Intestinal transplantation: evolution in immunosuppression protocols

Update on Maintenance Immunosuppression in Intestinal Transplantation

Outcomes in intestinal transplantation remain hampered by higher rates of rejection than any other solid organs. However, maintenance immunosuppression regimens have largely remained unchanged despite advances in therapies for induction and treatment of rejection and graft-versus-host disease. Recently, there have been a small number of new maintenance therapies attempted, and older agents have been used in new ways to achieve better outcomes. The authors herein review the traditional maintenance therapies and their mechanisms and then consider updates in new therapies and new ways of using old therapies for maintenance immunosuppression after intestinal transplantation.

Immune reactions following intestinal transplantation: Mechanisms and prevention

For patients with intestinal failure, small bowel transplantation remains one of the most effective treatments despite continuous advancements in parenteral nutrition techniques. Long-term use of parenteral nutrition can result in serious complications that lead to metabolic dysfunction and organ failure. However, the small intestine is a highly immunogenic organ with a large amount of mucosa-associated lymphoid tissue and histocompatibility antigens; therefore, the small intestine is highly susceptible to severe immune rejection. This article discusses the mechanisms underlying immune rejection after small bowel transplantation and presents various options for prevention and treatment. Our findings offer new insights into the development of small bowel transplantation.

Present state of intestinal transplantation in Japan

INTRODUCTION

Intestinal transplantation (ITx) is the ultimate treatment for intestinal failure (IF). In Japan, most cases of IF are a result of pediatric disease, including secondary or congenital intestinal disease or allied disorders of Hirschsprung's disease. Here, we report the results of the Japanese ITx registry.

METHODS

A web-based survey form was completed. We investigated the number, age, sex, indication, surgical procedure, immunosuppressants, postoperative course, and the effects of transplantation in patients who underwent cadaveric or living-donor ITx.

RESULTS

By the end of 2022, 42 cases of ITx have been performed in 38 patients in Japan. The donor sources included cadavers (29 cases) and living donors (13 cases). The surgical method was isolated ITx (N = 40) and combined liver and ITx (n = 2). Survival rates were 92%, 73%, and 59% at 1 year, 5 years, and 10 years, respectively. Ninety percent of patients completely discontinued parenteral nutrition. Approximately 80% of the patients had a performance status of 1 or less, indicating that the QOL of patients after ITx was extremely good.

CONCLUSION

The results of ITx are acceptable to treat IF patients and the QOL after transplantation is also good.

Late graft loss after intestinal transplantation

PURPOSE OF REVIEW

Despite improvement in short-term outcomes after intestinal transplantation in the last 20 years, long-term rates of graft attrition and patient survival remain unchanged, with worse outcomes compared with other solid organ transplants. This review investigates the multiple causes of late graft loss, including chronic rejection, infection, graft-versus-host disease, posttransplant lymphoproliferative disorder and postsurgical complications.

RECENT FINDINGS

New insights into immunology of the intestine and evolution of immunosuppression, as well as review of current persistent causes of late graft loss, shed light on findings that may help improve long-term intestinal allograft survival.

SUMMARY

Although intestinal transplantation remains a life-saving intervention with significant advancements since its inception, further understanding of mechanisms of injury is needed to improve long-term outcomes and prevent late intestinal graft loss.

Advances in small bowel transplantation

Small bowel transplantation is a life-saving surgery for patients with intestinal failure. The biggest problem in intestinal transplantation is graft rejection. Graft rejection is the main reason for morbidity and mortality. Rejection has a negative effect on the survival of the graft. While 50%-75% of small bowel transplantation patients experience acute rejection, chronic rejection occurs in approximately 15% of patients. Immune monitoring is crucial after small bowel transplantation. Unlike other types of transplantation, there are no non-invasive or reliable markers to predict rejection in small bowel transplantation. The diagnosis of AR is confirmed by clinical symptoms, endoscopic appearance, and pathological specimens taken by endoscopy. Thus, histopathological examinations obtained by protocol biopsies remain as the gold standard for intestinal graft monitoring; however, biopsies have some complications, especially in small grafts. In addition to the high complication rate, biopsies are non-diagnostic; thus, multiple biopsies should be performed to exclude rejection. Therefore, auxiliary assays, such as measurements of citrulline and calprotectin in the blood, cytofluorographic examination of peripheral blood immune cells, cytokine profiling, and distinct gene-set-change measurements, are increasingly being used in small bowel transplantation. Developments in the understanding of genes seem to be promising that limited gene sets, taken from blood or from intestinal biopsies, will enhance pathological diagnosis. Bone marrow mesenchymal stem cell transplantation with SBT and tissue engineering are also promising procedures.

