Antibody-mediated rejection in ABO compatible husband to wife living donor liver transplant and review of the literature.

Role of donor specific antibodies (DSAs) in liver allograft function has not been fully defined. We report an ABO compatible orthotopic liver transplant case with DSAs to donor HLA, where the patient developed immediate antibody-mediated rejection (AMR).The patient, a 43-year-old female with cirrhosis, underwent ABO-compatible living-donor liver transplant from her husband. On post-operative day (POD)1, serum transaminases were sharply elevated. Retrospective testing of pre-transplant serum demonstrated presence of strong class I and class II anti-HLA antibodies and positive T- and B-cell flow-cytometric crossmatches (FCXM). Transaminase levels improved with plasmapheresis and thymoglobulin. On POD7, her liver enzymes became elevated again and allograft biopsy stained positive for C4d. Patient was treated with intravenous immunoglobulin and rituximab and recovered over time. Pre-transplant sera of patient were retrospectively tested by C1q assay to determine the cytotoxic function of DSAs; DSAs were positive for C1q binding. Our results suggest that pre-liver transplant antibody testing may be helpful in identifying patients at risk for development of AMR.

Higher risk of kidney graft failure in the presence of anti-angiotensin II type-1 receptor antibodies.

Reports have associated non-HLA antibodies, specifically those against angiotensin II type-1 receptor (AT1R), with antibody-mediated kidney graft rejection. However, association of anti-AT1R with graft failure had not been demonstrated. We tested anti-AT1R and donor-specific HLA antibodies (DSA) in pre- and posttransplant sera from 351 consecutive kidney recipients: 134 with biopsy-proven rejection and/or lesions (abnormal biopsy group [ABG]) and 217 control group (CG) patients. The ABG's rate of anti-AT1R was significantly higher than the CG's (18% vs. 6%, p < 0.001). Moreover, 79% of ABG patients with anti-AT1R lost their grafts (vs. 0%, CG), anti-AT1R levels in 58% of those failed grafts increasing posttransplant. With anti-AT1R detectable before DSA, time to graft failure was 31 months-but 63 months with DSA detectable before anti-AT1R. Patients with both anti-AT1R and DSA had lower graft survival than those with DSA alone (log-rank p = 0.007). Multivariate analysis showed that de novo anti-AT1R was an independent predictor of graft failure in the ABG, alone (HR: 6.6), and in the entire population (HR: 5.4). In conclusion, this study found significant association of anti-AT1R with graft failure. Further study is needed to establish causality between anti-AT1R and graft failure and, thus, the importance of routine anti-AT1R monitoring and therapeutic targeting.

Liver and vascularized posterior rectus sheath fascia composite tissue allotransplantation.

Abdominal wall closure in pediatric solid organ recipients may be confounded by donor size discrepancy and structural insults from previous surgery. Here we describe the novel use of vascularized donor abdominal wall posterior rectus sheath fascia, as a composite tissue allotransplant (CTA), to achieve abdominal wall closure in a liver and double kidney pediatric recipient who could not be closed primarily due to donor/recipient size mismatch. The posterior rectus sheath fascia was procured in continuity with the liver and falciform ligament. Blood supply was achieved using the single hepatic artery anastomosis as part of the standard liver transplantation procedure. Specimens of posterior rectus sheath fascia taken on postoperative days 3 and 30 showed no signs of acute rejection. The patient succumbed to an overwhelming fungal infection on day 51, with no signs of intraabdominal involvement. The patient received no additional immunosuppression in conjunction with the posterior rectus sheath fascia allotransplant.

Acute humoral rejection in an ABO compatible combined liver-kidney transplant--the kidney is not always protected.

