Though the pathophysiology of keloid and hypertrophic scars is not completely known, various cytokines have been implicated, including interleukin (IL)-6, IL-8, and IL-10, as well as various growth factors including transforming growth factor-beta and platelet-derived growth factor.
It was found that HTscar formation coincided with a prolonged decreased expression of inflammatory genes (TNFα, IL-1α, IL-1RN, CCL2, CCL3, CXCL2, CXCR2, C3 and IL-10) and an extended increased expression of ECM-related genes (PLAU, Col3A1, TGFβ3).
In burn patients with HSc, serum IL-10 and transforming growth factor-beta (TGF-beta) levels were also significantly increased early after burn injury in patients who later developed HSc compared with normal volunteers and with a subset of burn patients who did not develop HSc, before returning to normal levels after 6 months.