Hemophagocytic lymphohistiocytosis presenting in a pediatric patient with near total colonic and small bowel aganglionosis: a case report

Background

Total colonic and small bowel aganglionosis is a rare condition typically requiring intestinal transplant for long-term survival. There have not been any previously reported cases of near total intestinal aganglionosis complicated by concerns for hemophagocytic lymphohistiocytosis and need for both multivisceral organ transplant and hematopoietic stem cell transplant.

Case presentation

Our patient is a 35-month-old Egyptian boy who presented with bilious emesis and failure to pass meconium shortly after birth. After evaluation, he was found to have near total colonic and small bowel aganglionosis up to the ligament of Treitz. When he was transferred to our tertiary facility, he was already diagnosed as having aganglionosis of total colon and partial small bowel whose case is complicated by the concern for hemophagocytic lymphohistiocytosis. He was not able to absorb any substantial nutrition enterally and was stabilized on long-term total parenteral nutrition which resulted in total parenteral nutrition-induced liver injury. While awaiting evaluation for liver and bowel transplant, he developed concerning symptoms consistent with hemophagocytic lymphohistiocytosis. He presents a complex challenge creating difficulty with management of whether to proceed with bowel transplant as a result of near-total intestinal aganglionosis or hematopoietic stem cell transplant for treatment of hemophagocytic lymphohistiocytosis. In this case, the transplant team proceeded with visceral transplant first, however he did not survive.

Conclusions

This presentation of aganglionosis of total colon and partial small bowel complicated by the concern for hemophagocytic lymphohistiocytosis is unique to medical literature. For many physicians involved it is hard to determine how best to proceed with next steps in care.

Intestinal transplantation: a review

PURPOSE OF REVIEW

The purpose of this article is to review the existing literature on the current indications, surgical techniques, immunosuppressive therapy and outcomes following intestinal transplantation (ITx).

RECENT FINDINGS

Over recent years, ITx has become a more common operation with approximately 2500 procedures carried out worldwide by 2014. It is reserved for patients with intestinal failure and who have developed complications of home parenteral nutrition or who have a high risk of dying from their underlying disease. Recent advances such as the improvement in survival rates, not only for isolated small bowel transplants but also following inclusion of a liver graft in combined liver-small bowel transplant, and the utility of citrulline as a noninvasive biomarker to appreciate acute rejection herald an exciting shift in the field of ITx.

SUMMARY

With advancements in immunosuppressive drugs, induction regimens, standardization of surgical techniques and improved postoperative care, survival is increasing. In due course, it will most likely become as good as remaining on home parenteral nutrition and as such could become a viable first-line option.

Clinical presentation and outcomes of norovirus infection in intestinal allograft compared to native intestine

BACKGROUND

No data are available on clinical manifestations and course of norovirus gastroenteritis (NVE) in intestinal allograft (from intestinal and multivisceral transplant recipients, ITR) compared to native intestine (from other allograft recipients, nITR).

METHODS

This was a retrospective study of solid organ transplant recipients with NVE at two centers from January 1, 2010 to April 1, 2014. Chi-square, t-test, linear and logistic regression analyses were done to compare NVE in ITR vs nITR patients.

