Gustaf Herlenius

Ten years of international experience with liver transplantation for familial amyloidotic polyneuropathy: results from the Familial Amyloidotic Polyneuropathy World Transplant Registry.

Background. Transthyretin (TTR) amyloidosis is a group of systemic amyloidoses disorders caused by an amyloidogenic TTR variant. Untreated, it slowly leads to severely disabling symptoms that relentlessly progress until the death of the patient. Because the mutant form of TTR is produced mainly in the liver, successful orthotopic liver transplantation (OLT) results in the elimination of the source of the variant TTR molecule and is presently the only known curative treatment. OLT in patients with familial amyloidotic polyneuropathy (FAP) was first performed in 1990 at the Karolinska Institute in Sweden, and because the results were promising other centers took up the procedure. Methods. To gain as great an experience as possible regarding this treatment, the Familial Amyloidotic Polyneuropathy World Transplant Registry (FAPWTR) was initiated in 1995, and this article presents the 10-year registry results. Results. A total of 54 centers in 16 countries have performed OLT for FAP, and today approximately 60 OLTs are performed annually worldwide. During the last decade, a total of 539 patients have undergone 579 OLTs. Patient survival is excellent (overall 5-year patient survival 77%) and comparable to the survival with OLT performed for other chronic liver disorders, but longer follow-up is needed to compare the outcome after OLT with the natural course of the disease. The main cause of death was cardiac related (39%). Conclusions. We believe that the FAPWTR has become a valuable tool that will help to accurately evaluate the potential risks and benefits of OLT in patients with FAP and promote a fruitful collaboration between centers engaged in this field.

Orthotopic liver or multivisceral transplantation as treatment of metastatic neuroendocrine tumors

Liver transplantation can be a therapeutic option for individual patients with neuroendocrine tumors metastatic only to the liver. In this consecutive series of 15 patients (5 multivisceral and 10 orthotopic liver transplantations) with well‐differentiated carcinoids, or endocrine pancreatic tumors, we allowed higher proliferation rate (Ki67 <10%), large tumor burden, and higher age than previous studies. Liver transplantation offered good relief of symptoms, long disease‐free intervals, and potential cure in individual patients. The survival of grafts and patients compared well with transplantation for benign disease. The overall 5‐year survival was 90%. The recurrence‐free survival of both multivisceral and liver transplantation related to the time after transplantation (about 20% at 5 years) despite inclusion of patients with higher risk. In conclusion, the critical prognosticators for long‐term outcome still remain to be defined. The experience with multivisceral transplantation for patients with endocrine tumors of the pancreatic head is still limited. Liver Transpl 13:327–333, 2007.

Liver transplantation for metastatic neuroendocrine tumor disease.

METASTASES from neuroendocrine tumors (NET) of the gastrointestinal tract, carcinoids, and endocrine pancreatic tumors (EPT) can be limited to the liver for long periods and may have slow growth. The symptoms are often related to hormone overproduction and debulking surgery, for example, liver resection, is recommended to achieve tumor remission or symptom palliation. If liver resection is not feasable, hepatectomy and orthotopic liver transplantation (OLT) have been proposed. For EPT where the primary tumor is located in the head of the pancrea it may be advantageous to resect the primary tumor and the liver metastases en bloc and perform a multivisceral transplantation (MVTx).

Practical recommendations for the early use of m‐TOR inhibitors (sirolimus) in renal transplantation

m‐TOR inhibitors (e.g. sirolimus) are well‐tolerated immunosuppressants used in renal transplantation for prophylaxis of organ rejection, and are associated with long‐term graft survival. Early use of sirolimus is often advocated by clinicians, but this may be associated with a number of side‐effects including impaired wound‐healing, lymphoceles and delayed graft function. As transplant clinicians with experience in the use of sirolimus, we believe such side‐effects can be limited by tailored clinical management. We present recommendations based on published literature and our clinical experience. Furthermore, guidance is provided on sirolimus use during surgery, both at transplantation and for subsequent operations.

Recellularization of Acellular Human Small Intestine Using Bone Marrow Stem Cells

We aimed to produce an acellular human tissue scaffold with a view to test the possibility of recellularization with bone marrow stem cells to produce a tissue‐engineered small intestine (TESI). Human small‐bowel specimens (n = 5) were obtained from cadaveric organ donors and treated sequentially with 6% dimethyl sulfoxide in hypotonic buffer, 1% Triton X‐100, and DNase. Each small intestine (SI) piece (6 cm) was recellularized with EPCAM+ and CD133+ allogeneic bone marrow stem cells. Histological and molecular analysis demonstrated that after decellularization, all cellular components and nuclear material were removed. Our analysis also showed that the decellularized human SI tissue retained its histoarchitecture with intact villi and major structural proteins. Protein films of common extracellular matrix constituents (collagen I, laminin, and fibronectin) were found in abundance. Furthermore, several residual angiogenic factors were found in the decellularized SI. Following recellularization, we found viable mucin‐positive goblet cells, CK18+ epithelial cells in villi adjacent to a muscularis mucosa with α‐actin+ smooth muscle cells, and a high repopulation of blood vessels with CD31+ endothelial cells. Our results show that in the future, such a TESI would be ideal for clinical purposes, because it can be derived from the recipients own immunocompatible bone marrow cells, thus avoiding the use of immunosuppression.

