Undine Gerlach

Clinical relevance of the de novo production of anti‐HLA antibodies following intestinal and multivisceral transplantation

Despite a negative pretransplant cross‐match, intestinal transplant recipients can mount humoral immune responses soon after transplantation. Moreover, the development of donor‐specific anti‐HLA antibodies (DSAs) is associated with severe graft injury. Between June 2000 and August 2011, 30 patients (median age 37.6 ± 9.8 years) received isolated intestinal transplantations (ITX, n = 18) or multivisceral transplantations (MVTXs, n = 12) at our center. We screened for human leukocyte antigen (HLA) antibodies pre‐ and post‐transplant. If patients produced DSAs, treatment with plasmapheresis and intravenous immunoglobulin (IVIG) was initiated. In the event of DSA persistence and/or treatment‐refractory rejection, rituximab and/or bortezomib were added. Ten patients developed DSAs and simultaneously showed significant signs of rejection. These patients received plasmapheresis and IVIG. Eight patients additionally received rituximab, and two patients were treated with bortezomib. DSA values decreased upon antirejection therapy in 8 of the 10 patients. The development of DSAs following ITX is often associated with acute rejection. We observed that the number of mismatched antigens and epitopes correlates with the probability of developing de novo DSAs. Early diagnosis and therapy, including B‐cell depletion and plasma cell inhibition, are crucial to preventing further graft injury.

Technical advances for abdominal wall closure after intestinal and multivisceral transplantation.

Purpose of reviewAbdominal wall closure after intestinal transplantation (ITX) or multivisceral transplantation (MVTX) is challenging because of the loss of abdominal domain and wall elasticity as a result of previous operations and donor-to-recipient weight and height mismatch. Recent findingsWe report on abdominal wall closure management in 30 ITX and MVTX recipients. In 60% of patients (n = 18), a primary abdominal closure (PAC) was achieved, in 40% (n = 12) a staged closure (SAC) was necessary. Patients with PAC had undergone less pretransplant operations and required less posttransplant relaparotomies. They were mainly ITX recipients or more abdominal domain because of a longer intestinal remnant. A literature review revealed different strategies to overcome a failed primary closure. They focus on graft reduction or an enlargement of the abdominal domain. The latter includes temporary coverage with prosthetic materials for SAC. Definite abdominal closure is achieved by skin only closure, or by using acellular dermal matrix, rotational flaps, rectus muscle fascia or abdominal wall grafts. SummaryAbdominal wall reconstruction after ITX/MVTX is commonly demanded and can be conducted by different strategies. The technique should be easy to use in a timely manner and should prevent abdominal infections, intestinal fistulation, incisional hernias, and wound dehiscence.

Salvage therapy for refractory rejection and persistence of donor-specific antibodies after intestinal transplantation using the proteasome inhibitor bortezomib

