Thrombotic microangiopathy following intestinal transplantation: a single center experience

BACKGROUND

Transplant-related thrombotic microangiopathy (TMA) is a well-recognized complication of all types of transplantations. Despite its known relationship with immunosuppressive therapy, only a few cases have been reported following intestinal transplantation.

METHODS

We retrospectively reviewed the medical files of nine consecutive intestinal transplant patients between 2000 and 2008.

RESULTS

The diagnosis of TMA was established in 3 patients (33%). At diagnosis the immunosuppressive therapy consisted of tacrolimus (n = 3), combined with azathioprine (n = 1) or sirolimus (n = 2) and steroids (n = 2). The median time between transplantation and TMA was 104 days (range, 55-167 days). Levels of ADAMTS13, a von Willebrand protease, were within normal ranges in all 3 patients. Treatment consisted of stopping/tapering of tacrolimus, together with initiation of plasma therapy, leading to complete remission in all 3 patients. During further follow-up, all 3 patients showed severe graft rejection necessitating more profound immunosuppressive therapy, leading to graft loss in 1 patient and infection-related death in the 2 others. At a median follow-up of 52 months (range, 9-100 months) all remaining TMA-free patients (n = 6) were alive with functioning grafts under minimal immunosuppression.

CONCLUSION

Herein we have described 3 intestinal transplant patients who were diagnosed with transplantation-related TMA. Despite excellent disease control the final outcomes were dismal, which clearly contrasts with the outcome among TMA-free patients, who were all well with functioning grafts at last follow-up.

Testicular torsion after pediatric kidney transplantation

Kidney transplantation has become the treatment of choice for children with end-stage renal disease and offers recipients an excellent quality of life. Following kidney transplantation several types of medical and surgical complications can arise. In this report, a testicular torsion occurring on the sixth day after pediatric kidney transplantation is described. It remains unclear whether this unusual complication should be regarded as coincidental or as a direct consequence of the transplantation.

Acute appendicitis after liver transplantation: a case report and review of the literature

INTRODUCTION

Acute appendicitis is rarely seen after liver transplantation.

CASE

We present a case of acute appendicitis 16 days after liver transplantation. CT-scan suggested this diagnosis, but there were also signs of biliary leakage. Surgical exploration only revealed an acute appendicitis and an appendectomy was performed. Histological examination confirmed the diagnosis. Postoperative course was uneventful.

LITERATURE

Until now only 15 cases of acute appendicitis after liver transplantation have been reported. CT-scan is considered to be an accurate diagnostic tool. The duration of hospitalization after appendectomy seems to be longer in the immunosuppressed patient.

CONCLUSION

Although acute appendicitis is not common after liver transplantation, quick diagnosis and treatment can prevent major complications.

Change in donor profile influenced the percentage of organs transplanted from multiple organ donors

We hypothesized that the change in donor profile over the years influenced the percentage of transplantations. We reviewed medical records for all multiple-organ donors (MODs) within our network. The percentage of transplanted organs was compared between 1991-1992 (A) and 2006-2007 (B). In period A, 156 potential MODs were identified compared with 278 in period B. Fifteen potential donors (10%) in period A and 114 (41%) in period B were rejected because they were medically not suitable (40% vs 75%) or there was no family consent (60% vs 25%). Of the remaining effective MODs (141 in period A and 164 in period B), mean (standard deviation = SD) age was 34 (5) years vs 49 (17) years (P < .001). Brain death resulted from craniocerebral trauma in 69% vs 39%, cerebrovascular disease in 24% vs 46%, hypoxia in 4% vs 15%, and brain tumor in 2% vs 0.6% (P < .001). Chest trauma was present in 19% vs 9% (P < .01). The percentage of MODs who received mechanical ventilation for more than 5 days was 8% vs 24% (P < .001). The percentage of organs transplanted in periods A vs B was kidneys, 97% vs 79%; livers, 64% vs 85%; hearts, 60% vs 26%; lungs, 7% vs 35%; and pancreas, 6% vs 13% (P < .001). The number of referred potential MODs increased by 80%, resulting in a small increase in effective MOD organs (17%), mainly because of medical contraindications. The MOD profile changed to older age, fewer traumatic brain deaths, and longer ventilation time. We transplanted more livers, lungs, and pancreases but fewer kidneys and hearts.