Combined liver-kidney transplantation has become a common practice for the treatment of patients with concurrent end-stage renal disease and end-stage liver disease. Liver transplantation in the setting of multiorgan transplantation is thought to have a protective effect against humoral rejection even when a positive crossmatch is obtained prior to surgery. In most centers, a pre liver-kidney transplant crossmatch is rarely performed because of the known immunoprotective effect of the liver allograft. In this report, a case of acute humoral rejection in the kidney allograft after a combined liver-kidney transplant is described. Although humoral rejection was treated using plasmapheresis, intravenous immunoglobulin and rituximab, the kidney required 3 months to recover function and finally progressed to chronic allograft nephropathy. A heightened index of suspicion for acute humoral rejection of the renal allograft is necessary when performing combined liver-kidney transplants to highly sensitized patients due to previous organ transplants.

Changes in pediatric renal transplantation after implementation of the revised deceased donor kidney allocation policy.

In October 2005, the United Network for Organ Sharing (UNOS) implemented a revised allocation policy requiring that renal allografts from young deceased donors (DDs) (<35 years old) be offered preferentially to pediatric patients (<18 years old). In this study, we compare the pre- and postpolicy quarterly pediatric transplant statistics from 2000 to 2008. The mean number of pediatric renal transplants with young DDs increased after policy implementation from 62.8 to 133 per quarter (p < 0.001), reflecting a change in the proportion of all transplants from young DDs during the study period from 0.33 to 0.63 (p < 0.001). The mean number of pediatric renal transplants from old DDs (> or =35 years old) decreased from 22.4 to 2.6 per quarter (p < 0.001). The proportion of all pediatric renal transplants from living donors decreased from 0.55 to 0.35 (p < 0.001). The proportion from young DDs with five or six mismatched human leukocyte antigen (HLA) loci increased from 0.16 to 0.36 (p < 0.001) while those with 0 to 4 HLA mismatches increased from 0.18 to 0.27 (p < 0.001). Revision of UNOS policy has increased the number of pediatric renal transplants with allografts from young DDs, while increasing HLA-mismatched allografts and decreasing the number from living donors.

Fifteen-year follow-up of transplantation of a cadaveric polycystic kidney: a case report.

INTRODUCTION: Kidneys from donors affected by autosomal-dominant polycystic kidney disease (ADPKD) are in general considered unsuitable for transplantation. To the best of our knowledge, only 12 cases of ADPKD transplanted renal units have been reported in the English literature; most have only short-term follow-up. METHODS: We provide a review of these patients and share our experience with an ADPKD patient who received a 21-year-old deceased donor ADPKD-affected renal transplant and has been closely followed for 15 years. Based on the current literature, this report is the longest follow-up of a ADPKD donor transplant. RESULTS: Over the 15-year follow-up period, there have been no complications related to the ADPKD-affected donor kidney, including three kidney transplant biopsies. The graft continues to function well with the serum creatinine currently 1.2 mg/dL. Serial axial imaging has demonstrated that the cystic disease has slowly progressed in the donor renal unit, with the largest cyst having only increasing from 1.2 to 2.9 cm in diameter. Metachronous, bilateral laparoscopic nephrectomies of the native kidneys were performed owing to intractable pain from cystic enlargement. CONCLUSIONS: Normal functioning deceased donor kidneys that show signs of early ADPKD should be considered acceptable for donation in select cases. These organs provide the recipient a safe, reasonable period of graft survival and have not been shown to cause adverse effects.

A reliable method for isolation of viable porcine islet cells.

HYPOTHESIS: Mechanical injury and oxidative stress caused by reoxygenation of isolated porcine islet cells result in their unresponsiveness to glucose stimulation. DESIGN: Adult pigs (weighing 25-30 kg) were anesthetized, and following intra-arterial infusion of ice-cold University of Wisconsin solution, a complete pancreatectomy was performed. The pancreatic duct was cannulated for infusion of digestion medium containing collagenase type P, 1.5 mg/mL; deoxyribonuclease I, 10 000 U; and a water-soluble analogue of vitamin E (Trolox), 1 mmol/L. After 20-minute incubations on ice, and at 37 degrees C, the pancreas was hand shaken for 1 minute, followed by filtration and separation on an automatic cell separator (COBE 2991). Islet cells, identified by dithizone staining, were perifused at 37 degrees C. RESULTS: The mean +/- SEM yield of intact purified islet cells (50-200 microm in diameter), and mostly present in clusters, was 2398 +/- 143 cells per gram (n = 12). Glucose stimulation caused a significant increase in biphasic insulin secretion in the perifusion experiments. CONCLUSION: We have developed a simple, reproducible, and reliable procedure for isolating intact and viable porcine islet cells suitable for xenotransplantation.

