Eculizumab Salvage Therapy for Antibody-Mediated Rejection in a Desensitization-Resistant Intestinal Re-Transplant Patient.

The presence of elevated calculated panel reactive antibody (cPRA) and anti-HLA donor specific antibodies (DSA) are high risk factors for acute antibody-mediated rejection (AAMR) in intestinal transplantation that may lead to graft loss. Eculizumab has been used for the treatment of AAMR in kidney transplantation of sensitized patients that do not respond to other treatment. Here, we report a case where eculizumab was used to treat AAMR in a desensitization-resistant intestinal re-transplant patient. A male patient lost his intestinal graft to AAMR 8.14 years after his primary transplant. He received a second intestinal graft that had to be explanted a month later due to refractory AAMR. The patient remained highly sensitized despite multiple treatments. He received a multivisceral graft and presented with severe AAMR on day 3 posttransplantation. The AAMR was successfully treated with eculizumab. The patient presently maintains an elevated cPRA level above 90% but his DSAs have decreased from 18 000 MFI (mean fluorescent intensity) to below the positive cut-off value of 3000 MFI and remains rejection free with a 2-year follow-up since his multivisceral transplant. Eculizumab offers an alternative to treat AAMR in intestinal transplantation in desensitization-resistant patients.

Factor V Leiden mutation is a risk factor for hepatic artery thrombosis in liver transplantation.

BACKGROUND: Hepatic artery thrombosis (HAT) after orthotopic liver transplantation (OLT) is associated with significant morbidity and mortality. Factor V Leiden (FVL) mutation is the most common genetic defect that predisposes to thrombosis. The reconstruction of hepatic artery with arterial graft is a documented risk factor for HAT. However, the relationship among FVL mutation, arterial graft, and HAT remains to be determined. METHODS: We randomly genotyped 485 patients who underwent OLT from April 2002 to January 2011 and studied the incidence of Hepatic artery thrombosis in the presence of FVL mutation. RESULTS: Of 485 patients, 21 patients (4.3%) developed HAT (13 male, 8 female); 10 patients (4 male, 6 female) were heterozygous for the FVL mutation. The incidences of HAT in patients without versus with the FVL mutation were 3.8% and 30% (P = .007). Of patients with HAT, 8 hepatic arteries were reconstructed with infrarenal aortic conduits. All 3 patients (100%) with vs 5 (28%) without FVL who received arterial grafts developed HAT (P = .042). CONCLUSION: Our study suggested that the FVL mutation may be a risk factor for HAT in liver transplantation; the risk is augmented in the presence of an arterial graft.

Citrulline level is a potent indicator of acute rejection in the long term following pediatric intestinal/multivisceral transplantation.

Citrulline has been advocated as a marker for acute cellular rejection (ACR) in intestinal transplantation; however, its significance as a forewarning in the long-term follow-up remains unknown. This study aimed to investigate the association between citrulline levels and the grading of ACR to establish a cutoff point that accurately predicts ACR beyond 3 months posttransplant in the pediatric patient population. During a 16-year period (1995-2011), a total of 13 499 citrulline samples were prospectively collected from 111 consecutive pediatric intestinal/multivisceral transplant recipients: 2155 were obtained concurrently with intestinal biopsies. There were 185 ACR episodes observed among 74/111 (67%) patients (median follow-up: 4.4 years). Citrulline levels were inversely proportional to the severity of ACR. Negative predictive values for any type of ACR (cutoff, 20 µmol/L) and moderate/severe ACR (cutoff, 10 µmol/L) were 95% and 99%, respectively. When patients were divided according to graft size, diagnostic accuracy using the same cutoff was identical. Similarly, subgroup analysis by the timing of citrulline measurement prior to biopsy varying from 1 to 7 days demonstrated comparable results. Citrulline is a potent indicator as a danger signal for ACR, being an exclusionary, noninvasive biomarker with excellent negative predictive values in the long term after pediatric intestinal/multivisceral transplant.

MicroRNA signature of intestinal acute cellular rejection in formalin-fixed paraffin-embedded mucosal biopsies.

