Aram Gazarian

Long-Term Follow-Up in Composite Tissue Allotransplantation: In-Depth Study of Five (Hand and Face) Recipients

Composite tissue allotransplantations (CTAs) have clinically shown little, if any, evidence of chronic rejection. Consequently, the effect of chronic rejection on bones, joints, nerves, muscles, tendons and vessels may still have undescribed implications. We thoroughly assessed all allograft structures by histology, magnetic resonance imaging, ultrasonography and high resolution peripheral quantitative computed tomography scan in four bilateral hand‐grafted patients (10, 7, 3 and 2 years of follow‐up, respectively) and in one facial allotransplantation (5 years of follow‐up). All the recipients presented normal skin structure without dermal fibrosis. Vessels were patent, without thrombosis, stenosis or intimal hyperplasia. Tendons and nerves were also normal; muscles showed some changes, such as a variable degree of muscular hypotrophy, particularly of intrinsic muscles, accompanied by fatty degeneration that might be related to denervation. In the majority of hand‐grafted patients graft radius and recipient tibia showed a decrease in trabecular density, although in the graft radius the alterations also involved the cortices. No deterioration of graft function was noted. In these cases of CTA no signs of chronic graft rejection have been detected. However, the possibility that chronic rejection may develop in CTA exists, highlighting the necessity of close continuous follow‐up of the patients.

Bilateral hand transplantation : Six years after the first case

In this study we present our experience concerning bilateral hand transplantation. Two cases were performed: the first in January 2000 and the second in April 2003. Both recipients received the same immunosuppressive treatment, which was similar to those used in solid organ transplantation, including tacrolimus, prednisone and mycophenolate mofetil while antithymocyte globulins were added for induction. Both recipients presented two episodes of acute rejection (maculopapular lesions) in the first 3 months after transplantation; however, these were easily reversed after a few days increasing oral steroid doses and using topical immunosuppressants. The first recipient presented hyperglycemia and serum sickness while the second recipient suffered a thrombosis of the right ulnar artery and an osteomyelitis of left ulna. All the complications were successfully treated. Functional Magnetic Resonance Imaging (fMRI) showed that cortical hand representation progressively shifted from the lateral to the medial region in the motor cortex. After 6 and 2 years respectively, they showed a relevant sensorimotor recovery particularly of sensibility and activity of intrinsic muscles. They were able to perform the majority of daily activities and to lead a normal social life. The first recipient has been working since 2003. They are both satisfied with their grafted hands.

Chronic Rejection in Human Vascularized Composite Allotransplantation (Hand and Face Recipients): An Update.

Vascularized composite tissue allografts (VCA) have become a viable option to restore severely damaged parts of the body that cannot be repaired with conventional surgical techniques. Acute rejection develops frequently in the early postgraft period both in human and experimental VCA, but the possibility of human VCA to undergo chronic rejection (CR) remained initially unknown. The experience gained over the years shows that, similar to solid organ transplants (SOT), human VCA can also develop CR. Chronic rejection is clinically mostly apparent on the skin and targets preferentially skin and deep vessels, leading, as in SOT, to graft vasculopathy and often to graft loss. Dermal sclerosis and adnexal atrophy are additional features of CR. The pathogenetic immune mechanisms involved (cell-mediated versus humoral) remain incompletely known. The changes of CR can be detected with skin and deep tissue biopsies. Modern in vivo imaging tools can detect vascular narrowing and have the advantage of being noninvasive. However, the diagnosis and treatment of CR remain challenging, as several important questions remain to be answered: a more accurate definition of CR in VCA is needed to establish criteria allowing an accurate and early diagnosis. The pathogenetic mechanisms of CR need to be better understood to allow more efficacious treatment. Favoring/triggering factors of CR need to be better known so that they can be avoided. As in SOT, there is a need for efficient tolerance-inducing protocols that will favor graft acceptance and (ideally) circumvent the necessity of lifelong immunosuppression.

Outcomes after bilateral hand allotransplantation: a risk/benefit ratio analysis.

