Stefan Schneeberger

Prognostic value of indoleamine 2,3-dioxygenase expression in colorectal cancer: effect on tumor-infiltrating T cells.

PURPOSE: The pathologic interactions between tumor and host immune cells within the tumor microenvironment create an immunosuppressive network that promotes tumor growth and protects the tumor from immune attack. In this study, we examined the contribution of the immunomodulatory enzyme indoleamine 2,3-dioxygenase (IDO) on this phenomenon. EXPERIMENTAL DESIGN: Expression of IDO was analyzed in colorectal cancer cell lines by reverse transcription-PCR and functional enzyme activity was assessed by high-pressure liquid chromatography. Semiquantitative immunohistochemistry was used to evaluate IDO expression in the tissue samples of 143 patients with colorectal carcinoma, and was then correlated with the number of tumor-infiltrating T cells and clinical variables. RESULTS: In vitro IDO expression and functional enzyme activity in colorectal cancer cells was found to be strictly dependent on IFN-gamma stimulation. Immunohistochemical scores revealed IDO-high expression in 56 of 143 (39.2%) tumor specimens, whereas 87 of 143 (60.8%) cases showed low IDO expression levels. IDO-high expression was associated with a significant reduction of CD3+ infiltrating T cells (46.02 +/- 7.25) as compared with tissue samples expressing low IDO (19.42 +/- 2.50; P = 0.0003). Furthermore, IDO-high immunoreactivity significantly correlated with the frequency of liver metastases (P = 0.003). Kaplan-Meier analysis showed the crossing of survival curves at 45 months. By multivariate Coxs analysis, IDO-high expression emerged as an independent prognostic variable (<45 months, P = 0.006; >45 months, P = 0.04). CONCLUSION: IDO-high expression by colorectal tumor cells enables certain cancer subsets to initially avoid immune attack and defeat the invasion of T cells via local tryptophan depletion and the production of proapoptotic tryptophan catabolites. Thus, IDO significantly contributes to disease progression and overall survival in patients with colorectal cancer.

The Banff 2007 working classification of skin-containing composite tissue allograft pathology.

Composite tissue allotransplantation (CTA) is a recently introduced option for limb replacement and reconstruction of tissue defects. As with other allografts, CTA can undergo immune‐mediated rejection; therefore standardized criteria are required for characterizing and reporting severity and types of rejection. This article documents the conclusions of a symposium on CTA rejection held at the Ninth Banff Conference on Allograft Pathology in La‐Coruňa, Spain, on 26 June 2007, and proposes a working classification, the Banff CTA‐07, for the categorization of CTA rejection. This classification was derived from a consensus discussion session attended by the first authors of three published classification systems, pathologists and researchers from international centers where clinical CTA has been performed. It was open to all attendees to the Banff conference. To the extent possible, the format followed the established National Institutes of Health (NIH) guidelines on Consensus Development Programs. By consensus, the defining features to diagnose acute skin rejection include inflammatory cell infiltration with involvement of epidermis and/or adnexal structures, epithelial apoptosis, dyskeratosis and necrosis. Five grades of severity of rejection are defined. This classification refines proposed schemas, represents international consensus on this topic, and establishes a working collective classification system for CTA reporting of rejection in skin‐containing CTAs.

Upper-extremity transplantation using a cell-based protocol to minimize immunosuppression.

Objective: To minimize maintenance immunosuppression in upper-extremity transplantation to favor the risk-benefit balance of this procedure. Background: Despite favorable outcomes, broad clinical application of reconstructive transplantation is limited by the risks and side effects of multidrug immunosuppression. We present our experience with upper-extremity transplantation under a novel, donor bone marrow (BM) cell-based treatment protocol (“Pittsburgh protocol”). Methods: Between March 2009 and September 2010, 5 patients received a bilateral hand (n = 2), a bilateral hand/forearm (n = 1), or a unilateral (n = 2) hand transplant. Patients were treated with alemtuzumab and methylprednisolone for induction, followed by tacrolimus monotherapy. On day 14, patients received an infusion of donor BM cells isolated from 9 vertebral bodies. Comprehensive follow-up included functional evaluation, imaging, and immunomonitoring. Results: All patients are maintained on tacrolimus monotherapy with trough levels ranging between 4 and 12 ng/mL. Skin rejections were infrequent and reversible. Patients demonstrated sustained improvements in motor function and sensory return correlating with time after transplantation and level of amputation. Side effects included transient increase in serum creatinine, hyperglycemia managed with oral hypoglycemics, minor wound infection, and hyperuricemia but no infections. Immunomonitoring revealed transient moderate levels of donor-specific antibodies, adequate immunocompetence, and no peripheral blood chimerism. Imaging demonstrated patent vessels with only mild luminal narrowing/occlusion in 1 case. Protocol skin biopsies showed absent or minimal perivascular cellular infiltrates. Conclusions: Our data suggest that this BM cell-based treatment protocol is safe, is well tolerated, and allows upper-extremity transplantation using low-dose tacrolimus monotherapy.