RESULTS

The ITR (45 patients) were compared to nITR (107 patients). ITR were younger (odds ratio [OR]=0.90; P<.0001), less likely to receive anti-lymphocyte induction therapy (OR=0.15; P<.0001), and had shorter time from transplant to NVE (OR=0.99; P=.008). On presentation ITR had less frequent nausea (OR=0.11; P<.0001) or vomiting (OR=0.36; P=.01), higher white blood cell count (OR=1.09; P=.001), and higher glomerular filtration rate (OR=1.02; P<.0001). ITR were less likely to receive anti-motility agents (OR=9.6; P<.0001). ITR were more likely to stay longer on intravenous (IV) fluids (OR=1.18; P<.0001); have recurrent NVE (OR=4.25; P<.0001); have longer hospital stay (OR=1.07; P<.0001); develop acute rejection (OR=5.1; P=.006); and have lower overall survival (OR=0.28; P=.006).

CONCLUSIONS

Compared to nITR, the ITR with NVE were significantly younger, had less nausea and vomiting at presentation, received less anti-motility agents, required more IV fluids, and had longer hospital stay. A trend was seen for lower survival with NVE in ITR.

Intestinal transplantation

Intestinal transplantation has now emerged as a lifesaving therapeutic option and standard of care for patients with irreversible intestinal failure. Improvement in survival over the years has justified expansion of the indications for intestinal transplantation beyond the original indications approved by Center for Medicare and Medicaid services. Management of patients with intestinal failure is complex and requires a multidisciplinary approach to accurately select candidates who would benefit from rehabilitation versus transplantation. Significant strides have been made in patient and graft survival with several advancements in the perioperative management through timely referral, improved patient selection, refinement in the surgical techniques and better understanding of the immunopathology of intestinal transplantation. The therapeutic efficacy of the procedure is well evident from continuous improvements in functional status, quality of life and cost-effectiveness of the procedure. This current review summarizes various aspects including current practices and evidence based recommendations of intestinal transplantation.

Current understanding of alloimmunity of the intestinal graft

PURPOSE OF REVIEW

This review focuses on the known mechanisms of alloimmunity that occur after transplantation and what is being done in order to improve graft and patient survival, particularly in the long term.

RECENT FINDINGS

The presence of mismatched antigens and epitopes might relate directly to the development of de-novo donor-specific antibodies (DSA), and thus, rejection. In an abdominal wall transplant, the skin graft could be the first to show signs of rejection. The epithelial or endothelial cells are the main targets in acute and chronic rejection, respectively. Possible therapeutical targets are gut homing T cells and cells of the innate immune system. Chimerism development might mostly occur in isolated lymph nodes, but also in the epithelium, particularly after transplantation of bone marrow mesenchymal stromal cells.

SUMMARY

Ischemia-reperfusion, surgical injury, and bacterial translocation trigger the innate immune system, starting acute rejection. Interaction between donor and recipient immune cells generate injury and tolerance, which occur mostly in secondary lymphoid organs, lamina propria, and epithelium. Chronic rejection mostly affects the endothelial cells, generating graft dysfunction. DSA increase the risk of graft rejection both acutely and chronically, and the liver protects against their effects. Induction therapies deplete lymphocytes prior to implantation, and maintenance therapies inhibit T-cell expansion. Rejection rates are the lowest when depleting drugs and a combination of interleukin 2 receptor blockade, inhibition of T-cell expansion, and steroids are used as maintenance therapy. Chimerism and tolerogenic regiments that induce Tregs and prevent the development of DSA are important treatment goals for the future.

Recollective homeostasis and the immune consequences of peritransplant depletional induction therapy

One's cellular immune repertoire is composed of lymphocytes in multiple stages of maturation - the dynamic product of their responses to antigenic challenges and the homeostatic contractions necessary to accommodate immune expansions within physiologic norms. Given that alloreactivity is predominantly a cross-reactive phenomenon that is stochastically distributed throughout the overall T-cell repertoire, one's allospecific repertoire is similarly made up of cells in a variety of differentiation states. As such, the continuous expansion and elimination of activated memory populations, producing a 'recollective homeostasis' of sorts, has the potential over time to alter the maturation state and effector composition of both ones protective and alloreactive T-cell repertoire. Importantly, a T cell's maturation state significantly influences its response to numerous immunomodulatory therapies used in organ transplantation, including depletional antibody induction. In this review, we discuss clinically utilized depletional induction strategies, how their use alters a transplant recipient's cellular immune repertoire, and how a recipient's repertoire influences the clinical effects of induction therapy.

