Tissue transplants in primates for upper extremity reconstruction: A preliminary report

Scoring of Skin Rejection in a Swine Composite Tissue Allograft Model

“…Indeed, the skin has been observed to be the first tissue component to demonstrate visual and histologic changes of acute rejection in both small-and large-animal CTA models, and has been used as the parameter for rejection of the entire transplant [1,[17][18][19]. Unfortunately, a multitude of different visual criteria for defining the time of rejection of the skin component of a CTA have been utilized in previous studies, and there appears to be no consensus or attempt at standardization.…”

“…Along these lines, Daniel et al [1] based diagnosis of rejection in primate hand and neurovascular free flap transplants solely on clinical signs, since it was difficult to distinguish infection from rejection on punch biopsies. Benhaim et al [18] and van den Helder et al [19] adopted a histopathologic grading system used by Saurat et al [24] for grading the cutaneous manifestations of graft-versus-host disease after bone marrow transplantation for evaluation of skin biopsies from rat hind limb allograft recipients treated with MMF.…”

“…These tissue blocks have tremendous potential clinical application for precise functional and structural restoration of large tissue defects after birth defects, resection of large tumors, or trauma. Despite the introduction of new, more potent immunosuppressants, preventing acute rejection of CTAs without significant systemic toxicity remains a major problem in both small-and large-animal models [1][2][3][4][5][6][7]. Along these lines, it has become clear that vascularized CTAs elicit nonsynchronized immune responses of varying intensity among their tissue components, with skin being the most antigenic, muscle of intermediate immunogenicity, bone of lower immunogenicity, and cartilage and tendon the least antigenic [3,8,9].…”

“…In an attempt to provide a means for standardization and comparison of results between protocols, Bü ttemeyer et al [3] recently developed a histopathologic grading system for defining the severity of rejection in the skin, muscle, bone, and articular cartilage components of rat hind limb allografts immunosuppressed with either tacrolimus or cyclosporin A (CsA). This system was based on a previously developed scheme for evaluating cardiac muscle rejection [10,11], as well as on prior descriptions of CTA rejection in other rodent and primate models [1,9,[12][13][14]. To our knowledge, a reproducible scoring system for quantifying skin rejection has not been previously described as part of a large-animal CTA model.…”

Hand transplantation: Comparisons and observations of the first four clinical cases

“…[17][18][19][20] The one thing that these early experiences had in common were the primitive forms of immunosuppression used. In the clinical case performed in Ecuador, azathioprine and hydrocortisone were used, resulting in complete limb rejection at 2 weeks posttransplant.…”