Not All Cellular Rejections Are the Same: Differences in Early and Late Hepatic Allograft Rejection

T cell-mediated rejection (TCMR) is common after liver transplantation (LT), and it is often thought to have a minimum impact on outcomes. Because alloimmune response changes over time, we investigated the role of the timing of TCMR on patient and allograft survival and examined the risk factors for early and late TCMR. We reviewed protocol liver biopsies for 787 consecutive LT recipients with an 8.6-year follow-up. The incidence of early TCMR (≤6 weeks after LT) was 33.5% with nonalcoholic steatohepatitis patients having the lowest incidence. Younger recipient age (P < 0.01), number of human leukocyte antigen mismatches (P < 0.01), and use of deceased donor allografts (P = 0.01) were associated with increased risk of early TCMR, which had no impact on allograft (hazard ratio [HR], 1.02; 95% CI, 0.79-1.32; P = 0.89) or overall survival (HR, 1.03; 95% CI, 0.78-1.34; P = 0.86). Late TCMR (>6 weeks after LT) was less common (17.7%) and was associated with different risk factors. The majority of late TCMR (56.2%) episodes had no antecedent early TCMR, although moderate-to-severe early TCMR (HR, 2.85; 95% CI, 1.55-5.23; P < 0.01) and steroid resistance (HR, 3.62; 95% CI, 1.87-6.99; P < 0.01) were associated with late TCMR. Late TCMR increased risk of mortality (HR, 1.89; 95% CI, 1.35-2.65; P = 0.001) and graft loss (HR, 1.71; 95% CI, 1.23-2.37; P = 0.001). Thus, these data suggest that the timing and histologic grade of TCMR determine its impact on patient and allograft survival. Early mild TCMR episodes after LT do not adversely impact patient or allograft survival provided that they are adequately treated. The occurrence of late TCMR carries deleterious effects with increased longterm risk of graft loss and decreased survival. Patients with moderate-to-severe early TCMR are at an increased risk for late TCMR and warrant closer clinical follow-up.

Hepatocellular Carcinoma Is the Most Common Indication for Liver Transplantation and Placement on the Waitlist in the United States

BACKGROUND & AIMS

Management strategies for patients with hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC) have changed, along with liver allocation policies based on model for end-stage liver disease score. We investigated etiologic-specific trends in liver transplantation in the United States during different time periods.

METHODS

We performed a retrospective study, using the United Network for Organ Sharing/Organ Procurement and Transplantation Network registry data, to identify all adult patients registered for liver transplantation in the United States from January 1, 2004, through December 31, 2015. For subjects listed with multiple diagnoses, HCC was considered the primary listing diagnosis. To determine whether availability of direct-acting antiviral agents, which began in 2011, affected pretransplant (death or drop-out) and post-transplant outcomes for patients with HCV infection, we compared data from the time periods of 2004 to 2010 and 2011 to 2014. We used competing-risk analysis to compare differences in end points between these periods. Differences between periods in pretransplantation and post-transplantation outcomes were estimated using Kaplan-Maier analysis and compared using the log-rank test. Associations between year of listing and pre-liver transplant outcome, and year of liver transplant and survival after transplant, were examined using the log-rank test. Proportional hazard regression was used to evaluate the reliability of the time period effect with potential confounders.

RESULTS

Among 109,018 registrants, 18.5% were registered for liver transplantation because of HCC. In 2015, HCC was the leading diagnosis among registrants (23.9% of registrations) and recipients (27.2% of recipients). Between 2004 and 2015, the ratio of registrants with vs without HCC increased 5.6-fold for patients with HCV infection, 1.9-fold for patients with hepatitis B virus (HBV) infection, 2.7-fold for patients with alcohol abuse, and 10.2-fold for patients with nonalcoholic steatohepatitis. After adjusting for covariates, we associated the period of 2011 to 2014 with a decreased probability that HCC registrants would undergo liver transplantation (hazard ratio [HR], 0.62; P < .0001). The period of 2011 to 2014 also was associated with a decreased probability of drop-out owing to deterioration or death from HCV-induced (HR, 0.90; P = .0003), HBV-induced (HR, 0.71; P = .002), or alcohol-induced (HR, 0.90; P = .01) liver disease, and an increased probability of delisting as a result of clinical improvement in patients with HCV infection (HR, 3.4; P < .0001), HBV infection (HR, 2.3; P = .004), or alcohol abuse (HR, 2.2; P < .0001). The period of 2011 to 2014 was associated with a decreased risk of graft loss or death, with the largest effect seen in HCV-infected recipients (HR, 0.76; P < .0001).