BACKGROUND The clinic era of composite tissue allotransplantation was inaugurated by hand allotransplantation in 1998, giving rise to many controversies and scepticism because of the lifelong immunosuppression, the unclear risk-benefit ratio, and the uncertain long-term functional results of the procedure. The aim of this study was to evaluate the outcomes and the risk/benefit balance in bilateral hand allotransplantation. METHODS The study included 5 cases of bilateral hand allotransplantation performed in a single center, with a follow-up ranging from 3 to 13 years. The recipients (4 men, 1 woman) were young. The level of amputation was distal in all cases except for 2 patients amputated at the midforearm level. All the recipients initially received the same immunosuppressive treatment that included tacrolimus, mycophenolate mofetil, prednisone, and, for induction, antithymocyte globulins. RESULTS Patient and graft survival was 100%. All recipients showed adequate sensorimotor recovery (protective and tactile sensitivity and partial recovery of intrinsic muscles), they were able to perform the majority of activities of daily living, and had a normal social life. Most complications occurred in the first posttransplant year and were successfully managed. All recipients experienced at least 1 episode of acute rejection, which was easily reversed by increasing oral steroid dose or by intravenous steroids, except for patient 3, who presented 6 episodes of acute rejection, the latest 2 treated with Campath-1H. CONCLUSIONS Although bilateral hand transplantation may be a satisfactory treatment option for amputees, a careful selection of candidates and a rigorous evaluation of recipients after transplantation are imperative.

Bilateral hand transplantation: Functional benefits assessment in five patients with a mean follow-up of 7.6 years (range 4-13 years).

Between January 2000 and July 2009, five adults who had suffered bilateral traumatic below-elbow amputations, received bilateral hand-forearm allografts performed by the Lyon team. We report the functional benefits achieved over a mean follow-up period of 7.6 years (range 4-13 years), up to December 31st, 2013. Clinical measurement is hampered by the lack of specific validated assessment tools, obliging us to use non-specific standardized evaluation means. Our assessment shows that the restoration of motion, strength, and sensibility are fair. Functional results (Carroll upper extremity function test, 400-point test, Activities of daily living) are good, as well as quality of life evaluation (RAND-36). Subjective and overall results explored with questionnaires - Disabilities of the Arm Shoulder and Hand (DASH), Hand Transplantation Score System (HTSS), are very good. Improvement was seen to continue during the first three years, and then tend to become stable. Continued efforts should be directed at designing comprehensive, condition-specific, reliable outcome measurement tools. Continuous monitoring and evaluation of patients is required to assess the long-term risk-benefit balance.

Capillary thrombosis in the skin: A pathologic hallmark of severe/chronic rejection of human vascularized composite tissue allografts?

Background Vascularized composite tissue allografts (VCA) can undergo rejection, manifesting pathologically with skin changes that form the basis of the Banff 2007 classification of VCA rejection. Methods We have followed 10 human VCA recipients (7 with hand allografts, 3 with face allografts) for pathological signs of rejection. All of them developed episodes of acute rejection. Two patients with hand allografts presented in some of their skin biopsies an as yet unreported pathological finding in human VCA, consisting of capillary thromboses (CT) in the upper dermis. Results Capillary thrombosis was associated with other typical changes of grade II to III VCA rejection, namely, perivascular T cell infiltrates, but not with vascular C4d deposits (in formalin-fixed tissue). Clinically, the lesions presented as red or violaceous (lichenoid) cutaneous maculopapules. The first patient had several episodes of acute rejection during the 7-year follow-up. The second patient developed donor-specific antibodies; some months after CT were first observed, he developed chronic rejection leading to partial amputation of the allograft. Pathological examination of the skin showed graft vasculopathy and occasional C4d deposits in cutaneous capillaries. Conclusions Capillary thrombosis seems to be a novel pathologic finding associated with human VCA rejection. Although its mechanism (immunologic vs nonimmunologic) remains unclear, this finding could carry an unfavorable prognostic significance, prompting close monitoring of the patients for severe/chronic rejection.

Composite tissue allotransplantation in newborns: A swine model

BACKGROUND Management of congenital limb aplasia or facial malformations could be improved by composite tissue allotransplantation (CTA), a technique that has never been performed in newborns. For this, however, the induction of donor-specific tolerance would be mandatory, as long-term immunosuppression is not acceptable in this non-lifesaving procedure. Induction of tolerance has been shown to be possible in a newborn CTA rat model but has never been tested in large-animal models. Our goals were to establish a model of CTA in newborn swine to see if tolerance could be obtained without immunosuppression and to assess rejection or tolerance properties via clinical and histologic examinations. MATERIALS AND METHODS We applied a CTA heterotopic knee swine model. We performed two series of surgical procedures: Series 1 was 20 autografts in 6-day-old (1-10) 2,544 kg (1,140-4,060 kg) piglets; Series 2 was 10 allografts without immunosuppression between outbred animals aged 7.8 d (6-10) and weighing 2,770 kg (2,200-3,550 kg). RESULTS In Series 1, six early deaths and two cases of vascular failure were observed. In Series 2, no spontaneous deaths were observed and all piglets presented clinical and histologic rejection. CONCLUSIONS Our findings strongly suggest that newborn immunologic status is not sufficient for the development of tolerance in large animals without immunologic intervention. Complications and animal death after transplantation correlate with age and weight. Low rates for both vascular failure and postoperative death permit the use of this model in piglets weighing over 2 kg and aged more than 6 d for research on newborn CTA.

