Update on liver transplantation using cyclosporine

After the introduction of cyclosporine into liver transplantation in 1983, 1-year patient survival more than doubled. Later, with the improved microemulsified formulation of cyclosporine (Neoral) more stable pharmacokinetics were achieved. Today, C(2) monitoring of cyclosporine blood levels allows a more accurate estimation of the area under the concentration-versus-time curve as the single best indicator of cyclosporine exposure. As a consequence, with better control of side effects as well as desired effects the results of cyclosporine in liver transplantation have been further improved. The introduction of mycophenolate mofetil and basiliximab/daclizumab combination therapy has provided new options for the prevention of allograft rejection. The safety profile of individual immunosuppressive regimens comes more into focus since acute allograft rejection may be controlled successfully with competing strategies. As the focus in liver transplantation is shifting toward greatly improved long-term results, late posttransplant mortality with a functioning graft is a major concern. Prevention of long-term complications associated with highly effective immunosuppressants--posttransplant lymphoproliferative disease, cytomegalovirus infection, diabetes, hypertension, and hyperlipidemia-gains importance. Technical advances in living-related and cadaveric split-liver transplantation have lead to increasing use of segmental liver transplantation with the need to consider the effects of immunosuppression on liver regeneration and metabolism. The individualized orchestration of immunosuppression taking into account the underlying liver disease as well as other individual predispositions remains a future challenge.

[Surgical treatment for hilar cholangiocarcinoma (Klatskin's tumor)]

Surgical treatment of hilar bile duct carcinoma remains difficult, which is due to the inadequate possibilities in assessing tumor extent during the preoperative diagnostic procedure as well as intraoperatively. Radical resection with negative histologic margins offers the best chance for long-term survival. The decision regarding the appropriate surgical approach is challenging due to the complexity of tumor localization and neighboring vascular structures. Aggressive resection demands extended liver resection, which is associated with the risk of postoperative liver failure. However, even limited surgery such as hilar resection can be curative and leads to long-term survival in individual cases. The principles of surgical oncology have led to more aggressive procedures, including the combination of liver transplantation and multivisceral resection, and can be performed with calculable morbidity and mortality. Nevertheless, the high risk of tumor recurrence under long-term immunosuppression, the limited availability of donor organs and the excellent results of liver transplantation in non-malignant diseases do not justify this procedure at present. Neoadjuvant radiochemotherapy has failed to demonstrate major benefit. In patients with irresectable tumor or distant metastases palliative measures are aimed at restoring an unobstructed bile flow with endoscopic placement of metal stents. Palliative treatment with additional radio- or photodynamic therapy may be considered in individual cases.

[Living kidney transplantation. A comparison of Scandinavian countries and Germany]

The discussion of compensating for shortages of cadaveric donation with increased living donation often reveals differences between the Scandinavian countries and Germany. Possible adoption of Scandinavian structures to improve the rate of living donations in Germany warrants analysis of the actual differences between these two regions. Close examination reveals that significantly higher rates of living donation are achieved only in Sweden and Norway. In Norway, a frequently postulated negative effect on cadaveric donation due to very high rates of living donation could not be confirmed. In contrast to Germany and as a consequence of Norwegian geography, kidney transplantation has been regarded in Norway as the first-line therapy for endstage renal disease for more than 35 years. Living donation has since been actively pursued and is traditionally the transplantation of first choice. In Germany, living donation is still regarded as the second choice after cadaveric donation, due to legal regulations. Significant improvements in living donation frequencies could be achieved there by adopting the active Norwegian approach to living donor identification.

Successful outcome of acute graft-versus-host disease in a liver allograft recipient by withdrawal of immunosuppression

BACKGROUND

Graft-versus-host disease (GVHD) after liver transplantation is uncommon, and the outcome is almost always fatal. Since 1987, about 30 cases have been described, and patient survival is mostly exceptional.