CONCLUSIONS

HCC was the leading indication for liver transplantation in the United States in 2015. Despite this, the probability of liver transplantation decreased the most in registrants with HCC. Pretransplantation and post-transplantation outcomes have improved, particularly in patients with HCV infection.

Factors Influencing Surveillance for Hepatocellular Carcinoma in Patients with Liver Cirrhosis

OBJECTIVE

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related mortality worldwide, and a rising cause of cancer mortality in the U.S. Liver cirrhosis is the major risk factor for HCC. Surveillance of persons with cirrhosis facilitates early detection and improves outcomes. We assessed the surveillance rate for HCC within a major academic health system and identified factors influencing surveillance.

PATIENTS AND METHODS

We examined the surveillance rate for HCC using liver ultrasound, CT, or MRI, and factors influencing surveillance in a cohort of 369 Minnesota residents with cirrhosis seen at the Mayo Clinic between 2007 and 2009.

RESULTS

Ninety-three percent of cirrhosis patients received at least one surveillance study, but only 14% received the recommended uninterrupted semiannual surveillance. Thirty percent received ≥75% of recommended surveillance, and 59% received ≥50% of recommended surveillance. Factors increasing surveillance included gastroenterology or hepatology specialist visits (p < 0.0001), advanced liver disease as assessed by hepatic encephalopathy (p = 0.0008), and comorbid illness as assessed by diabetes mellitus (p = 0.02). Age, sex, race, residence, cirrhosis etiology, or number of primary care visits did not significantly affect the rate of surveillance.

CONCLUSIONS

While the rate of surveillance in a major academic health system was higher than reported in other studies, surveillance was heavily dependent on visits to a subspecialist. This suggests a major and urgent national need to improve identification of individuals at risk for HCC in the primary care setting and the initiation and maintenance of surveillance by primary care practitioners.

Primary biliary cirrhosis has high wait-list mortality among patients listed for liver transplantation

Patients with primary sclerosing cholangitis (PSC) have frequent episodes of cholangitis with potential for high mortality while waiting for liver transplantation. However, data on wait-list mortality specific to liver disease etiology are limited. Using United Network for Organ Sharing (UNOS) database (2002-2013), of 81 592 listed patients, 11 284 (13.8%) died while waiting for transplant. Primary biliary cirrhosis (PBC) patients (N = 3491) compared to PSC (N = 4905) differed with age (56 vs. 47 years), female gender (88% vs. 33%), black race (6% vs. 13%), and BMI (25 vs. 27), P < 0.0001 for all. A total of 993 (11.8%) patients died while waiting for the transplant list. Using competing risk analysis controlling for baseline recipient factors and accounting for receipt of liver transplantation (LT), PBC compared to patients with PSC had higher overall and 3-month wait-list mortality (21.6% vs. 12.7% and 5.0% vs. 2.9%, respectively, Gray's test P < 0.001), [1.25 (1.07-1.47)]. Repeat analysis including all etiologies showed higher wait-list mortality for PBC compared to most etiologies, except for patients listed for diagnosis of alcoholic liver disease (ALD) + hepatitis C virus (HCV). Patients with PBC have high mortality while waiting for liver transplantation. These novel findings suggest that patients with PBC listed for LT may be considered for model for end-stage disease (MELD) exception points.

