Basiliximab decreases the incidence of acute rejection after intestinal transplantation

Updates in induction immunosuppression regimens for intestinal transplantation

Intestinal allografts are the most immunologically complex and carry the highest risk of rejection among solid organ transplantation, necessitating complex immunosuppressive management. We evaluated the latest information regarding induction immunosuppression, with an emphasis on established, novel, and emergent therapies. We also reviewed classic and novel induction immunosuppression strategies for highly sensitized recipients. Comparable progress has been made in intestinal transplantation clinical outcomes since the implementation of induction strategies. This review shows a clear diversity of induction protocols can be observed across different centers. The field of intestinal transplantation is still in its early stages, which is further complicated by the limited number of institutions capable of intestinal transplantation and their geographical variation, which further hinders the development of adequately powered studies in comparison to other organs. As the implementation of institution-specific induction protocols becomes more refined and results are disseminated, future research efforts should be directed towards the development of efficacious induction strategies.

Update on immunosuppressive strategies in intestinal transplantation

PURPOSE OF REVIEW

The intestine is the most immunologically complex solid organ allograft with the greatest risk of both rejection and graft-versus-host disease (GVHD). High levels of immunosuppression are required, further increasing morbidity. Due to low volume of transplants and few centers with experience, there is paucity of evidence-based, standardized, and effective therapeutic regimens. We herein review the most recent data about immunosuppression, focusing on novel and emerging therapies.

RECENT FINDINGS

Recent data are moving the field toward increasing use of basilixumab and consideration of alemtuzumab for induction and inclusion of mammalian target of rapamycin inhibitors and antimetabolites for maintenance. For rejection, we highlight novel roles for tumor necrosis factor-α inhibition, α4β7 integrin inhibition, microbiome modulation, desensitization protocols, and tolerance induction strategies. We also highlight emerging novel therapies for GVHD, especially the promising role of Janus kinase inhibition.

SUMMARY

New insights into immune pathways associated with rejection and GVHD in intestinal allografts have led to an evolution of therapies from broad-based immunosuppression to more targeted strategies that hold promise for reducing morbidity from infection, rejection, and GVHD. These should be the focus of further study to facilitate their widespread use.

Chronic intestinal pseudo-obstruction: a case report with review of the literature and practical guidance for the clinician

Chronic Intestinal Pseudo-obstruction (CIPO) is a rare but debilitating and severe form of gastrointestinal dysmotility. The diagnosis is often made very late in the disease course due to its rarity and complexity. Treatment is mainly supportive, as there is no definitive cure. Pharmacologic therapy comprises prokinetics, antibiotics for bacterial overgrowth and pain management. Pain can also be alleviated with intestinal decompression in selected cases. Beside the pharmacologic therapy, nutrition and fluid replacement play a key role. Rarely, intestinal transplantation is necessary in patients with CIPO and intestinal failure. In this review, we describe an advanced CIPO case and provide an update of the clinical and diagnostic features and current management strategies. The goal of our review is to raise awareness around CIPO and to give practical guidance for the clinician.

Bloodstream infection caused by enteric organisms during the first 6 months after intestinal transplant

BACKGROUND

Data on bloodstream infection (BSI) due to enteric organisms are scarce.

METHODS

This retrospective study (1/2009-5/2017) was aimed to evaluate the incidence of BSI episodes due to enteric organisms during the first 6 months after intestinal transplant (ITx). Differences between the first (2009-2012) and second period (2013-2017) were evaluated as they differed from each other in the perioperative fungal prophylaxis and immunosuppressive regimen.

RESULTS

Fifty-five adult patients were analyzed. Twenty-eight (51%) patients developed a total of 51 episodes of BSI. Mean time from transplant to BSI was 85.5 ± 58.8 days. The most common organisms were Klebsiella pneumoniae (33%), Enterococcus spp (31%), and Candida spp (18%). Twenty-three (45%) were multidrug resistant. The most common sources were gut translocation (35%), central line infection (20%), and intra-abdominal abscess (14%). Biopsy-proven rejection was associated with 16 (31%) of the BSI episodes. Patients during the first period were more likely to develop BSI (79% vs 41%, P = 0.03). There were more episodes of rejection associated with BSI in the first period (45% vs 14%, P = 0.03). The rate of reoperation into the abdominal cavity within 2 weeks after ITx was higher and the transplant hospital stay was longer among those who developed BSI (P = 0.04 for both).

