Review of the early diagnoses and assessment of rejection in vascularized composite allotransplantation

Abstract

The emerging field of vascular composite allotransplantation (VCA) has become a clinical reality. Building upon cutting edge understandings of transplant surgery and immunology, complex grafts such as hands and faces can now be transplanted with success. Many of the challenges that have historically been limiting factors in transplantation, such as rejection and the morbidity of immunosuppression, remain challenges in VCA. Because of the accessibility of most VCA grafts, and the highly immunogenic nature of the skin in particular, VCA has become the focal point for cross-disciplinary approaches to developing novel approaches for some of the most challenging immunological problems in transplantation, particularly the early diagnoses and assessment of rejection. This paper provides a historically oriented introduction to the field of organ transplantation and the evolution of VCA.

Figure 1

Banff Grading of Acute Skin Rejection in VCA; Allograft histology rejection grades. Grade 0: no or rare inflammatory cells, Grade I: mild perivascular infiltration. No involvement of overlying epidermis, Grade II: moderate. Perivascular inflammation with/without mild epidermal or adnexal involvement (limited to spongiosis and exocytosis). No epidermal dyskeratosis or apoptosis, Grade III: dense inflammation and epidermal involvement with apoptosis, dyskeratosis, and/or keratinolysis, Grade IV: necrotizing acute rejection. Frank necrosis of epidermis or other skin structures.

Figure 2

IL-6, TNFα, and MIP-1α are highly expressed from fullness skin (FS) allografts in comparison with that from hind limb (HL) and vascularized skin muscle bone (VSMB) allograft at POD 1 and POD 3.