With a high risk for cellular and humoral alloimmune responses and no reliable noninvasive rejection markers, intestinal transplant (ITX) recipients require a close posttransplant monitoring. Graft biopsies are performed regularly, but their restriction to the mucosal component imposes limitations in the evaluation of processes occurring in deeper layers of the intestine [1]. C4d staining is not established and its interpretation varies largely in ITX recipients [2]. As a result of a significant association between the early appearance of anti-HLA antibodies and acute rejection episodes, frequent donor-specific antibody (DSA) screening is crucial and may disclose antibodymediated rejection (AMR) [3]. In addition, AMR is less responsive to anti-rejection treatment, entailing chronic manifestations of graft rejection and allograft losses [4]. Even though plasmapheresis and rituximab reduce the concentration of circulating HLA antibodies, both methods are ineffective against antibody-producing plasma cells, which belong to the bone marrow CD138CD20 long-lived plasma cells compartment. Consequently, splenic and bone marrow plasma cells do not respond to typical desensitization regimens [5]. Proteasome inhibitors like bortezomib deplete nonmalignant plasma cells in experimental models [6]. The immune-modulating effects include activity against normal plasma cells and suppression of T-cell function [7], providing effective treatment of antibody-mediated and acute cellular rejection (ACR) [8]. Preliminary reports have provided evidence of its efficacy in the reduction and elimination of DSA after renal, pancreas, and multivisceral transplantation representing an alternative treatment strategy for AMR [9–11]. We report the successful salvage treatment with bortezomib in a patient with refractory acute rejection associated with persisting DSA levels after ITX. A 46-year-old patient received an isolated intestinal graft for ultra-short bowel syndrome. Initial immunosuppression consisted of tacrolimus (trough levels 15–20 ng/ml) and steroids (40 mg/day). Induction therapy consisted of thymoglobulin [total dose 7.5 mg/kg bodyweight (BW)] and infliximab (5 mg/kg BW single dose), of which the latter is regularly applied to mitigate ischemia/reperfusion injury and to deplete effector memory CD8 T cells [12,13]. Graft biopsies were performed every 2 days. The HLA antibody status was assessed using a combination of tests including complement-dependent lymphocytotoxicity test (CDC) (Biotest, Dreieich, Germany) and the LABScreen test (One Lambda, Canoga Park, CA, USA). Sera were screened for lymphocytotoxic HLA antibodies by CDC according to the protocol of the National Institute of Health. To differentiate between specific HLAIgG antibodies and non-HLA-specific IgM antibodies, the CDC test was performed in parallel by adding dithiothreitol (DTT) to reduce the non-HLA-specific IgM antibodies. For the detection and specification of panel reactive HLA antibodies (PRA), a lymphocyte panel of HLA-typed blood donors was used. On postoperative day (POD) 14, DSA testing revealed high levels of anti-donor HLA DQ7 (2000MFI) and DQ8 (900MFI) antibodies, together with nondonor-specific antibodies (NDSA), entailing immediate plasmapheresis (Fig. 1). DQ4 and DR53 were immunodominant NDSA. On POD 19, the patient experienced a mild ACR and received steroid pulse therapy (5 · 1000 mg) and rituximab (375 mg/m), which decreased histological rejection signs. Five days later, rejection relapsed to grade 1 (Fig. 2 a) and DSA levels continued to rise, so that thymoglobulin (1.5 mg/kg BW for five consecutive days) and intravenous immunoglobulin (i.v. Ig; total: 1 mg/kg/BW) were initiated together with a second dose of rituximab. By POD 42, the patient had received three cycles of plasmapheresis (five applications on five consecutive days each) and two applications of rituximab, but DSA testing still revealed high levels of DSA (DQ7: 4500MFI; DQ8: 1500MFI). Allograft biopsies displayed persistent inflammatory signs, low-grade fibrosis, cryptitis, and an increased rate of apoptoses (up to six apoptotic bodies/10 crypts) defined as indeterminate for rejection (Fig. 2b). C4d staining revealed inconclusive results. The patient complained of diarrhea, abdominal distension, and pain. The persistence of DSA level, histological changes, and clinical signs indicative of an ongoing AMR stimulated discussion about

Tumor Necrosis Factor Alpha Inhibitors as Immunomodulatory Antirejection Agents after Intestinal Transplantation

We reported the successful administration of infliximab for late‐onset OKT3‐resistant rejection in two patients, who presented persistent ulcerative inflammation of the ileal graft after intestinal transplantation (ITX). Based on this experience, the present study demonstrated our long‐term experience with infliximab for different types of rejection‐related and inflammatory allograft alterations. Infliximab administration (5 mg/kg body weight (BW)) was initiated at a mean of 18.2 ± 14.1 months after transplantation. The number of administrations per patient averaged 8.4 ± 6.7. Repeat dosing was timed according to clinical signs and graft histology in addition to serum‐levels of tumor necrosis factor alpha (TNFα), lipopolysaccharide binding protein (LBP) and C‐reactive protein (CRP). Infliximab was successful in the following patients: patients with late‐onset OKT3‐ and steroid‐refractory rejection who presented persistent ulcerative alterations of the ileal graft (n = 5), patients with ulcerative ileitis/anastomositis, who did not show typical histological rejection signs (n = 2), and one patient with early‐onset OKT3‐resistant rejection. Infliximab was not successful in one patient with early‐onset OKT3‐resistant rejection that was accompanied by treatment‐refractory humoral rejection. In conclusion, infliximab can expand therapeutic options for late‐onset OKT3‐ and steroid‐refractory rejection and chronic inflammatory graft alterations in intestinal allograft recipients.

Short-term TNF-alpha inhibition reduces short-term and long-term inflammatory changes post-ischemia/reperfusion in rat intestinal transplantation.