Storage and microencapsulation of islets for transplantation.

Microencapsulation is an effective means of immunoisolation for pancreatic islet transplants. However, the process of isolating, purifying, encapsulating, and transplanting islets in a single day is labor intensive and difficult for routine use. There is an apparent need for reliable methods of islet storage, and cryopreservation has emerged as an attractive system of islet banking. While studies have shown that cryopreserved islets are viable when tested unencapsulated after thawing, it is not clear if the combination of freezing and encapsulation would affect islet function. The purpose of the present study was to determine the in vitro function of cryopreserved islets following thawing and microencapsulation. Islets were isolated from the pancreata of Sprague-Dawley rats and cryopreserved under liquid nitrogen for either 1 week or 1 month, following an overnight culture at 37 degrees C. Upon thawing, the islets were tested either unencapsulated or after encapsulation in polylysine-alginate membrane. In all experiments islets were preperifused for 1 h at 37 degrees C with a modified Krebs-Ringer bicarbonate buffer containing 3.3 mM (60 mg/dl) glucose and maintained at pH 7.4 by continuous gassing with 95% air/5% CO2. Following basal effluent sample collection on ice, the glucose concentration was raised to 16.7 mM (300 mg/dl). It was found that, within 10 min of high glucose stimulation, an average of twofold increase in insulin secretion (p < 0.01) was obtained in islets within or without microcapsules. We conclude that islets cryopreserved for 1 month prior to thawing and microencapsulation retained functional viability as determined in in vitro experiments.

Bile acids in xenogeneic ex-vivo liver perfusion: function of xenoperfused livers and compatibility with human bile salts and porcine livers.

BACKGROUND: In recent years, hepatic support systems using xenogeneic cells have been developed to support patients in fulminant hepatic failure. The extent to which xenogeneic hepatocytes metabolize and excrete human organic anions is unclear. In these studies we examined the ability of the ex vivo porcine liver to clear human bile acids during extracorporeal liver perfusion (ELP). METHODS: Four patients with fulminant hepatic failure underwent extracorporeal liver perfusion with 9 porcine livers. The venovenous circuit was designed as previously described (NEJM,1994,331:234) as were the immunologic features (Transplantation 1994,58:1162). Bile from the porcine liver and serum samples were collected hourly during perfusion. Three bile acids (glycocholic, glycodeoxycholic, taurodeoxycholic acid) were selected as markers for human bile and three (glycohyocholic, glycohyodeoxycholic, and glyco-3alpha-hydroxy-6-oxo-5beta-cholanoic acid) for markers of pig bile. Bile acids from both serum and bile were processed and analyzed through high performance liquid chromatography. The Students' t test was used for statistical analysis. RESULTS: The mean duration of perfusions was 4.1+/-1.5 hr. The mean total bile acid clearance from serum (243+/-44 micromol/h) was similar to the total bile acid biliary excretion (286+/-84 micromol/hr, P = 0.06). After 1 hr of perfusion, bile samples demonstrated a predominance of pig bile salts (65%). After 3 hr of perfusion, human bile acids made up 85% of total biliary bile acids. Pig bile acids appeared in patients' sera after 1 hr of perfusion, and after 3 hr, 35% of serum bile salts were pig-specific. CONCLUSIONS: Porcine livers perfused with human blood can clear the serum of potentially toxic human bile acids and excrete them into bile. Simultaneously, the percentage of pig-specific bile acids in patient serum increases during xenogeneic perfusion for unknown reasons. The relative hepatic uptake of bile acid from serum is similar to bile acid excretion in bile. Further development of systems using porcine livers or hepatocytes is warranted.