CONCLUSIONS

Half of our patients developed BSI (typically during the first 3 months). Gut translocation was the most common source of BSI. Patients with rejection and/or enteritis should be monitored closely for BSI.

Intestinal transplantation: current improvements and perspectives

PURPOSE OF REVIEW

This review summarizes the most recent relevant knowledge in clinical practice in the field of intestinal transplantation.

RECENT FINDINGS

Three important factors that have allowed improving results during the last few years are reviewed here. The first relates to the development of a different approach to tackle the underlying cause of intestinal failure and to the patient's characteristics in terms of liver function, age, and body size. The second involves immune modulation and especially the immunosuppressive regimen at induction. The third refers to posttransplantation monitoring, in particular the diagnosis and treatment of intestinal graft rejection and lymphoproliferative disorders. Patient status and referral for intestinal transplantation remain debated. The Intestinal Transplant Registry and a report from an individual program have demonstrated the relationship between a patient's pretransplant status and outcome. Candidacy for intestinal transplantation was analysed in a European survey of home parenteral nutrition patients. Early referral and listing are important for successful outcomes after intestinal grafting.

SUMMARY

Patient management should include therapies adapted to each stage of intestinal failure based on a multidisciplinary approach in centers involving surgery, gastroenterology, parenteral nutrition expertise, home parenteral nutrition programs, and liver-intestinal transplantation experience. Timing for referral of patients in specialized centers remains a crucial issue.

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.

Basiliximab application on liver recipients: a meta-analysis of randomized controlled trials

BACKGROUND

The benefits of the application of basiliximab induction therapy in liver transplantation are not clear. The present meta-analysis was to evaluate the pros and cons of basiliximab use in liver transplantation.

DATA SOURCES

We searched the associated publications in English from July 1998 to December 2015 in the following databases: MEDLINE, PubMed, Ovid, EMBASE, Web of Science and Cochrane Library.

RESULTS

Basiliximab significantly decreased the incidence of de novo diabetes mellitus after liver transplantation (RR=0.56; 95% CI: 0.34-0.91; P=0.02). Subgroup analysis showed that basiliximab in combination with steroids-free immunosuppressant significantly decreased the incidence of biopsy-proven acute rejection (RR=0.62; 95% CI: 0.39-0.97; P=0.04) and new-onset hypertension (RR=0.62; 95% CI: 0.42-0.93; P=0.02).

CONCLUSIONS

Basiliximab may be effective in reducing de novo diabetes mellitus. What is more, basiliximab in combination with steroids-free immunosuppressant shows statistical benefit to reduce biopsy-proven acute rejection and de novo hypertension.

Ten-Year Experience With Bowel Transplantation at Seoul St. Mary's Hospital

A retrospective review of intestinal transplantation (ITx) at Seoul St. Mary's Hospital was made by collecting clinical data over the past 10 years. Fifteen consecutive cases from 2004 were analyzed. Five children and 10 adults (6 months to 69 years of age) were included. Primary diseases in adults included 4 mesenteric vessel thromboses, 2 strangulations, and 1 each of visceral myopathy, malignant gastrointestinal stromal tumor (GIST), mesenteric lymphangiectasis, and injury. Pediatric cases involved 2 Hirschsprung disease, 2 visceral myopathy, and 1 necrotizing enterocolitis. Three of 7 stomas were closed using a serial transverse enteroplasty procedure before transplantation. The ITx were performed using 3 living-donor Itx, 12 deceased-donor ITx, 14 isolated Itx, and 1 modified multivisceral transplantation. Daclizumab, basiliximab, alemtusumab, or basiliximab with rabbit antithymocyte globulin (rATG) was used for the induction; tacrolimus monotherapy was used as the basic maintenance immunosuppressant; and m-TOR inhibitor was used for renal dysfunction patients. Seven cases of acute cellular rejection were treated with rATG. Three cases of antibody-mediated rejection were treated with rituximab alone or with rituximab and bortezomib combination. There were 4 cases of early mortality within 6 months after Itx. Causes of death were declamping shock, cardiac tamponade with acute cellular rejection, dysmotility, and sepsis. Surgical complications consisted of 1 feeding jejunostomy displacement, and a minor leakage at a colo-colostomy site. One-year survival of the patient and graft was 73.33% (Kaplan-Meier survival curve). Although the total number of ITx is small, its social impact has been remarkable in changing the related laws and reimbursement policy in Korea.