Hypothermic Liver Machine Perfusion With EKPS-1 Solution vs Aqix RS-I Solution: In Vivo Feasibility Study in a Pig Transplantation Model

OBJECTIVE

Hypothermic machine perfusion (HMP) is superior to simple cold storage for kidney preservation. We previous observed in a porcine liver transplantation model increased tumor necrosis factor-alpha (TNF-alpha) production eventually leading to poor recipient survival after HMP using standard kidney perfusion solution (KPS-1) compared with simple cold storage. We compared two solutions for HMP preservation of the liver: enriched KPS-1 (EKPS-1) and Aqix RS-I.

METHODS

Pig livers were obtained after cold flushing with histidine-tryptophan-ketoglutarate solution. Subsequently, the livers were subjected to dual-vessel perfusion with two preservation solutions: EKPS-1 (n = 6) and Aqix RS-I (n = 3). After HMP preservation and transplantation, graft and recipient survival, hepatocellular damage (aspartate aminotransferase concentration), TNF-alpha production, and endothelial cell damage (hyaluronic acid clearance) were recorded.

RESULTS

No primary graft nonfunction was observed. Recipient survival at postoperative day 3 was similar in both groups (33%). Aspartate aminotransferase concentration measured in serum samples after reperfusion was similar in both groups. After reperfusion, TNF-alpha concentration was higher and hyaluronic acid clearance was lower in the EKPS-1 group vs the Aqix RS-I group at 60, 120, and 180 minutes (all P < .05).

CONCLUSION

Hypothermic machine perfusion provided adequate longer term graft survival. After reperfusion, TNF-alpha production seems to be reduced, and endothelial cell dysfunction remains pronounced with Aqix RS-1 solution compared with EKPS-1 solution.

Delayed introduction of reduced-dose tacrolimus, and renal function in liver transplantation: the 'ReSpECT' study

We report a multicenter, prospective, randomized, open-label trial investigating the effect of lower levels and delayed introduction of tacrolimus on renal function in liver transplant recipients. Adult patients with good renal function undergoing primary liver transplant were randomized to either: group A (standard-dose tacrolimus [target trough levels >10 ng/mL] and corticosteroids; n = 183); group B (mycophenolate mofetil [MMF] 2g/day, reduced-dose tacrolimus [target trough levels </=8 ng/mL], and corticosteroids; n = 170); group C (daclizumab induction, MMF, reduced-dose tacrolimus delayed until the fifth day posttransplant and corticosteroids, n = 172). The primary endpoint was change from baseline in estimated glomerular filtration rate (eGFR) at 52 weeks. The eGFR decreased by 23.61, 21.22 and 13.63 mL/min in groups A, B and C, respectively (A vs C, p = 0.012; A vs B, p = 0.199). Renal dialysis was required less frequently in group C versus group A (4.2% vs. 9.9%; p = 0.037). Biopsy-proven acute rejection rates were 27.6%, 29.2% and 19.0%, respectively. Patient and graft survival was similar. In conclusion, daclizumab induction, MMF, corticosteroids and delayed reduced-dose tacrolimus was associated with less nephrotoxicity than therapy with standard-dose tacrolimus and corticosteroids without compromising efficacy or tolerability.

Living donor kidney transplantation: analysis of the first 40 cases performed in UZ Leuven

Living donation kidney transplantation has been popular worldwide to try to increase the donor pool. In Belgium, the rate of living donation kidney transplantation has been traditionally relatively low compared to other countries. This is--in part--due to the relatively higher cadaveric organ offer that is available in Belgium (around 25 donors per million inhabitants), compared to other countries. However, the increasing waiting times on cadaveric waiting list and the superiority of the results of live donation versus cadaveric kidney transplantation have led to a reappraisal of this strategy. In our center a living donation kidney transplant programme was started in 1997. Since then 40 cases of live donation kidney transplantation have been performed and are reported herein.

