[Clinical study on the immunoregulation effects of cytokines on the acellular xenogenic dermal matrix]

To investigate the relationship between some cytokines and early outcome of grafts in burn patients receiving xeno-/allo-ADM grafting.

Nineteen xeno-ADMs were grafted onto the wounds of 12 patients after escharectomy in extremities, and 18 allo-ADMs were grafted onto the escharectomy wounds of 15 patients in extremities. All the grafts were covered with thin split thickness skin autografts. Six patients grafted with split thickness skin autografts (auto-TTS) were employed as control. After the grafts survived for 4 to 8 weeks, immunohistochemistry and ELISA methods were employed to determine the contents of IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma in the exudation fluid from wounds after the rejection of xeno-ADM, local skin and peripheral blood.

It was exhibited by immunochemistry staining that the positive cellular density and staining intensity of the IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma in the grafts were ranked as following: Xeno-ADM > allo-ADM > auto-TTS (P < 0.05 - 0.01). The levels of IL-4, IL-6, TNF-alpha and IFN-gamma in the exudation fluid during the rejection of xeno-ADM were obviously higher than those in the blood of the patients as determined by ELISA, while the serum levels of IL-4 and IFN-gamma in xeno-ADM group were lower and higher than those in xeno-ADM when without rejection respectively. The serum levels of IL-4, TNF-alpha and IFN-gamma in xeno-ADM group were significantly higher than those in allo-ADM and auto-TTS groups (P < 0.05 - 0.01).

Local detection of high levels of IL-1 beta, IL-4, IL-6, TNF-alpha and IFN-gamma might be related to the immune augmentation mediated by cytotoxic lymphocytes and cytokines. The dynamic changes of these cytokines might be helpful to the explanation of the bad outcome of xeno-ADMs.