Despite continuous improvement of immunosuppression, small bowel transplantation (SBT) is plagued by a high incidence of acute cellular rejection (ACR) that is frequently intractable. Therefore, there is a need to uncover novel insights that will lead to strategies to achieve better control of ACR. We hypothesized that particular miRNAs provide critical regulation of the intragraft immune response. The aim of our study was to identify miRNAs involved in intestinal ACR. We examined 26 small intestinal mucosal biopsies (AR/NR group; 15/11) obtained from recipients after SBT or multivisceral transplantation. We investigated the expression of 384 mature human miRNAs and 280 mRNAs associated with immune, inflammation and apoptosis processes. We identified differentially expressed 28 miRNAs and 58 mRNAs that characterized intestinal ACR. We found a strong positive correlation between the intragraft expression levels of three miRNAs (miR-142-3p, miR-886-3p and miR-132) and 17 mRNAs including CTLA4 and GZMB. We visualized these miRNAs within cells expressing CD3 and CD14 proteins in explanted intestinal allografts with severe ACR. Our data suggested that miRNAs have a critical role in the activation of infiltrating cells during intestinal ACR. These differences in miRNA expression patterns can be used to identify novel biomarkers and therapeutic targets for immunosuppressive agents.

Liver transplantation for hepatopulmonary syndrome due to noncirrhotic portal hypertension.

BACKGROUND: Hepatopulmomary syndrome is defined by the triad of chronic liver disease, increased alveolar-arterial gradient, and evidence of intrapulmonary vasodilation. It is commonly seen in association with cirrhosis (90%). Four percent to 8% of the hepatopulmomary syndrome cases are reported in noncirrhotic portal hypertension. The management of patients with hepatopulmomary syndrome due to noncirrhotic portal hypertension is not well described. METHODS: We report a case of a 26-year-old woman who underwent liver transplantation for hepatopulmomary syndrome due to noncirrhotic portal hypertension. The patient presented with dyspnea and platypnea, requiring home oxygen therapy. She had orthodexia, severe hypoxemia, and positive bubble echocardiography consistent with hepatopulmomary syndrome. Her Model for End-stage Liver Disease score was 10. Liver biopsy revealed diffuse nodular regenerative hyperplasia. RESULTS: The patient underwent liver transplantation with Model for End-stage Liver Disease exception points. Her oxygen requirements gradually improved during the postoperative period. The patient's symptoms and hypoxemia resolved at 15-month follow-up posttransplantation. CONCLUSION: We suggest hepatopulmonary syndrome in this setting is an indication for liver transplantation despite the absence of cirrhosis.

Gene expression profiling of MicroRNAs in small-bowel transplantation paraffin-embedded mucosal biopsy tissue.

BACKGROUND: The molecular mechanisms and regulation of immune-mediated rejection of organ allografts remains unclear. Recent studies have reported that small non-coding RNAs, microRNAs (miRNAs) play a critical role in the immune system via modulation of transcription and translation. PURPOSE: We hypothesized that particular miRNAs provide regulation of an ensuing intragraft immune effector response. The aim of our study was to detect miRNAs involved in acute cellular rejection (AR) in human small intestinal allografts. MATERIALS: We examined 12 small intestinal mucosal biopsies (AR, 7 cases, all grade 2 or 3) and non-rejecting (NR) allografts (5 cases, all grade 0) obtained from recipients after small bowel or multivisceral transplantation. RNA was isolated from the formalin-fixed paraffin-embedded (FFPE) biopsy samples and transcribed to cDNA. After preamplification we utilized a PCR based TaqMan Low Density Array (TLDA) containing 365 mature human miRNAs. Relative quantification was done based on pooled normal intestine using a comparative Ct method. RESULTS: We identified 62 miRNA upregulated genes in small bowels with ACR, and 35 were downregulated. Forty-two miRNA genes were upregulated in non-ACR small bowel biopsy samples (grade IND), and 45 were downregulated. The relative fold change ratio of ACR to non-ACR was calculated, and 50 upregulated and 8 downregulated miRNAs were detected as significant. Several interesting miRNAs will be evaluated further from this preliminary study. Our data suggests that intragraft miRNAs are potentially involved in the activation of a host alloimmune response to donor. These miRNAs may serve as targets for appropriate intervention and may be useful to monitor the allograft status.

Mycophenolate mofetil-related gastrointestinal mucosal injury in multivisceral transplantation.