Intestinal transplantation: from the laboratory to the clinics

The intestine has long been seen as a "forbidden" organ to transplant. This is because the first attempts at Intestinal Transplantation (ITx) were defeated by rejection, technical problems, infection and graft versus host disease. Results of ITx have improved in the short-term (70 to 80% 1-year patient survival) but remain inferior to other solid organ transplants in the long-term (5 years patient survival of 50% or less). Reasons for this difference between intestine and other organ transplants are reviewed. Development of immunomodulatory protocols--e.g. protocols aiming at reducing the rejection response and facilitating engraftment--are described. Our center experience with a consecutive series of five intestinal transplants utilizing a new protolerogenic protocol and low immunosuppression is described. At time of writing, these five patients are rejection-free, nutritionally independent and lead a normal life.

What is the limiting factor for organ procurement in Belgium: donation or detection ? What can be done to improve organ procurement rates?

In trying to overcome the growing gap between demand and offer of organs for transplantation, solutions are usually searched for by comparing successful and unsuccessful models in different countries. In particular, one element in the more successful countries such as for instance presumed consent, or one element in the less successful countries such as for instance refusal by relatives, are seen as possible reasons for these differences. This article tackles the problem of organ donor shortage through a new multi-level approach. Organ donation can indeed be analyzed on three different levels: the macro-level, the meso-level and the micro-level. The macro-level refers to the governmental structure where legislation, policies and funding are three essential elements necessary to make donation possible. The meso-level refers to the health care organization and the professionals who surround the process of organ donation and transplantation. Facilitating this process through standardized protocols and improving detection of organ donors are the two major elements. The micro-level refers to the individual believes and personal attitudes towards organ donation. This new multi-level approach gives a thorough and complete analysis of problems and allows to propose potential solutions to try to overcome the chronic organ shortage.

Liver transplantation from non-heart-beating donors: current status and future prospects in an experimental model

The widening gap between supply and demand for liver transplantation has prompted many transplant centers to use donors after cardiac death or non-heart-beating donors. These livers--contrary to "classical" brain-dead donors--are exposed to an unavoidable period of warm ischemia, jeopardizing graft function post-transplantation. In a newly developed preclinical model of liver transplantation, we studied--in a biologically unmodified environment--the exact tolerance of the liver to warm ischemia. Following the evidence that liver transplantation from non-heart-beating donors is feasible and safe, provided that warm and cold ischemia are kept short, a clinical programme of liver transplantation from non-heart-beating donors was successfully initiated in our and other Belgian centers. Recently, we demonstrated that the tolerance of such livers to warm ischemia could be substantially improved when some of the previously identified mechanisms leading to graft non-function were tackled by a multi-factorial pharmacological strategy. Meanwhile, cold storage has proven to be insufficient to optimally preserve organs from non-heart-beating donors. As an alternative, machine perfusion preservation was found to consistently improve outcome in kidney transplantation from non-heart-beating donors. Similarly, machine perfusion preservation could improve the preservation of livers, allowing to predict viability prior to transplantation and to ameliorate tolerance to warm ischemia. At present, the definition and development of optimal machine perfusion settings are under investigation at our institution.

