Endoscopic treatment of bile duct complications after orthotopic liver transplantation

AIM

To assess the indications and results of endoscopic retrograde cholangio-pancreatography (ERCP) in patients who have undergone ortotopic liver transplantation (OLT).

METHODS

We reviewed data from 42 consecutive patients who underwent ERCP for biliary complications after OLT over an 8-year period, in particular recording indications and success of the treatment after a mean of 17 months follow-up.

RESULTS

Cholangiograms performed in 33/42 patients (79%) displayed anastomotic strictures in 17 patients (52%), bile duct stones in 8 (24%), both bile duct stones and an anastomotic stricture in 2 (6%), papillary stenosis in 1 (3%), and anastomotic biliary leakage in 1 (3%). In contrast, the contrastogram was normal in four patients (12%). Stone extraction was completed in 9/10 patients (90%) with a mean of 1.2 sessions, while stricture dilation was achieved in 12/19 patients (63%) after a mean of 1.7 sessions, by stent positioning (n = 7), balloon dilation (n = 4), or Soehendra dilator (n = 1). Both biliary leakage and papillary stenosis were cured by ERCP. Only one procedure-related complication -- severe pancreatitis (2.4%) -- was observed and no mortality.

CONCLUSION

ERCP is a safe and effective mode of management of bile duct complications after OLT. It should be attempted before a surgical approach. Better results are obtained for treatment of biliary stones than of anastomotic strictures.

Prognostic Impact of Model for End-Stage Liver Disease Score in Patients Undergoing Liver Transplantation With Suboptimal Livers

BACKGROUND/AIMS

The aim of this retrospective study is to analyze the prognostic impact of Model for End-Stage Liver Disease (MELD) score in patients undergoing liver transplantation (OLT) with suboptimal livers.

METHODS

Between January 2002 and January 2006, 160 adult patients with liver cirrhosis received a whole liver for primary OLT at our institution including 81 with a suboptimal liver (SOL group) versus 79 with an optimal liver (group OL). The definition of suboptimal liver was: one major criterion (age >60 years, steatosis >20%) or at least two minor criteria: sodium >155 mEq/L, Intensive Care Unit stay >7 days, dopamine >10 microg/kg/min, abnormal liver tests, and relevant hemodynamic instability.

RESULTS

Baseline recipients characteristics were comparable in the two study groups. The SOL group had a significantly greater number of early graft deaths (<30 days) than the OL group, while the 3-year Kaplan-Meier patient survivals were similar. Using logistic regression, MELD score was significantly related to patient death only in the SOL group (P = .01), and the receiver operator characteristics curve method identified 17 as the best MELD cutoff with the 3-year survival of 93% versus 85% for MELD < or =7 versus >17, respectively (P > 05). In comparison, it was 94% and 72% in the SOL group (P < .05). Similarly, MELD >17 was significantly associated with early graft death rates only in the SOL group.

CONCLUSION

This study advised surgeons to not use suboptimal livers for patients with advanced MELD scores, thus supporting a donor-recipient matching policy.

Pediatric Liver Transplantation: The University of Padua Experience

OBJECTIVE

The objective of this study was to analyze experience on pediatric liver transplantation (LT) between June 1993 and September 2006, including split liver transplantation (SLT), living donor liver transplantation (LDLT), and auxiliary partial orthotopic liver transplantation (APOLT). Furthermore, hepatocyte transplantation (HT) had a role in one patient with metabolic disease.

METHODS

From November 1990 to September 2006, 657 LTs were performed including 63 pediatric LTs (9.6%) in 57 patients (32 boys and 25 girls). Six were retransplantations (9.5%). Thirty-two patients (57%) were younger than 5 years. The types of graft included the following: 26 whole organs (41%), 32 in situ split organs (51%), 4 reduced-size organs (6%), and 1 graft from a living donor (2%). Two patients received an APOLT, 4 patients received a combined kidney-liver transplantation (CKLT), and 1 patient received HT. Of the 63 pediatric LTs, 16 were behaved to be highly urgent (25%).

