A comparison of sirolimus vs. calcineurin inhibitor-based immunosuppressive therapies in liver transplantation.

BACKGROUND: Sirolimus is a potent immunosuppressive agent whose role in liver transplantation has not been well-described. AIM: To evaluate the efficacy and side-effects of sirolimus-based immunosuppression in liver transplant patients. METHODS: Retrospective analysis of 185 patients who underwent orthotopic liver transplantation. Patients were divided into three groups: group SA, sirolimus alone (n = 28); group SC, sirolimus with calcineurin inhibitors (n =56) and group CNI, calcineurin inhibitors without sirolimus (n = 101). RESULTS: One-year patient and graft survival rates were 86.5% and 82.1% in group SA, 94.6% and 92.9% in group SC, and 83.2% and 75.2% in group CNI (P = N.S.). The rates of acute cellular rejection at 12 months were comparable among the three groups. At the time of transplantation, serum creatinine levels were significantly higher in group SA, but mean creatinine among the three groups at 1 month was similar. More patients in group SA required dialysis before orthotopic liver transplantation (group SA, 25%; group SC, 9%; group CNI, 5%; P = 0.008), but at 1 year, post-orthotopic liver transplantation dialysis rates were similar. CONCLUSIONS: Sirolimus given alone or in conjunction with calcineurin inhibitors appears to be an effective primary immunosuppressant regimen for orthotopic liver transplantation patients. Further studies to evaluate the efficacy and side-effect profile of sirolimus in liver transplant patients are warranted.

Long-term results of metallic stents for benign biliary strictures.

BACKGROUND: Historically, surgical correction has been the treatment of choice for benign biliary strictures (BBS). Self-expandable metallic stents (MSs) have been useful for inoperable malignant biliary strictures; however, their use for BBS is controversial and their natural history unknown. HYPOTHESIS: To test our hypothesis that MSs provide only short-term benefit, we examined the long-term outcome of MSs for the treatment of BBS. Our goal was to develop a rational approach for treating BBS. DATA EXTRACTION: Between July 1990 and December 1995, 15 patients had MSs placed for BBS and have been followed up for a mean of 86.3 months (range, 55-120 months). The mean age of the patients was 66.6 years and 12 were women. Stents were placed for surgical injury in 5 patients and underlying disease in 10 patients (lithiasis, 7; pancreatitis, 2; and primary sclerosing cholangitis, 1). One or more MSs (Gianturco-Rosch "Z" for 4 patients and Wallstents for 11 patients) were placed by percutaneous, endoscopic, or combined approaches. We considered patients to have a good clinical outcome if the stent remained patent, they required 2 or fewer invasive interventions, and they had no biliary dilation on subsequent imaging. DATA SYNTHESIS: Metallic stents were successfully placed in all 15 patients, and the mean patency rate was 30.6 months (range, 7-120 months). Five patients (33%) had a good clinical result with stent patency from 55 to 120 months. Ten patients (67%) required more than 2 radiologic and/or endoscopic procedures for recurrent cholangitis and/or obstruction (range, 7-120 months). Five of the 10 patients developed complete stent obstruction at 8, 9, 10, 15, and 120 months and underwent surgical removal of the stent and bilioenteric anastomosis. Four of these 5 patients had strictures from surgical injuries. The patient who had surgical removal 10 years after MS placement developed cholangiocarcinoma. CONCLUSIONS: Surgical repair remains the treatment of choice for BBS. Metallic stents should only be considered for poor surgical candidates, intrahepatic biliary strictures, or failed attempts at surgical repair. Most patients with MSs will develop recurrent cholangitis or stent obstruction and require intervention. Chronic inflammation and obstruction may predispose the patient to cholangiocarcinoma.

Metastasis of hepatocellular carcinoma to the right colon manifested by gastrointestinal bleeding.

An 82-year-old black woman with a history of hepatocellular carcinoma presented with gastrointestinal bleeding. Barium enema and fibrocolonoscopy revealed a 4-cm polypoid mass at the level of the ascending colon with evidence of active bleeding. Biopsies of the lesion proved it to be metastatic hepatocellular carcinoma. Exploratory laparotomy revealed no further dissemination of the tumor, and the patient underwent an ileocolectomy. The serosal side of the colonic lesion was free from tumor, and there was no peritoneal implantation, direct extension, or lymph node involvement. This case represents an extremely rare presentation of metastatic hepatocellular carcinoma.

Transarterial chemoembolization is a safe treatment for unresectable hepatic malignancies.