Chronic intestinal pseudo-obstruction in children and adults: diagnosis and therapeutic options

BACKGROUND

Chronic intestinal pseudo-obstruction (CIPO) represents the most severe form of gastrointestinal dysmotility with debilitating and potentially lethal consequences. Symptoms can be non-specific, and result in this condition being diagnosed incorrectly or too late with consequences for morbidity and even mortality.

PURPOSE

The present article aims to provide pediatric and adult gastroenterologists with an up to date review about clinical features, diagnosis and therapeutic options for CIPO. Although pediatric and adult CIPO share many clinical aspects distinctive features can be identified. There is no single diagnostic test or pathognomonic finding of CIPO, thus a stepwise approach including radiology, endoscopy, laboratory, manometry, and histopathology should be considered in the diagnostic work-up. Treatment of patients with CIPO is challenging and requires a multidisciplinary effort with participation of appropriately experienced gastroenterologists, pathologists, dieticians, surgeons, psychologists, and other subspecialists based on the presence of comorbidities. Current treatment options invariably involve surgery and specialized nutritional support, especially in children. Medical therapies are mainly aimed to avoid complications such as sepsis or intestinal bacterial overgrowth and, where possible, restore intestinal propulsion. More efficacious therapeutic options are eagerly awaited for such difficult patients.

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.

Short bowel syndrome and small bowel transplantation

PURPOSE OF REVIEW

The purpose of this review is to provide an update of recent advances in the areas of short bowel syndrome (SBS) and small bowel transplantation (SBT).

RECENT FINDINGS

Recent reports from two of the largest multicenter randomized, controlled trials in patients with SBS support the safety and efficacy of teduglutide as an aid to parenteral nutrition weaning. In well selected SBS patients, outcomes as diverse as survival, macronutrient absorption and parenteral nutrition weaning are improved after autologous gastrointestinal reconstructive surgery. SBT is no longer considered investigational and given improved outcomes noted in recent reports, indications for transplantation are expanding. Although SBT early survival rates are approaching those of other organ allografts, long-term graft survival remains suboptimal.

SUMMARY

Recently available trophic factors hold promise as aids in restoring freedom from parenteral nutrition support; however, their long-term benefits, preferred timing of administration in relation to the onset of SBS, optimal patient selection for use, duration of treatment and cost effectiveness require further study. Despite recent evidence of improved early survival after SBT, more dedicated research is needed to design more effective strategies to better tolerize small bowel grafts, prevent rejection and, ultimately, improve long-term outcomes. Reserved for well selected patients, autologous gastrointestinal reconstruction should be considered complementary and not antagonistic to SBT.

Intestinal transplantation: a review

Parenteral nutrition is a life-saving therapy for patients with intestinal failure. Intestinal transplantation is now recognized as a treatment for patients who develop complications of parenteral nutrition and in whom attempts at intestinal rehabilitation have failed. Patients with parenteral nutrition related liver disease will require a liver graft typically part of a multivisceral transplant. Isolated intestinal transplants are more commonly performed in adults while multivisceral transplants are most commonly performed in infants. Isolated intestinal transplants have the best short-term outcome, with over 80 % survival at 1 year. Patients requiring multivisceral transplants have a high rate of attrition with a 1 year survival less than 70 %. Prognostic factors for a poor outcome include patient hospitalization at the time of transplant and donor age greater than 40 years while systemic sepsis and acute rejection are the major determinant of early postoperative outcome. For patients surviving the first year the outcome of transplantation of the liver in addition to intestine affords some survival advantage though long-term outcome does not yet match other abdominal organs. Outcomes for intestinal retransplantation are poor as a result of immunology and patient debility. Overall intestinal transplantation continues to develop and is a clear indication with cost and quality of life advantages in patients with intestinal failure that do not remain stable on parenteral nutrition.