Abdominal Transplant Surgery and Transplant Coordination University Hospitals Leuven 1997-2007: an overview

The transplant surgery and transplant coordination department was created in 1997 to meet up with the demand of the growing abdominal transplant surgery and organ procurement activity at the University Hospitals in Leuven. Since then, the procurement activity has increased and is currently distributed within the University Hospital Gasthuisberg and a network of approximately 25 collaborative hospitals. The profile of the donors has changed with older donors and more co-morbidity factors (obesity, hypertension, etc.). This donor activity represents approximately 30% of the national donor pool. Over the last 10 years, more than 1100 kidneys, more than 500 livers, approximately 50 pancreas, and 5 intestines have been transplanted in both adults and children. One year survival equal to- or exceeding 90% has been achieved for all abdominal organs and this compares favorably with international registries. More than 40 multi-visceral transplants {liver in combination with abdominal (kidney, pancreas, intestine) or thoracic (heart, double lung, heart-lung) organs} have been performed with results equivalent to isolated liver transplants and very little immunological graft loss (probably due to the immunoprotective effect of the liver). A live donation program was started for the kidney (40 cases) and for the liver (10 cases) in adults and children and no surgical graft loss has been seen so far. Introduction of new machine perfusion systems (and development of donor protocols) has made it possible to restart a non-heart-beating donor program for kidney transplantation. Experimental demonstration that livers tolerate short periods of warm ischemia has also allowed to start liver transplantation from non-heart-beating donors. In the future, machine perfusion of livers, viability testing, and biological modulation are likely to widen the use of marginal livers for transplantation and improve the results. An immunomodulatory protocol proven in the lab to induce the development of regulatory T cells has been applied clinically to 5 consecutive intestinal transplants. All 5--at the time of writing--have been rejection-free and have achieved nutritional independence. Continuous research and development is warranted to increase the organ donor pool (currently the solely limiting factor of transplantation) and to optimize long-term graft and patient outcome.

Donor categories: heart-beating, non-heart-beating and living donors; evolution within the last 10 years in UZ Leuven and Collaborative Donor Hospitals

Over the past 10 years, the University Hospitals Leuven and their group of Collaborative Donor Hospitals (approximately 20) have tried to maximize their contribution to the national and Eurotransplant donor pool. In this time period, 1042 potential donors and 703 effective donors were coordinated and their organs allocated through Eurotransplant. This activity represented approximately 30% of the national donor pool and approximately 32% of the national organ pool. For Belgium, the non-heart-beating donor activity represented 11.38% of all donors in 2006. Since 1997, 167 potential live donors have been screened in our center. Of these, 48 transplants (28.74%) (39 kidneys--9 livers) have been performed. A boost of screened candidates was seen over the last 3 years, with a 500% increase of records being evaluated. Although the Belgian live donation activity remains one of the lowest in the world, there has been a clear increase over the last 3 years with about 10% of all kidney transplant activity originating now from live donors.

Pancreas transplantation: towards minimization of technical graft loss

The objective of the study is to determine whether evolution in surgical techniques results in minimization of technical graft loss after simultaneous pancreas-kidney transplantation (SPKTx). Eighty consecutive patients with insulin-dependent diabetes mellitus and end-stage nephropathy, and who received SPKTx, were studied. Patient, pancreas and kidney survival at 5 years were 89, 84 and 84% respectively. The porto-systemic venous anastomosis laterally to the arterial vessels resulted in exclusion of technical graft loss due to venous thrombosis. The switch from exocrine bladder drainage to enteric drainage lowered significantly the posttransplant surgical morbidity. This series indicates that excellent short- and long-term survival can be obtained after SPKTx and this with a low perioperative surgical morbidity.

Evolution in allocation rules for renal, hepatic, pancreatic and intestinal grafts

Organ transplantation is the victim of his own success. The results of transplantation are excellent and more patients are activated on the waiting list. The need for organs exceeds the supply. Which criteria are used to allocate available grafts to patients on the waiting list ? Organ allocation and finding the "best match" between donor and recipients, is the goal of Eurotransplant, the organ sharing organization for seven European countries (Austria, Croatia, Germany, Luxemburg, Slovenia, The Netherlands and Belgium). Last decade, the allocation system has switched from a "center-driven" (organ allocated to a center) to a "patient-driven" system (organ allocated to a particular patient). For the allocation of abdominal organs some general allocation rules are followed: blood group compatibility, priority for high urgencies. The allocation of kidneys is based on a point score system based on waiting time, HLA and donor location (to reduce the cold ischemia time). In addition to this standard allocation procedure, there are still specific procedures for pediatric recipients and for candidates > or = 65 year old. There is also an "acceptable" mismatch program for recipients at high immunological risk. The liver allocation system recently changed and is now based on the MELD score, a formula that calculates the probability of death within 3 months on the waiting list. For pancreas and intestine, the system is based on blood group, medical urgency, waiting time, donor region and weight (for intestine).

