Dr Ruilong Zhao1,2, Dr Thomas Lang1, Dr Albert Kim2, Dr Rachel McGrath2, Dr Meilang Xue1, Dr Haiyan Lin1, Mrs Susan Smith3, Dr Siobhan Fitzpatrick2, Dr Nancy Huang2, Dr Andrew Zimmerman1, Dr Aruna Wijewardena2, Prof Gregory Fulcher2, Dr John Vandervord2, Prof Chris Jackson1
1Sutton Laboratory, Kolling Institute at Royal North Shore Hospital, St Leonards, Australia, 2Royal North Shore Hospital, St Leonards, Australia, 3Raymond Purves Laboratory, Kolling Institute at Royal North Shore Hospital, St Leonards, Australia
The natural course of some severe burns patients is difficult to predict without robust biomarkers to assist traditional evaluation. We have recently shown that plasma protein C (PC) levels are reduced following burn injuries (Lang et al. 2019). Here we elucidated PC’s potential utility as a dynamic marker of injury severity and extent, and value as an early predictor of clinical outcome.
We enrolled 86 patients in a single-centre prospective cohort study conducted at Royal North Shore Hospital in Sydney. Serial blood samples were taken and analysed for PC and a panel of six pro-inflammatory cytokines including CRP. Clinical outcome was determined by a previously described composite of fluid/ICU/surgical requirements termed “increased support”.
Plasma PC and CRP both tracked injury recovery over time. Notably, PC was markedly reduced on Day 0 before recovering to normal levels. Throughout the first 1-2 weeks, PC was consistently lower in patients with larger burns (p<0.01), deeper burns (p<0.01), and those with inhalational burns (p<0.05). Whereas in CRP these differences were not apparent until 3-6 days after injury. At baseline on Day 0, burn size (p<0.0005), depth (p<0.0005), inhalational injury (p<0.0005), and PC levels (p<0.0005) – but not any other inflammatory mediator tested – were predictors of clinical outcome. Multivariable regression showed Day 0 PC predicted increased support even when adjusted for burn size, depth and presence of inhalational injury (OR 0.879 (0.793-0.973), p=0.013), with 78.9% sensitivity and 92.3% specificity.
PC may therefore provide a simple yet powerful adjunct for assessment of the burns patient.
Lang, C, Zhao, R, Kim, A, Wijewardena, A, Vanderword, J, McGrath, R, Fitzpatrick, S, Fulcher, G & Jackson, C 2019, ‘Plasma protein C levels are directly associated with better outcomes in patients with severe burns’, Burns, (accepted 01/05/2019)
Ruilong is a junior doctor and a final year PhD student based at the Royal North Shore Hospital in Sydney. There he has discovered a keen interest in burns and reconstructive surgery. His research focuses on protein C’s actions in wound healing and as a biomarker in burn injuries.