1469 Factors affecting keratinocyte and fibroblast culture

Autologous skin substitute production for severe burn patients requires particular attention to culture conditions in order to maintain stem cells, as various factors can affect their preservation and give variable clinical results. The goal of this study was to create a database from all the culture data and medical records available since the beginning of the LOEX’s activities to find which factors affect the culture of keratinocytes and fibroblasts. With this retrospective epidemiological study, 538 clinical and cell culture datasets for 299 Canadian patients were collected. We focused on the effect of sex, age, biopsy location, burn etiology, percentage of total body surface area (TBSA) burned, delay between the burn and the biopsy and the presence of hair or fat on cell extraction yield and on cell proliferation. Relationships between factors were explored in univariate analysis. Regarding extraction yield, more keratinocytes (p=0.001; R2=0.032) and fibroblasts (p<0.001; R2=0.221) were obtained from younger patients. Biopsy location had an impact too (p=0.005) with the pubis, the armpit and the neck giving higher yield. Other variables had no effect on yield. Proliferation was impacted by biopsy location (p<0.001), delay (p=0.004; R2=0.04), etiology (p=0.075), and TBSA burned (p<0.001; R2=0.071), mainly keratinocyte growth at passage 1 (P1) was affected. Etiology had an influence on P1 after thawing (p<0.001) such as the age (p<0.001; R2=0.003) which also impacted keratinocyte proliferation at P0 (p=0.043; R2=0.13). Sex was the only factor affecting fibroblasts just at P0 (p=0.017). The other variables tested had no effect on cell proliferation. To conclude, we showed that both keratinocytes and fibroblasts can be affected by various factors at different levels of culture confirming the need to identify them for improved treatment of patients.