Intestinal Transplantation from Living Donors

Intestinal transplantation (ITx) represents the physiologic alternative to total parenteral nutrition (TPN) for patients suffering from life-threatening complications of irreversible intestinal failure. The number of transplants performed worldwide has been increasing for several years until recently. ITx has recently become a valid therapeutic option with a graft survival rate between 80 % and 90 % at 1 year, in experienced centers. These results have been achieved due to a combination of several factors: better understanding of the pathophysiology of intestinal graft, improved immunosuppression techniques, more efficient strategies for the monitoring of the bowel graft, as well as control of infectious complications and posttransplant lymphoproliferative disease (PTLD). In fact, this procedure is associated with a relatively high rate of complications, such as infections, acute rejection, graft versus host disease (GVHD), and PTLD, if compared to the transplantation of other organs. These complications may be, at least in part, the consequence of the peculiarity of this graft, which contains gut-associated lymphoid tissue and potentially pathogenic enteric flora. Furthermore, in these patients, the existing disease and the relative malnutrition could predispose them to infectious complications. Additionally, other factors associated with the procedure, such as laparotomy, preservation injury, abnormal motility, and lymphatic disruption, could all be implicated in the development of complications.

Comparison of several functional methods to evaluate the immune response on stable kidney transplant patients

The introduction of new immunosuppressive drugs in the last two decades has been associated with a significant decline in the prevalence of acute rejection and a huge improvement of graft survival. Monitoring blood levels of immunosuppressive drugs is the most common way to control drug doses in renal transplant patients. This approach is useful and widely used but doesn't give accurate information about the immune status of the patient. For this goal, there are many "in house" protocols which give more information, but cannot be standardized, limiting their applicability to compare results between different laboratories. In this study we compare three classical functional methods to evaluate the immune response: Mixed lymphocyte reaction (MLR), phytohemagglutinin stimulated peripheral blood lymphocytes (PBLs), and anti-CD3 monoclonal antibodies (mAbs) against PBL with the only FDA-labeled assay to measure the patient immune status: Cylex ImmuKnow® that measures the intracelullar ATP in CD4+ lymphocytes. We used n=111 stable renal transplant patients, all the patients with more than one year functioning grafts. We referred the results to a control population of healthy blood donors (n=125).

RESULTS

Measurement of intracellular ATP in CD4+ lymphocytes is able to differentiate immunosuppressed populations in renal transplant patients from health controls (242.30±21.62 vs. 386.43±25.12, p 0.0001). By contrary, there were no differences between controls and renal recipients when functional response was measured by MLR, PHA and anti-CD3 mAbs (2.48±0.45 vs. 2.37±0.41; 2.84±0.76 vs. 2.37±0.32; 2.32±0.34 vs. 1.89±0.38 respectively). In summary, our results show that the measurement of ATP in CD4+ lymphocytes gives more accurate information in comparison to the classical methods.

Mucosal changes induced by ischemia-reperfusion injury in a jejunal loop transplanted in oropharynx

Tissues exposed to ischemia and reperfusion develop an inflammatory response. We investigate the morphological and immunological changes occurring in the mucosa of a jejunal loop transplanted in the oropharynx of a man undergoing circular pharyngolaryngectomy. Jejunal biopsies were collected during the transplantation procedures (cold and warm ischemia, reperfusion), during the 7 post-operative days through an exteriorized jejunal segment for flap monitoring, and 45 days after transplantation through an upper endoscopy. Matrix metalloproteinase (MMP)-3 and MMP-12 increase was accompanied by a parallel rise in apoptotic enterocytes, and by a concomitant reduction of surface area to volume ratio and enterocyte height. Goblet cell hyperplasia is coupled with Paneth cell disappearance at the crypt base. CD8-positive intraepithelial lymphocytes initially decrease, then they increase in accordance with the peak of enterocyte apoptosis. We identified alterations in lymphocyte infiltration, mucosal architecture and epithelial cell turnover, which may give a window to mechanisms of small bowel ischemia-reperfusion in humans.