Mitochondria in the Cold

Development of hibernation strategies for cold preservation of human organs represents a far-reaching goal in transplantation surgery. Short cold storage times of <6 h tolerated by the human heart remain a major clinical problem. Mitochondrial cold storagereperfusion injury is becoming recognized as a limiting factor in preservation of organs from non-hibernating mammals. Damaged mitochondria lead to cellular injury by reduction of ATP supply, oxidative stress, disturbance of ion balance, cytochrome c release and induction of apoptosis and necrosis. Profiles of mitochondrial injuries differed after (1) cold preservation of isolated rat heart mitochondria, (2) cold preservation of the rat heart, and (3) after transplantation and rewarming/reperfusion. Importantly, a specific defect of complex I of the electron transport chain, uncoupling of oxidative phosphorylation and the pronounced release of cytochromec from mitochondria were absent after cold storage but developed during reperfusion, in proportion to the loss of heart function. Cold preservation of isolated heart mitochondria could be significantly prolonged by a mitochondrial preservation solution containing antioxidants, mitochondrial substrates, ATP, histidine, and oncotic agents. Successful cold storage of heart mitochondria demonstrates a large scope for improvement of heart preservation solutions. In this context, comparison of intracellular conditions and cold ischemia-reperfusion injury in hibernating and non-hibernating mammals may provide a rationale for improvement of clinical organ hibernation strategies.

The world's experience with facial transplantation: What have we learned thus far?

The objective of this review article is to summarize the published details and media citations for all seven face transplants performed to date to point out deficiencies in those reports so as to provide the basis for examining where the field of face transplantation stands, and to act as a stimulus to enhance the quality of future reports and functional outcomes. Overall long-term function of facial alloflaps has been reported satisfactorily in all seven cases. Sensory recovery ranges between 3 and 6 months, and acceptable motor recovery ranges between 9 and 12 months. The risks and benefits of facial composite tissue allotransplantation, which involves mandatory lifelong immunosuppression analogous to kidney transplants, should be deliberated by each institution’s multidisciplinary face transplant team. Face transplantation has been shown thus far to be a viable option in some patients suffering severe facial deficits which are not amenable to modern-day reconstructive technique.

A double-hand transplant can be worth the effort!

Background. Composite-tissue transplantation offers a new therapeutic option for patients with loss of a hand. Little is known, however, about the long-term outcome after such a transplant with regard to graft function and immunosuppression and its side effects. We here report on our experience with a double-hand transplant performed more than 18 months ago. Methods. Both distal forearms and hands of an age-, gender-, and size-matched cadaveric donor were transplanted to a 47-year-old policeman 6 years after loss of both hands. He received antithymocyte globulin as induction therapy and tacrolimus, mycophenolate mofetil, and prednisone as maintenance immunosuppression. Ganciclovir and co-trimoxazole were given prophylactically for cytomegalovirus and Pneumocystis carinii infection. A special rehabilitation program based mainly on cognitive therapy was designed and continued for 1 year. Results. Apart from a small area of skin that became necrotic early and some arteriovenous fistulas in the left forearm, which required ligation 6 months after transplantation, there were no surgical complications. One acute rejection episode occurred on day 55 and resolved completely after high-dose steroids and topical tacrolimus. Despite ganciclovir prophylaxis, virus replication was observed. The patient became negative for cytomegalovirus only after additional treatment with foscarnet (Foscavir) and cidofovir. At the end of 18 months, graft function with regard to motility is overall 60% of normal and enables the patient to pursue activities he could not with his myoelectric prostheses. Conclusions. Excellent long-term results can be achieved with double-hand transplantation. Prerequisites are an appropriate surgical technique, careful immunosuppression, and an extensive rehabilitation program.