Can apparent diffusion coefficient discriminate ischemic from nonischemic livers? A pilot experimental study

PURPOSE

Using magnetic resonance imaging, the apparent diffusion coefficient (ADC) is an indicator to assess cerebral ischemia. The aim of this porcine study was to evaluate whether ADC assessed hepatic ischemia during ex vivo hypothermic machine perfusion (HMP) as well as in vivo.

METHODS

Ex vivo: ADC of normal versus warm ischemic (WI) livers was assessed during HMP and subsequent rewarming to mimic ischemia-reperfusion injury. As the preservation solution, we used either an acellular solution or diluted blood. WI was induced in the left lobe or in the whole liver and compared 2-hour WI and non-WI. In vivo: One liver was scanned with the left lobe vessels occluded for 2-hour WI and subsequently for 3 hour reperfusion to compare with the right lobe without WI. Aspartate aminotransferase (AST) in the perfusate and morphology were used as surrogates of WI.

RESULTS

In all WI livers, AST reached high levels and histology showed severe injury. Ex vivo ADC during acellular perfusion showed negligible differences between the livers with versus without WI, namely, 0.75 x 10(-3) or 0.88 x 10(-3) mm(2)/s during HMP. Ex vivo ADC using sanguineous perfusion showed 1.11 x 10(-3) or 0.83 x 10(-3) mm(2)/s during HMP in regions with versus without WI, respectively, a difference that remained stable during the whole experiment. ADC in vivo decreased from the physiological level of 1.07 x 10(-3) mm(2)/s to 0.75 x 10(-3) mm(2)/s in the first 30 minutes of WI, whereas ADC in the non-WI liver remained constant.

CONCLUSION

ADC in vivo decreased during hepatic ischemia, as previously seen in cerebral ischemia. However, the effect of WI on ADC was less clear during ex vivo HMP.

Influence of flow and addition of oxygen during porcine liver hypothermic machine perfusion

INTRODUCTION

In contrast with kidneys, data on hypothermic machine perfusion (HMP) of livers remain scarce. Optimal liver HMP is poorly defined. Superiority of liver HMP over simple cold storage (SCS), the current standard preservation, must be proven before HMP is applied clinically. In this study, morphology and adenosine triphosphate (ATP) contents of HMP livers at different flows and with versus without O(2) studied in a porcine ex vivo model were compared to SCS.

METHODS

Pig livers were procured, flushed with HTK and preserved via SCS or HMP at 3 HMP settings: high flow (HF); low flow (LF); low flow + O(2) (300 mm Hg) (LFO). HMP livers were perfused via the hepatic artery (HA) and portal vein (PV) with KPS-1 TM at 4 degrees C to 6 degrees C for 24 hours with HF: PV: 3 to 5 mm Hg, 1 mL/g liver/min for HA and 25 mm Hg; LF: PV: 3 to 5 mm Hg, 0.5 ml/g liver/min with HA: 20 mm Hg. Morphology and ATP levels were measured in preserved liver tissues.

RESULTS

Throughout the SCS preservation, livers remained intact. In HMP livers, vacuoles appeared after 4 hours of preservation in the HF group and after 12 hours in the LF livers. LFO livers remained intact with limited vacuoles. Compared to SCS, HMP livers showed dilated sinusoids, particularly in the HF group. ATP remained relatively constant or even increased during HMP, particularly in the LF group, whereas ATP decreased after SCS.