Premalignant and Malignant Skin Lesions in Two Recipients of Vascularized Composite Tissue Allografts (Face, Hands)

Recipients of solid organ transplants (RSOT) have a highly increased risk for developing cutaneous premalignant and malignant lesions, favored by the lifelong immunosuppression. Vascularized composite tissue allografts (VCA) have been introduced recently, and relevant data are sparse. Two patients with skin cancers (one with basal cell carcinoma and one with squamous cell carcinomas) have been so far reported in this patient group. Since 2000 we have been following 9 recipients of VCA (3 face, 6 bilateral hands) for the development of rejection and complications of the immunosuppressive treatment. Among the 9 patients, one face-grafted recipient was diagnosed with nodular-pigmented basal cell carcinoma of her own facial skin 6 years after graft, and one patient with double hand allografts developed disseminated superficial actinic porokeratosis, a potentially premalignant dermatosis, on her skin of the arm and legs. Similar to RSOT, recipients of VCA are prone to develop cutaneous premalignant and malignant lesions. Prevention should be applied through sun-protective measures, regular skin examination, and early treatment of premalignant lesions.

Transplant Tolerance Induction in Newborn Infants: Mechanisms, Advantages, and Potential Strategies

Although several tolerance induction protocols have been successfully implemented in adult renal transplantation, no tolerance induction approach has, as yet, been defined for solid organ transplantations in young infants. Pediatric transplant recipients have a pressing demand for the elaboration of tolerance induction regimens. Indeed, since they display a longer survival time, they are exposed to a higher level of risks linked to long-term immunosuppression (IS) and to chronic rejection. Interestingly, central tolerance induction may be of great interest in newborns, because of their immunological immaturity and the important role of the thymus at this early stage in life. The present review aims to clarify mechanisms and strategies of tolerance induction in these immunologically premature recipients. We first introduce the discovery and mechanisms of neonatal tolerance in murine experimental models and subsequently analyze tolerance induction in human newborn infants. Hematopoietic mixed chimerism in neonates is also discussed based on in utero hematopoietic stem cell (HSC) transplant studies. Then, we review the recent advances in tolerance induction approaches in adults, including the infusion of HSCs associated with less toxic conditioning regimens, regulatory T cells/facilitating cells/mesenchymal stem cells transplantation, costimulatory blockade, and thymus manipulation. Finally, IS withdrawal in pediatric solid organ transplant is discussed. In conclusion, the establishment of transplant tolerance induction in infants is promising and deserves further investigations. Future studies could focus on the selection of patients, on less toxic conditioning regimens, and on biomarkers for IS minimization or withdrawal.

Oral cyclosporine A in neonatal swines for transplantation studies

Abstract The purpose of this study is to define the optimal dose of oral cyclosporine A (CsA) microemulsion in newborn swine for transplantation studies and to describe its pharmacokinetics and acute renal effects in short-term administration. Thirteen neonatal pigs were randomized into four groups: one control and three groups with CsA administration at 4, 8 and 12 mg/kg/d for 15 days (D). Blood samples were collected on D 0, 2, 4, 9 and 14 to determine the changes of the CsA trough concentrations, the creatinine (Cr) and blood urea nitrogen (BUN) serum concentrations. On D 14, blood samples were collected every hour from 1 h to 10 h after CsA administration to determine the area under the curve (AUC). On D 15, kidneys were removed for histological analysis. We observed a stabilization of CsA trough concentrations from D 4 to D 14. On D 14, in the three treated groups, CsA trough concentrations were 687 ± 7, 1200 ± 77 and 2211 ± 1030 ng/ml, respectively; AUC (0–10 h) were 6721 ± 51 ng·h/ml in group 4 mg/kg/d, 13431 ± 988 ng·h/ml in group 8 mg/kg/d and 28264 ± 9430 ng·h/ml in group 12 mg/kg/d. Cr concentrations were not significantly different among the four groups; but compared to control group, BUN concentrations of the three treated groups increased significantly. CsA was well tolerated; neither acute, severe adverse event nor renal histological abnormality was observed. In conclusion, a 15-d course of oral CsA treatment ranged from 4 to 12 mg/kg/d is safe for newborn pigs, which need much lower CsA dose than adult pigs to reach comparable trough level and AUC. As immunosuppressive therapy in newborn pigs, we recommend a CsA dose of 4 mg/kg/d to achieve a trough blood concentration between 400 and 800 ng/ml.