Vascularized composite allotransplantation: a closer look at the banff working classification

What is needed to ensure long-term sustainability for the field of vascularized composite allotransplantation?

The field of vascularized composite allotransplantation (VCA) has demonstrated remarkable advances since its inception with some excellent long-term results in a variety of graft types. However, unlike solid organ transplantation, it has yet to become mainstream. We therefore discuss strategies on ensuring long-term sustainability by addressing continued clinical developments of VCA to improve the risk-to-benefit balance, importance of public support, improved policy and financial support, and need for a bridge to the future of transplant surgery. There has been headway on all fronts and collaboration among the VCA centers for centralization of data and incorporation of patient voices will be essential for continued progress.

Minimally and Non-invasive Approaches to Rejection Identification in Vascularized Composite Allotransplantation

OBJECTIVE

Rejection is common and pernicious following Vascularized Composite Allotransplantation (VCA). Current monitoring and diagnostic modalities include the clinical exam which is subjective and biopsy with dermatohistopathologic Banff grading, which is subjective and invasive. We reviewed literature exploring non- and minimally invasive modalities for diagnosing and monitoring rejection (NIMMs) in VCA.

METHODS

PubMed, Cochrane, and Embase databases were queried, 3125 unique articles were reviewed, yielding 26 included studies exploring 17 distinct NIMMs. Broadly, NIMMs involved Imaging, Liquid Biomarkers, Epidermal Sampling, Clinical Grading Scales, and Introduction of Additional Donor Tissue.

RESULTS

Serum biomarkers including MMP3 and donor-derived microparticles rose with rejection onset. Epidermal sampling non-invasively enabled measurement of cytokine & gene expression profiles implicated in rejection. Both hold promise for monitoring. Clinical grading scales were useful diagnostically as was reflection confocal microscopy. Introducing additional donor tissue showed promise for preemptively identifying rejection but requires additional allograft tissue burden for the recipient.

CONCLUSION

NIMMs have the potential to dramatically improve monitoring and diagnosis in VCA. Many modalities show promise however, additional research is needed and a multimodal algorithmic approach should be explored.

Methods of ex vivo analysis of tissue status in vascularized composite allografts

Vascularized composite allotransplantation can improve quality of life and restore functionality. However, the complex tissue composition of vascularized composite allografts (VCAs) presents unique clinical challenges that increase the likelihood of transplant rejection. Under prolonged static cold storage, highly damage-susceptible tissues such as muscle and nerve undergo irreversible degradation that may render allografts non-functional. Skin-containing VCA elicits an immunogenic response that increases the risk of recipient allograft rejection. The development of quantitative metrics to evaluate VCAs prior to and following transplantation are key to mitigating allograft rejection. Correspondingly, a broad range of bioanalytical methods have emerged to assess the progression of VCA rejection and characterize transplantation outcomes. To consolidate the current range of relevant technologies and expand on potential for development, methods to evaluate ex vivo VCA status are herein reviewed and comparatively assessed. The use of implantable physiological status monitoring biochips, non-invasive bioimpedance monitoring to assess edema, and deep learning algorithms to fuse disparate inputs to stratify VCAs are identified.

Immunohistochemical Analysis of Lymphocyte Populations in Acute Skin Rejection: The University Health Network Addition to the Banff Classification

Acute rejection in vascularized composite allotransplantation has been identified using the Banff 2007 working classification. We propose an addition to this classification based on histological and immunological assessment within the skin and subcutaneous tissue.

Methods

Biopsies from vascularized composite transplant patients were obtained at scheduled visits and whenever skin changes occurred. Histology and immunohistochemistry were performed on all samples, looking at infiltrating cells.

Results

Observations were made specifically related to each component of the skin, including the epidermis, dermis, vessels, and subcutaneous tissue. Our findings led to the establishment of the University Health Network addition of skin rejection.

Conclusions

The high rate of rejection where the skin is involved requires novel techniques for early detection. The University Health Network skin rejection addition can serve as an adjunct to the Banff classification.

A Systematic Review of the Reported Complications Related to Facial and Upper Extremity Vascularized Composite Allotransplantation

INTRODUCTION

Twenty three years after the first successful upper extremity transplantation, the role of vascularized composite allotransplantation (VCA) in the world of transplantation remains controversial. Face and upper extremity reconstruction via transplantation have become successful options for highly selected patients with severe tissue and functional deficit when conventional reconstructive options are no longer available. Despite clear benefit in these situations, VCA has a significant potential for complications that are more frequent when compared to visceral organ transplantation. This study intended to perform an updated systematic review on such complications.

MATERIALS AND METHODS

MEDLINE database via PubMed, Embase and Cochrane Library were searched. Face and upper extremity VCA performed between 1998 and 2021 were included in the study. Relevant media and press conferences reports were also included. Complications related to face and upper extremity VCA were recorded and reviewed including their clinical characteristics and complications.

RESULTS

One hundred fifteen patients underwent facial (43%) or upper extremity (57%) transplantation. Overall, the surgical complication rate was 23%. Acute and chronic rejection was identified in 89% and 11% of patients, respectively. Fifty eight percent of patients experienced opportunistic infection. Impaired glucose metabolism was the most common immunosuppression-related complication other than infection. Nineteen percent of patients ultimately experienced partial or complete allograft loss.

CONCLUSIONS

Complications related to VCA are a significant source of morbidity and potential mortality. Incidence of such complications is higher than previously reported and should be strongly emphasized in patient consent process. Strict patient selection criteria, complex preoperative evaluation, consideration of alternatives, and thorough disclosure to patients should be routinely performed prior to VCA indication.

