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The proceedings of the second international workshop on reliable networks design and modeling, which was held in Moscow, Oct. 19 and 20, 2010.

Wilson's disease is a hereditary defect in copper excretion leading to the accumulation of copper in the tissues, with subsequent tissue damage. The most serious sequela is that of progressive central nervous system involvement. The use of orthotopic liver transplantation (OLT) has been controversial for those patients with neurological symptoms attributed to Wilson's disease. The aim of this study is to determine the effectiveness of OLT for patients with Wilson's disease, including those with neurological involvement attributed to copper accumulation in the central nervous system. OLT was performed in 45 patients (19 men [42.2%], 26 women [57.8%]) with Wilson's disease between 1971 and 1993 who were followed up for at least 4 years. The age at diagnosis of Wilson's disease ranged from 3 to 41 years (mean, 17.7 +/- 7.4 years). The age at OLT ranged from 8 to 52 years (mean, 22.3 +/- 9.4 years). Nineteen patients (42.2%) were aged younger than 18 years at OLT. The indications for OLT included chronic hepatic failure in 15 patients (33.3%) and fulminant (FHF) or subfulminant hepatic failure in 30 patients (66. 6%). All but 1 of the 19 pediatric patients (94.7%) were in the latter group. Twenty-five patients (55.5%) were receiving D-penicillamine, 9 patients for more than 1 year; none of the patients treated long term presented as FHF. Thirty-three patients (73.3%) survived more than 5 years after OLT. Fourteen patients (31%) died during the posttransplantation period; 7 of the 14 patients (50%) were aged younger than 18 years. Twelve patients died during the first 3 months after OLT of complications of disease and surgery, 10 of whom underwent transplantation for FHF. The other 2 patients died 6 and 9 years after transplantation of infectious problems. Eleven patients (24.4%) required retransplantation because of a primary nonfunctioning graft (n = 6), chronic rejection (n = 4), and hepatic artery thrombosis (n = 1). Seventeen patients (37.7%) presented with neurolog

The aim of our study was to quantitatively assess the impact of hepatic retransplantation on patient and graft survival and resource utilization. We studied patients undergoing hepatic retransplantation among 447 transplant recipients with primary biliary cirrhosis (PBC) and primary sclerosing cholangitis (PSC) at 3 transplantation centers. Cox proportional hazards regression analysis was used for survival analysis. Measures of resource utilization included the duration of hospitalization, length of stay in the intensive care unit, and the duration of transplantation surgery. Forty-six (10.3%) patients received 2 or more grafts during the follow-up period (median, 2.8 years). Patients who underwent retransplantation had a 3.8-fold increase in the risk of death compared with those without retransplantation (P < .01). Retransplantation after an interval of greater than 30 days from the primary graft was associated with a 6.7-fold increase in the risk of death (P < .01). The survival following retransplantations performed 30 days or earlier was similar to primary transplantations. Resource utilization was higher in patients who underwent multiple consecutive transplantations, even after adjustment for the number of grafts during the hospitalization. Among cholestatic liver disease patients, poor survival following hepatic retransplantation is attributed to late retransplantations, namely those performed more than 30 days after the initial transplantation. While efforts must be made to improve the outcome following retransplantation, a more critical evaluation may be warranted for late retransplantation candidates.

The introduction of tacrolimus has shown decreased rates of acute and steroid-resistant rejection after liver transplantation (LTx). The aim of the present study is to examine the long-term efficacy and safety of tacrolimus in primary liver transplant recipients. The first 121 consecutive adults (aged > 16 years) who underwent primary LTx at a single center from August 1989 to February 1990 were followed up until August 1997. The mean follow-up was 93.2 ± 1.2 months (range, 90.5 to 96.5 months). Patient survival, graft survival, rate of rejection, and adverse events were examined. The actual 7- year patient survival rate was 67.8%, and the graft survival rate was 63.6%. Infections, recurrence of disease, de novo malignancies, and cardiovascular events constituted the main causes of graft loss and death in the long term. Graft loss related to acute or chronic rejection was rare. The rate of acute rejection beyond 2 years was approximately 3% per year, and most rejections were steroid responsive. Approximately 70% of the patients received only tacrolimus after 1 year. Four patients developed endstage renal disease, and 2 patients underwent kidney transplantation. Hyperkalemia and hypertension were observed in one third of the patients New-onset insulin-dependent diabetes mellitus was observed in 9% and 13% of the patients at the 1-year and 7-year follow-up, respectively. Seven patients developed de novo malignancies, including two skin malignancies. Six patients developed posttransplantation lymphoproliferative disorder during the entire follow-up period. Actual patient and graft survival at 7 years was excellent, and few adverse events developed after the first year. Graft loss from acute or chronic rejection was rare under tacrolimus, and approximately 70% of the patients were steroid free on tacrolimus monotherapy after the first year after LTx.