Cutaneous graft versus host disease in pediatric multivisceral transplantation

Multivisceral transplantation (MvTx) is the concurrent transplantation of the stomach, pancreaticoduodenal complex, and intestine, with or without the liver. Its use is increasing worldwide as it has been considered as a therapy for patients with functional disturbance of several organs. Graft-versus-host disease (GvHD) has been a relevant clinical problem in MvTx ever since the procedure was first performed, but little has been reported about its specific cutaneous features. Our study included all pediatric patients with clinical and histopathologic evidence of cutaneous GvHD who received MvTx between October 1999 and December 2010 in University Hospital La Paz. Seventeen children underwent MvTx at our center during this period of time. Five patients developed cutaneous GvHD (29.4%). The median onset was 45.2 days after transplantation. Acute cutaneous GvHD, consisting of symmetrical maculopapular exanthema with prominent acral erythema and accentuated lesions on the face and pinnae, was clinically suspected and pathologically confirmed in four patients (80%). Three children (60%) experienced disease progression to a formation and a positive Nikolsky sign. Only one girl (20%) showed lichenoid GvHD. The first therapeutic approach was steroids and tacrolimus adjustment; many other drugs were used in refractory cases. Three of the five patients (60%) died with concomitant GvHD, the immediate cause of death being another comorbid disease. Knowledge of the features of cutaneous GvHD in MvTx allows clinicians early recognition and prompt therapeutic intervention that may prevent progression to higher-grade disease and improve outcomes for these patients.

Nonsurgical care of intestinal and multivisceral transplant recipients: a review for the intensivist

Intestinal and multivisceral transplantation has evolved from an experimental procedure to the treatment of choice for patients with irreversible intestinal failure and serious complications related to long-term parenteral nutrition. Increased numbers of transplant recipients and improved survival rates have led to an increased prevalence of this patient population in intensive care units. Management of intestinal and multivisceral transplant recipients is uniquely challenging because of complications arising from the high incidence of transplant rejection and its treatment. Long-term comorbidities, such as diabetes, hypertension, chronic kidney failure, and neurological sequelae, also develop in this patient population as survival improves. This article is intended for intensivists who provide care to critically ill recipients of intestinal and multivisceral transplants. As perioperative care of intestinal/multivisceral transplant recipients has been described elsewhere, this review focuses on common nonsurgical complications with which one should be familiar in order to provide optimal care. The article is both a review of the current literature on multivisceral and isolated intestinal transplantation as well as a reflection of our own experience at the University of Miami.

Intestinal and multivisceral transplantation in patients with chronic intestinal failure

BACKGROUND

Patients with chronic intestinal failure are treated primarily with parenteral nutrition, often for many years. If serious complications arise for intravenous nutritional therapy, it is possible to perform intestinal or multi-organ transplantation in selected patients. We have established a collaboration with Professor Michael Olausson at Sahlgrenska University Hospital in Gothenburg and Professor Andreas Tzakis at the Jackson Memorial Hospital in Miami, USA, to provide an option for Norwegian patients with chronic intestinal failure.

MATERIAL AND METHOD

Retrospective long-term study of seven patients (five in Gothenburg and two in Miami) with chronic intestinal failure who underwent intestinal or multi-organ transplantation (ventricle, duodenum, pancreas and small intestine) in the period 2001-2009. At the same time, liver and kidney transplantations were performed on six and two patients, respectively.

RESULTS

Four of seven patients are alive and have a good quality of life 24-120 months after the transplantation. The graft function is satisfactory, so that the patients' food intake is mainly oral. Three patients died following a serious infection one, ten and 24 months, respectively, after transplantation took place.

INTERPRETATION

Intestinal and multi-organ transplantation is a demanding and expensive treatment. Life-long multi-disciplinary follow-up of the patients is necessary after the transplantation in order to ensure early diagnosis of rejection and infections. Collaboration with international centres has given Norwegian patients with chronic intestinal failure an option of transplantation with satisfactory long-term results.