Quantification of Facial Allograft Edema During Acute Rejection: A Software-Based 3-Dimensional Analysis

BACKGROUND

Acute rejection (AR) is a common complication in facial transplant (FT) patients associated with allograft edema and erythema. Our study aims to demonstrate the feasibility of using software-based 3-dimensional (3D) facial analysis to quantify edema as it resolves during/after AR treatment in an FT patient.

METHODS

Our patient is a 23-year-old man who underwent a face and bilateral hand allotransplant in August 2020. The Vectra H1 (Canfield, Fairfield, NJ) portable scanner was used to capture 3D facial images at 8 time points between postoperative day (POD) 392 and 539. The images were analyzed with the Vectra Software using a rejection-free image (POD 539) as a control.

RESULTS

Edema increased in the periorbital, lower third, and submandibular regions before AR treatment (POD 392-415). At POD 448, total facial edema was reduced to near baseline values in response to plasmapheresis and thymoglobulin (+156.94 to +28.2 mL). The fastest and most notable response to treatment was seen in the periorbital region, while some edema remained in the submandibular (+19.79 mL) and right lower third (+8.65 mL) regions. On POD 465, after the initial improvement, the edema increased but was resolved with steroid use. Facial edema did not correlate with the histopathological evaluation in our patient.

CONCLUSIONS

We demonstrated the feasibility of analyzing 3D facial images to quantify edema during/after AR treatment in an FT patient. Our analysis detected edema changes consistent with AR followed by an improvement after treatment. This technology shows promise for noninvasive monitoring of FT patients.

Uterine transplantation: legal and regulatory implications in England

Uterus transplantation (UTx) is fast evolving from an experimental to a clinical procedure, combining solid organ transplantation with assisted reproductive technology. The commencement of the first human uterus transplant trial in the United Kingdom leads us to examine and reflect upon the legal and regulatory aspects closely intertwined with UTx from the process of donation to potential implications for fertility treatment and the birth of the resultant child. As the world's first ephemeral transplant, the possibility of organ restitution requires consideration and is discussed herein. TWEETABLE ABSTRACT: Uterine transplantation warrants a closer look at the legal frameworks on fertility treatment and transplantation in England.

Software-based Detection of Acute Rejection Changes in Face Transplant

BACKGROUND

 An objective, non-invasive method for redness detection during acute allograft rejection in face transplantation (FT) is lacking.

METHODS

 A retrospective cohort study was performed with 688 images of 7 patients with face transplant (range, 1 to 108 months post-transplant). Healthy controls were matched to donor age, sex, and had no prior facial procedures. Rejection state was confirmed via tissue biopsy. An image-analysis software developed alongside VicarVision (Amsterdam, Netherlands) was used to produce R, a measure of differences between detectable color and absolute red. R is inversely proportional to redness, where lower R values correspond to increased redness. Linear mixed models were used to study fixed effect of rejection state on R values. Estimated marginal means of fitted models were calculated for pairwise comparisons.

RESULTS

 Of 688 images, 175, 170, 202, and 141 images were attributable to Banff Grade 0,1,2, and 3, respectively. Estimated change in R value of facial allografts decreased with increasing Banff Grade (p = 0.0001). The mean R value of clinical rejection (Banff Grade ⅔) (16.67, 95% Confidence Interval [CI] 14.79-18.58) was lower (p = 0.005) than non-rejection (Banff Grade 0/1) (19.38, 95%CI 17.43-21.33). Both clinical and non-rejection mean R values were lower (p = 0.0001) than healthy controls (24.12, 95%CI 20.96-27.28).

CONCLUSION

 This proof-of-concept study demonstrates that software-based analysis can detect and monitor acute rejection changes in FT. Future studies should expand on this tool's potential application in telehealth and as a screening tool for allograft rejection.

Local FK506 implants in non-human primates to prevent early acute rejection in vascularized composite allografts

Background

Previous vascularized composite allograft (VCA) studies from our laboratory have shown that topical FK506 delivery in non-human primates (NHPs) was limited by inadequate dermal penetration and rejection persisted. Herein, we report the first utilization of FK506 via subcutaneously implanted discs to mitigate VCA rejection in NHPs.

Methods

Full major histocompatibility complex (MHC)-mismatched NHP pairs underwent partial-face VCA and FK506 disc implantation along the suture line. All allotransplants were maintained post-operatively for two months on the FK506 discs, methylprednisolone, mycophenolate mofetil, and supplemented with intramuscular FK506 if necessary. Group 1 (n=4) was used for optimization of the implant, while Group 2 (n=3) underwent delayed bone marrow transplantation (DBMT) after two months. VCA skin biopsies and peripheral blood samples were obtained for serial assessment of rejection and mixed chimerism by histopathology and flow cytometry respectively.

Results

In Group 1, two technical failures occurred. Of the remaining two NHPs, one developed supratherapeutic levels of FK506 (50–120 ng/mL) and had to be euthanized on postoperative day (POD) 12. Reformulation of the implant resulted in stable FK506 levels (20–30 ng/mL) up to POD12 when further intramuscular (IM) FK506 injections were necessitated. In Group 2, two NHPs survived to undergo conditioning and one successfully developed chimerism at 2–3 weeks post-DBMT (96–97% granulocytes and 7–11% lymphocytes of recipient-origin). However, all three NHPs had to be terminated from study at POD64, 77 and 86 due to underlying post-transplant lymphoproliferative disorder. All VCAs remained rejection-free up to study endpoint otherwise.

Conclusions

This study shows preliminary results of local FK506 implants in potentially mitigating VCA acute rejection for tolerance protocols based on mixed chimerism approach.