METHODS

A 29-year-old man underwent retransplantation due to chronic cholestatic syndrome, 5 years after his first liver transplantation. Indication for the first liver transplantation was acute liver failure caused by exsiccosis. After the second transplantation, the patient had an initially uneventful course, developing thrombocytopenia at day 21 followed by skin rash and septic complications. Diagnosis of acute GVHD was made by using serological techniques for HLA-A and HLA-DRB and subsequently by fluorogenic sequence-specific primed polymerase chain reaction. In addition, donor lymphocytes were marked by immunohistochemical methods via biopsies of the skin. Immunosuppressive therapy was withdrawn to allow the patient's own immune system to eliminate donor cells.

RESULTS

By withdrawing the immunosuppressive therapy, clinical and morphological signs of GVHD vanished. The patient is doing well without recurrence 13 months after transplantation.

CONCLUSION

Withdrawal of immunosuppressive therapy is a promising approach in the treatment of acute GVHD to allow the patient's immune system to reconstitute itself, reject offending lymphocytes, and avoid lethal septic complications.

CMV in kidney transplantation: a single center experience over 22 years

Analysis of a historic renal transplant population for risks of developing CMV disease demonstrated a low mortality (0.2%) and morbidity. In our population of 1,959 patients, 411 (21%) developed subclinical CMV infection and 220 (11%) had CMV disease which was severe in 41 (2%). Important factors for infection were baseline immunosuppression, indicating that triple therapy with the proliferation inhibitors, azathioprine and MMF, had significantly higher infection numbers in comparison to dual, CsA-based immunosuppression. The cumulative dose of steroids correlated strongly with an increased number of CMV infections and disease, as did the addition of ALG/ATG or OKT3 for either steroid-resistant rejections or induction therapy. While CMV serology had an impact on infection in cases of seropositive donors to seronegative recipients, seropositive patients, in general, demonstrated increased infection rates most likely due to reactivation of the virus. Prophylaxis had no impact on the incidence of infection but reduced the severity.

[Perfusion parameters in MRI diagnosis of pancreas transplants]

PURPOSE

Evaluation of the role of perfusion parameters in the detection of circulatory disturbance and chronic rejection in patients after pancreas transplantation.

MATERIALS AND METHODS

70 examinations of 39 patients after pancreas transplantation were performed. Using a dynamic gadolinium-enhanced Turbo-FLASH-sequence, we evaluated the perfusion parameters in a group of patients with chronic rejection, with circulatory disturbance, and in a control group with normal organ function.

RESULTS

There were statistically significant differences of the perfusion parameters in patients with chronic rejection and circulatory disturbance compared to the control group.

CONCLUSION

Dynamic MRI can help detect patients with chronic rejection and circulatory disturbance and should therefore be part of the routine follow-up in patients after pancreas transplantation.

ConStruct: a tool for thermodynamic controlled prediction of conserved secondary structure

A tool for prediction of conserved secondary structure of a set of homologous single-stranded RNAs is presented. For each RNA of the set the structure distribution is calculated and stored in a base pair probability matrix. Gaps, resulting from a multiple sequence alignment of the RNA set, are introduced into the individual probability matrices. These 'aligned' probability matrices are summed up to give a consensus probability matrix emphasizing the conserved structural elements of the RNA set. Because the multiple sequence alignment is independent of any structural constraints, such an alignment may result in introduction of gaps into the homologous probability matrices that disrupt a common consensus structure. By use of its graphical user interface the presented tool allows the removal of such misalignments, which are easily recognized, from the individual probability matrices by optimizing the sequence alignment with respect to a structural alignment. From the consensus probability matrix a consensus structure is extracted, which is viewable in three different graphical representations. The functionality of the tool is demonstrated using a small set of U7 RNAs, which are involved in 3'-end processing of histone mRNA precursors. Supplementary Material lists further results obtained. Advantages and drawbacks of the tool are discussed in comparison to several other algorithms.