Embolization of portosystemic shunts for treatment of medically refractory hepatic encephalopathy

Treatment options for refractory hepatic encephalopathy (HE) are limited. Patients who fail medical management may harbor large portosystemic shunts (PSSs) which are possible therapeutic targets. This study aims to describe patient selection, effectiveness, and safety of percutaneous PSS embolization in those with medically refractory HE. A retrospective evaluation of consecutive adult patients with medically refractory HE referred for PSS embolization at a tertiary center was performed (2003-2015). Patient data collected included the type of HE, medications, Model for End-Stage Liver Disease (MELD) score, shunt type, embolization approach, and materials used. Outcomes of interest were immediate (7 days), intermediate (1-4 months), and longer-term (6-12 months) effectiveness and periprocedural safety. Effectiveness was determined based on changes in hospitalization frequency, HE medications, and symptoms. Twenty-five patients with large PSS were evaluated for shunt embolization. Five were excluded due to high MELD scores (n = 1), comorbid conditions (n = 1), or technical considerations (n = 3). Of 20 patients who underwent embolization, 13 had persistent and 7 had recurrent HE; 100% (20/20) achieved immediate improvement. Durable benefit was achieved in 100% (18/18) and 92% (11/12) at 1-4 and 6-12 months, respectively. The majority (67%; 8/12) were free from HE-related hospitalizations over 1 year; 10% developed procedural complications, and all resolved. Six developed new or worsening ascites. In conclusion, PSS embolization is a safe and effective treatment strategy that should be considered for select patients with medically refractory HE. Liver Transplantation 22 723-731 2016 AASLD.

Impact of fibrosis progression on clinical outcome in patients treated for post-transplant hepatitis C recurrence

BACKGROUND & AIMS

Patients who achieve sustained virological response (SVR) following the treatment of post-liver transplant (LT) recurrence of hepatitis C virus (HCV) infection have improved outcomes. The full impact of eradication of HCV on allograft histology is, however, not clearly known.

METHODS

We studied allograft histology in protocol-based paired liver biopsies in consecutive LT recipients who underwent post-LT treatment of recurrence of HCV.

RESULTS

A total of 116 patients were treated with interferon-based therapy for recurrent HCV. Paired pre-treatment baseline biopsies and post-treatment biopsies were available in 83.2% of patients. SVR was achieved in 37.9% of patients. Among the patients who achieved SVR, 20.5% had progression of fibrosis on post-treatment biopsies vs. 65.5% of patients with non-response/relapse (P < 0.001). The impact of virological response on fibrosis progression was sustained and a similar outcome was observed in the subset of patients who had 4-5 year post-treatment biopsies available. In the SVR group, 12.8% progressed to fibrosis stage ≥3 on post-treatment biopsies vs. 37.9% in the non-response/relapse group (P = 0.001). The 5-year survival in patients with progression of fibrosis 86% vs. 98% among patients who had improvement/stable fibrosis [P = 0.003; HR 3.8 (1.2-11.8)]. A small subset of patients who achieve SVR unfortunately still experience progression of fibrosis, most commonly associated with plasma cell hepatitis.

CONCLUSIONS

In post-transplant patients treated for HCV, SVR is associated with improved graft survival and also with sustained and significant improvement in histological outcome. Importantly, progression of fibrosis still occurred in a small subset of patients who achieved SVR.

Evolving trends in liver transplantation: listing and liver donor allocation

The success of liver transplantation in the past three decades as a life-saving procedure for patients with end-stage liver disease has led to the ever-increasing disparity between the demands for liver transplantation and the supply of donor liver organs. Donor allocation and distribution remains a challenge and a moral issue as to how these organs can be equitably distributed. This article reviews the evolution of the liver allocation policy and discusses in detail the challenges clinicians face today in this area of medicine.