Sensitization and Desensitization in Vascularized Composite Allotransplantation

Vascularized composite allotransplantation (VCA) is a field under research and has emerged as an alternative option for the repair of severe disfiguring defects that result from severe tissue loss in a selected group of patients. Lifelong immunosuppressive therapy, immunosuppression associated complications, and the effects of the host immune response in the graft are major concerns in this type of quality-of-life transplant. The initial management of extensive soft tissue injury can lead to the development of anti-HLA antibodies through injury-related factors, transfusion and cadaveric grafting. The role of antibody-mediated rejection, donor-specific antibody (DSA) formation and graft rejection in the context of VCA still remain poorly understood. The most common antigenic target of preexisting alloantibodies are MHC mismatches, though recognition of ABO incompatible antigens, minor histocompatibility complexes and endothelial cells has also been shown to contribute to rejection. Mechanistically, alloantibody-mediated tissue damage occurs primarily through complement fixation as well as through antibody-dependent cellular toxicity. If DSA exist, activation of complement and coagulation cascades can result in vascular thrombosis and infarction and thus rejection and graft loss. Both preexisting DSA but especially de-novo DSA are currently considered as main contributors to late allograft injury and graft failure. Desensitization protocols are currently being developed for VCA, mainly including removal of alloantibodies whereas treatment of established antibody-mediated rejection is achieved through high dose intravenous immunoglobulins. The long-term efficacy of such therapies in sensitized VCA recipients is currently unknown. The current evidence base for sensitizing events and outcomes in reconstructive transplantation is limited. However, current data show that VCA transplantation has been performed in the setting of HLA-sensitization.

Dynamic Maxillary Sinus Changes of Facial Vascularized Composite Allotransplants

SUMMARY

Skin is one of the target tissues of rejection in face transplants and, because of its easy accessibility, has become the gold standard in the diagnosis of rejection. The allograft contains deeper tissues where rejection can occur, but samples cannot be obtained because of difficult access. Deep tissue changes were monitored on computed tomographic scans of the midface in six face transplant recipients with the help of image segmentation. The maxillary sinus was identified as a dynamic anatomical compartment. Observed changes in volume of the aeration relative to the opacification (aeration coefficient) of the maxillary sinus were quantified with the help of image segmentation. Changes in the aeration coefficient as a surrogate of mucosal swelling were quantified and related to time, treatment, and skin rejection grade. Lower aeration coefficients were found only in patients with transplanted maxillary sinus mucosa. Pathologic changes were not observed in face transplant recipients with a native maxillary sinus. The data show that the aeration coefficient was significantly lower at the time of biopsy-proven allograft rejection. Neither mechanical, nor infectious, nor medication side effects sufficiently explain the findings presented herein. The authors' findings are important to consider for clinical management of face transplant patients who receive parts of the sinonasal tract. The authors identify a potential radiologic biomarker of deep tissue allograft rejection. In the future, the proposed methodology might prove useful in monitoring deeper dynamic tissue changes in vascularized composite allografts and might help in designing patient-specific, individualized treatment strategies.

Early recognition of chronic rejection in a face allotransplant patient with alopecia

The features of chronic rejection (CR) in full-face vascularized composite allotransplantation (VCA) are not well-known. Herein, we report a full-face transplant patient that experienced two episodes of acute rejection (AR) and three episodes of AR/CR over the course of 6-years. The patient noticed a small, round patch of hair loss in his beard 9 months after the second AR episode, which occurred 21 months post-transplantation. Biopsy of the alopecic patch showed lichen-planopilaris-like features, which was suggestive of early CR. Despite an increase in immunosuppressive dosages, the alopecia progressed. Following the second and third AR/CR episodes, the alopecia became more pronounced, with the addition of hyperpigmentation as well as sclerosis and telangiectasia. The findings of multiple biopsies showed CR. Based on these findings we think that alopecia with lichen-planopilaris-like histopathological features similar to grade III AR features, particularly in hair follicles appears to be an early finding of CR in the presented patient. The findings further indicate that follicular involvement may be a significant feature of CR in VCA patients and that it can present prior to sclerosis, vasculopathy, or loss of adnexa. The present case is uniquely important because of the distinctive presentation of CR, with hair follicles clinically and histopathologically affected, leading to progressive and irreversible alopecia with lichen-planopilaris-like histopathology.

The Effects of Tacrolimus on Tissue-Specific, Protein-Level Inflammatory Networks in Vascularized Composite Allotransplantation

Systems-level insights into inflammatory events after vascularized composite allotransplantation (VCA) are critical to the success of immunomodulatory strategies of these complex procedures. To date, the effects of tacrolimus (TAC) immunosuppression on inflammatory networks in VCA, such as in acute rejection (AR), have not been investigated. We used a systems biology approach to elucidate the effects of tacrolimus on dynamic networks and principal drivers of systemic inflammation in the context of dynamic tissue-specific immune responses following VCA. Lewis (LEW) rat recipients received orthotopic hind limb VCA from fully major histocompatibility complex-mismatched Brown Norway (BN) donors or matched LEW donors. Group 1 (syngeneic controls) received LEW limbs without TAC, and Group 2 (treatment group) received BN limbs with TAC. Time-dependent changes in 27 inflammatory mediators were analyzed in skin, muscle, and peripheral blood using Principal Component Analysis (PCA), Dynamic Bayesian Network (DyBN) inference, and Dynamic Network Analysis (DyNA) to define principal characteristics, central nodes, and putative feedback structures of systemic inflammation. Analyses were repeated on skin + muscle data to construct a "Virtual VCA", and in skin + muscle + peripheral blood data to construct a "Virtual Animal." PCA, DyBN, and DyNA results from individual tissues suggested important roles for leptin, VEGF, various chemokines, the NLRP3 inflammasome (IL-1β, IL-18), and IL-6 after TAC treatment. The chemokines MCP-1, MIP-1α; and IP-10 were associated with AR in controls. Statistical analysis suggested that 24/27 inflammatory mediators were altered significantly between control and TAC-treated rats in peripheral blood, skin, and/or muscle over time. "Virtual VCA" and "Virtual Animal" analyses implicated the skin as a key control point of dynamic inflammatory networks, whose connectivity/complexity over time exhibited a U-shaped trajectory and was mirrored in the systemic circulation. Our study defines the effects of TAC on complex spatiotemporal evolution of dynamic inflammation networks in VCA. We also demonstrate the potential utility of computational analyses to elucidate nonlinear, cross-tissue interactions. These approaches may help define precision medicine approaches to better personalize TAC immunosuppression in VCA recipients.