Combination therapy of tacrolimus and infliximab reduces inflammatory response and dysmotility in experimental small bowel transplantation in rats

BACKGROUND

Intestinal transplantation initiates a functionally relevant inflammatory response by activation of resident macrophages within the muscularis associated with dysmotility. Infliximab is used successfully as a potent anti-inflammatory agent for the treatment of chronic inflammatory bowel diseases and as rescue therapy in acute steroid-resistant rejection in selected settings in clinical small bowel transplantation. We hypothesize that additional perioperative treatment with infliximab diminishes initiation of the inflammatory cascade and improves motility in small bowel grafts using a standard tacrolimus immunosuppressive protocol.

METHODS

Orthotopic intestinal transplantation was performed in rats. In two treatment groups (24/168 hr), infliximab was administered intravenously directly after reperfusion and tacrolimus was injected intramuscularly after transplantation and once a day. Two other treatment groups (24/168 hr) received standard immunosuppressive therapy with tacrolimus. Isogenic and allogenic transplanted vehicle-treated animals (24/168 hr) and native gut served as control.

RESULTS

Infliximab-treated grafts exhibited significantly less leukocyte infiltration at 24/168 hr after transplantation and at 168 hr significantly less apoptosis in the tunica muscularis compared with tacrolimus monotherapy. Additional infliximab treatment resulted in increased smooth muscle contractility (30%) after 24 hr compared with tacrolimus control.

CONCLUSIONS

Dysmotility of transplanted small bowel results from reperfusion injury and acute rejection. Additional perioperative treatment with infliximab reduces early unspecific inflammatory responses and complements immunosuppressive therapy with tacrolimus.

Risk factors and outcomes of Staphylococcus aureus infections after small bowel and multivisceral transplantation

BACKGROUND

No studies have evaluated the risk factors and outcomes of Staphylococcus aureus (SA) infections in small bowel (SBT) and multivisceral (including small bowel) transplantation (MVT).

METHODS

SBT and MVT recipients with SA infections (22 cases) were retrospectively identified and compared with matched non-SA-infected recipient controls (44). The characteristics were compared with Friedman and Cochran-Mantel-Haenszel tests. Conditional logistic regression analysis was performed to identify risk factors, and Kaplan-Meier curve and Cox proportional hazard model were performed for survival analysis.

RESULTS

The median age was 2.07 years (range, 0.76-54.04). Forty-three percent of the first SA infections were bloodstream infections, 30% lung infections, and 26% surgical site infections; 36% of these isolates were methicillin-resistant SA. Median time (days) to surgical site infections (41.0; range, 0-89) was significantly shorter than that to lung infections (266; range, 130-378) (P = 0.01). By univariate analysis, it was found that cases were more likely to have cytomegalovirus (CMV) sero-mismatch (odds ratio [OR] = 3.03 [95% confidence interval, 0.88-10.43]; P = 0.08), and controls were more likely to receive mycophenolate mofetil (MMF) treatment (0.09 [0.001-0.82]; P = 0.03). By multivariable analysis, patients with CMV sero-mismatch were found to have higher odds of developing SA infection (OR, 2.92; P = 0.085), whereas MMF had a protective effect (OR, 0.08; P = 0.031), adjusting for matched criteria. SA cases had shorter survival than controls (mean survival, 28.5 vs. 45.8 months [P = 0.04]) and were 2.18 times more likely to die (1.02-4.67, P = 0.04).

CONCLUSIONS

SA infections were associated with a significant shorter survival time and higher risk of death. The presence of CMV sero-mismatch and the absence of MMF treatment were found to be the risk factors for SA infections after SBT and MVT.

Perioperative infliximab application has marginal effects on ischemia-reperfusion injury in experimental small bowel transplantation in rats

PURPOSE

Ischemia-reperfusion injury leads to impaired smooth muscle function and inflammatory reactions after intestinal transplantation. In previous studies, infliximab has been shown to effectively protect allogenic intestinal grafts in the early phase after transplantation with resulting improved contractility. This study was designed to reveal protective effects of infliximab on ischemia-reperfusion injury in isogenic transplantation.