P-Selectin mediates reperfusion injury through neutrophil and platelet sequestration in the warm ischemic mouse liver.

Hepatic damage following ischemia-reperfusion injury involves polymorphonuclear leukocytes (PMN) and platelet sequestration, however the mechanisms of adhesion remain elusive. In this study, using gene-targeted deficient mice, we evaluated P-selectin and its contribution to PMN and platelet adhesion in hepatic damage. In an in vivo warm ischemia model, hepatic injury was assessed by serum transaminase levels, survival, PMN adhesion by histological analysis, and platelet sequestration by immunostaining. Serum transaminase levels were strikingly reduced (by up to threefold) in the P-selectin deficient mice, particularly at 90 minutes of ischemia, when compared with wild-type controls. PMN adhesion and platelet sequestration was also significantly decreased in P-selectin deficient mice following 90 minutes of partial ischemia. Animal survival was significantly improved after 75 minutes of total hepatic ischemia in P-selectin deficient mice when compared with wild-type mice. Survival was also achieved after 90 minutes of ischemia in the mutant mice whereas none of the wild-type animals survived. These data show that P-selectin plays a critical role in PMN and platelet adhesion following ischemia-reperfusion injury to the liver.

L-selectin and ICAM-1 mediate reperfusion injury and neutrophil adhesion in the warm ischemic mouse liver.

Leukocytes recruited during ischemia-reperfusion to the liver are important mediators of injury. However, the mechanisms of leukocyte adhesion and the role of adhesion receptors in hepatic vasculature remain elusive. L-selectin may critically contribute to injury, priming adhesion for later action of intercellular adhesion molecule-1 (ICAM-1). Paired experiments were performed using mutant mice (L-selectin -/-, ICAM-1 -/-, and L-selectin/ICAM-1 -/-) and wild-type mice (C57BL/6) to investigate leukocyte adhesion in the ischemic liver. Leukocyte adhesion and infiltration were assessed histologically. Aspartate aminotransferase levels were significantly reduced (2- to 3-fold) in mutant vs. wild-type mice in most groups but most significantly after 90 min of partial hepatic ischemia. Leukocyte adhesion was significantly reduced in all mutant mice. Areas of microcirculatory failure, visualized by intravital microscopy, were prevalent in wild-type but virtually absent in L-selectin-deficient mice. After total hepatic ischemia for 75 or 90 min, survival was better in mutant L-selectin and L-selectin/ICAM-1 mice vs. wild-type mice and ICAM-1 mutants. In conclusion, L-selectin is critical in the pathogenesis of hepatic ischemia-reperfusion injury. Poor sinusoidal perfusion due to leukocyte adhesion and clot formation is a factor of injury and appears to involve L-selectin and ICAM-1 receptors.

Optimization of the microencapsulated islet for transplantation.

BACKGROUND: Microencapsulation of isolated islets is a good method for providing protection against immunologic reactions to the cells in both allogeneic and xenogenic grafts. Current methods of microencapsulation require chelation of the alginate-calcium core, which solubilizes the structural support of the capsules and may adversely affect durability. The purpose of the present study was to determine the in vitro response to glucose stimulation, of microencapsulated islets that have not been subjected to chelation. MATERIALS AND METHODS: Using an air-jet-syringe-pump droplet generator, islets isolated from male Sprague-Dawley rats were encapsulated in alginate, followed by washes with poly-L-lysine, saline, and a second coat of alginate. Different groups of the microencapsulated islets were then tested for response to high glucose perifusion, before or after chelation, and the responses were compared with those of unencapsulated islets. RESULTS: Chelated microencapsulated islets showed a normal biphasic insulin response to stimulation with 16.7 mM (300 mg%). Thus, insulin secretion increased from a mean +/- SEM basal rate of 3005 +/- 645 to a stimulated rate of 5165 +/- 1030 pg/min (P < 0.05, n = 6) in the first phase, comparable to results obtained with the unencapsulated islets. In contrast, unchelated microencapsulated islets did not respond to stimulation with 16.7 mM glucose. However, after a 24-h culture of these unchelated microcapsules, a small but significant response was observed. CONCLUSIONS: Although culturing unchelated microcapsules of islets may enhance their function, chelation of the microcapsular core is essential for optimal function of the enclosed islets.