Immunoregulatory and lipid presentation pathways are upregulated in human face transplant rejection

BACKGROUNDRejection is the primary barrier to broader implementation of vascularized composite allografts (VCAs), including face and limb transplants. The immunologic pathways activated in face transplant rejection have not been fully characterized.METHODSUsing skin biopsies prospectively collected over 9 years from 7 face transplant patients, we studied rejection by gene expression profiling, histology, immunostaining, and T cell receptor sequencing.RESULTSGrade 1 rejection did not differ significantly from nonrejection, suggesting that it does not represent a pathologic state. In grade 2, there was a balanced upregulation of both proinflammatory T cell activation pathways and antiinflammatory checkpoint and immunomodulatory pathways, with a net result of no tissue injury. In grade 3, IFN-γ-driven inflammation, antigen-presenting cell activation, and infiltration of the skin by proliferative T cells bearing markers of antigen-specific activation and cytotoxicity tipped the balance toward tissue injury. Rejection of VCAs and solid organ transplants had both distinct and common features. VCA rejection was uniquely associated with upregulation of immunoregulatory genes, including SOCS1; induction of lipid antigen-presenting CD1 proteins; and infiltration by T cells predicted to recognize CD1b and CD1c.CONCLUSIONOur findings suggest that the distinct features of VCA rejection reflect the unique immunobiology of skin and that enhancing cutaneous immunoregulatory networks may be a useful strategy in combatting rejection.Trial registrationClinicalTrials.gov NCT01281267.FUNDINGAssistant Secretary of Defense and Health Affairs, through Reconstructive Transplant Research (W81XWH-17-1-0278, W81XWH-16-1-0647, W81XWH-16-1-0689, W81XWH-18-1-0784, W81XWH-1-810798); American Society of Transplantation's Transplantation and Immunology Research Network Fellowship Research Grant; Plastic Surgery Foundation Fellowship from the American Society of Plastic Surgeons; Novo Nordisk Foundation (NNF15OC0014092); Lundbeck Foundation; Aage Bangs Foundation; A.P. Moller Foundation for the Advancement of Medical Science; NIH UL1 RR025758.

Mucosa and Rejection in Facial Vascularized Composite Allotransplantation: A Systematic Review

BACKGROUND

Facial vascularized composite allotransplantation (fVCA) presents an established approach to restore form and function of patients with catastrophic facial defects. Skin is one of the target tissues of the rejection process, and due to its easy accessibility has become the gold standard in the diagnosis of rejection. Mucosal rejection frequently occurs; however, the added value of mucosal rejection assessment for patient management is unknown.

METHODS

We conducted a systematic review of manuscripts listed in the MEDLINE/PubMed and GoogleScholar databases to identify articles that provide data on mucosal rejection following fVCA. For inclusion, papers had to be available as full-text and written in English. Non-VCA studies and animal studies were excluded. We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We included 17 articles that described changes in allotransplanted mucosa of fVCAs. These articles yielded data on 168 BANFF graded biopsies of corresponding skin and mucosa biopsies. Rejection grades were consistently higher in mucosal biopsies. Concordance between allograft skin and mucosa biopsy grades increased with an increasing skin-BANFF grade. Mucosa rejection grades were on average lower in the early stages of the posttransplant period (<postoperative mo 12, time of motor, and sensory recovery) when compared to the later stages (>postoperative mo 12).

CONCLUSIONS

The mucosa of facial allotransplants is one of the primary targets of rejection. The data indicates that higher-grade skin rejection does not occur in absence of mucosal rejection. Further investigations are needed to elucidate the exact role of mucosal biopsies for fVCA patient management.

Vascularized composite allotransplantation in the United States: A retrospective analysis of the Organ Procurement and Transplantation Network data after 5 years of the Final Rule

On July 3, 2014, the Organ Procurement and Transplantation Network (OPTN) began overseeing vascularized composite allotransplantation/allografts (VCA) in the United States. For the past 6 years, centers performing VCAs have been requested to submit data into a biometric repository, in parallel with systems used by solid organ transplant centers. Currently, 62 VCAs are reported in the entire OPTN database, with 36 of these transplants reported as performed after VCA was added to the OPTN Final Rule. Of these 36 recipients, 16 received uterus transplants, most of which (11) occurred from living donors. Ten patients received hand transplants and 6 received face transplants. Two patients received abdominal wall transplants, 1 patient received a scalp transplant, and 1 patient received a penile transplant. The present manuscript represents the query of a nationalized database for VCA type, immunosuppression treatment, and clinical outcomes for VCAs. This manuscript provides a report of the current VCA data reported to the OPTN after the Final Rule.