De novo sirolimus and reduced-dose tacrolimus versus standard-dose tacrolimus after liver transplantation: the 2000-2003 phase II prospective randomized trial

We studied whether the use of sirolimus with reduced-dose tacrolimus, as compared to standard-dose tacrolimus, after liver transplantation is safe, tolerated and efficacious. In an international multicenter, open-label, active-controlled randomized trial (2000-2003), adult primary liver transplant recipients (n=222) were randomly assigned immediately after transplantation to conventional-dose tacrolimus (trough: 7-15 ng/mL) or sirolimus (loading dose: 15 mg, initial dose: 5 mg titrated to a trough of 4-11 ng/mL) and reduced-dose tacrolimus (trough: 3-7 ng/mL). The study was terminated after 21 months due to imbalance in adverse events. The 24-month cumulative incidence of graft loss (26.4% vs. 12.5%, p=0.009) and patient death (20% vs. 8%, p=0.010) was higher in subjects receiving sirolimus. A numerically higher rate of hepatic artery thrombosis/portal vein thrombosis was observed in the sirolimus arm (8% vs. 3%, p=0.065). The incidence of sepsis was higher in the sirolimus arm (20.4% vs. 7.2%, p=0.006). Rates of acute cellular rejection were similar between the two groups. Early use of sirolimus using a loading dose followed by maintenance doses and reduced-dose tacrolimus in de novo liver transplant recipients is associated with higher rates of graft loss, death and sepsis when compared to the use of conventional-dose tacrolimus alone.

Hepatopulmonary syndrome: favorable outcomes in the MELD exception era

Hepatopulmonary syndrome (HPS) is a pulmonary vascular disorder occurring as a consequence of advanced liver disease, characterized by hypoxemia due to intrapulmonary vascular dilatations. HPS independently increases mortality, regardless of the cause or severity of liver disease. Liver transplantation (LT) improves survival in HPS. We present the largest consecutive series of HPS patients specifically addressing long-term survival relative to the degree of hypoxemia and the era in which LT was conducted. We evaluated 106 HPS patients at the Mayo Clinic from 1986 through 2010. Survival was assessed using Kaplan-Meier methodology. LT was accomplished in 49 HPS patients. Post-LT survival (1, 3, 5, and 10 years) did not differ between groups based on baseline partial pressure of arterial oxygen (PaO2 ) obtained at the time of HPS diagnosis. Improvements in overall survival at 1, 3, and 5 years post-LT in those HPS patients transplanted after January 1 2002 (n = 28) (92%, 88%, and 88%, respectively) as compared with those transplanted prior to that time (n = 21) (71%, 67%, and 67%, respectively) did not reach statistical significance (5-year P = 0.09). Model for Endstage Liver Disease (MELD) exception to facilitate LT was granted to 21 patients since January 1 2002 with post-LT survival of 19/21 patients and one wait-list death.

CONCLUSION

Long-term outcome after LT in HPS is favorable, with a trend towards improved survival in the MELD exception era since 2002 as compared to earlier HPS transplants. Survival after LT was not associated with PaO2 levels at the time of HPS diagnosis. (HEPATOLOGY 2012).

Evolving frequency and outcomes of liver transplantation based on etiology of liver disease

BACKGROUND

In the background of availability of better treatments for specific liver diseases and listing of nonalcoholic steatohepatitis (NASH) as an etiology for liver transplantation (LT), data are unclear on the impact of disease etiology on the frequency of LT and liver posttransplantation outcomes.

METHODS

The United Network for Organ Sharing database (1994-2009) was queried for adults receiving first LT for primary biliary cirrhosis (PBC; n=3052), primary sclerosing cholangitis (PSC; n=3854), hepatitis C virus (HCV; n=15,147), alcoholic cirrhosis (AC; n=8940), HCV+alcohol (n=6066), NASH (n=1368), cryptogenic cirrhosis (CC; n=5856), hepatitis B virus (HBV; n=1816), and hepatocellular carcinoma (HCC; n=8588). Graft and patient survival were compared and Cox models were built to determine independent prediction of outcomes by disease etiology.

RESULTS

The frequency of LT increased for NASH, HCC, and HCV+alcohol, remained stable for AC, and decreased for PBC, PSC, HCV, CC, and HBV. The proportion of simultaneous liver-kidney transplants increased from approximately 3% in 2001 to 10% in 2009. Compared with PBC, 5-year graft and patient survival were (a) similar for PSC, NASH, and HBV (80-85%), (b) poorer for AC and CC (hazard ratio, 1-1.5), and (c) worst for HCV, HCV+alcohol, and HCC (hazard ratio, 1.5-2.4). Five-year outcomes for HCV-associated HCC were poorer compared with HCC due to other etiologies.