Background. Tacrolimus (Tac) and mycophenolate mofetil (MMF) are newly approved immunosuppressive agents. However, the safety and efficacy of the combination of MMF and Tac in primary liver transplantation has not been determined. Methods. An Institutional Review Board-approved, open-label prospective randomized protocol was initiated to study the efficacy and toxicity of Tac and steroids (double-drug therapy) versus Tac, steroids, and MMF (triple-drug therapy) in primary adult liver transplant recipients. Both groups of patients began on the same doses of Tac and steroids. Patients randomized to triple-drug therapy also received 1 g of MMF twice a day. Results. Between August 1995 and January 1997, 200 patients were enrolled, 99 in double-drug therapy and 101 in triple-drug therapy. All patients were followed until May 1997, with a mean follow-up of 12.7 months. During the study period, 28 of 99 patients in double-drug therapy received MMF to control ongoing acute rejection, nephrotoxicity, and/or neurotoxicity. On the other hand, 61 patients in triple-drug therapy discontinued MMF for infection, myelosuppression, and/or gastrointestinal disturbances. By an 'intention-to-treat analysis,' the actuarial 1-year patient survival rate was 85.1% in double-drug therapy and 83.1% in triple-drug therapy (P=0.77). The actuarial 1-year graft survival rate was 80.2% for double-drug therapy and 79.2% for triple-drug therapy (P=0.77). Forty-one patients (41.4%) in double- drug therapy and 32 (31.7%) in triple-drug therapy had at least one episode of rejection, but this was not statistically significant (P=0.15). The mean maintenance dose of corticosteroids was slightly lower in triple-drug compared with double-drug therapy. Conclusion. Patient and graft survival rates were similar in both groups. There was a trend to a lower incidence of rejection, reduced nephrotoxicity, and a lesser amount of maintenance corticosteroids in triple-drug therapy compared with double-drug therapy.

Background: Although tacrolimus-based immunosuppression has made intestinal transplantation feasible, the risk of the requisite chronic high- dose treatment has inhibited the widespread use of these procedures. We have examined our 1990-1997 experience to determine whether immunomodulatory strategies to improve outlook could be added to drug treatment. Study Design: Ninety-eight consecutive patients (59 children, 39 adults) with a panoply of indications received 104 allografts under tacrolimus-based immunosuppression: intestine only (n = 37); liver and intestine (n = 50); or multivisceral (n = 17). Of the last 42 patients, 20 received unmodified adjunct donor bone marrow cells; the other 22 were contemporaneous control patients. Results: With a mean followup of 32 ± 26 months (range, 1-86 months), 12 recipients (3 intestine only, 9 composite grafts) are alive with good nutrition beyond the 5-year milestone. Forty-seven (48%) of the total group survive bearing grafts that provide full (91%) or partial (9%) nutrition. Actuarial patient survival at 1 and 5 years (72% and 48%, respectively) was similar with isolated intestinal and composite graft recipients, but the loss rate of grafts from rejection was highest with intestine alone. The best results were in patients between 2 and 18 years of age (68% at 5 years). Adjunct bone marrow did not significantly affect the incidence of graft rejection, B-cell lymphoma, or the rate or severity of graft-versus-host disease. Conclusions: These results demonstrate that longterm rehabilitation similar to that with the other kinds of organ allografts is achievable with all three kinds of intestinal transplant procedures, that the morbidity and mortality is still too high for their widespread application, and that the liver is significantly but marginally protective of concomitantly engrafted intestine. Although none of the endpoints were markedly altered by donor leukocyte augmentation (and chimerism) with bone marrow, establishment

The outcome of hepatitis C virus (HCV) infection on patient and graft survival after orthotopic liver transplantation (OLT) has been controversial. An earlier experience with a higher dose of tacrolimus (≥0.1 mg/kg/d intravenously and ≥0.2 mg/kg/d orally) was associated with a worse clinical outcome in patients infected with HCV. The clinical outcome of 183 liver transplant recipients with end-stage liver disease (ESLD) secondary to HCV infection (HCV group) was compared with a contemporary cohort of 556 patients with HCV infection who underwent transplantation for nonviral, nonmalignant ESLD (control group). All patients were prospectively screened for anti-HCV antibodies and HCV RNA by reverse-transcriptase polymerase chain reaction. All OLT patients were receiving low-dose tacrolimus immunosuppression. Cumulative patient survival rates for the HCV group were 80% after I year and 75% after 3 years compared with rates of 84% and 78%, respectively, in the control group (P = .452). Primary graft survival rates at the same time intervals for the HCV group and the control group were 72% and 77.5% at 1 year and 67% and 72% at 3 years, respectively (P = .144). The incidence of re-transplantation (re-OLT) in the HCV group and the control group was 12.6% and 10.4%, respectively (P = .42). Chronic HCV infection as an indication for OLT with a lower dose of tacrolimus immunosuppression (≤0.05 mg/kg/d intravenously and ≤0.1 mg/kg/d orally) is associated with a similar patient and graft survival as those without HCV infection.