Background Tumor necrosis factor (TNF)-&agr; inhibition was shown to reduce ischemia/reperfusion injury (IRI) after intestinal transplantation (ITX). We studied the effects of different TNF&agr; inhibitors on acute IRI and long-term inflammatory responses in experimental ITX. Methods Orthotopic ITX was performed in an isogenic ischemia/reperfusion model in Lewis rats. The TNF&agr; inhibition groups received infliximab post-reperfusion; etanercept pre-reperfusion and at postoperative days (POD) 1, 3, 5, and 7; or pentoxifylline pre-reperfusion and at POD 1 to 5. Tissue samples were taken from proximal and distal graft sections and mesenteric lymph nodes at 20 min, 12 hr, 7 day, and 6 months post-reperfusion for histopathology, immunohistology, terminal deoxyribosyl transferase-mediated dUTP nick-end labeling (TUNEL) assay, and real-time RT-PCR. Lung sections were stained for the myeloperoxidase assay. Results TNF&agr; inhibitors decreased inflammatory changes after IRI in all treatment groups. Infliximab significantly improved 7-day survival and reduced the histological and immunohistochemical signs of IRI, the numbers of graft-infiltrating T cells and ED1+ monocytes and macrophages, and pulmonary neutrophil infiltration, and also enhanced the accumulation of cytoprotective markers. Graft injury was more prominent in the distal graft than in the proximal graft in all groups, regardless of TNF&agr; inhibition. Conclusion Infliximab significantly reduced both acute IRI and, as with other TNF&agr; inhibitors, long-term inflammatory responses after rat ITX. TNF&agr; inhibition may help diminish chronic inflammatory long-term effects and avoid chronic allograft enteropathy.

Elevation of CD4+ differentiated memory T cells is associated with acute cellular and antibody-mediated rejection after liver transplantation.

Background It is now well known that the outcome after allogeneic transplantation, such as incidence of acute rejections, very much depends on the individual’s immune reactivity status. There is also increasing evidence that the presence of preexisting memory T cells can affect antigraft immune responses. Methods In a prospective study, we monitored peripheral CD4+ and CD8+ central memory, effector memory, and terminal differentiated effector memory (TEMRA) T cells in 55 patients who underwent deceased liver transplantation and received conventional immunosuppressive treatment with or without basiliximab induction. The primary endpoint of the study was acute allograft rejection during a 1-year follow-up period. Results We observed significantly increased proportions of CD4+ and CD8+ TEMRA cells in patients before transplantation compared with healthy controls (P=0.006 and 0.009, respectively). This characteristic was independent of the underlying disease. In patients with no signs of acute rejection, we observed an immediate reduction of CD4+ TEMRA cells. In contrast, patients who experienced acute cellular rejection, and especially antibody-mediated rejection, displayed persistent elevated TEMRA cells (P=0.017 and 0.027, respectively). Basiliximab induction therapy did not influence CD4+ and CD8+ TEMRA numbers. Conclusions Conventional immunosuppressive or basiliximab treatment cannot control the persistence of TEMRA T cells, which may contribute to acute cellular rejection and antibody-mediated rejection after liver transplantation. In the future, specific targeting of TEMRA cells in selected patients may prevent the occurrence of difficult to treat steroid-resistant rejections, thereby leading to improved patient outcome.

Abdominal Wall Transplantation: Skin as a Sentinel Marker for Rejection

Abdominal wall transplantation (AWTX) has revolutionized difficult abdominal closure after intestinal transplantation (ITX). More important, the skin of the transplanted abdominal wall (AW) may serve as an immunological tool for differential diagnosis of bowel dysfunction after transplant. Between August 2008 and October 2014, 29 small bowel transplantations were performed in 28 patients (16 male, 12 female; aged 41 ± 13 years). Two groups were identified: the solid organ transplant (SOT) group (n = 15; 12 ITX and 3 modified multivisceral transplantation [MMVTX]) and the SOT‐AWTX group (n = 14; 12 ITX and 2 MMVTX), with the latter including one ITX‐AWTX retransplantation. Two doses of alemtuzumab were used for induction (30 mg, 6 and 24 h after reperfusion), and tacrolimus (trough levels 8–12 ng/mL) was used for maintenance immunosuppression. Patient survival was similar in both groups (67% vs. 61%); however, the SOT‐AWTX group showed faster posttransplant recovery, better intestinal graft survival (79% vs. 60%), a lower intestinal rejection rate (7% vs. 27%) and a lower rate of misdiagnoses in which viral infection was mistaken and treated as rejection (14% vs. 33%). The skin component of the AW may serve as an immune modulator and sentinel marker for immunological activity in the host. This can be a vital tool for timely prevention of intestinal graft rejection and, more important, avoidance of overimmunosuppression in cases of bowel dysfunction not related to graft rejection.

