Tuo Zang1, Daniel A. Broszczak2, Leila Cuttle3, Tony J. Parker4

1. Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
Wound Management Innovation Co-operative Research Centre, Brisbane, Australia. tuo.zang@hdr.qut.edu.au
2. Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
Wound Management Innovation Co-operative Research Centre, Brisbane, Australia. dan.broszczak@qut.edu.au
3. Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
Centre for Children’s Burns and Trauma Research, Queensland University of Technology, Institute of Health and Biomedical Innovation at the Centre for Children’s Health Research, South Brisbane, Australia. leila.cuttle@qut.edu.au
4. Tissue Repair and Regeneration Program, Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Australia.
School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia. a.parker@qut.edu.au

The degree of burn severity (superficial-, deep-, or full-thickness injury) dictates the clinical management of the injury and the extent of later scar formation. It can often take several days for the true depth of a burn injury to become apparent. Additionally, the biological processes by which burn injuries continue to deepen over time (burn wound conversion) is not well understood. Burn blister fluid (BF), which forms following injury, contains proteins that reflect both the systemic and local microenvironment response to the injury and is an ideal resource to study wound biochemistry.
Burn BF from 101 children were analysed using qualitative and quantitative mass spectrometry techniques. This enabled the development of a comprehensive library of all detectable proteins in BF. This protein library was then used to extract quantitative information from data independent acquired mass spectra to obtain relative abundances of more than 600 proteins in each individual sample. Significant differences in relative protein abundance were detected between burns of different depth. In particular, specific hemoglobin subunits exhibit significant fold change differences between different burn depths (p<0.05) and have the most importance in classification of depth. In addition, gene ontology analysis of the BF proteome revealed a number of significantly over-represented cellular components such as extracellular vesicle transport which were associated with burn depth. This will open new avenues for diagnostic and prognostic development and perhaps assist with the production of a more timely objective and quantitative measure for classification of burn severity in children at point of presentation.

Key Words
Paediatric burn, burn depth, mass spectrometry, proteomics, blister fluid, gene ontology