Changes and clinical significance of multiple cytokines in exhaled breath condensate in patients with severe inhalation injury / 中华危重病急救医学

ABSTRACT

Objective:To investigate the changes and clinical significance of multiple cytokine levels in exhaled breath condensate (EBC) in patients undergoing tracheotomy with severe inhalation injury.Methods:A prospective study was conducted. A total of 32 patients with severe burn combined with severe inhalation injury admitted to the department of burns and plastic surgery of Affiliated Suzhou Hospital of Nanjing Medical University from May 2021 to August 2022 were enrolled. Twenty healthy volunteers from the same period were served as controls. EBC of patients at 12 hours after burn and the samples of healthy controls were collected. The levels of 27 cytokines in EBC, including tumor necrosis factor-α (TNF-α) and interleukins (IL-1β, IL-6, IL-8, IL-10, and IL-17), were determined by liquid phase chip technology. Meanwhile, plasma of patients at 12 hours after burn and the plasma of volunteers were collected, and the levels of inflammatory cytokines were detected by liquid chip technology, and the differences between the levels in plasma and those in EBC were analyzed. Plasma and EBC of patients with aspiration injury were collected at 12 hours and 3, 7, 14 and 21 days after burn, and TNF-α levels were determined by enzyme-linked immunosorbent assay (ELISA).Results:Finally, 32 patients were enrolled, and the total burned area was (40±16)% of total body surface area (TBSA). The time of admission was (4.2±2.3) hours after injury. ① Twenty-seven cytokines in EBC: 18 kinds of cytokines including macrophage inflammatory protein-1β (MIP-1β), IL-6, IL-5, IL-2, IL-1β, IL-8, IL-10, IL-15, IL-9, interferon-γ (IFN-γ), IL-1 receptor antagonist (IL-1ra), TNF-α, chemotactic factor for eosinophil (Eotaxin), basic fibroblast growth factor (bFGF), platelet derived growth factor-BB (PDGF-BB), interferon-inducible protein-10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), granulocyte colony-stimulating factor (G-CSF) were significantly increased in patients with severe aspiration injury compared with health controls. Eotaxin was not detected in EBC of healthy controls. Five cytokines, granulocyte-macrophage colony-stimulating factor (GM-CSF), chemokine ligand 5 (CCL5/RANTES), IL-13, IL-4 and MIP-1α, were not detected in EBC of severe inhalation injury patients and healthy controls. Vascular endothelial growth factor (VEGF) and IL-12 p70 in EBC of severe aspiration injury patients were slightly decreased as compared with healthy controls, while IL-7 and IL-17 were slightly increased, but the differences were not statistically significant. ② Six inflammatory cytokines in plasma: the levels of IL-6 and IL-8 in the severe aspiration injury group were significantly increased as compared with healthy controls [IL-6 (ng/L): 18.51 (10.87, 26.21) vs. 0.22 (0.10, 0.36), IL-8 (ng/L): 10.75 (8.58, 18.79) vs. 1.06 (0.81, 2.14), both P < 0.01]. The plasma levels of TNF-α, IL-1β and IL-10 were slightly increased in patients with severe aspiration injury as compared with healthy controls, and IL-17 was slightly decreased, but the difference was not statistically significant. In the EBC collected during the same period, five inflammatory cytokines, including TNF-α, IL-1β, IL-6, IL-8 and IL-10, in patients with severe inhalation injury were significantly increased as compared with healthy controls [TNF-α (ng/L): 16.42 (12.57, 19.21) vs. 7.34 (6.11, 8.69), IL-1β (ng/L): 15.57 (10.53, 20.25) vs. 0.99 (0.67, 1.41), IL-6 (ng/L): 13.36 (9.76, 16.54) vs. 0.70 (0.42, 0.85), IL-8 (ng/L): 1 059.29 (906.91, 1 462.37) vs. 10.36 (8.40, 12.37), IL-10 (ng/L): 2.69 (1.54, 3.33) vs. 1.54 (1.18, 2.06), all P < 0.05]. ③ Dynamic changes of TNF-α in plasma and EBC: the level of TNF-α in EBC of patients with severe aspiration injury was lower than that in plasma. Plasma TNF-α level was increased gradually with the extension of time after injury, and was significantly higher than that of healthy controls on day 3 [ng/L: 30.38 (24.32, 39.19) vs. 22.94 (17.15, 30.74), P < 0.05], and reached the peak on day 14, then fell back. The level of TNF-α in EBC at 12 hours after injury was significantly higher than that in healthy controls [ng/L: 15.34 (11.75, 18.14) vs. 6.99 (6.53, 7.84), P < 0.01], and reached the peak on 3 days after injury, and then gradually decreased. Conclusion:There are changes in the expression of multiple cytokines in EBC of patients with severe inhalation injury, and the changes of many inflammatory cytokines including TNF-α are more sensitive than those in plasma, which can be used to monitor and evaluate the condition of patients with inhalation injury.