RESULTS

Overall 1-, 3-, 5-, and 10-year patient survival rates were 82%, 82%, 78%, and 78%, respectively. Overall 1-, 3-, 5-, and 10-year graft survival rates were 76%, 76%, 72%, and 72%, respectively. In patients younger than 1 year, the 5-year survival rate was 100%. Perioperative mortality was 8.8%. Vascular complications occurred in 4 patients (6.3%). Six children required retransplantation due to primary nonfunction (PNF) in 4 cases (7%) and vascular thrombosis in 2 cases (3.5%).

CONCLUSIONS

Cholestatic liver disease and age younger than 1 year were the best prognostic factors for excellent survival.

A dose finding pharmacokinetic study of the tumor-targeting human L19-IL2 monoclonal antibody-cytokine fusion protein in patients with advanced solid tumors

3057

Background: L19-IL2 is a tumor targeting immunocytokine constituted by a single chain Fragment variable format directed against ED-B domain of fibronectin and the human cytokine interleukin-2 (IL-2). It has striking anticancer activity in preclinical models. We evaluated safety, pharmacokinetic profile (PK) and activity of L19-IL2 in advanced cancer patients. Patients and Methods: Five cohorts of patients with recurrent/refractory solid tumors received a dose escalation intravenous infusion of L19-IL2 (5, 10, 15, 22.5 e 30 Mio IU IL2 equivalent dose) on days 1, 3 and 5 every 21 days. Serum samples for PK assessment, immunophenotyping and assays for detection of human antifusion protein antibodies to L19 (HAFA) were collected at screening and on day 1, 3, 5 and 10 of each cycle. Results: Eighteen solid cancer patients were enrolled from 11/05 to 9/06 (6 colorectal and 3 renal cell cancer (RCC) patients, 3 with melanoma, and 1 neuroendocrine tumor, thymic carcinoma, biliary tract carcinoma, breast cancer, peritoneal mesothelioma and parotid gland carcinoma). Median age was 49 years (range 35–69), 14 patients were male and 4 female. All patients were evaluable for safety and activity. The maximum tolerated dose was determined to be 22.5 Mio IU IL-2 equivalent. Drug-related dose-limiting toxicities at 30 Mio IU L19-IL2 were hypotension requiring vaso-pressor support and acute renal failure. Treatment-related deaths did not occur, and all toxicities were reversible. Five patients achieved stable disease (RCC, n=3; biliary tract carcinoma, n=1; peritoneal mesothelioma, n=1). All other patients progressed. Immunophenotyping disclosed IL2-typical transient activation of T-cell subsets. Very preliminary data showed a weak induction of HAFA at day 10 in 5 patients. These data could not be confirmed by competition ELISA experiments. Conclusions: Up to 22.5 Mio IU IL2 equivalent of L19-IL2 can be safely administered to advanced solid cancer patients in an outpatient setting. Some evidence of clinical activity in patients susceptible to immunomodulatory therapy (RCC) was found. All observed toxicity was mild and reversible. An expanded study at recommended dose in RCC patients is currently ongoing.

[Table: see text]

Characterisation and radioimmunotherapy of L19-SIP, an anti-angiogenic antibody against the extra domain B of fibronectin, in colorectal tumour models