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 for motility disorders

Intestinal transplantation (ITx) has now become an accepted form of replacement therapy for intestinal failure (IF) and its complications. Disorders of bowel motility may represent up to 25% of patients on waiting lists for ITx. Some patients with short bowel as a cause for IF may also have dysmotile bowel. Underlying pathology of the intestine is heterogeneous and may be due to abnormalities in the nerve supply, intestinal smooth muscle, or may be regarded as idiopathic (chronic intestinal pseudo-obstruction). Outcome after ITx for dysmotility has previously been guarded, but providing the appropriate graft is used and taking into account the functional motility of residual bowel, it should not be different from other indications. The subject is reviewed emphasizing the potential pitfalls in case selection and management. The results of the ITx unit in Birmingham, UK are briefly reviewed.

Treatment of intestinal failure: intestinal transplantation

Over the past 15 years, intestinal transplantation for the treatment of intestinal failure has changed from a desperate last-ditch effort into a standard therapy for which a good outcome is expected. Patient survival after intestinal transplantation has improved in the past 3-5 years and now approaches that of other solid organ allograft recipients, including liver and kidney, and is similar to survival on permanent therapy with parenteral nutrition. Complications are more common and often more severe during the initial hospitalization period after intestinal transplantation than they are after transplantation of other solid organs. After intestinal transplantation the initial hospitalization period is, therefore, usually 3-8 weeks long. Nearly all patients discharged after intestinal transplantation have good allograft function and have been weaned from total parenteral nutrition. The cost of the initial hospitalization period is one to two times the cost of permanent total parenteral nutrition for 1 year, which means that, in most cases, intestinal transplantation is cost-saving within 2 years of transplantation. In addition, quality of life after intestinal transplantation, as determined by standardized quality of life measures, is good or normal.

Calprotectin: a novel noninvasive marker for intestinal allograft monitoring

OBJECTIVE

To identify a noninvasive screening test for intestinal allograft monitoring.

SUMMARY BACKGROUND DATA

Intestinal allograft rejection is difficult to distinguish from other causes of diarrhea and can rapidly lead to severe exfoliation or death. Protocol biopsies are standard for allograft monitoring but may cause serious complications. No noninvasive test has shown clinical utility for monitoring of the intestinal allograft.

METHODS

Calprotectin levels (n = 68) were measured in this pilot study from ileostomy effluent in patients with histologic evidence of acute rejection (n = 12), viral enteritis (n = 5), and nonspecific inflammation (n = 16) and compared with those with normal allograft histology (n = 35).

RESULTS

Median stool calprotectin levels from patients with rejection were significantly higher than those from patients with viral enteritis or normal biopsies [198 mg/kg compared with 7 and 19 mg/kg, respectively (P = 0.0002)]. Receiver operator characteristics suggest the optimal cut-off level to distinguish rejection from other diagnoses is 92 mg/kg with specificity of 77% and sensitivity of 83%. Although false-positive results occurred in 26% of patients with normal biopsies and 30% with nonspecific changes, no treated episode of acute rejection was below the cutoff. In addition, in 2 patients with serial levels, elevations in the calprotectin levels preceded histologic changes by 6 to 18 days.

CONCLUSIONS

Low stool calprotectin levels correlate well with a low risk for intestinal allograft rejection. If confirmed, biopsies may be reserved in the future for confirmation of rejection, eliminating protocol biopsies, and immunosuppressive changes could potentially be made before allograft injury.

Rejection Episodes and 3-Year Graft Survival Under Sirolimus and Tacrolimus Treatment After Adult Intestinal Transplantation

PURPOSE

Mammalian target of rapamycin (mTOR) inhibitors have been recently introduced in clinical practice after intestinal transplantation. We focused on Sirolimus (Rapamycin) to examine effects on rejection and graft survival following intestinal transplantation.

PATIENTS AND METHODS

Twenty isolated intestinal recipients and 5 multivisceral patients (2 with liver) in our series were divided into 3 groups: patients started on Sirolimus (because of nephrotoxicity or biopsy-proven rejection), who continued therapy longer than 3 months (n = 11); patients started on Sirolimus (because of nephrotoxicity or biopsy-proven rejection), who received therapy less than 3 months because of side effects (n = 4); and a control group, who never received rapamycin (n = 10).