Chronic Intestinal Failure After Crohn Disease: When to Perform Transplantation

IMPORTANCE Because of the severity of disease and additional surgery, Crohn disease (CD) may result in intestinal failure (IF) and dependency on home parenteral nutrition (HPN). Defining the indication and timing for intestinal transplantation (ITx) is challenging. OBJECTIVES To determine the limitations of conventional surgery and to facilitate the decision making for transplantation. DESIGN, SETTING, AND PARTICIPANTS Data were collected prospectively and obtained by retrospective review of medical records from all patients with CD who were assessed for ITx in Oxford, United Kingdom, and Berlin, Germany, from October 10, 2003, through July 31, 2013. Patients were considered suitable for ITx if a diagnosis of irreversible IF was established and life-threatening complications under HPN were unresolvable. Twenty patients with CD and IF, established on HPN, were evaluated for ITx. The mean (SD) age at CD onset was 17.8 (9.8) years. On first diagnosis, most patients had a stricturing CD. By the time of referral, most had a combination of stricturing and fistulizing disease. INTERVENTIONS New scoring system: a modification of the American Gastroenterology Association guidelines for ITx. Modifications are related to CD-specific issues that potentially lead to a poorer outcome and are based on the findings of the study to determine the expected benefit from ITx. MAIN OUTCOMES AND MEASURES A scoring system that would alert the physician to the severity of the patients CD and trigger early referral for ITx. This system may translate into better long-term outcomes for patients with CD. In addition, the Karnofsky performance status score was used to compare pretransplantation and posttransplantation outcomes. RESULTS Ten patients underwent ITx, 4 were on the waiting list, and 4 were unavailable for follow-up. One patient was taken off the waiting list because of severe deterioration. One patient underwent conventional stricturoplasty and did not need transplantation. Among the transplant recipients, 17 (85%) had a stoma or enterocutaneous fistula, and the mean (SD) residual bowel length was 71.5 (38) cm. A total of 80% of transplant recipients had life-threatening catheter infections, and 13 (65%) had a significant decrease in the estimated glomerular filtration rate. At a mean (SD) follow-up of 27.6 (36.1) months for transplant recipients, the patient and graft survival is 80%, and their Karnofsky performance status score increased by a mean of 18.6%. CONCLUSIONS AND RELEVANCE Intestinal transplantation is a suitable treatment option for patients with CD and IF. It should be considered before any additional attempts at conventional surgery, which may cause eligible patients to miss this opportunity through perioperative complications. The suggested scoring system enables the physician to identify patients who may benefit from transplantation before HPN-associated secondary organ failure.

Bile duct strictures after liver transplantation.

Purpose of review Biliary complications account for relevant morbidity and mortality after liver transplantation. Advances have taken place in understanding their aetiology, in preventive operative techniques, imaging procedures, as well as interventional and endoscopic management. However, progress in living donation, donation after cardiac death as well as paediatric transplant procedures have changed the incidence and causes of biliary complications. This review summarizes recent progress in the field, particularly related to biliary strictures after liver transplantation. Recent findings Significant findings in the period of interest for this review focussed on improvements of endoscopic treatment of postliver transplant biliary complications, including novel stenting devices, the routine analysis of bacterial and fungal flora, and the use of steroids to prevent postendoscopic retrograde cholangiopancreaticography pancreatitis. The importance of cytomegalovirus and hepatitis C in the aetiology of biliary complications was highlighted. Under certain circumstances, biliary complications after liver transplantation of organs secondary to donation after cardiac death may be reduced to a level known from liver transplantation after brain death. Further evidence was added to support the risk-adapted use of biliary drainage during liver transplantation. Summary The ongoing research in the aetiology, prevention, and treatment of biliary strictures after liver transplantation highlights the significance of biliary complications for patient and graft outcome.

Endovascular treatment of supra-celiac aortic pseudoaneurysms following liver transplantation.

Heidenhain C, Werk M, Gebauer B, Gerlach U, Puhl G, Neuhaus P, Heise M. Endovascular treatment of supra‐celiac aortic pseudoaneurysms following liver transplantation.
Clin Transplant 2009 DOI: 10.1111/j.1399‐0012.2009.01046.x
© 2009 John Wiley & Sons A/S.