Mycophenolate mofetil (MMF) has become an important and commonly used drug for maintenance immunosuppression therapy in recipients of all types of organ transplants. The drug is an antimetabolite that blocks the de novo pathway of purine synthesis. Although it selectively inhibits B- and T-lymphocyte proliferation, enterocytes are partially susceptible to MMF. One of the main limitations of this drug is gastrointestinal toxicity, with diarrhea the most frequently reported adverse effect. Most studies of MMF-associated gastrointestinal toxicity have been performed in patients with solid-organ transplants, although no data on changes related to MMF toxicity in bowel allografts have been published in the English literature. We evaluated mucosal intestinal biopsy tissue from patients with multivisceral transplants receiving MMF therapy. Our objective was to find morphologic changes that might be attributed to MMF toxicity, as well as changes that could differentiate MMF toxicity from acute rejection. Examination of the surface epithelium, lamina propria, and crypts in this small group of patients showed no specific changes that could be associated with MMF toxicity. Changes such as graft-vs-host disease or inflammatory bowel disease described in previous studies of solid-organ transplantation were not observed. Larger studies and the use of special stains and new markers might be necessary to characterize possible patterns of MMF toxicity and their differences from acute rejection.

Immediate antibody-mediated (hyperacute) rejection in small-bowel transplantation and relationship to cross-match status and donor-specific C4d-binding antibodies: case report.

BACKGROUND: The role of preformed donor-specific antibodies (DSAs) as a barrier to isolated intestinal transplantation (ITx) remains ambiguous; thus, a positive cross-match has not been a contraindication to ITx. OBJECTIVE: To report the case of a patient with Crohn's disease who underwent ITx and developed immediate antibody-mediated rejection on reperfusion of the allograft. METHODS: Percent reactive antibody testing was performed using pretransplantation serum samples and at transplantation using bead-based assays (Luminex, Luminex Corp, Austin, Tex) and flow cytometry solid-phase assays (FlowPRA single-antigen beads (One Lambda, Inc, Canoga Park, Calif). Serologic tests, flow cytometry cross-matching, and flow cytometry assays of C4d-binding serum antibodies were also performed. Histologic and immunofluorescent analysis of biopsy specimens was performed. RESULTS: HLA typing revealed no sharing of class I or II antigens between donor and recipient. Pretransplantation donor-specific antibodies (DSA) were present at transplantation. Cross-matching (performed during surgery) was positive for class I and II by serologic testing and flow cytometry. After reperfusion, the graft immediately developed severe ischemic injury and arteritis on mucosal biopsy specimens, with immunoglobulin deposition. The DSA C4d binding antibodies were also present. After intense immunosuppression and plasmapheresis, the graft and the biopsy histologic findings showed marked improvement (day 2). By day 7 posttransplantation, patient and graft status were stable. The patient has remained clinically stable for more than a year after transplantation. CONCLUSIONS: Pretransplant DSA in ITx can be a risk factor for immediate (hyperacute) but potentially reversible antibody-mediated rejection. Thus, pretransplantation DSA and cross-match results are critical components to be considered in patients awaiting or undergoing ITx.

Effect of pretransplant hepatitis C virus RNA status on posttransplant outcome.

Undetectable hepatitis C virus (HCV) RNA [RNA(-)] before liver transplantation (OLT) has been shown to decrease the rates of disease recurrence. We sought to determine whether RNA(-) subjects differ in post-OLT recurrence (virological/VR, histological/HR), graft failure (GF), or patient survival from RNA(+) patients using a retrospective review. From 1995 to 2004, a total of 49 patients were RNA(-) at OLT as a result of interferon-based therapy: 22 SVR and 27 with end-of-treatment response (ETR) transplanted when RNA(-) within 6 months of ET. Forty-eight RNA(+) patients were analyzed as controls. Virological recurrence (VR) was seen in 55% of RNA(-) subjects with no difference in HR between RNA(-) vs (+) groups, namely 36.7% versus 56.3% (P = .068), respectively. The RNA(+) subjects showed a lower time to HR (5.6 vs 11 months; P = .027). The SVR subjects displayed lower VR (36.4%) and histological recurrence (HR) (13.6%) compared to ETR (VR 70.4%, P = .023; HR 55.6%, P = .003) or RNA(+) (HR 56%, P = .0008). The SVR subjects, who were identified with a sensitive assay (SVR(S), lower limit <600 IU/mL) showed no VR, HR, or GF. The 1- and 5-year survivals were 87.8%/75.6% and 89.6%/77.8% for RNA(-) and (+) groups, respectively (P = .77). In conclusion, RNA(-)-transplanted patients displayed lower VR and longer time to HR. The SVR patients showed lower VR and HR compared to ETR and RNA(+) patients.