Background. End-stage liver disease due to hepatitis C virus (HCV) is the most common indication for liver transplantation in U.S. veterans. We investigated the influence of HCV genotypes on the incidence and timing of recurrent HCV hepatitis, survival, infectious morbidity, and response to interferon-α therapy in this unique patient population. Methods. HCV genotype was determined by direct sequencing of the NS5 region of HCV with type-specific primers. Results. Genotype 1a (66%, 32/47) was the predominant genotype. Type 1b was found in 25% (12/47) of patients and type 2b was found in 9% (4/47). His topathologically recurrent HCV hepatitis developed in 53% (25/47) of the patients after transplantation. This group included 45% (14/31) of the patients with type 1a, 67% (8/12) of the patients with type 1b, and 25% (1/4) of the patients with type 2b (P>0.5). The time to recurrence and the severity of HCV recurrence as defined by aminotransferase levels or Knodell scores were not different among the three genotypes. There was a trend toward a higher incidence of major infections in patients with type 1b (75%) versus type 1a (48%) and type 2b (50%) (P=0.11). The response to interferon-α therapy did not differ significantly among the genotypes. Mortality at 5 years was 16% (5/31) in patients with genotype 1a, 42% (5/12) in patients with genotype 1b, and 50% (2/4) in patients with genotype 2b (P=0.06). Conclusions. The incidence, time to recurrence, and response to interferon-α therapy did not differ be tween the various genotypes in our liver transplant recipients. However, there was a trend toward higher infectious morbidity and overall mortality in patients with genotype 1b after transplantation.

To investigate the causes of gastrointestinal bleeding (GIB) and its impact on patient and graft survival after orthotopic liver transplantation (OLTx), the first 1000 consecutive OLTx using tacrolimus were studied. Our patient population consisted of 834 adults. The bleeding episodes of patients with GIB (n=74) were analyzed, and patients without GIB (n=760) were used as controls. The mean age, gender, and United Network for Organ Sharing status were similar in both groups. Endoscopy was done in 73 patients with GIB and yielded a diagnosis in 60 patients (82.2%): 39 with a single, and 21 with multiple GIB episodes. In the remaining 13 patients (17.8%), the bleeding source was not identified. Of 92 GIB episodes with endoscopic diagnoses, ulcers (n=25) were the most common cause of bleeding, followed by enteritis (n=24), portal hypertensive lesions (n=15), Roux-en-Y bleeds, and other miscellaneous events (n=28). The majority (73%) of the GIB episodes occurred during the first postoperative trimester. The patient and graft survival rates were statistically lower in the GIB group compared with the control group. The adjusted relative risk of mortality and graft failure was increased by bleeding. In summary, the cumulative incidence of GIB was 8.9%. Endoscopy identified the source of GIB in most cases. Ulcers were the most common cause of GIB after OLTx. The onset of GIB after OLTx was an indicator of decreased patient and graft survival.

We studied the outcome of 436 patients with primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC) who underwent orthotopic liver transplant (OLT) at three major liver transplant centers. Univariate predictors of outcome included age, Karnofsky score, Child's class, Mayo risk score, United Network for Organ Sharing (UNOS) status, nutritional status, serum albumin, serum bilirubin, international normalized ratio, and the presence of ascites, encephalopathy, renal failure (serum creatinine > 2 mg/dL), and edema refractory to diuretics. Using these predictors, we developed a four variable mathematical prognostic model to help the liver transplant physician predict the following: 1) the amount of intraoperative blood loss; 2) the number of days in the intensive care unit (ICU); and 3) severe complications after surgery. The model uses age, renal failure, Child's class, and United Network for Organ Sharing status. This study is the first to model the outcome of liver transplant in patients with a specific etiology of chronic liver disease (PBC or PSC). The model may be used to help select patients for OLT and to plan the timing of their transplantation.

Transjugular intrahepatic portosystemic shunt (TIPS) is becoming an accepted procedure as a bridge to orthotopic liver transplantation (OLT) in patients with end-stage liver disease (ESLD) and bleeding from portal hypertension. It allows the immediate control of acute bleeding and decreases the risk of recurrent acute bleeding while the patient is awaiting OLT. We review in this report, our experience with 85 patients who underwent a TIPS procedure for gastrointestinal variceal bleeding from September 1991 until April 1994. All patients had liver cirrhosis and all had previous sclerotherapy before TIPS. Child-Pugh score was calculated at enrollment, and all patients were evaluated for possible OLT. Thirteen patients were Child A, 49 were Child B, and 23 were Child C. Fifty-three patients were candidates for OLT, and 32 were not. TIPS was performed urgently in 25 patients. At a median follow-up of 582 days (range, 1 to 1,095), 35 patients underwent transplantation, 21 patients died, and 29 patients are still alive and did not undergo transplantation. Technical complications were observed in 7% of patients and new onset of clinical encephalopathy in 37%. The 30-day mortality rate after TIPS was 13%. Actuarial survival was 60% at 1 and 3 years. Child class C and urgent TIPS were shown to be two independent predictor factors for mortality. TIPS was shown to be a valuable procedure, not only as a bridge to OLT but also as palliation for bleeding from portal hypertension in patients who were not candidates for either surgical shunt or OLT. However, its role in bleeding patients with acceptable liver function needs further investigation.