A new and simple technique of total hepatic ischemia in the mouse.

BACKGROUND: A model of total hepatic ischemia is currently not available in mice. Models described in rats using portosystemic shunts to achieve total ischemia have been notoriously difficult. In mice, the problem is compounded further when using this type of technique because of the small size of the animal. A new technique is described combining partial hepatectomy with clamping of the remnant liver. METHODS: A partial (30%) hepatectomy is performed with resection of the caudate, right lateral, and quadrate lobes, and papillary process. Vascular microclamps are placed across the pedicles of the median and left lateral lobe at the level of the hilum to achieve total ischemia. Spontaneous portocaval shunts through caudate branches and collateral vessels prevent mesenteric congestion. Animals were studied for survival. RESULTS: The procedure consistently took less than 30 min (25+/-2 min), and no bleeding of the resected tissue was observed. Evidence for total hepatic ischemia and spontaneous shunts was demonstrated by the use of an intraportal dye. All animals survived 60 min of ischemia, whereas all died after 90 min of ischemia. CONCLUSION: This is a technically simple and rapid procedure to perform. In the current environment of multiple knockout mice and bioreagents that are available, a model of this type is essential.

The role of antibodies in acute vascular rejection of pig-to-baboon cardiac transplants.

Long-term success in xenotransplantation is currently hampered by acute vascular rejection. The inciting cause of acute vascular rejection is not yet known; however, a variety of observations suggest that the humoral immune response of the recipient against the donor may be involved in the pathogenesis of this process. Using a pig-to-baboon heterotopic cardiac transplant model, we examined the role of antibodies in the development of acute vascular rejection. After transplantation into baboons, hearts from transgenic pigs expressing human decay-accelerating factor and CD59 underwent acute vascular rejection leading to graft failure within 5 d; the histology was characterized by endothelial injury and fibrin thrombi. Hearts from the transgenic pigs transplanted into baboons whose circulating antibodies were depleted using antiimmunoglobulin columns (Therasorb, Unterschleisshein, Germany) did not undergo acute vascular rejection in five of six cases. Biopsies from the xenotransplants in Ig-depleted baboons revealed little or no IgM or IgG, and no histologic evidence of acute vascular rejection in the five cases. Complement activity in the baboons was within the normal range during the period of xenograft survival. In one case, acute vascular rejection of a xenotransplant occurred in a baboon in which the level of antidonor antibody rose after Ig depletion was discontinued. This study provides evidence that antibodies play a significant role in the pathogenesis of acute vascular rejection, and suggests that acute vascular rejection might be prevented or treated by therapies aimed at the humoral immune response to porcine antigens.

Liver transplantation complicated by misplaced TIPS in the portal vein.

OBJECTIVE: The purpose of this study was to determine the incidence and complications related to transjugular intrahepatic portosystemic shunt (TIPS) stents found in the portal vein at the time of an orthotopic liver transplantation. BACKGROUND: Transjugular intrahepatic portosystemic shunts are frequently used in patients with end-stage liver disease as a bridge to liver transplantation. The incidence of finding the metal stent outside of the liver parenchyma at the time of transplantation is reported as high as 30%. Most cases that have been detailed involve stents misplaced in the vena cava with various outcomes. Almost no data are available regarding stents misplaced into the portal vein. METHODS AND RESULTS: We report our experience with four patients with whom a TIPS stent was found misplaced in the portal vein at the time of liver transplantation, including one patient with a stent extending into the superior mesenteric vein. This patient required extensive venous reconstruction using a retropancreatic "pant" donor-iliac vein graft. The three other patients were transplanted without the need for extensive venous reconstruction. There was no significant difference in operative times for this group of patients, but there was a significant increase in the requirement for blood transfusion. In a follow-up period ranging from 6 months to 2 years, all patients remained alive and had normal portal venous flow and functioning allografts. Most misplaced stents were placed in patients with small cirrhotic livers and by radiologists with minimal experience with the procedure. CONCLUSIONS: Misplaced TIPS in the portal vein before liver transplantation is a more frequent complication than previously reported; however, it does not represent major technical difficulty if a clamp can be placed proximally on the portal vein. In the case of a stent extending below the spleno-mesenteric confluence, interposition grafts such as a donor-iliac vein graft are necessary for venous reconstruction. The experience of the radiologist is critical to prevent this complication.

