Characteristics and significance of blister fluid cell-free mitochondrial DNA in pediatric small area intermediate-depth burn wounds.

Abstract

Mitochondrial DNA (mtDNA) plays a crucial role in inflammation regulation and can be passively or accidentally released in setting of cellular stress or traumatic injury. In this study, we try to evaluate the distribution and significance of mtDNA in blister fluid of paediatric small area intermediate depth burn wounds. This trial was conducted as a follow-up analysis of a single-centre, prospective observational study that enrolled 62 children with small area partial-thickness thermal burns. The mtDNA in blister fluid was measured with a PCR-based assay. The levels of cytokines including interleukin-6 (IL-6), interleukin-8 (IL-8) and transforming growth factor β1 (TGF-β1) were evaluated by using ELISA. Association of mtDNA with inflammatory markers and wound healing outcome was analysed. The mtDNA copy number (mtDNA-CN) was determined as median (min, max) value of 76.30 (16.5, 219.1). Spearman rank correlation coefficient analysis showed that the levels of IL-6, IL-8, and TGF-β1 all exhibited significant correlations with mtDNA-CN in burn blister fluid samples (all P < 0.05). Moreover, a significant association between wound healing time and mtDNA-CN in blister fluid was observed (P < 0.05); Kaplan-Meier curves by log-rank test demonstrated that mtDNA-CN in blister fluid was significantly associated with for time to re-epithelialization (P < 0.05). Blister fluid mtDNA may serve to evaluate burn wound severity in children with small area intermediate-depth burns.