Ten-year experience in porto-caval hemitransposition for liver transplantation in the presence of portal vein thrombosis.

Porto-caval hemitransposition (PCH) in liver transplantation allows revascularization of the liver when the porto-mesenteric axis is thrombosed. We, here, review our experience over an 11-year period. A total of 23 patients underwent liver transplantation using PCH. Immunosuppression was based on tacrolimus, with sirolimus used in case of renal insufficiency. Most common diagnoses were hepatitis C, Laennec's, Budd-Chiari and cryptogenic cirrhosis. Six patients needed splenectomy prior to transplant, 5 during transplant, 1 post-transplant, 11 had no splenectomy. Overall survival was 60% at 1 year and 38% at 3 years, with 10 of 23 patients currently alive and the longest survivor at 9.3 years. Most common cause of death was sepsis/multisystem organ failure, followed by pulmonary embolism. A total of 7/23 patients experienced post-operative gastrointestinal bleeding episodes, 6/23 patients developed thrombosis of the vena cava (median 162 days post-op). Post-operative ascites was noted in almost all patients. Renal dysfunction was commonly seen even after the first month post-transplant. PCH offers a feasible option for liver transplantation in those patients with complex thrombosis of the mesenteric and portal circulation.

Liver transplantation at the Miami Transplant Institute: a 14-year single-center experience.

The clinical outcome of LT has improved significantly with refinements in surgical skill and immunosuppressive agents. Over the past decade, nationally most LT centers have improved their standard care in LT. As a result, short-term survival after LT has increased remarkably. However, recurrence of original liver disease, chronic rejection, and the adverse effect of immunosuppressive agents still impose significant limitations on long-term survival. Here at the MTI, it is our mission to continue technical innovation, improve the management of hepatitis C patients, search for better immunosuppressive protocols, and work towards achieving tolerance after LT to improve the long-term outcome.

The Miami experience with almost 100 multivisceral transplants.

We report our experience with 98 patients who received primary multivisceral transplantations. Three eras can be distinguished based on the evolution of technique, immunosuppression, and monitoring: August 1994 to December 1997 (first era); January 1998 to December 2000 (second era); and January 2001 to present (third era). Sixteen patients were transplanted during the first era, 18 during the second era, and 64 during the third era. Fifty-three patients are alive with a median follow-up of 37.5 months (range: 1 to 116 months). The leading cause of mortality was infection (n = 17), followed by rejection (n = 6). Seven patients required retransplantation and five of them subsequently died. The estimated 3-year survival was 25% +/- 11% for era 1; 44% +/- 12% for era 2; and 58% +/- 7% for era 3. Additionally, 45.3% (29/64) of patients in the third era never developed rejection versus 23.5% (8/34) of patients in the first two eras combined. The percentage of patients who developed a moderate or severe rejection was significantly less in the third era compared with the first two eras combined, 31.6% (20/64) versus 67.6% (23/34). A comparison of the hazard rate of developing severe rejection showed a protective effect of the multivisceral graft (P = .0001). In conclusion, multivisceral transplantation is indicated for patients with short bowel syndrome and extended abdominal catastrophies. Evolution in surgical techniques, immunosuppression, and monitoring have improved patient survival, which is now similar to that of other complex solid organ transplants.

International grading scheme for acute rejection in small bowel transplantation: implementation and experience at the University of Miami.