The hepatitis B virus post-transcriptional regulatory element contains two conserved RNA stem-loops which are required for function

Human Hepatitis B Virus (HBV) RNAs contain a cis -acting sequence, the post-transcriptional regulatory element (HPRE), which facilitates the cytoplasmic localization of intronless transcripts. Our previous studies have shown that the HPRE is composed of at least two independent sub-elements, HPREalpha and HPREbeta, which co-activate a reporter for RNA export in a greater than additive manner. Utilizing deletion, mutation and co-variational analyses, we have identified three regions important for full HPRE activity. The three separate regions of the HPRE function can function independently in a dose-dependent manner when multimerized. Two of these regions contain stem loops, HSLalpha and HSLbeta1, which are necessary for full HPRE function. These structures are conserved throughout the mammalian Hepadnaviruses. Disruption of either stem-loop structure by mutagenesis decreases HPRE function while compensatory mutations restore activity. The location of the stem-loops in the genome reveal that they are present in all of the HBV transcripts. HSLalpha and HSLbeta1 are likely to contain the binding sites for the cellular factor(s) which mediates HPRE function.

Experience with color-coded duplex sonography after combined kidney/pancreas transplantation--preliminary results

The value of color-coded duplex sonography in the assessment of combined kidney and pancreatic transplantations (KTX/PTX) was studied in 9 patients. In normal graft function the median resistive index (RI) was 0.69 (range 0.60-0.80) for the kidney and 0.61 (range 0.55-0.70) for the pancreas. Ten episodes of graft dysfunction (kidney n = 4; pancreas n = 6) were observed. During renal rejection and hemolytic uremic syndrome the RI was above 0.80. In pancreatic rejection the RI exceeded 0.80 while all other causes of pancreatic dysfunction were not associated with changes in the RI. Color-coded duplex sonography may prove to be a reliable noninvasive diagnostic method in the evaluation of the posttransplant course after combined KTX/PTX, in particular in the diagnosis of pancreatic rejection.

Thermodynamic prediction of conserved secondary structure: application to the RRE element of HIV, the tRNA-like element of CMV and the mRNA of prion protein

An algorithm for prediction of conserved secondary structure of single-stranded RNA is presented. For each RNA of a set of homologous RNAs optimal and suboptimal secondary structures are calculated and stored in a base-pair probability matrix. A multiple sequence alignment is performed for the set of RNAs. The resulting gaps are introduced into the individual probability matrices. These homologous probability matrices are summed to give a consensus probability matrix emphasizing the conserved secondary structure elements of the RNA set. Thus the algorithm combines the advantages of thermodynamic structure prediction by energy minimization with the information obtained from phylogenetic alignment of sequences. The algorithm is applied to three examples. The REV-responsive element of HIV, the structure of which is well known from the literature, was chosen to test the algorithm. The second example is the 3' terminal segment of genomic single-stranded RNAs of cucumber mosaic viruses; a structure similar to that of the related brome mosaic virus was expected and was confirmed. The third example is the prion-protein mRNA from different organisms; the structure of this mRNA is not known. By application of the algorithm highly conserved hairpins were found in the prion-protein mRNA.

Genetic requirements for the development of the GVH reaction following small-bowel transplantation

The genetic requirements for the development of graft-versus-host (GVH) disease have been investigated in a model of semiallogenic, heterotopic small-bowel transplantation in the rat. Following semiallogenic MHC-incompatible small-bowel transplantation, all graft recipients showed characteristic signs of GVH disease and died within 14 days. On autopsy the transplanted bowel was normal, while the recipient's bowel was dilated and distended with gas. Histology showed a generalized cell infiltration of the connective tissue with macrophages and lymphocytes. After semiallogenic, RT1.A-incompatible, small-bowel transplantation, the graft recipients developed mild and temporary symptoms of GVH disease between days 25 and 40. Only two of the six animals died, while the remaining animals survived the observation period. Small-bowel transplantation across an isolated RT1.C barrier was unable to induce GVH reaction. These results indicate that the development of GVH disease after small-bowel transplantation is controlled genetically by the MHC. Class II MHC incompatibility is necessary for the induction of an acute and lethal GVH reaction.