Steroid- and ATG-Resistant Rejection After Double Forearm Transplantation Responds to Campath-1H

We herein report on immunological and histological observations in the first bilateral forearm transplant recipient. The last of three rejection episodes occurring on day 95 after transplantation was resistant to steroid and antithymocyte globulin (ATG) treatment. Histology demonstrated lymphocytic infiltrates, apoptotic and necrotic keratinocytes and focal desquamation of the epidermis. Therapy with Campath‐1H, however, resulted in complete restitution of normal skin. This is the first report on a successful rescue therapy with Campath‐1H in a severe, steroid‐ and ATG‐resistant rejection. Hence, Campath‐1H treatment might be a novel and powerful therapeutic option for multiresistant allograft rejection.

Achievements and challenges in composite tissue allotransplantation.

Overall, more than 60 hand/forearm/arm transplantations and 16 face transplantations have been performed in the past 12 years. In the European experience summarized here, three grafts have been lost in response to a vascular thrombosis (n = 1), rejection and incompliance with immunosuppression (n = 1) and death (n = 1). The overall functional and esthetic outcome is very satisfactory, but serious side effects and complications related to immunosuppression are challenges hindering progress in this field. The high levels of immunosuppression, skin rejection, nerve regeneration, donor legislation and the acceptance level need to be addressed to promote growth of this promising new field in transplantation and reconstructive surgery.

First forearm transplantation : Outcome at 3 years

We here report on the surgical procedure, postoperative course and functional results at 3 years following the first bilateral forearm transplantation. A 41‐year‐old male underwent bilateral forearm transplantation on February 17, 2003. After ATG induction therapy, tacrolimus, prednisone and MMF were given for maintenance immunosuppression. At 16 months, MMF was switched to everolimus. Hand function, histology, immunohistochemistry, radiomorphology, motor and nerve conduction and somatosensory‐evoked potentials were investigated at frequent intervals. A total of six rejection episodes required treatment with either steroids, basiliximab, ATG, alemtuzumab or tacrolimus dose augmentation. At 3 years, the patient is free of clinical signs of rejection despite a persisting minimal perivascular lymphocytic dermal infiltrate. No signs of myointimal proliferation in graft vessels were seen. Motor function continuously improved, resulting in satisfactory hand function. Intrinsic hand muscle function was first observed at 16 months and continues to improve. Although discrimination of hot and cold recovered, overall sensitivity remains poor. The patient is satisfied with the outcome. Bilateral forearm transplantation represents a novel therapeutic option after loss of forearms.

Lipocalin-2 Regulates the Inflammatory Response During Ischemia and Reperfusion of the Transplanted Heart

Ischemia and reperfusion (IR) are known to negatively affect early allograft function following solid organ transplantation. Lipocalin‐2 (Lcn‐2) has been described as a marker and potential positive modulator of acute inflammation during these processes. Using a heterotopic murine heart transplant model we previously found that IR resulted in a pronounced upregulation of Lcn‐2 mRNA in the heart at 12 (22.7‐fold increase) and 24 h (9.8‐fold increase) of reperfusion. We now confirm this increase at the protein level and provide evidence for infiltrating polymorphonuclear cells as the primary source of Lcn‐2 protein. Lcn‐2 levels are increased 6.6‐fold at 12 h, 11.4‐fold at 24 h and 6.4 fold at 48 h after reperfusion. In Lcn‐2−/− grafts the number of infiltrating granulocytes is reduced by 54% (p < 0.05) at 2 h, 79% (p < 0.01) at 12 h, 72% (p < 0.01) at 24 h and 52% (p < 0.01) at 48 h after reperfusion compared to Lcn‐2+/+ grafts, without any differences in cardiomyocyte apoptosis. These data suggest a function of Lcn‐2 in the initiation of the inflammatory response. Moreover, an increase in Lcn‐2 is not only restricted to the transplanted heart, but is also observed in the kidney, hinting at a possible involvement of Lcn‐2 in the systemic response to IR.