Lymphocytic Vasculitis Associated With Mild Rejection in a Vascularized Composite Allograft Recipient: A Clinicopathological Study

BACKGROUND

Histologic criteria for diagnosing acute rejection in vascularized composite tissue allograft (VCA) have been established by the Banff 2007 Working Classification of Skin-Containing Composite Tissue Allograft, but the role of early vascular lesions in graft rejection warrants additional analysis.

METHODS

We performed a retrospective study of 34 skin biopsies performed over 430 d for rejection surveillance, in Canada's first face allotransplant recipient. Three observers reviewed all biopsies to assess the nature and intensity of the inflammatory skin infiltrate. A complete histological and immunohistochemical review of the vascular components was performed with a focus on lymphocytic vasculitis, intravascular fibrin, vessel caliber, extent of injury, C4d positivity, and inflammatory cell phenotyping. We then correlated these data points to clinical and immunosuppression parameters.

RESULTS

Acute vascular damage in biopsies that would be classified as mild acute rejection correlates with troughs in immunosuppression and subsides when immunosuppressive tacrolimus doses are increased. Grade 0 Banff rejection and Grade I without lymphocytic vasculitis were almost indistinguishable, whereas Grade I with lymphocytic vasculitis was an easy and reproducible histologic finding.

CONCLUSIONS

Our results highlight the possible relevance of vascular injury in the context of VCA, as its presence might underlie a more aggressive form of immune rejection. If these findings are validated in other VCA patients, vascular injury in mild rejection might warrant a different clinical approach.

Defining chronic rejection in vascularized composite allotransplantation-The American Society of Reconstructive Transplantation and International Society of Vascularized Composite Allotransplantation chronic rejection working group: 2018 American Society of Reconstructive Transplantation meeting report and white paper Research goals in defining chronic rejection in vascularized composite allotransplantation

Objectives:

This report summarizes a collaborative effort between the American Society of Reconstructive Transplantation and the International Society of Vascularized Composite Allotransplantation to establish what is known about chronic rejection in recipients of vascularized composite allografts, with an emphasis on upper extremity and face transplants. As a picture of chronic rejection in hand and face vascularized composite allografts emerges, the results will be applied to other types of vascularized composite allografts, such as uterine transplantation.

Methods:

The overall goal is to develop a definition of chronic rejection in vascularized composite allografts so that we can establish longitudinal correlates of factors such as acute rejection, immunosuppressive therapy, de novo donor-specific antibody and trauma/infection and other external factors on the development of chronic rejection. As Dr Kanitakis eloquently stated at the 2017 International Society of Vascularized Composite Allotransplantation meeting in Salzburg, “Before we can correlate causative factors of chronic rejection, we have to define what chronic rejection in VCA is.”

Results:

The first meeting report was presented at the sixth Biennial meeting of the American Society of Reconstructive Transplantation in November 2018. Based on collaborative efforts and descriptions of clinical cases of chronic rejection in vascularized composite allograft recipients, a working definition of chronic rejection in vascularized composite allografts with respect to overt functional decline, subclinical functional decline, histologic evidence without functional decline, and normal allograft function in the absence of histologic evidence of chronic rejection is proposed.

Conclusions:

It is the intent of this collaborative working group that these working definitions will help to focus ongoing research to define the incidence, risk factors and treatment regimens that will identify mechanisms of chronic rejection in vascularized composite allografts. As with all good research, our initial efforts have generated more questions than answers. We hope that this is the first of many updates.

Accelerated chronic skin changes without allograft vasculopathy: A 10-year outcome report after face transplantation

BACKGROUND

Long-term outcomes after face transplantation are rarely reported in the scientific literature. Here we present outcome data of a partial face allograft recipient 10 years after transplantation.

METHODS

Medical records were reviewed for functional and psychosocial outcomes as well as complications. Histopathologic analyses of autopsy tissues and characterization of skin immune cells were performed.

RESULTS

The patient retained long-term motor and sensory function, though with a noticeable drop in sensory function after year 5. Social reintegration of the patient was marked by reconnection with his family and participation in public social activities. Immunosuppressive therapy consisted of tacrolimus (target levels 6-8 ng/mL after the first year), mycophenolate, and prednisone, while steroids were completely weaned between years 1 and 7. One acute cellular rejection episode of grade II or higher occurred on average per year and led to chronic skin changes (papillary dermal sclerosis with superficial hyalinization, epidermal thinning with loss of rete ridges, perieccrine fibrosis), but the allograft vessels, muscles, adipose tissue, and bone were spared. Allograft skin was characterized by increased number of CD4+ TNF-α/IL17A producing T-cells as compared with native skin. Long-term kidney function was maintained at 60 mL/min estimated glomerular filtration rate. Unfortunately, the preexisting hepatitis C virus infection with liver cirrhosis was resistant to 3 treatments with new direct-acting antivirals and eventually hepatocellular carcinoma developed, causing the patient's death 10 years after transplantation.

CONCLUSION

This report suggests that face transplants can maintain their function for at least 10 years. Chronic skin changes can occur independently of allograft vasculopathy.

The Evolving Clinical Presentation of Acute Rejection in Facial Transplantation

Importance

Acute rejection is one of the most frequent complications in facial transplantation, with potentially severe consequences for the recipient if overlooked. Clinical signs, such as erythema or edema, are helpful to diagnose acute rejection in the early follow-up stage; however, it is not well known whether these clinical signs remain reliable markers of acute rejection beyond the second posttransplant year.