In 2003, an international collection of pathologists and clinicians proposed a unified grading system for acute cellular rejection in endoscopically derived small intestine allograft biopsies. This grading system was implemented at the University of Miami over the past 2 years and the results are presented herein. A total of 1136 small bowel allograft biopsies with sufficient tissue for analysis were obtained from 123 hospitalized, clinic, and referral patients. The overall most common diagnosis assessing all time periods was grade IND (40%), and grade 1 rejection or greater was present in 19% percent of biopsies. A suspected vascular component to the acute rejection as identified by specific mucosal vascular changes was present in 6% of cases. Clinical decision making was very consistent with different grades. Our experience has confirmed that this new grading system is reliable and identifies clinical subsets of patients that can receive different therapy. We recommend that this international grading system be implemented for acute cellular rejection in bowel allografts as a means to standardize pathological assessment of alloimmune-induced graft injury, which will allow comparisons between different centers and clinical trials.

Mucosal fibrosis in intestinal transplant biopsies correlates positively with the development of chronic rejection.

Endoscopic biopsies of intestinal allografts are limited to the superficial layers of the bowel. We investigated whether the presence of mucosal fibrosis in graft biopsies was indicative of chronic allograft rejection. We examined graft biopsies of 182 intestinal transplant recipients for the presence of mucosal fibrosis. Kaplan-Meier analysis showed that within 5 years posttransplantation 33% of intestinal transplant patients had graft biopsies positive for mucosal fibrosis. Although the presence of mucosal fibrosis did not affect patient or graft survival, patients with this lesion were at higher risk of developing chronic allograft enteropathy.

An association of lower serum citrulline levels within 30 days of acute rejection in patients following small intestine transplantation.

INTRODUCTION: In a prospective protocol we studied whether serum citrulline level within 30 days of an acute rejection was predictive of the episode. METHODS: An acute rejection episode was defined as the date of occurrence of any biopsy-proven rejection in which treatment was initiated until two successive biopsies showed no further rejection. We compared the mean citrulline level based on values determined within 30 days of the start of an acute rejection episode with the mean citrulline level measured on the same patient during a rejection-free period. Serum citrulline measurements were available immediately prior to the occurrence of rejection for 22 patients who experienced 37 episodes. RESULTS: For the 12 episodes of mild rejection, the mean serum citrulline level +/- SE (standard error) was 15.0 + 2.3 micromol/L prior to rejection and 18.8 +/- 2.4 micromol/L during the rejection-free periods. A paired t test of the mean differences was not significant (P = 17). For the 25 episodes of moderate or severe rejection, the mean serum citrulline level was 12.4 +/- 1.1 micromol/L before rejection and 18.8 +/- 2.0 micromol/L during the rejection-free periods. A paired t test of the mean difference was statistically significant (P = .002). CONCLUSIONS: Although further study of citrulline as a marker for the early detection of acute rejection episodes is needed, our hope is that its use will help to prevent some of these early episodes from evolving into full-blown moderate or severe grades of rejection.

Intestinal transplantation with alemtuzumab (Campath-1H) induction for adult patients.

BACKGROUND: Alemtuzumab (Campath-1H [C1H]) is a humanized monoclonal antibody directed against the CD 52 antigen that is present on the surface of T cells, B cells, natural killer cells and monocytes. We studied its application in intestinal transplantation. METHODS: This is a retrospective review of adult patients who underwent intestinal transplantation between December 1994 and May 2005. Group 1: non-C1H group (n = 39); group 2: C1H group (n = 37). C1H was administered as an induction immunosuppression in four doses (0.3 mg/kg), or in two doses (30 mg/kg). Tacrolimus levels were maintained at low level (5-10 ng/dL). No maintenance steroids were given. RESULTS: One-year survival of group 1 and group 2 patients were 57% and 70%, respectively. This difference is not statistically significant. Of 37 patients in group 2, 21 are alive. The incidence of rejection was lower in group 2 (P < .005). Average current tacrolimus level is 6.97 +/- 3.98 ng/dL. Seventeen patients (81%) are steroid free, and 15 (71%) are maintained solely on tacrolimus. There was no graft versus host disease in group 2. CONCLUSIONS: Our preliminary data suggest that C1H can provide effective immunosuppression for intestinal transplantation. Incidence of rejection was less with this regimen using low maintenance tacrolimus and minimal steroids.

CD55 and CD59 deficiency in transplant patient populations: possible association with paroxysmal nocturnal hemoglobinuria-like symptoms in Campath-treated patients.