RESULTS

During prolonged treatment combined with Tacrolimus (Prograf), both Sirolimus groups showed a decreased number of acute cellular rejections (P < .01). Cumulative 3-year graft and patient survival rates were 81% in the Sirolimus greater than 3 months group, 100% in the Sirolimus less than 3 months group, and 80% and 90% in the control group, respectively (P = .63 and P = .62).

CONCLUSION

In our experience, the use of mTOR-inhibitors in combination with calcineurin-inhibitors seemed to be more effective than monotherapy to reduce the number of rejections. Side effects can limit its use as maintenance therapy.

La greffe intestinale

Even though surgical techniques for isolated intestine, liver-intestine, and multivisceral transplantations were developed in the 1960's, very few patients were transplanted before 1990 because initial immunosuppression regimens were insufficient, making intestine transplantation impossible. Intestine transplantation resulted in death in most patients within days or months. The discouraging results of the first clinical trials were due to technical complications, sepsis, and the failure of conventional immunosuppression to control rejection. By 1990 the development of tacrolimus-based immunosuppression and improved surgical techniques, the increased array of potent immunosuppressive medications, infection prophylaxis, and suitable patient selection helped improve actuarial graft and patient survival rates for all types of intestine transplantation. The aims of this review are to describe the current status of intestine transplantation including the underlying diseases and conditions that may be indications for intestine transplantation, to identify patient populations for this indication, to provide key steps for patient evaluation, to summarize current recommendations for immunosuppression, to list the most common postoperative complications, and to discuss the international experience of small bowel transplantation compiled and analyzed by the International Intestine Transplant Registry since 1985.

Daclizumab and alemtuzumab as induction agents in adult intestinal and multivisceral transplantation: A comparison of two different regimens on 29 recipients during the early post-operative period

INTRODUCTION

Induction therapy has been recently adopted for intestinal transplant.

PATIENTS AND METHODS

We compared during first 30 days post-transplantation 29 recipients, allocated in two groups, treated with Daclizumab (Zenapax) or Alemtuzumab (Campath-1H).

RESULTS

During first month, 45% of Daclizumab recipients experienced six acute cellular rejections (ACRs) of mild degree, while 63% of them developed an infection requiring treatment. We found three acute cellular rejections in 17.6% of Alemtuzumab recipients, two with moderate degree; 64.7% of them required treatment for infection.

DISCUSSION AND CONCLUSIONS

Graft and patient 3-years cumulative survival rate were not significantly different between groups. Alemtuzumab seems to offer a better immunosuppression during first month.

Small intestine transplantation today

INTRODUCTION

Intestinal transplantation has become a life-saving therapy in patients with irreversible loss of intestinal function and complications of total parenteral nutrition.

DISCUSSION

The patient and graft survival rates have improved over the last years, especially after the introduction of tacrolimus and rapamycin. However, intestinal transplantation is more challenging than other types of solid organ transplantation due to its large amount of immune competent cells and its colonization with microorganisms. Moreover, intestinal transplantation is still a low volume procedure with a small number of transplanted patients especially in Germany. A current matter of concern is the late referral of intestinal transplant candidates.

CONCLUSION

Thus, patients often present after onset of life-threatening complications or advanced cholestatic liver disease. Earlier timing of referral for candidacy might result in further improvement of this technique in the near future.

Intestinal transplantation in The Netherlands: first experience and future perspectives

Intestinal transplantation for intestinal failure is no longer an experimental procedure, but an accepted treatment for patients who fail total parenteral nutrition (TPN) therapy. Early referral for evaluation for small bowel transplantation has to be considered in patients with permanent intestinal failure who have occlusion of more than two major veins, frequent line-related septic episodes, impairment of liver function or an unacceptable quality of life. With the increased experience in post-transplant patient care and newer forms of induction (thymoglobulin, IL-2 receptor antagonists) and maintenance (tacrolimus) therapies the 1-year graft survival has increased to 65% for isolated and to 59% for liver/small bowel transplantation, and is further improving. Rejection, bacterial, fungal and viral (CMV, EBV) infection, post-transplant lymphoproliferative disease (PTLD) and graft versus host disease (GvHD) are the most common complications after intestinal transplantation. Although most of the long-term survivors are TPN-independent and have a good quality of life, the risk of the procedure and long-term adverse effects of immunosuppressive medication limits small bowel, or liver/small bowel transplantation only to patients with severe complications of TPN therapy.

