Fear Vanessa S, Boyd James H, Rea Suzanne, Wood Fiona M, Duke Janine M, Fear Mark W
Tumour Immunology Group, School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia.
Burn Injury Research Unit, School of Surgery, University of Western Australia, Perth, Western Australia, Australia.
PLoS One. 2017 Jan 9;12(1):e0169302. doi: 10.1371/journal.pone.0169302. eCollection 2017.
Burn injury initiates an acute inflammatory response that subsequently drives wound repair. However, acute disruption to the immune response is also common, leading to susceptibility to sepsis and increased morbidity and mortality. Despite increased understanding of the impact of burn injury on the immune system in the acute phase, little is known about long-term consequences of burn injury on immune function. This study was established to determine whether burn injury has long-term clinical impacts on patients' immune responses.
Using a population-based retrospective longitudinal study and linked hospital morbidity and death data from Western Australia, comparative rates of hospitalisation for respiratory infections in burn patients and a non-injured comparator cohort were assessed. In addition, a mouse model of non-severe burn injury was also used in which viral respiratory infection was induced at 4 weeks post-injury using a mouse modified version of the Influenza A virus (H3NN; A/mem/71-a).
The burn injured cohort contained 14893 adult patients from 1980-2012 after removal of those patients with evidence of smoke inhalation or injury to the respiratory tract. During the study follow-up study a total of 2,884 and 2,625 respiratory infection hospital admissions for the burn and uninjured cohorts, respectively, were identified. After adjusting for covariates, the burn cohort experienced significantly elevated admission rates for influenza and viral pneumonia (IRR, 95%CI: 1.73, 1.27-2.36), bacterial pneumonia (IRR, 95%CI: 2.05, 1.85-2.27) and for other types of upper and lower respiratory infections (IRR, 95% CI: 2.38, 2.09-2.71). In the mouse study an increased viral titre was observed after burn injury, accompanied by a reduced CD8 response and increased NK and NKT cells in the draining lymph nodes. This data suggests burn patients are at long-term increased risk of infection due to sustained modulation of the immune response.
烧伤会引发急性炎症反应，随后推动伤口修复。然而，免疫反应的急性紊乱也很常见，导致患者易患败血症，发病率和死亡率增加。尽管人们对烧伤急性期对免疫系统的影响有了更多了解，但对于烧伤对免疫功能的长期后果知之甚少。本研究旨在确定烧伤是否对患者的免疫反应有长期临床影响。
采用基于人群的回顾性纵向研究，并结合西澳大利亚州的医院发病率和死亡数据，评估烧伤患者和未受伤对照队列中呼吸道感染的住院比较率。此外，还使用了非严重烧伤损伤的小鼠模型，在损伤后4周使用甲型流感病毒（H3NN；A/mem/71-a）的小鼠改良版本诱导病毒性呼吸道感染。
烧伤队列包括1980年至2012年期间的14893名成年患者，排除了有吸入烟雾或呼吸道损伤证据的患者。在研究随访期间，分别确定烧伤队列和未受伤队列的呼吸道感染住院总数为2884例和2625例。在调整协变量后，烧伤队列中流感和病毒性肺炎（发病率比值比，95%置信区间：1.73，1.27 - 2.36）、细菌性肺炎（发病率比值比，95%置信区间：2.05，1.85 - 2.27）以及其他类型的上、下呼吸道感染（发病率比值比，95%置信区间：2.38，2.09 - 2.71）的住院率显著升高。在小鼠研究中，烧伤损伤后观察到病毒滴度增加，同时引流淋巴结中的CD8反应降低，自然杀伤细胞和自然杀伤T细胞增加。这些数据表明，由于免疫反应的持续调节，烧伤患者长期感染风险增加。
