Genetic influence on scar height and pliability after burn injury in individuals of European ancestry: A prospective cohort study.

After similar extent of injury there is considerable variability in scarring between individuals, in part due to genetic factors. This study aimed to identify genetic variants associated with scar height and pliability after burn injury. An exome-wide array association study and gene pathway analysis were performed on a prospective cohort of 665 patients treated for burn injury. Outcomes were scar height (SH) and scar pliability (SP) sub-scores of the modified Vancouver Scar Scale (mVSS). DNA was genotyped using the Infinium® HumanCoreExome-24 BeadChip. Associations between genetic variants (single nucleotide polymorphisms) and SH and SP were estimated using an additive genetic model adjusting for age, sex, number of surgical procedures and % total body surface area of burn in subjects of European ancestry. No individual genetic variants achieved the cut-off threshold of significance. Gene regions were analysed for spatially correlated single nucleotide polymorphisms and significant regions identified using comb-p software. This gene list was subject to gene pathway analysis to find which biological process terms were over-represented. Using this approach biological processes related to the nervous system and cell adhesion were the predominant gene pathways associated with both SH and SP. This study suggests genes associated with innervation may be important in scar fibrosis. Further studies using similar and larger datasets will be essential to validate these findings.

Identification of factors predicting scar outcome after burn injury in children: a prospective case-control study.

BACKGROUND: There is a lack of rigorous research investigating the factors that influence scar outcome in children. Improved clinical decision-making to reduce the health burden due to post-burn scarring in children will be guided by evidence on risk factors and risk stratification. This study aimed to examine the association between selected patient, injury and clinical factors and the development of raised scar after burn injury. Novel patient factors were investigated including selected immunological co-morbidities (asthma, eczema and diabetes type 1 and type 2) and skin pigmentation (Fitzpatrick skin type). METHODS: A prospective case-control study was conducted among 186 children who sustained a burn injury in Western Australia. Logistic regression was used to explore the relationship between explanatory variables and a defined outcome measure: scar height measured by a modified Vancouver Scar Scale (mVSS). RESULTS: The overall correct prediction rate of the model was 80.6%; 80.9% for children with raised scars (>1 mm) and 80.4% for children without raised scars (≤1 mm). After adjustment for other variables, each 1% increase in % total body surface area (%TBSA) of burn increased the odds of raised scar by 15.8% (95% CI = 4.4-28.5%). Raised scar was also predicted by time to healing of longer than 14 days (OR = 11.621; 95% CI = 3.727-36.234) and multiple surgical procedures (OR = 11.521; 1.994-66.566). CONCLUSIONS: Greater burn surface area, time to healing of longer than 14 days, and multiple operations are independently associated with raised scar in children after burn injury. Scar prevention strategies should be targeted to children with these risk factors.

Identification of factors predicting scar outcome after burn in adults: A prospective case-control study.

This study examined influences on scarring after burn in a prospective study using a defined outcome measure: scar height measured by a modified Vancouver Scar Scale (mVSS). A prospective case-control study was conducted among 616 adult subjects who sustained a burn in Western Australia. Patient factors influencing scar outcome including gender, Fitzpatrick skin type and selected co-morbidities were explored, as well as injury and clinical factors. A logistic regression model for raised scar after burn was developed which achieved an overall correct prediction rate of 81.1%; 74.8% for those with raised scar and 86.0% for those without raised scar. From this study, injury and clinical predictors for raised scar after adjustment for other variables are: increasing %TBSA, greater burn depth as indicated by level of surgical intervention, wound complications and prolonged hospital stay. Intrinsic patient predictors for raised scar in patients with comparable injuries are: young age (≤30 years), female gender and Fitzpatrick skin types 4-6. The strength of association statistics (odds ratios and 95% confidence intervals) reported will be of practical benefit for clinical decision-making and counselling of patients, and plausible biological explanations for the findings support the validity of the results.