Early renal function post-liver transplantation is predictive of progressive chronic kidney disease

Objective. With improvements in long-term results after liver transplantation, chronic kidney disease (CKD) has become a highly relevant problem. The early measurement of the glomerular filtration rate (GFR) can identify those patients who are at risk of developing CKD years after liver transplantation. The aims of this study were to describe the prevalence of CKD 5 years after liver transplantation, to study the correlation between measured GFR early after transplantation and late renal function and to identify patients at risk of developing late CKD after liver transplantation. Material and methods. A total of 152 patients who were at least 5 years post-liver transplantation were studied. Measured GFR with Chromium EDTA or iohexol clearance was followed-up for 5 years (n=152) and 10 years (n=41). Results. The overall decrease in measured GFR was 36% after 5 years and 42% after 10 years. Eight patients (5%) required renal replacement therapy. GFR levels pretransplantation showed a poor correlation with later renal function (at 5 years). The GFR measured at 3 months and 1 year post-transplantation correlated well with measured GFR at 5 years post-transplantation. Multivariate analysis showed that measured GFR of less than 30 ml at 3 months post-transplantation was significantly associated with CKD at 5 years post-transplantation. Conclusions. GFR levels below 30 ml/min/1.73 m2 at 3 months post-liver transplantation are associated with the development of later CKD Stage 4–5 long after liver transplantation. The importance of this finding is the possibility of identifying at an early stage those individuals that may benefit from early implementation of calcineurin sparing or a withdrawal regimen with the goal of preserving long-term renal function.

Improved intestinal preservation using an intraluminal macromolecular solution: evidence from a rat model.

Background. Intestinal preservation injury consists of progressive submucosal edema, with fluid originating both from the lumen and the interstitium. Although vascular flushing aims to control electrolyte shifts in the tissue, the lumen is not addressed, and luminal water and electrolytes enter the tissue during ischemia. Because macromolecular solutions may retain water and electrolytes intraluminally, we investigated whether these solutions administered intraluminally may alleviate preservation injury. Methods. Sprague-Dawley rat intestines were perfused with University of Wisconsin solution. After excision of the intestines, we intraluminally introduced solutions containing polyethylene glycol 3350 with high (125 mEq) or low (65 mEq) sodium before cold preservation. Controls underwent only vascular flush. After 8, 14, or 20 hr of cold storage, the intestines were analyzed for extent of tissue injury, water retention, brush-border maltase, and tight junction proteins zonula occludens-1 and claudin-3. Results. Intraluminal composition changed over time, indicating sodium absorption and potassium secretion. After 8 and 14 hr of cold storage, intestines from the low-sodium group had the best morphology and least edema, followed by the controls. Maltase activity slightly decreased in all groups over time and was not affected by the intraluminal polyethylene glycol solutions. Various degrees of delocalization and degradation of zonula occludens-1 and claudin-3 were recorded within the tight junctions, with the most significant effects in intestines from the high-sodium group. Conclusions. Intraluminal macromolecular solutions may modulate the preservation injury in University of Wisconsin- perfused intestines. Low-sodium solutions administered immediately before preservation may improve preservation injury, but high-sodium solutions may be detrimental.

Isolation and characterization of human primary enterocytes from small intestine using a novel method

Abstract Cell culture studies of enterocytes are important in many fields. However, there are difficulties in obtaining cell lines from adult human intestine, such as microbial contamination of cultures from the tissue samples, short life span of enterocytes, overgrowth of mesenchymal cells, etc. Various model used to obtain adult intestinal cell lines are very complex requiring use of feeder layer or gel matrices. The aim of this study was to establish a novel method for the simple and reproducible isolation of human enterocytes. Enterocytes were isolated from SI samples (n = 5) obtained from cadaveric donors using a mechanical procedure, and separation with immunomagnetic beads coated with anti-EpCAM antibodies. Light and electron microscopy, flow cytometry and immunocytochemistry techniques were used to characterize the isolated cells. Immunohistochemical staining of normal SB biopsies confirmed that the cell cultures maintained an in vivo phenotype as reflected in cytokeratin expression CK18, CK20 and expression of intestine-specific markers such as sucrase isomaltase and maltase glucoamylase. Furthermore, the cells strongly expressed TLR-5, 6, 7, 8 and 10 and several molecules such as CD40, CD86, CD44, ICAM-1 and HLA-DR which are important in triggering cell-mediated immune responses. This novel technique provides a unique in vitro system to study the biology of enterocytes in normal conditions as well as to study inflammatory processes in various small bowel disorders.