Progressive deterioration of endocrine function after intraportal but not kidney subcapsular rat islet transplantation

In inbred streptozocin-induced diabetic rats, the long-term function of different endocrine pancreatic isografts was compared. Isolated islets transplanted into the portal vein showed a progressive deterioration of function over time. In contrast, islets under the kidney capsule sustained a constant long-term function controlling all clinical signs of diabetes. Recipients of kidney subcapsular islets displayed normal growth rate, peripheral serum glucose and insulin levels, and metabolic parameters. However, their functional reserve was markedly reduced as revealed by diminished glucose tolerance and reduced insulin-secreting capacity after an intravenous glucose challenge. Vascularized whole-organ pancreatic grafts with portal venous drainage led to complete normalization of all parameters determined in this study. This study showed that the long-term function of islets transplanted under the kidney capsule is superior compared with islets transplanted into the portal vein.

[Suppression of exocrine secretion does not lead to disruption of endocrine function of pancreas transplants]

The adequate management of the exocrine secretion of vascularized pancreas transplants is still controversial. Basically, the exocrine graft secretion may either be suppressed by obstruction of the pancreatic ducts or preserved by drainage into the recipient's enteric or urinary tract. In a model of isogenic pancreas transplantation in streptozotocin diabetic rats the impact of preserved versus suppressed exocrine secretion on the quality of endocrine graft function was investigated. Preservation of the exocrine secretion was accomplished by pancreaticoduodenal transplantation, while duct ligation was used to suppress the exocrine secretion. Endocrine graft function was monitored by determination of non-fasting blood glucose levels, intravenous glucose tolerance tests, peripheral insulin levels, water and food intake as well as urine and faeces production. Suppression of the exocrine graft secretion induced acinar atrophy, proliferation of pancreatic ducts, interstitial cell infiltration and fragmentation of islets of Langerhans, while drainage of the exocrine graft secretion completely preserved the architecture of the transplant. Despite the fundamental structural changes induces by exocrine suppression no deterioration of endocrine graft function was noted within the observation period of one year. Both techniques were equally effective in ameliorating the diabetic hyperglycemia, hypoinsulinemia, reduced glucose tolerance, polydipsia, polyphagia, polyuria and restored normal growth rate and general health of diabetic pancreas graft recipients. Thus it can be concluded that suppression of the exocrine secretion does not impair the quality of endocrine function of pancreas transplants.

Comparison of graft morphology and endocrine function after vascularized whole-pancrease transplantation in the rat by different surgical techniques

Graft morphology and endocrine function following vascularized pancreas transplantation by different surgical techniques were determined in streptozotocin-diabetic rats. Eight different surgical techniques were studied. Intestinal drainage of exocrine secretion was accomplished by pancreaticoduodenal transplantation or by utilizing only a patch of the donor duodenum for duodenojejunostomy. Following pancreaticoureterostomy and pancreaticocystostomy, the graft's exocrine secretion was drained to the recipient's urinary tract. The exocrine secretion was allowed to drain freely into the recipient's peritoneal cavity following transverse or longitudinal incision of the common bile duct. Exocrine secretion was suppressed either by duct ligation or by retrograde ductal injection of prolamine. Following enteric or urinary exocrine graft drainage, the architecture of both the endocrine and exocrine pancreas was perfectly preserved. Pancreatic juice had remarkably few adverse effects on the recipient's urinary tract. Obstruction of the exocrine secretion induced atrophy of the acinar cells, proliferation of small pancreatic ducts, and a typical fragmentation of the islets of Langerhans. Prolamine was biologically degraded within 28 days. Following free intraperitoneal drainage, spontaneous suppression of the exocrine graft function occurred early after transplantation. Metabolic signs of diabetes mellitus including hypoinsulinemia, hyperglycemia, polydipsia, polyuria, and impaired glucose tolerance were completely normalized by pancreas transplantation irrespective of the surgical technique used. Despite fundamental differences in graft architecture no alteration of endocrine graft function was noted following vascularized pancreas transplantation by different surgical techniques.