Acute liver failure has been reported as a frequent complication of transarterial chemoembolization (TACE). We prospectively evaluated the adverse effects and biochemical changes of TACE. From 10/95 to 9/96, 35 patients with hepatic malignancies were evaluated for TACE. Fifteen patients (9 male and 6 female) received 23 treatments. Ten of 15 patients had hepatocellular carcinoma, and 5 had metastatic tumors. Treatment exclusion criteria included advanced liver disease, hepatic vascular thrombosis, and severe comorbidity. TACE consisted of intra-arterial infusion of a mixture of doxorubicin, cisplatin, and mitomycin followed by embolization. Clinical symptoms and laboratory studies were monitored following treatment. Technical success was achieved in all patients. Adverse symptoms were transient, and most resolved within 1 week. Changes in hepatic, renal, and hematologic function were temporary and returned to pre-TACE levels by 1 month. None developed acute liver failure. The mean hospital stay was 3 days. Ten of 13 patients had a significant decrease in baseline tumor markers. The actual survival was 93 per cent with a median follow-up of 10 months. TACE can be performed safely in patients with hepatic tumors. The adverse effects can be anticipated and easily managed.

Efficacy of tacrolimus as rescue therapy for chronic rejection in orthotopic liver transplantation: a report of the U.S. Multicenter Liver Study Group.

BACKGROUND: A study was performed by 17 different U.S. liver transplantation centers to determine the safety and efficacy of conversion from cyclosporine to tacrolimus for chronic allograft rejection. METHODS: Ninety-one patients were converted to tacrolimus a mean of 319 days after liver transplantation. The indication for conversion was ongoing chronic rejection confirmed by biochemical and histologic criteria. Patients were followed for a mean of 251 days until the end of the study. RESULTS: Sixty-four patients (70.3%) were alive with their initial hepatic allograft at the conclusion of the study period and were defined as the responder group. Twenty-seven patients (29.7%) failed to respond to treatment, and 20 of them required a second liver graft. The actuarial graft survival for the total patient group was 69.9% and 48.5% at 1 and 2 years, respectively. The actuarial patient survival at 1 and 2 years was 84.4% and 81.2%, respectively. Two significant positive prognostic factors were identified. Patients with a total bilirubin of < or = 10 mg/dl at the time of conversion had a significantly better graft and patient survival than patients converted with a total bilirubin > 10 mg/dl (P=0.00002 and P=0.00125, respectively). The time between liver transplantation and conversion also affected graft and patient survival. Patients converted to tacrolimus < or = 90 days after transplantation had a 1-year actuarial graft and patient survival of 51.9% and 65.9%, respectively, compared with 73.2% and 87.7% for those converted > 90 days after transplantation. The mean total bilirubin level for the responder group was 7.1 mg/dl at the time of conversion and decreased significantly to a mean of 3.4 mg/dl at the end of the study (P=0.0018). Thirteen patients (14.3%) died during the study. Sepsis was the major contributing cause of death in most of these patients. CONCLUSIONS: Our results suggest that conversion to tacrolimus for chronic rejection after orthotopic liver transplantation represents an effective therapeutic option. Conversion to tacrolimus before development of elevated total bilirubin levels showed a significant impact on long-term outcome.

Phase I safety and pharmacokinetic studies of brequinar sodium after single ascending oral doses in stable renal, hepatic, and cardiac allograft recipients.

Brequinar sodium (BQR), a substituted 4-quinoline carboxylic acid, was in clinical development in combination with cyclosporine (CsA) as a potentially effective therapy for the treatment and prophylaxis of rejection in organ transplant patients. This phase I study was performed in stable renal, hepatic, and cardiac transplant patients receiving CsA and prednisone maintenance therapy for immunosuppression. The pharmacokinetic objectives of this study were to characterize the pharmacokinetics of (a) single oral 0.5- to 4-mg/kg doses of BQR when given in combination with CsA and prednisone to stable renal, hepatic, and cardiac transplant patients and (b) steady-state oral doses of CsA, with and without single oral doses of BQR. In all three patient populations, the pharmacokinetics of BQR were characterized by a lower oral clearance (12-19 mL/min) than that seen in previous studies in patients with cancer (approximately 30 mL/min at similar doses) and a long terminal half life (13-18 hrs). This slower oral clearance for BQR could be due either to a drug interaction between BQR and CsA or to altered clearance or metabolic processes in patients with transplants. Steady-state CsA trough levels and the oral clearance of CsA were not affected by BQR coadministration. Among the three transplant populations, the cardiac transplant patients had lower oral clearance values of BQR and of CsA. The cause of this lower clearance is not known. Safety results indicate that BQR was well tolerated by this patient population.

Transjugular intrahepatic portosystemic shunt: efficacy for the treatment of portal hypertension and impact on liver transplantation.

Variceal bleeding (VB) and ascites refractory to diuretics (RA) represent a significant cause of morbidity and mortality in patients with portal hypertension. Transjugular intrahepatic portosystemic shunts (TIPS) have been used effectively in patients with these complications, especially those individuals awaiting orthotopic liver transplantation (OLT). From April 1992 to July 1995, 41 adult patients underwent an attempt at TIPS placement for refractory VB or ascites at Cedars-Sinai Medical Center. Technical success was achieved in 37 of 41 cases (90.3%) with only two technical complications. Immediate control of hemorrhage and significant improvement of ascites was obtained in 91.9% and 83.5% of the patients, respectively. Six patients (16.2%) died within a week of TIPS placement due to uncontrollable ascites and multiorgan failure. Four of 31 patients (12.9%) developed mild to moderate grades of hepatic encephalopathy that was controlled with lactulose. Rebleeding from recurrent portal hypertension was noted in 5 of 31 cases (16.1%). Shunt stenosis or occlusion was seen in 7 of 31 cases (22.6%) at an average of 6.3 months following TIPS placement. Six patients underwent OLT within an average of 87 days after TIPS. These results indicate that TIPS appears to be an effective method for treatment of refractory VB and RA, especially for patients who are poor candidates for a surgical shunt or awaiting OLT. However, TIPS may not be considered a definitive solution for all patients with portal hypertension because of its current rate of shunt occlusion or stenosis.