Objective

To determine the diagnostic value of clinical signs of acute rejection after facial transplantation over time.

Design, Setting, and Participants

A retrospective, single-center cohort study was conducted of patients who underwent facial transplantation at Brigham and Women's Hospital between April 2009 and October 2014, with up to an 8-year follow-up. Medical records were reviewed until September 30, 2017. The medical records from 104 encounters with 7 patients who underwent partial or full facial transplantation were analyzed for symptoms of rejection, immunosuppressive therapy, and histopathologic findings.

Main Outcomes and Measures

The occurrence of 5 clinical signs of acute rejection were evaluated: erythema, edema, exanthema, suture line erythema, and mucosal lesions. Odds ratios (ORs) were calculated to determine the statistically significant association of these signs with the histopathologic diagnosis of rejection. In addition, tacrolimus blood levels, as a surrogate marker of immunosuppressive therapy, were evaluated.

Results

Of the 7 patients included in the study, 5 were men. The mean follow-up was 66 months (range, 35-101). Of 104 clinical encounters, 46 encounters (44.2%) represented rejection episodes and 58 encounters (55.8%) represented no-rejection episodes. Beyond 2 years posttransplantation, only erythema (OR, 6.53; 95% CI, 1.84-20.11; P = .004) and exanthema (OR, ∞; 95% CI, 2.2-∞; P = .004) were demonstrated to be reliable clinical signs of acute rejection in facial transplantation. There was also a statistically significant association of subtherapeutic tacrolimus levels with late rejection episodes (OR, 3.79; 95% CI, 1.25-12.88; P = .03). In addition, the occurrence of subclinical rejection was more frequent during later follow-up times (7 [24.1%] late rejections vs 1 [5.9%] early rejection). Five of 8 subclinical rejections (62.5%) were associated with subtherapeutic tacrolimus levels.

Conclusions and Relevance

Clinical signs of acute rejection in facial transplantation appear to be of limited diagnostic value, particularly after the second postoperative year. Until alternative biomarkers for rejection are identified, protocol skin biopsies will remain necessary for guiding assessments of allograft rejection.

Level of Evidence

3.

Blood proteome profiling using aptamer-based technology for rejection biomarker discovery in transplantation

Face transplantation is a promising solution for patients with devastating facial injuries who lack other satisfactory treatment options. At the same time, this type of transplantation is accompanied with high risks of acute transplant rejection. The limitations of traditional skin biopsy and the need to frequently monitor the condition of face transplant call for less invasive biomarkers to better diagnose and treat acute rejection. Discovery of peripheral serum proteins accurately reflecting the transplant status would represent a reasonable solution to meet this demand. However, to date, there is no clinical data available to address the feasibility of this approach. In this study, we used the next generation aptamer-based SOMAscan proteomics platform to profile 1305 proteins of peripheral blood serum in twenty-four samples taken from 6 patients during no-rejection, nonsevere rejection, and severe rejection episodes. Also, we provide a detailed description of biosample processing and all steps to generate and analyze the SOMAscan dataset with hope it will assist in performing biomarker discovery in other transplantation centers using this platform.

MMP3 Is a Non-invasive Biomarker of Rejection in Skin-Bearing Vascularized Composite Allotransplantation: A Multicenter Validation Study

Background: There is unmet need for non-invasive immunomonitoring to improve diagnosis and treatment of acute rejection in vascularized composite allotransplantation (VCA). Circulating matrix metalloproteinase 3 (MMP3) was described as a candidate non-invasive biomarker to predict treatment response to acute rejection in clinical VCA. However, larger validation studies are yet to be reported to allow for more definitive conclusions.

Methods: We retrospectively measured MMP3 levels using ELISA in a total of 140 longitudinal serum samples from six internal and three external face transplant recipients, as well as three internal and seven external upper extremity transplant recipients. The control groups comprised serum samples from 36 kidney transplant recipients, 14 healthy controls, and 38 patients with autoimmune skin disease. A linear mixed model was used to study the effect of rejection state (pre-transplant, no-rejection, non-severe rejection (NSR), and severe rejection) on MMP3 levels.

Results: In VCA, MMP3 levels increased significantly (p < 0.001) between pre- and post-transplant no-rejection states. A further increase occurred during severe rejection (p < 0.001), while there was no difference in MMP3 levels between non-severe and no-rejection episodes. A threshold of 5-fold increase from pre-transplant levels could discriminate severe from NSR with 76% sensitivity and 81% specificity (AUC = 0.79, 95% CI = 0.65–0.92, p < 0.001). In kidney transplantation, the MMP3 levels were significantly (p < 0.001) elevated during antibody-mediated rejection but not during T-cell mediated rejection (TCMR) (p = 0.547). MMP3 levels in healthy controls and autoimmune skin disease patients were comparable with either pre-transplant or no-rejection/NSR episodes of VCA patients.

Conclusion: The results of this study suggest that serum MMP3 protein is a promising marker for stratifying patients according to severity of rejection, complementary to biopsy findings.

Noninvasive Monitoring of Allograft Rejection Using a Novel Epidermal Sampling Technique

Supplemental Digital Content is available in the text.

Despite promising short- and long-term results to date in vascularized composite allotransplantation (VCA), acute rejection remains the most common major complication in recipients. Currently, diagnosis of acute rejection relies on clinical inspection correlated with histopathological analysis. However, disagreement exists regarding the value of full-thickness skin and mucosal biopsies and histopathology remains semiquantitative, subject to sampling bias, and prone to intra- and inter-observer variabilities. Additionally, biopsies may cause infection, scarring, and/or potentially incite rejection through immune activation after injury. Noninvasive methods to diagnose rejection represent a critical unmet need for the emerging field of VCA. Here, we propose a novel technique utilizing skin stripping of the epidermis and subsequent molecular analysis to detect known markers of acute rejection. Using a small animal VCA model, we sought to validate our epidermal sampling technique as a noninvasive diagnostic test for acute rejection.