METHODS

Isogenic, orthotopic small bowel transplantation was performed in Lewis rats (3 h cold ischemia). Five groups were defined: non-transplanted animals with no treatment (group 1), isogenic transplanted animals with vehicle treatment (groups 2/3) or with infliximab treatment (5 mg/kg body weight intravenously, directly after reperfusion; groups 4/5). The treated animals were sacrificed after 3 (group 2/4) or 24 h (group 3/5). Histological and immunohistochemical analysis, TUNEL staining, real-time RT-PCR, and contractility measurements in a standard organ bath were used for determination of ischemia-reperfusion injury.

RESULTS

All transplanted animals showed reduced smooth muscle function, while no significant advantage of infliximab treatment was observed. Reduced infiltration of neutrophils was noted in the early phase in animals treated with infliximab. The structural integrity of the bowel and infiltration of ED1-positive monocytes and macrophages did not improve with infliximab treatment. At 3 h after reperfusion, mRNA expression of interleukin (IL)-6, TNF-α, IL-10, and iNOS and MCP-1 displayed increased activation in the infliximab group.

CONCLUSION

The protective effects of infliximab in the early phase after experimental small bowel transplantation seem to be unrelated to ischemia-reperfusion injury. The promising effects in allogenic transplantation indicate the need for further experiments with infliximab as complementary treatment under standard immunosuppressive therapy. Further experiments should focus on additional infliximab treatment in the setting of acute rejection.

Intestinal transplantation: current status and future directions

Three decades after the first intestinal transplant was performed in humans, this life-saving procedure has come of age and now offers hope of long-term survival in a small group of patients with life-threatening complications of intestinal failure and parenteral nutrition. Success rates have greatly improved, largely through advances in immunosuppression protocols, improved surgical technique and postoperative care, and accumulated experience. Management of the intestinal transplant recipient entails careful surveillance, prevention, and treatment of rejection and infection, as well as optimization of feeding and nutrition. With this approach, survival and quality of life are demonstrably improved, such that intestinal transplantation is now an established and accepted procedure for this very select group of highly-complex patients.

Management and clinical outcome of penetrating keratoplasty for long-term corneal changes in sympathetic ophthalmia

Purpose. To report the visual outcome of penetrating keratoplasty performed on the sympathizing eye in three cases of sympathetic ophthalmitis. Methods. Interventional case series of three patients, diagnosed with sympathetic ophthalmitis, with corneal changes in the form of band keratopathy and decompensation underwent penetrating keratoplasty to the sympathizing eye. They had each sustained penetrating trauma as a child and had undergone previous cataract surgery and superficial keratectomy. Two patients had undergone lamellar keratoplasty prior to this procedure. One patient had undergone trabeculectomy for glaucoma, and she was on antiglaucoma medication. The preoperative visual acuity was 1/60 in the affected eye of each patient. Penetrating keratoplasty was performed in the sympathizing eye and the donor graft size was 7.50 mm, and the host graft size was 7.25 mm. Our patients were immunosuppressed prior to the procedure to help prevent graft rejection. Result. At one year follow-up, a BCVA of 6/36 or better was achieved in all three patients. Postoperative examination of the fundus showed peripheral chorioretinal atrophy with pigmentary changes at the macula, accounting for the limited vision. The grafts remain clear to date, and there has been no recurrence of uveitis or rejection. Conclusion. Penetrating keratoplasty can be considered as a surgical option to restore useful vision in a stable sympathizing eye in sympathetic ophthalmitis, and this depends on the extent of the pathology. However, these cases require treatment with immunosuppressives to prevent graft rejection and to prolong graft survival.

Intestinal transplantation in children: a review of immunotherapy regimens

This review summarizes the outcomes and known adverse effects of current immunosuppression strategies in use in pediatric intestinal transplantation. Intestinal transplantation has evolved from an experimental therapy to a highly successful treatment for children with intestinal failure who have complications with total parenteral nutrition. Because of continued success with intestinal transplantation over the past decade, the focus of clinicians and researchers is shifting from short-term patient survival to optimizing long-term outcomes. Current 5-year patient and graft survival rates after intestinal transplantation are 58% and 40%, respectively, in the US; single centers have reported nearly 80% patient and 60% graft survival rates at 5 years. The immunosuppression strategy in intestinal transplantation includes a tacrolimus-based regimen, usually in conjunction with an antibody induction therapy such as rabbit-antithymocyte globulin, interleukin-2 receptor antagonists, or alemtuzumab. The use of these immunosuppressive regimens, along with improved medical and surgical care, has contributed significantly toward improved outcomes. Optimization of post-transplant immunosuppression strategies to reduce adverse effects while minimizing acute and chronic graft rejection is a strong clinical and research focus.