Conversion From Calcineurin Inhibitor to Either Mycophenolate Mofetil or Sirolimus Improves Renal Function in Liver Transplant Recipients With Chronic Kidney Disease : Results of a Prospective Randomized Trial

BACKGROUND Chronic kidney disease (CKD) has emerged as a significant cause of morbidity and a risk factor for mortality after orthotopic liver transplantation (OLT). The use of calcineurin inhibitor (CNI)-based immunosuppression is an important etiologic factor for developing CKD. CNI discontinuation or minimization protocols with replacement of the CNI with non-nephrotoxic drugs, such as mycophenolate mofetil (MMF) or sirolimus (SRL), may have the potential to preserve or recover renal function. PATIENTS AND METHODS In this prospective, randomized, single-center study with CNI discontinuation, OLT recipients with CKD (measured glomerular filtration rate [GFRm] 15-45 mL/min/1.73 m(2)) were randomized to either SRL or MMF-based immunosuppression. The main objective was to study the effect of CNI discontinuation on renal function. Secondary aims were to assess the frequency of biopsy-proven acute rejection episodes (BPAR) and adverse events (AE). Renal function was followed with GFRm using 51-Chromium EDTA clearance at baseline, 3 months, and 1 year. Patients were stratified according to baseline GFRm > versus <30 mL/min/1.73 m(2). The 25 patients were enrolled for MMF (n = 13) or SRL (n = 12). The median age at inclusion was 59 years (range, 25-66) and the median number of years after OLT was 4.4 (range, 1-13). Twenty-two patients were followed up for a year; MMF (n = 12) and SRL (n = 10). RESULTS Mean GFRm for the whole cohort (n = 25) was 31+/-8 mL/min/1.73 m(2) at baseline. After 3 months the GFRm (n = 23) increased to 40+/-10 mL/min/1.73 m(2) (P = .0001) and at 1 year 42 +/- 11 mL/min/1.73 m(2) (n = 22). There was not significant difference between the MMF and the SRL study arms. The cohort (n = 8) with baseline GFRm <30 mL showed a 63% (P = .003) increased filtration after 1 year. There was no significant difference in the frequency or severity of AE between the study arms with the exception of oral ulcerations and persistent hypertriglyceridemia in the SRL group. Two deaths occurred, 1 in each study arm, both probably unrelated to the change in immunosuppression. There were no BPAR episodes. CONCLUSION CNI discontinuation and replacement with either MMF or SRL resulted in a significant improvement in renal function even in those patients with severe CKD. The protocol was effective with no acute rejection episodes. The SRL arm showed a higher frequency of oral apthous ulcerations and hypertriglyceridemia. Future studies addressing long-term renal function after CNI discontinuation are needed.

Intraluminal Polyethylene Glycol Stabilizes Tight Junctions and Improves Intestinal Preservation in the Rat

Rapidly progressing mucosal breakdown limits the intestinal preservation time below 10 h. Recent studies indicate that intraluminal solutions containing polyethylene glycol (PEG) alleviate preservation injury of intestines stored in UW‐Viaspan. We investigated whether a low‐sodium PEG solution is beneficial for intestines stored in histidine‐tryptophane‐ketoglutarate (HTK) preservation solution. Rat intestines used as control tissue (group 1) were perfused with HTK, groups 2 and 3 received either a customized PEG‐3350 (group 2) or an electrolyte solution (group 3) intraluminally before cold storage. Tissue injury, brush‐border maltase activity, zonula occludens‐1 (ZO‐1) and claudin‐3 expression in the tight junctions (TJ) were analyzed after 8, 14 and 20 h. We measured epithelial resistance and permeability (Ussing chamber) after 8 and 14 h. Group 2 had superior morphology while maltase activity was similar in all groups. TJ proteins rapidly decreased and decolocalized in groups 1 3; these negative events were delayed in group 2, where colocalization persisted for about 14 h. Intestines in group 2 had higher epithelial resistance and lower permeability than the other groups. These results suggest that a customized PEG solution intraluminally reduces the intestinal preservation injury by improving several major epithelial characteristics without negatively affecting the brush‐border enzymes or promoting edema.