Evidence that ursodeoxycholic acid prevents steroid-resistant rejection in adult liver transplantation.

Steroid-resistant rejection continues to be a serious problem in liver transplantation. Since ursodeoxycholic acid (UDCA) is beneficial in several cholestatic disorders and possesses in vitro immunomodulatory and immunosuppressive effects, we have tested in a pilot study the effects of adjuvant UDCA in the prevention of steroid-resistant rejection. Fifty consecutive liver transplant patients were treated with a standard cyclosporine immunosuppressive regimen. Treatment with UDCA (10 mg/kg/d) was initiated in each patient who developed biopsy-proven rejection or biochemical evidence of cholestasis. Clinical and laboratory features were monitored for evidence of rejection. Data were analyzed after at least a 10-month follow-up period was available in each patient. Seven patients died during the study period, all within 4 wk of surgery. No evidence of rejection was documented in these patients. Twenty three of the 43 survivors 53% (23/43) developed an episode of rejection, and UDCA was initiated in each of them. Only one patient had a second episode of rejection, which responded to intravenous methylprednisolone therapy; no patient required antilymphocyte therapy. There was no evidence of toxicity for UDCA. These data suggest that UDCA can be given safely following OLT and may contribute to prevention of steroid-resistant rejection in liver transplant recipients.

Prospects for xenotransplantation of the liver.

Because of the tremendous success of clinical transplantation of the liver and other organs in the last three decades, the demand for organs for transplantation has risen sharply and there is now a substantial shortage. The utilization of organs from other species, xenotransplantation, is increasingly viewed as a potential solution to this problem. The major limitation to xenotransplantation is the formidable immunological barriers that prevent the successful transplantation of non-human organs into human recipients. Here we review current knowledge about the immunology of xenotransplantation and the limited clinical and experimental experience in xenotransplantation of the liver.

Quality of life after treatment for pancreatitis.

OBJECTIVE: The authors evaluated the morbidity, mortality, and quality of life after pancreatic debridement for necrosis and compared these values to those for quality of life after elective medical and surgical management for chronic pancreatitis. SUMMARY BACKGROUND DATA: Quality of life after pancreatic debridement for necrosis has received little attention. Although quality of life after other pancreatic surgery has been evaluated and is though to be good, management of patients with pancreatic necrosis can be labor intensive and require extraordinary resources. Therefore, further evaluation of the quality of life achieved after treatment is appropriate. METHODS: Forty patients (group 1) underwent operative debridement for necrosis between 1986 and 1994. Medical records of these patients were reviewed for morbidity, mortality, and in-hospital costs. Follow-up of quality of life was assessed by the Short Form-36 Health Survey. Patients in group 2 (n = 89) underwent medical management of chronic pancreatitis. Group 3 included 47 patients who underwent elective operations for ductal abnormalities. The Short Form-36 Health Surveys were administered to all three groups and compared statistically. RESULTS: Mortality and morbidity from pancreatic debridement was 18% and 77%, respectively. Quality-of-life evaluations in groups 1 through 3 and age-matched controls were statistically similar. CONCLUSIONS: Pancreatic debridement for necrosis requires intense application of resources and is associated with a high mortality and morbidity. Long-term follow-up shows good quality of life for patients who survive this morbid disease. This study supports the continued aggressive approach to the management of pancreatic necrosis, given that long-term outcome about quality of life is good.