Campath-1H therapy is directed to CD52, a small mw protein that has a glycosylphosphatidylinositol (GPI) anchor, which has a conventional structure similar to other GPI anchors such as CD55 and CD59. Paroxysmal nocturnal hemoglobinuria (PNH) results when cells have a somatic defect in the synthesis of GPI anchors and lack CD55 and CD59, as well as CD52. Several patients treated with Campath developed PNH-like symptoms with hemolysis and thrombosis. These patients were followed after therapy by measurement of peripheral CD55 and CD59 levels and showed an increased number of cells deficient in the expression of these molecules. Thereafter we instituted a screening program for the presence of CD55/59 levels in all pretransplant patients. Our results show that 17.3% of all pretransplant samples contained abnormal (9.7% of samples) or slightly abnormal (7.6% of samples) levels of granulocytes deficient in CD55 or CD59. This high prevalence of CD55/59 deficiency in Campath-treated patients with PNH-like symptoms suggests that a lack of these molecules (including CD52) could predispose to a complication of this immunosuppressive therapy.

Etiology and management of alimentary tract ulcers in pediatric intestinal transplantation patients.

Patients who undergo intestinal transplantation encounter several complications in the posttransplant period, one of them being ulcer formation in the alimentary tract. During postoperative endoscopic monitoring of 112 pediatric intestinal transplantation patients at our institution, we identified chronic ulcer formation in 11 patients. There were no common or defining demographic or clinical variables that were found in the patients with ulcers. The ulcers could be located within the allograft or in native tissue. Biopsies were obtained from the ulcer edge and the intervening mucosa as well as an evaluation of possible infectious agents. The most common changes in the ulcers were compatible with Epstein-Barr virus-associated posttransplant lymphoproliferative disorder (PTLD; seven cases), acute rejection (six cases), and less commonly, infectious causes (one case). These changes could occur concomitantly and retrospective analysis after therapy showed that the ulcers could have multiple etiologies. Directed biopsies of ulcer edges often displayed morphological changes compatible with acute rejection of the graft, although some biopsies of the intervening mucosa did not show similar changes. Some patients treated based on the changes within the intervening mucosa responded well and led to resolution of the ulcers. Our findings demonstrate that PTLD and acute rejection are the most common causes of chronic ulcer formation and that biopsy samples should be collected simultaneously from both the ulcer edge and intervening mucosa since pathological changes can vary depending on the underlying cause(s). Infectious agents were rarely present but could be seen superimposed with the underlying cause.

Bacterial infections after intestine and multivisceral transplantation. The experience of the University of Miami (1994-2001).

BACKGROUND/AIMS: Bacterial infections (BI) are frequent after intestinal transplantation (ITx). Bacteremia, intraabdominal and respiratory infections are the leading forms. The objective of this study is to analyze the occurrence, determinants and outcome of BI. METHODOLOGY: One hundred and twenty-four patients with ITx (39 isolated, 33 liver-intestine, 63 multivisceral). Only major BI were considered, including bacteremia, pneumonia, intraabdominal infections, severe wound infections. RESULTS: BI occurred in 92.7% of patients during follow-up, with an average of 2.9 episodes per patient. Bacteremia was the commonest picture (1.7 per patient). More than 80% of patients had a BI before the end of the second month. Multivariate analysis showed that the presence of BI was higher during the first 2 months after Itx in patients hospitalized before Tx [p=0.029, odds ratio (OR) 5.4] and during months 3 to 6 in those treated with Zenapax (p=0.003, OR 6.2). Occurrence of BI was increased with mycophenolate mofetil treatment (p=0.045 OR 4.2). Intraabdominal infection was more frequent when reTx was needed (p=0.0178 OR 15.2), admission before Tx (p=0.034 OR 2.7), IS with MMF (p=0.004 OR 6.2) and Zenapax (p=0.026 OR 3.6). BI was the direct cause of death in 17.8% of patients, and it was present in 76.2% of patients that died. An infectious episode during the first month, a clinically manifested abdominal infection and a positive intraabdominal culture were determinants of shorter patient survival. CONCLUSIONS: BI continue to be a frequent and dreadful complication after ITx. Pretransplant patient condition, IS used and postoperative complications are crucial on BI onset and outcome.