Angiogenesis is a characteristic feature of tumours and other disorders. The human monoclonal antibody L19- SIP targets the extra domain B of fibronectin, a marker of angiogenesis expressed in a range of tumours. The aim of this study was to investigate whole body distribution, tumour localisation and the potential of radioimmunotherapy with the L19-small immunoprotein (SIP) in colorectal tumours. Two colorectal tumour models with highly different morphologies, the SW1222 and LS174T xenografts, were used in this study. Localisation and retention of the L19-SIP antibody at tumour vessels was demonstrated using immunohistochemistry and Cy3-labelled L19-SIP. Whole body biodistribution studies in both tumour models were carried out with ¹²⁵I-labelled L19-SIP. Finally, ¹³¹I-labelled antibody was used to investigate the potential of radioimmunotherapy in SW1222 tumours. Using immunohistochemistry, we confirmed extra domain B expression in the tumour vasculature. Immunofluorescence demonstrated localisation and retention of injected Cy3-labelled L19-SIP at the abluminal side of tumour vessels. Biodistribution studies using a ¹²⁵I-labelled antibody showed selective tumour uptake in both models. Higher recorded values for localisation were found in the SW1222 tumours than in the LS174T (7.9 vs 6.6 %ID g⁻¹), with comparable blood clearance for both models. Based on these results, a radioimmunotherapy study was performed in the SW1222 xenograft using ¹³¹I-Labelled L19-SIP (55.5 MBq), which showed selective tumour uptake, tumour growth inhibition and improved survival. Radio- and fluorescence-labelled L19-SIP showed selective localisation and retention at vessels of two colorectal xenografts. Furthermore, ¹³¹I-L19-SIP shows potential as a novel treatment of colorectal tumours, and provides the foundation to investigate combined therapies in the same tumour models.

Nitric oxide generation is associated with an unbalance of protein tyrosine phosphatases during liver transplantation

Organ dysfunction secondary to ischemia-reperfusion (I/R) injury still represents a major problem in liver transplantation. Apoptosis has been observed in hepatocytes and sinusoidal endothelial cell, following I/R injury and it has been postulated as a contributing factor in ischemia-reperfusion graft dysfunction, involving a complex series of events, as changes of protein tyrosine-kinase phosphorylation. We evaluated hepatic purine metabolites, protein tyrosine phosphatases (PTPs), nitrate plus nitrite levels (NOx), caspase-3 (C-3) activity and DNA fragmentation in the time course of twelve pig orthotopic liver transplantation. Biopsies were taken before explantation (t0), after cold ischemic storage (t1) and 30 min from reperfusion (t2). During the ischemic period we observed a reduction of high energy phosphates and an increase of purine bases; PTP activity was largely increased. At t2 high energy phosphates showed a tendency to increase with respect to t1, with a partial restoration of phosphorylation potential, measured as ATP/ADT ratio. PTP activity was significantly reduced, with a concomitant increase of NOx production and C-3 activity; in a considerable number of cases we observed a sustained DNA fragmentation. We speculate that NOx production could be related to nitrosative stress, which in turn leads to dynamic alteration in PTP balance and cell signalling, regulating the activity of a number of proteins implicated in apoptotic cell death. These findings could be of interest in new potential strategy to prevent and treat I/R injury.

Vascular tumor targeting

The growth of solid tumors is dependent on their capacity to acquire blood supply. Therefore, much effort has been directed towards the development of anti-angiogenic agents which inhibit the process of neovascularization. More recently, it has become apparent that the targeted destruction of the established tumor vasculature represents a complementary avenue for growing therapeutic opportunities. This review provides evidence that vascular tumor targeting is an effective anti-tumor strategy in animal models. It further describes strategies for the identification of putative tumor vascular targets and discusses future prospects for vascular targeting applications in the clinical setting.

Percutaneous radiofrequency thermal ablation for hepatocellular carcinoma

BACKGROUND

Radiofrequency thermal ablation is the first therapeutic option in percutaneous treatment of hepatocellular carcinoma but data on its long-term efficacy and safety are not conclusive.

AIM

This study reports a prospective survey on radiofrequency thermal ablation in north-east Italy.

METHODS

Data were collected on 401 patients with hepatocellular carcinoma (males 301, mean age: 68 years) treated by radiofrequency thermal ablation in 13 centres. Indication to treatment was: single nodule not eligible for surgery in 77% of patients, 2-3 nodes in 18% and multiple lesions in 5%. Mean size was 3 cm (1-8 cm). Treatment response was assessed at 1 month by spiral computerized tomography and then with ultrasound examination and new spiral computerized tomography.