Perioperative infliximab application ameliorates acute rejection associated inflammation after intestinal transplantation

As we have shown in the past, acute rejection-related TNF-α upregulation in resident macrophages in the tunica muscularis after small bowel transplantation (SBTx) results in local amplification of inflammation, decisively contributing to graft dysmotility. Therefore, the aim of this study is to investigate the effectiveness of the chimeric-monoclonal-anti-TNF-α antibody infliximab as perioperative single shot treatment addressing inflammatory processes during acute rejection early after transplantation. Orthotopic, isogenic and allogenic SBTx was performed in rats (BN-Lewis/BN-BN) with infliximab treatment. Vehicle and IV-immunoglobulin-treated animals served as controls. Animals were sacrificed after 24 and 168 h. Leukocyte infiltration was investigated in muscularis whole mounts by immunohistochemistry, mediator mRNA expression by Real-Time-RT-PCR, apoptosis by TUNEL and smooth muscle contractility in a standard organ bath. Both, infliximab and Sandoglobulin® revealed antiinflammatory effects. Infliximab resulted in significantly less leukocyte infiltration compared to allogenic controls and IV-immunoglobulin, which was accompanied by lower gene expression of MCP-1 (24 h), IFN-γ (168 h) and infiltration of CD8-positive cells. Smooth muscle contractility improved significantly after 24 h compared to all controls in infliximab treated animals accompanied by lower iNOS expression. Perioperative treatment with infliximab is a possible pharmaceutical approach to overcome graft dysmotility early after SBTx.

Intestine transplantation in children: update 2010

This article reviews the current status of pediatric intestinal transplantation, focusing on referral and listing criteria, surgical techniques, patient management, monitoring, complications after transplant, and short- and long-term patient outcome. Intestine transplantation has become the standard of care for children who develop life-threatening complications associated with intestinal failure. The results of intestinal failure treatment have significantly improved in the last decade following the establishment of gut rehabilitation programs and advances in transplant immunosuppressive protocols, surgical techniques, and posttransplant monitoring. The 1-year patient survival is now 80% and more than 80% of the children who survive the transplant are weaned off parenteral nutrition. Early referral for pretransplant assessment and careful follow-up after transplant with prompt recognition and treatment of transplant-related complications are key factors contributing to superior patient outcomes and survival. The best results are being obtained at high-volume centers with survival rates of up to 75% at 5 years.

Intestinal transplantation: current outcomes and opportunities

PURPOSE OF REVIEW

This review highlights current outcomes in intestinal transplantation and summarizes advances that have recently occurred in five interrelated areas: progress in intestinal rehabilitation, immunologic and technical modifications, awareness of opportunities for improved allograft monitoring, and better assessment of long-term complications and morbidities.

RECENT FINDINGS

Improved long-term management of patients with intestinal failure as well as improved outcomes with intestine transplant are changing the previously established paradigms of timing for referral. For those requiring transplant, use of monoclonal and polyclonal antibody induction protocols have been associated with improved outcomes. Experience at centers of excellence demonstrates 1 and 5 year patient survival rates of 93 and 78%, respectively with ongoing investigations focusing on lowering long-term causes of graft loss such as chronic rejection or morbidities such as renal dysfunction. Descriptions of tissue, proteomic and genomic technologies to complement traditional methodologies to monitor graft function are emerging.

SUMMARY

Optimal timing for referral of children with intestinal failure and improved medical and surgical therapies increase the opportunity for intestinal adaptation without the need for transplant. For those undergoing transplant, technical and immunologic modifications, developments in graft monitoring, and reduction of long-term morbidities are leading to improved outcomes.