Current issues in the management of intestinal failure

Successful long term parenteral nutrition has transformed the prognosis for children with irreversible intestinal failure in the last three decades, but has also highlighted the long term complications: intestinal failure associated liver disease; recurrent catheter sepsis; and impaired venous access. Recent advances in small bowel transplantation and non-transplant surgical techniques now offer hope of sustained survival in the future without parenteral nutrition.

Advances in the management of short bowel syndrome

Short bowel syndrome (SBS) is the predominant cause of intestinal failure and is thus associated with a high degree of morbidity and mortality. One of the reasons this occurs is the dramatic reduction in nutrient absorptive capacity. Of the many causes of SBS, the most common cause is extensive surgical resection. The impressive ability of the bowel to adapt functionally and morphologically is critical for decreasing morbidity and mortality in these patients. The degree of adaptation is vital in decreasing the dependence on parenteral nutrition (PN) and for improving patient quality of life and long-term outcome. Provision of appropriate and sufficient nutritional and fluid support is essential for the management of these patients. The primary goal is to prevent or eliminate the need for PN. Recent developments have promoted a greater understanding of the process of intestinal adaptation. Various intestinal trophic factors have been recognized. These efforts have led to the early development of hormonal therapy to stimulate intestinal adaptation and enhance intestinal absorption. Intestinal transplantation remains an option for those who have developed life-threatening complications from PN and cannot be managed using more conservative techniques.

IL-2 Antagonists: The European Perspective

Acute rejection remains the main risk factor following intestinal transplantation. New immunosuppressive agents have substantially reduced the incidence of severe acute rejection. The question arises, which is the most powerful immunosuppressive combination with the lowest incidence of side effects? According to International Intestinal Transplant Registry data, anti-IL-2 antibodies are slightly advantageous compared with antilymphocyte preparations with respect to long-term patient survival. However, different antilymphocyte preparations are used in different doses and at different time points. The anti-IL-2 antibodies daclizumab and basiliximab were also used in different protocols. Therefore, final results on efficacy are awaited. The most important difference between IL-2 antibodies and antilymphocyte preparations is the suppression of CD4+ CD25+ T lymphocytes by anti-IL-2 antibodies. Antilymphocyte preparations do not affect CD4+ CD25+ T cells. Because regulatory CD4+ CD25+ T cells are essential for tolerance induction, protocols attempting tolerance may omit anti-IL-2 antibodies in the future.

Bacterial translocation in acute rejection after small bowel transplantation in rats

Acute rejection after small bowel transplantation (SBTx) may facilitate bacterial translocation (BT) and subsequent changes in the liver, spleen, and lungs. This study investigated whether BT occurs after acute rejection and whether this is followed by changes in the structure of the intestine and the phagocytic organs interposed between the gut and the general circulation. Orthotopic SBTx was performed in allogeneic (ALLO) rat-strain combinations (BN-Wistar, n=5). For comparison we used syngeneic SBTx (SYN) (BN-BN, n=6) controls. Animals were sacrificed on postoperative day 7. Mesenteric lymph nodes and portal and caval blood were cultured for aerobes and anaerobes. Escherichia coli beta-galactosidase DNA was assessed by polymerase chain reaction in the blood samples. Intestine, liver, spleen, and lung protein and DNA contents were measured. Histologic changes were graded according to standard criteria of acute rejection. For comparisons we used chi(2) and nonparametric Mann-Whitney test with a threshold of significance of p<0.05. ALLO rats lost more weight after SBTx than SYN rats (-13.02+/-4.39% vs. -8.04+/-5.08% of preoperative weight), although the difference was not significant (ns). A variable degree of graft rejection was histologically demonstrated in all ALLO rats, and DNA/protein content in the graft was significantly higher in this group (0.245+/-0.85 vs. 0.134+/-0.21, p<0.05). Gram-negative enteric bacteria were found in 4/5 ALLO and 4/6 SYN rats (ns), and aerobic Gram-positive bacteria in 2/5 and 3/6 (ns), respectively. Anaerobic growth occurred in mesenteric lymph nodes in one ALLO rat and in the bloodstream in another one. E. coli DNA was isolated in none of the ALLO but in two SYN rats (ns). BT was frequent after SBTx in both syngeneic and allogeneic strain combinations. Contrary to our expectations, BT after SBTx was not higher in ALLO group rats. However, anaerobic germs were isolated only in this group.