Enhanced oral cyclosporine absorption with water-soluble vitamin E early after liver transplantation.

We evaluated the effect of Liqui-E, a water-soluble vitamin E preparation, on cyclosporin A (CyA) whole blood concentration in liver transplant recipients, and its impact on the cost of CyA. Patients were 26 liver transplant recipients (19 adults, 7 children) who were unable to achieve and maintain therapeutic CyA whole blood concentrations with the standard recommended oral daily dose in the early post-transplant period. Liqui-E 6.25 IU/kg orally was administered with CyA every 12 hours (median time of starting Liqui-E day 14.5). With Liqui-E, the daily oral CyA requirements (mean +/- SD) were decreased in adults from 22.6 +/- 8.9 to 16.2 +/- 7.3 mg/kg/day (p < 0.001) and in children from 78.6 +/- 34.1 to 53.7 +/- 35.0 mg/kg/day (p < 0.02); intravenous administration of CyA was unnecessary. The CyA trough concentrations (mean +/- SD) before and after Liqui-E were 670 +/- 186 and 1012 +/- 216 ng/ml, respectively, in adults (p < 0.001) and 732 +/- 187 and 1052 +/- 166 ng/ml, respectively, in children (p < 0.01). When given with Liqui-E, the daily cost of CyA decreased by 26% in both adults and children. No clinical or biochemical evidence of Liqui-E toxicity was observed. Thus its administration in the early post-transplantation period can enhance CyA absorption in adults and children who are unable to achieve adequate whole blood concentrations with the usual recommended oral dosages. In addition, a significant cost saving can be realized by coadministration.

Acute liver failure due to lymphoma. A diagnostic concern when considering liver transplantation.

Lymphomatous involvement of the liver may present as acute liver failure but is an absolute contraindication for liver transplantation. Therefore it is imperative to diagnose such patients since survival in this group is poor and recurrence is high. We describe two patients with acute liver failure referred for liver transplantation whose diagnostic testing revealed hepatic lymphoma. These cases underscore the importance of considering lymphoma in the differential diagnosis of acute liver failure prior to liver transplant.

The development of Brequinar as an immunosuppressive drug for transplantation.

The preclinical and clinical characterization of Brequinar sodium has demonstrated the potential for the use of this drug as a component of a polytherapeutic treatment strategy to prevent the rejection of organ grafts. Brequinar, along with several other new immunosuppressive drugs, including Mizorbine, 15-deoxyspergualin, and Mycophenolate mofetil, is an antimetabolite with immunosuppressive activity and toxic side effects that are distinctly different from those of CsA and the newly characterized FK 506. This combination of effective antiproliferative activity exhibited by these newer agents and the well-established effect of CsA on T-lymphocyte activation offers the potential for the development of immunosuppressive regimens that are significantly more effective with fewer side effects for the patient. The concept of synergistic interaction between these two classes of immunosuppressive agents has been tested experimentally and found to be extremely effective for both allograft and xenograft models of graft rejection (Cosenza et al. 1993, 1993a, Stepkowski & Kahan 1993). It remains to be established that a similar synergism will exist for clinical transplantation. The effectiveness of CsA as a primary immunosuppressive agent, however, assures the inclusion of CsA in any polytherapeutic approach to be tested in the near future. New clinical trials designed to prove efficacy for immunosuppressive agents, such as BQR, will use CsA or FK 506 as a primary component of the treatment protocol. The combination of immunosuppressive agents that will eventually be applied in wide clinical use is not clear. While some new immunosuppressive agents have been more extensively tested clinically, BQR exhibits a number of unique features that make this compound particularly attractive for inclusion in new immunosuppressive regimens. The drug is readily soluble in aqueous solutions and can be administered intravenously or orally with equal effectiveness. Brequinar exhibits a high level of bioavailability following oral administration and an extended half-life that permits less frequent administration. While the metabolic byproducts of BQR have not been clearly described, there is good evidence that the parent compound exhibits the majority, if not all, of the immunosuppressive activity. The ability to monitor the parent drug directly or measure the depletion of enzyme products that reflect the activity of the drug are important features of the drug that simplify its use in a clinical setting. Although BQR exhibits important adverse side effects at high doses, the effects of the drug are characteristic of antimetabolites and are therefore predictable, constant, and reversible.(ABSTRACT TRUNCATED AT 400 WORDS)