RESULTS

Complete response was obtained in 67% of patients and in 27% response was 75-99%. Complete response raised to 77% in lesions smaller than 3 cm. The morbidity rate was 34%; the mortality was 0.5%, seeding was observed in four patients. Ten patients presented an unexpected rapid disease progression.

CONCLUSION

The above data show that by radiofrequency thermal ablation, complete response can be achieved only in about two-third of the cases, clearly less than expected, and that, beyond seeding, unexpected progression can be observed.

High expression of tenascin-C extra domains, markers of angiogenesis, in human lung cancer

20051

Background: Tumor-associated extracellular matrix molecules are isoforms of proteins with a wide distribution in normal adult tissues, such as fibronectin and tenascin. Large Tenascin-C isoforms are present in almost all normal adult tissues but are upregulated in fetal, regenerating, and neoplastic tissues. In this study we investigated the expression of three tenascin isoforms in tumor tissue samples from lung cancer patients to evaluate the diagnostic and therapeutic value for clinical applications. Methods: In total, 35 corresponding tissue samples (tumor and normal lung tissue of the same patient) have been analyzed by immunohistochemistry using three different human monoclonal antibodies to domains A1 (F16), C (G11) and D (P12). All tumor specimens have been non-small cell lung cancer types. Results: Three isoforms G11, F16 and P12 have exhibited a very intense staining of all types of lung cancer. Almost all samples of squamous cell carcinomas, adenocarcinomas as well as large cell carcinomas have been positively stained. In contrast, none of the corresponding normal lung tissue specimens showed an expression of either tenascin domains. Conclusions: The results show that tenascin-C isoforms are highly expressed around the neovasculature and in the stroma of the majority of non-small cell lung cancers but is undetectable in the normal lung tissue. Therefore these isoforms could represent valuable candidates for the development of antibody based biopharmaceuticals for the treatment of lung cancer.

No significant financial relationships to disclose.

Liver transplant: adenosine metabolism and apoptosis

Apoptosis and necrosis coexist in ischemia-reperfusion (I/R) injury following organ transplant. During experimental liver transplant we evidenced a deep alteration in energy and antioxidant status. The activity of purine catabolic enzymes was also altered. Caspase-3 (C-3), protein tyrosine phosphatase (PTP) showed significative alterations that lead to DNA fragmentation. These findings could be of interest in new potential strategy to prevent and treat I/R injury.

Single-chain antibody and its derivatives directed against vascular endothelial growth factor: application for antiangiogenic gene therapy

Single-chain antibodies (scFv) have an enormous potential for clinical application. However, rapid blood clearance and difficulties in large-scale production of active scFvs have limited the practical use of these antibody fragments. Recently, an anti-vascular endothelial growth factor (VEGF) scFv (scFv V65) was selected in our laboratory from a human antibody phage-display library. This antibody was able to reduce tumor growth in mice by approximately 50%. Here, we employ a gene therapy strategy for sustained in vivo expression of scFv V65 and its derivatives. scFv fusion proteins containing parts of the constant IgG1 region were generated (minibody and scFv V65-Fc) to increase the serum half-life of the scFv V65. Systemic administration of recombinant adenovirus encoding scFv V65 resulted in substantial tumor inhibition. This effect could be improved by multiple virus injections. We found that the efficacy of different scFv V65 formats was dependent on the mode of administration: whereas scFv V65-Fc was the most efficient when expressed locally, scFv V65 was superior when delivered systemically. Our results show that therapeutic levels of scFv V65 can be obtained by systemic injection of recombinant adenoviruses. Therefore, therapeutic gene delivery of scFv is a feasible strategy that overcomes several limitations of conventional antibody therapy.