ADVANCES IN SMALL-INTESTINE TRANSPLANTATION

Intestinal transplantation has become the treatment of choice for patients who are experiencing life-threatening complications of intestinal failure. Early attempts with intestinal transplantation were unsuccessful as a consequence of both technical and immunologic failures. The introduction of tacrolimus provided the immunologic foundation needed for the field to advance. Guidelines for patient selection combined with standardization of operative procedures and postoperative management has allowed for improved patient and graft survival. There has been a gradual improvement in patient survival over the past 10 years, most notably in the past 3 years. Nutritional autonomy has been achieved in hundreds of patients worldwide. Further advancements in the understanding of the immune response to the transplanted intestine are still needed and will allow the use of new antirejection medications, resulting in improved outcomes.

Pediatric transplantation

Analysis of the OPTN/SRTR database demonstrates that, in 2002, pediatric recipients accounted for 7% of all recipients, while pediatric individuals accounted for 14% of deceased organ donors. For children fortunate enough to receive a transplant, there has been continued improvement in outcomes following all forms of transplantation. Current 1-year graft survival is generally excellent, with survival rates following transplantation in many cases equaling or exceeding those of all other recipients. In renal transplantation, despite excellent early graft survival, there is evidence that long-term graft survival for adolescent recipients is well below that of other recipients. A causative role for noncompliance is possible. While the significant improvements in graft and patient survival are laudable, waiting list mortality remains excessive. Pediatric candidates awaiting liver, intestine, and thoracic transplantation face mortality rates generally greater than those of their adult counterparts. This finding is particularly pronounced in patients aged 5 years and younger. While mortality awaiting transplantation is an important consideration in refining organ allocation strategies, it is important to realize that other issues, in addition to mortality, are critical for children. Consideration of the impact of end-stage organ disease on growth and development is often equally important, both while awaiting and after transplantation.

Induction therapy with interleukin-2 receptor antagonist after intestinal transplantation is associated with reduced acute cellular rejection and improved renal function

PURPOSE

To determine the effectiveness of induction immunotherapy with interleukin-2 receptor antagonists (IL2RA) after intestinal transplantation (IT).

METHODS

A single-center, retrospective study was undertaken of all patients undergoing IT using existing medical records and database. Immunotherapy was either triple (standard maintenance triple therapy [SMTT]) or IL2RA [induction IL2RA plus SMTTx] or OKT3 [induction antilymphocyte preparations plus SMTTx]). Data was collected for the first 175 postoperative days. Outcomes included pretransplant renal function, posttransplant serum creatinine normalized to age (nl-sCR), rejection (ACR), and survival. Standard statistical analysis was undertaken.

RESULTS

There were no significant differences in the groups: triple (n = 10, median age 3.5 years, cGFR 106 +/- 44 mL/min), IL2RA (n = 13, median age 3.2 years, cGFR 101 +/- 61 mL/min), OKT3 (n = 4, median age 7.7 years, cGFR 104 +/- 27 mL/min). nl-sCR was significantly (P <.01) lower in IL2RA at most postoperative weeks. IL2RA had significantly fewer rejection and infectious episodes than the other two groups. Three-year patient survival was 92% in IL2RA versus 50% triple and OKT3.

CONCLUSIONS

IL2RA immunotherapy after IT is associated with a lower incidence of renal dysfunction as compared with historical controls. Furthermore, IL2RA therapy resulted in a lower incidence of rejection and improved survival. IL2RA should be considered in select patients undergoing IT.