CONCLUSION

Among the various HMP settings, HMP with LFO was superior. ATP levels were the highest in LF. In contrast with all HMP groups, SCS showed the lowest ATP levels, indicating that HMP has the potential to better preserve energy stores.

Liver transplantation using non-heart-beating donors: Belgian experience

Mortality on liver transplantation (OLT) waiting lists has increased dramatically. Until recently, non-heart-beating donors (NHBD) were not considered suitable for OLT, because of a higher risk of primary graft nonfunction (PNF) and biliary strictures. However, recent experimental/clinical evidence has indicated that NHBD-OLT is feasible when the period of warm ischemia is short.

PURPOSE

To characterize the results of NHBD-OLT in Belgium, a survey was sent to all Belgian OLT centers.

RESULTS

Between January 2003 and November 2005, 16 livers originating from NHBD were procured and transplanted. The mean donor age was 48.8 years, including 9 males and 7 females with mean time of stop-therapy to cardiac arrest being 18 minutes and from cardiac arrest to liver cold perfusion, 10.5 minutes. Mean recipient age was 52.2 years including 12 males and 4 females. Mean cold ischemia time was 7 hours 15 minutes. No PNF requiring re-OLT was observed. Mean post-OLT peak transaminase was 2209 IU/L, which was higher among imported versus locally procured grafts. Biliary complications occurred in 6 patients requiring re-OLT (n = 2), endoscopic treatment (n = 2), surgical treatment (n = 1), or left untreated (n = 1). These tended to be more frequent after prolonged warm ischemia. Graft and patient survivals were 62.5% and 81.3%, respectively, with a follow-up of 3 to 36 months.

CONCLUSION

This survey showed acceptable graft/patient survivals after NHBD-LT. The NHBD-liver grafts suffered a high rate of ischemic injury and biliary complications and therefore should be used carefully, namely with no additional donor risk factors, lower risk recipients, and short cold/warm ischemia.

The clinicopathological and prognostic relevance of cytokeratin 7 and 19 expression in hepatocellular carcinoma. A possible progenitor cell origin

AIMS

Cytokeratin (CK) 7 and CK19 expression, present in hepatic progenitor cells (HPCs) and in cholangiocytes but not in normal hepatocytes, has been reported in some hepatocellular carcinomas (HCCs); however, the incidence and relevance of this expression in HCC in Caucasians is not known. Therefore, our aim was to study the occurrence and clinicopathological characteristics of HCC expressing CK7 and/or CK19 in 109 Caucasian patients.

METHODS AND RESULTS

The expression of hepatocellular differentiation markers (Hepar, canalicular polyclonal carcinoembryonic antigen), biliary/progenitor cell markers (CK7, CK19), alpha-fetoprotein (AFP), p53 and beta-catenin in HCC was semiquantitatively assessed by immunohistochemistry. Of 109 HCCs, 78 were CK7-/CK19- (72%), 13 CK7+/CK19- (12%), seven CK7-/CK19+ (6%), 11 CK7+/CK19+ (10%). CK19 expression was significantly associated with elevated serum AFP (400 ng/ml) (P = 0.023), tumour AFP expression (P < 0.0001), presence in serum of anti-hepatitis B core (P = 0.016), less fibrosis in non-neoplastic parenchyma (P = 0.009) and less nuclear beta-catenin expression (P = 0.021). CK7 expression was significantly associated with elevated serum bilirubin (> 2 mg/dl) (P = 0.0005) and less nuclear beta-catenin expression (P = 0.003). HCC expressing CK19 had a higher rate of recurrence (P = 0.009, hazard ratio 12.5, n = 31) after liver transplantation compared with CK19- tumours.

CONCLUSIONS

In our series, 28% of HCCs contained cells expressing CK7 and/or CK19. They potentially derive from HPCs. The higher recurrence rate of CK19+ HCC after transplantation suggests a worse prognosis for these HCCs compared with CK19- HCC.