Prolongation of survival of alloskin grafts with no concurrent general suppression of the burned patientʹs immune system: a preliminary clinical investigation

The adequate managentent of burns is the requisite to save the patientʹs life, to prevent the onset of secondary infections and to obtain healing with acceptable cosmetic results. Previous data have shown that the use of alloskin grafts in the acule phase of burns yields the best clinical results. Unfortunately, this approach is curbed by the patientʹs immune response which induces the rejection of the allografts. In this report we endeavoured to solve this problem by ways that would not imply the general suppression of the patientʹs immune system. Thus, we can noto report that a longer survival of alloskin grafts can be induced in situ by pretreating the alloskin samples to be grafted with both an anti-β2-microglobulin monoclonal antibody (β2mAb) and irradiation with ultraviolet-C light (UVC). The advantage of our novel approach is that it does not need any concomitant administration of immunosuppressive agent(s) to the burned patients. In this study, we followed five severely burned patients grafted with alloskin samples pretreated with either β2mAb or β2mAb plus UVC irradiation. In comparison with untreated alloskin samples from the same source grafted in parallel, the mean survival time (MST) of the β2mAb-pretreated alloskin specimens increased by 35 per cent (i.e.from 18.3 ± 3.2 days to 24.7 ± 5.5 days) in three patients. Moreover, the MST of the alloskin grafts pretreated with both β2mAb and UVC irradiation was lengthened by 100 per cent (i.e. from 18.5 ± 4.5 days to 37.0 ± 8.0 days) in the remaining two patients. These preliminary results lend credence to the view that local immune suppression could be achieved in situ by our approach via: (1) the impairment of the proper functions of the HLA-class I antigen by the bound β2mAb; and (2) the inhibition of immune reactions taking place inside the alloskin grafts by some immunosuppressive signal(s) generated by the UVC-prefreated alloepidermal cells. Hence, our approach stands as an exciting and useful alternative to the otherwise well-known, deleterious general suppression of the burned patientʹs immune system.