Gamma interferon treatment in vivo provokes accumulation of activated monocytes in the venous circulation of rats

Activated monocytes forming intravascular clumps in the veins of most organs appeared in LEW rats after a 3-day intravenous treatment with recombinant rat gamma interferon. Phenotyping in situ and in cytospot preparations of perfusates revealed that the cells coexpressed the rat monocyte/macrophage antigen ED1 and class II MHC molecules. In addition, most cells reacted with a rat CD11b antibody and weakly expressed determinants detected by the W3/13 and Ox22 reagents. Minor fractions of the activated monocytes were positive for rat CD4 and the Ox2 and ED3 determinants. Cell proliferation was assessed by double staining for bromodeoxyuridine (BrdUrd) incorporation and phenotypic markers. Of the ED 1-positive class II-positive cells, 80% were labeled with BrdUrd after 3 days of combined infusion with gamma interferon. Pulse labeling for 30 minutes revealed 8% BrdUrd-positive intravascular ED 1-positive class II-positive monocytes in situ on day 3 of treatment, which contrasted with almost-absent labeling of this cell population in normal LEW rats. It is concluded that interferon not only promotes activation but also intravascular division of monocytes or their immediate precursors. Interestingly, cells of identical morphology and phenotype were observed in the vasculature of rats during lethal graft-versus-host reactions. Activated monocytes may thus contribute to the pathologic consequences of cytokine treatment and severe systemic immune reactions in vivo.

Genetic control of rat heart allograft rejection: effect of different MHC and non-MHC incompatibilities

We investigated the genetic control of heterotopic heart allograft rejection using a family of standard inbred, major histocompatibility complex (MHC)-congenic, and intra-MHC recombinant rat strains. Gene products of the various regions within the rat MHC differed markedly in their capacity to induce rejection. Isolated incompatibility at class I antigens encoded by the RTl.A and RTl.C regions failed to induce rejection within the observation period of 100 days, whereas class II antigens encoded by the RTl.B/D region provoked rapid rejection within 10 days. By comparison of the rejection times of isolated and combined incompatibilities a number of functional interactions could be demonstrated between individual MHC regions which either prolonged or shortened allograft survival. In contrast to rapid rejection of MHC-mismatched heart allografts, differences at non-MHC histocompatibility antigens were associated with graft survival beyond 100 days, although chronic rejection of variable severity was detected histologically. Disparity at non-MHC plus class I antigens, however, provoked acute heart allograft rejection.

[Eosinophilic leukaemia with chloroacetate-esterase-positive granules in a child (author's transl)]

Eosinophilic leukaemia was diagnosed in a 13-year-old boy with clinical and haematological signs of acute leukaemia. A positive naphthol-AS-D-chloroacetate esterase reaction was present in 93% of bone marrow eosinophils. This confirms earlier findings for this sub-group of leukaemia in adultsmcharcot-Leyden's crystals were found in bone marrow, and the eosinophils were further characterized by other cytochemical and electronmicroscopic studies. Only short remission periods were achieved, the patient dying 53 weeks after diagnosis. Attacks of cardiac arrhythmias, thought to be due to adriamycin treatment, were probably related to thrombi in the coronary arteries as a result of disseminated intravascular coagulation. It is thought that eosinophilic leukaemia with a positive naphthol-AS-D-chloroacetate esterase reaction is a variant of acute myeloid leukaemia.

[Clinical, biochemical, morphological and electrophysiological studies of glycogenosis Type II in childhood with double deficiency of enzymes (author's transl)]

The clinical, biochemical, morphological and electrophysiological findings in a 13-month-old child, who died of glycogenosis type II, is presented. In addition to the deficiency of alpha-1,4-glucosidase, which is typical for the disease, a deficiency in hyaluronidase could be detected for the first time in the skeletal and heart muscles and in the liver. On the other hand, the beta-glucoronidase and beta-acetylglucosaminidase activity was highly increased. Deposits of a substance, most probably an acid mucopolysaccharide, which could be differentiated from glycogen by chromography and electronmicroscopy, could be detected in the muscle. A pathogenetical connection with the hyaluronidase defect is imminent.