 18:2 = linoleic acid; 20:4 = arachidonic acid. Surfactant apoproteins SP-A, SP-B and SP-C were determined in large surfactant aggregates and were depicted as percent (w/w) of phospholipids. Surfactant apoprotein D was determined in bronchoalveolar lavage fluid (BALF) and is given in ng/ml. Surface tension of LA after 11 sec film adsorption (γ ads) is given in mN/m. * = p < 0.05; ** = p < 0.01; *** = p < 0.001: T0 compared to healthy controls (Mann-Whitney-U test) and § = p < 0.05; §§ = p < 0.01; §§§ = p < 0.001: T1, T2 compared to T0 (Wilcoxon test).