[Endoscopic approach to biliary stones: experience acquired in a general surgery unit. Comparison of 2 periods]

The outcome of the laparoscopic technique, that in the first years needed to be applied in non complicated situations, imposed a more frequent use of ERCP preoperatively; this procedure was originally confined to a handful of European and American centers, but later spread to almost all large hospitals. Improvements in the techniques and materials have gone side by side with more specific indications and the assessment of complications. The purpose of the present study was to analyze the experience of a General Surgery Unit in terms of acquiring and developing skills in treating biliary stones by ERCP.

Cytotoxic targeting of F9 teratocarcinoma tumours with anti-ED-B fibronectin scFv antibody modified liposomes

We prepared small unilamellar liposomes derivatised with single chain antibody fragments specific for the ED-B domain of B-fibronectin. This extracellular matrix associated protein is expressed around newly forming blood vessels in the vicinity of many types of tumours. The single chain antibody fragments were functionalised by introduction of C-terminal cysteines and linked to liposomes via maleimide groups located at the terminal ends of poly(ethylene glycol) modified phospholipids. The properties of these anti-ED-B single chain antibody fragments-liposomes were analysed in vitro on ED-B fibronectin expressing Caco-2 cells and in vivo by studying their biodistribution and their therapeutic potential in mice bearing subcutanous F9 teratocarcinoma tumours. Radioactively labelled ((114m)Indium) single chain antibody fragments-liposomes accumulated in the tumours at 2-3-fold higher concentrations during the first 2 h after i.v. injection compared to unmodified liposomes. After 6-24 h both liposome types were found in similar amounts (8-10% injected dose g(-1)) in the tumours. Animals treated i.v. with single chain antibody fragments-liposomes containing the new cytotoxic agent 2'-deoxy-5-fluorouridylyl-N(4)-octadecyl-1-beta-D-arabinofuranosylcytosine (30 mg kg(-1) per dose, five times every 24 h) showed a reduction of tumour growth by 62-90% determined on days 5 and 8, respectively, compared to animals receiving control liposomes. Histological analysis revealed a marked reduction of F9 tumour cells and excessive deposition of fibronectin in the extracellular matrix after treatment with single chain antibody fragments-2-dioxy-5-fluorouridylyl-N(4)-octadecyl-1-beta-D-arabinofuranosylcytosine-liposomes. Single chain antibody fragments-liposomes targeted to ED-B fibronectin positive tumours therefore represent a promising and versatile novel drug delivery system for the treatment of tumours.

Antibody-Based targeting of angiogenesis

Angiogenesis-the sprouting of new blood vessels from pre-existing ones-is a characteristic feature of relevant diseases such as cancer, some blinding ocular disorders, rheumatoid arthritis, and psoriasis. This article reviews recent progress in the generation of monoclonal antibodies, which recognize and target new blood vessels in vivo, while sparing mature vessels and healthy tissues. The use of such antibodies as selective "molecular vehicles" is likely to open new important diagnostic and therapeutic opportunities.

Enhancement of the antitumor activity of interleukin-12 by targeted delivery to neovasculature

Interleukin-12 (IL-12) is a heterodimeric cytokine with potent immunostimulatory activity and anti-angiogenic properties. Its clinical applications are limited, however, by severe side-effects. Here we report that an IL-12 fusion protein, consisting of IL-12 fused to a human antibody fragment specific to the oncofetal ED-B domain of fibronectin, markedly enhances the antitumor activity of this cytokine, as demonstrated in a mouse lung-metastasis model and in two models of mice bearing different aggressive murine tumors. The residual small tumor masses seen in the treated mice were infiltrated with lymphocytes, macrophages, and natural killer cells and had elevated interferon gamma (IFN-gamma). These results are of therapeutic relevance as the ED-B domain of fibronectin, a naturally occurring marker of angiogenesis identical in mouse and man, is expressed in the majority of aggressive solid tumors but is not detectable in normal vessels and tissues.