Penis Transplantation: First US Experience

OBJECTIVE

We describe the first successful penis transplant in the United States in a patient with a history of subtotal penectomy for penile cancer.

BACKGROUND

Penis transplantation represents a new paradigm in restoring anatomic appearance, urine conduit, and sexual function after genitourinary tissue loss. To date, only 2 penis transplants have been performed worldwide.

METHODS

After institutional review board approval, extensive medical, surgical, and radiological evaluations of the patient were performed. His candidacy was reviewed by a multidisciplinary team of surgeons, physicians, psychiatrists, social workers, and nurse coordinators. After appropriate donor identification and recipient induction with antithymocyte globulin, allograft procurement and recipient preparation took place concurrently. Anastomoses of the urethra, corpora, cavernosal and dorsal arteries, dorsal vein, and dorsal nerves were performed, and also inclusion of a donor skin pedicle as the composite allograft. Maintenance immunosuppression consisted of mycophenolate mofetil, tacrolimus, and methylprednisolone.

RESULTS

Intraoperative, the allograft had excellent capillary refill and strong Doppler signals after revascularization. Operative reinterventions on postoperative days (PODs) 2 and 13 were required for hematoma evacuation and skin eschar debridement. At 3 weeks, no anastomotic leaks were detected on urethrogram, and the catheter was removed. Steroid resistant-rejection developed on POD 28 (Banff I), progressed by POD 32 (Banff III), and required a repeat course of methylprednisolone and antithymocyte globulin. At 7 months, the patient has recovered partial sensation of the penile shaft and has spontaneous penile tumescence. Our patient reports increased overall health satisfaction, dramatic improvement of self-image, and optimism for the future.

CONCLUSIONS

We have shown that it is feasible to perform penile transplantation with excellent results. Furthermore, this experience demonstrates that penile transplantation can be successfully performed with conventional immunosuppression. We propose that our successful penile transplantation pilot experience represents a proof of concept for an evolution in reconstructive transplantation.

Graft vasculopathy of vascularized composite allografts in humans: a literature review and retrospective study

Mechanisms of chronic rejection of vascularized composite allografts (VCA) remain poorly understood and likely present along a spectrum of highly varied clinicopathological findings. Across both animal and human VCA however, graft vasculopathy (GV) has been the most consistent pathological finding resulting clinically in irreversible allograft dysfunction and eventual loss. A literature review of all reported clinical VCA cases with documented GV up to December 2018 was thus performed to elucidate the possible mechanisms involved. Relevant data extracted include C4d deposition, donor-specific antibody (DSA) formation, extent of human leukocyte antigen (HLA) mismatch, pretransplant panel reactive antibody levels, induction and maintenance immunosuppression used, the number of preceding acute rejection episodes, and time to histological confirmation of GV. Approximately 6% (13 of 205) of all VCA patients reported to date developed GV at a mean of 6 years post-transplantation. 46% of these patients have either lost or had their VCAs removed. Neither C4d nor DSA alone was predictive of GV development; however, when both are present, VCA loss appears inevitable due to progressive GV. Of utmost concern, GV in VCA does not appear to be abrogated by currently available immunosuppressive treatment and is essentially irreversible by the time of diagnosis with allograft loss a likely eventuality.

Mechanisms of rejection in vascular composite allotransplantation

PURPOSE OF REVIEW

For patients with devastating injuries in whom standard reconstruction is not an option, vascularized composite allotransplantation (VCA) has become a viable means of restoring form and function. However, immunological rejection continues to be a problem in VCA and has not yet been fully characterized. As the field is relatively new, much of the data on rejection and immunosuppression have been extrapolated from that of solid organ transplantation. In this review, we cover the basic mechanisms of rejection as they relate specifically to VCA with analysis of recent literature and future directions.

RECENT FINDINGS

Recent clinical studies have supported previously postulated T-cell-mediated mechanism of acute rejection and have also made strides in differentiating rejection from inflammation from other skin conditions and with different treatment regimens. Antibody-mediated rejection has been described in recent cases as well as treatment of presensitized patients receiving VCAs. With more long-term grafts, chronic changes, including vasculopathy, are being reported.

SUMMARY

Clinically observed types of rejection in VCA include mainly cell-mediated, antibody-mediated and chronic rejection. Advances in diagnosis and treatment of rejection have been made, but there is still much to be learned about VCA-specific rejection.

Increased levels of circulating MMP3 correlate with severe rejection in face transplantation

Face transplantation is a viable treatment option for carefully selected patients with devastating injuries to the face. However, acute rejection episodes occur in more than 80% of recipients in the first postoperative year. Unfortunately, neither a correlation between histological grades of rejection and anti-rejection treatment nor systemic surrogate markers of rejection in face transplantation are established in clinical routine. Therefore, we utilized next generation aptamer-based SOMAscan proteomics platform for non-invasive rejection biomarker discovery. Longitudinal serum samples from face transplant recipients with long-term follow-up were included in this study. From the 1,310 proteins analyzed by SOMAscan, a 5-protein signature (MMP3, ACY1, IL1R2, SERPINA4, CPB2) was able to discriminate severe rejection from both no-rejection and nonsevere rejection samples. Technical validation on ELISA platform showed high correlation with the SOMAscan data for the MMP3 protein (r_s = 0.99). Additionally, MMP3 levels were significantly increased during severe rejection as compared to no-rejection (p = 0.0009) and nonsevere rejection (p = 0.0173) episodes. Pathway analyses revealed significant activation of the metallopeptidase activity during severe face transplant rejection. This pilot study demonstrates the feasibility of SOMAscan to identify non-invasive candidate biomarkers of rejection in face transplantation. Further validation in a larger independent patient cohort is needed.

Eponychial lesions following bilateral upper extremity vascular composite allotransplantation: a case report

Vascularized composite allotransplantation represents a useful addition to reconstructive options available to the plastic surgeon. Though the procedure provides beneficial functional outcomes, there remain complications, often associated with the immunosuppression necessary to maintain an allograft. We report a case of eponychial fold lesions following successful bilateral upper extremity allotransplantation.

Accommodation and related conditions in vascularized composite allografts

PURPOSE OF REVIEW

The outcome of vascularized composite allografts (VCA) often appear unrelated to the presence of donor-specific antibodies (DSA) in blood of the recipient or deposition of complement in the graft. The attenuation of injury and the absence of rejection in other types of grafts despite manifest donor-specific immunity have been explained by accommodation (acquired resistance to immune-mediated injury), adaptation (loss of graft antigen) and/or enhancement (antibody-mediated antigen blockade). Whether and how accommodation, adaptation and/or enhancement impact on the outcome of VCA is unknown. Here we consider how recent observations concerning accommodation in organ transplants might advance understanding and resolve uncertainties about the clinical course of VCA.

RECENT FINDINGS

Investigation of the mechanisms through which kidney allografts avert antibody-mediated injury and rejection provide insights potentially applicable to VCA. Interaction of DSA can facilitate replacement of donor by recipient endothelial cells, modulate or decrease synthesis of antigen, mobilize antigen that in turn blocks further immune recognition and limit the amount of bound antibody, allowing accommodation to ensue. These processes also can explain the apparent dissociation between the presence and levels of DSA in blood, deposition of C4d in grafts and antibody-mediated rejection. Over time the processes might also explain the inception of chronic graft changes.

SUMMARY

The disrupted tissue in VCA and potential for repopulation by endothelial cells of the recipient establish conditions that potentially decrease susceptibility to acute antibody-mediated rejection. These conditions include clonal suppression of donor-specific B cells, and adaptation, enhancement and accommodation. This setting also potentially highlights heretofore unrecognized interactions between these 'protective' processes.

The combination of mitomycin-induced blood cells with a temporary treatment of ciclosporin A prolongs allograft survival in vascularized composite allotransplantation

BACKGROUND

Vascularized composite allotransplantation (VCA) is a rapidly expanding field of transplantation and provides a potential treatment for complex tissue defects. Peripheral blood mononuclear cells (PBMCs) shortly incubated with the antibiotic and chemotherapeutic agent mitomycin C (MMC) can suppress allogeneic T cell response and control allograft rejection in various organ transplantation models. MMC-incubated PBMCs (MICs) are currently being tested in a phase I clinical trial in kidney transplant patients. Previous studies with MICs in a complex VCA model showed the immunomodulatory potential of these cells. The aim of this study is to optimize and evaluate the use of MICs in combination with a standard immunosuppressive drug in VCA.

METHODS

Fully mismatched rats were used as hind limb donors [Lewis (RT1¹)] and recipients [Brown-Norway (RT1ⁿ)]. Sixty allogeneic hind limb transplantations were performed in six groups. Group A received donor-derived MICs combined with a temporary ciclosporin A (CsA) treatment. Group B received MICs in combination with a temporarily administered reduced dose of CsA. Group C served as a control and received a standard CsA dose temporarily without an additional administration of MICs, whereas Group D was solely medicated with a reduced CsA dose. Group E received no immunosuppressive therapy, neither CsA nor MICs. Group F was given a continuous standard immunosuppressive regimen consisting of CsA and prednisolone. The endpoint of the study was the onset of allograft rejection which was assessed clinically and histologically.

RESULTS

In group A and B, the rejection-free interval of the allograft was significantly prolonged to an average of 23.1 ± 1.7 and 24.7 ± 1.8 days compared to the corresponding control groups (p < 0.01). Rejection in groups C, D, and E was noted after 14.3 ± 1.1, 7.8 ± 0.7, and 6.9 ± 0.6 days. No rejection occurred in control group F during the follow-up period of 100 days. No adverse events have been noted.

CONCLUSION

The findings of this study show that the combination of MICs with a temporary CsA treatment significantly prolongs the rejection-free interval in a complex VCA model. The combination of MICs with CsA showed no adverse events such as graft-versus-host disease. MICs, which are generated by a simple and reliable in vitro technique, represent a potential therapeutic tool for prolonging allograft survival through immunomodulation.

Vascularized Composite Allotransplantation: Medical Complications

The objective of this review is to summarize the collective knowledge regarding the risks and complications in vascularized composite tissue allotransplantation (VCA), focusing on upper extremity and facial transplantation. The field of VCA has entered its second decade with an increasing experience in both the impressive good outcomes, as well as defining challenges, risks, and experienced poor results. The limited and selective publishing of negative outcomes in this relatively new field makes it difficult to conclusively evaluate outcomes of graft and patient survival and morbidities. Therefore, published data, conference proceedings, and communications were summarized in an attempt to provide a current outline of complications. These data on the medical complications of VCA should allow for precautions to avoid poor outcomes, data to better provide informed consent to potential recipients, and result in improvements in graft and patient outcomes as VCA finds a place as a therapeutic option for selected patients.