CONCLUSIONS

LT performed for NASH and HCC are increasing. Potent treatment options resulted in a decrease in number of transplants for HBV, HCV, and PBC. Better treatment modalities for HCV are expected to further reduce the number of LT for HCV. Excellent posttransplantation outcomes for NASH and AC are encouraging, resulting in wider acceptance of transplants for these etiologies.

Combined liver transplantation and gastric sleeve resection for patients with medically complicated obesity and end-stage liver disease

Obesity is increasingly common before and after liver transplantation (LT), yet optimal management remains unclear. Our aim was to analyze the effectiveness of a multidisciplinary protocol for obese patients requiring LT, including a noninvasive pretransplant weight loss program, and a combined LT plus sleeve gastrectomy (SG) for obese patients who failed to lose weight prior to LT. Since 2006, all patients referred LT with a BMI > 35 were enrolled. There were 37 patients who achieved weight loss and underwent LT alone, and 7 who underwent LT combined with SG. In those who received LT alone, weight gain to BMI > 35 was seen in 21/34, post-LT diabetes (DM) in 12/34, steatosis in 7/34, with 3 deaths plus 3 grafts losses. In patients undergoing the combined procedure, there were no deaths or graft losses. One patient developed a leak from the gastric staple line, and one had excess weight loss. No patients developed post-LT DM or steatosis, and all had substantial weight loss (mean BMI = 29). Noninvasive pretransplant weight loss was achieved by a majority, though weight gain post-LT was common. Combined LT plus SG resulted in effective weight loss and was associated with fewer post-LT metabolic complications. Long-term follow-up is needed.

Immunomodulating therapy in liver transplantation: principles and practice

Liver transplantation has enjoyed dramatic success as a treatment option for patients suffering from chronic end-stage liver diseases. It also serves as a definitive treatment for certain genetic conditions such as familial amyloidosis and primary oxalosis, and as a potential curative therapy in selected cases of primary liver cancer. Currently, over 50,000 patients are alive with functioning liver transplants. Liver transplantation owes its success to advances in surgical technique, improvements in anesthesia and critical care, and advances in treatment of post-transplant complications including improved therapies for cytomegalovirus infections. But perhaps the most important advances in liver transplantation arise in the context of improvements in our understanding of the molecular biology of transplant immunology and the development of new agents that allow for manipulation of immunological signaling pathways. These improvements in immunosuppressive therapy have dramatically increased both graft and patient survival.

Anti-tumour necrosis factor treatment of inflammatory bowel disease in liver transplant recipients

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease can sometimes relapse and be refractory to standard treatment following orthotopic liver transplantation (OLT) despite post-transplantation immunosuppressive therapy.

AIM

To evaluate the efficacy and safety of anti-tumour necrosis factor (anti-TNF) agents for the management of IBD following OLT.

METHODS

We reviewed the records of patients with a diagnosis of IBD who underwent OLT at Mayo Clinic Rochester between 1985 and 2009. Patients were included if they had received anti-TNF therapy post-OLT. Clinical response was defined as a physician's assessment of improvement after 12 weeks of anti-TNF usage, and mucosal healing was defined as the absence of ulcerations on follow-up endoscopy.

RESULTS

The median age of the eight study patients was 42.0 years and 37.5% were female patients. All had been diagnosed with IBD prior to OLT (UC in three and Crohn's disease in five). Indication for OLT was cirrhotic stage primary sclerosing cholangitis (PSC), and three concomitantly had cholangiocarcinoma. Clinical response was demonstrated in seven of eight patients (87.5%) and mucosal healing was demonstrated in three of seven (42.9%). Four infections (oral candidiasis, Clostridium difficile colitis, bacterial pneumonia and cryptosporidiosis) in three patients were reported. One patient developed an Epstein-Barr virus-positive post-transplant lympho-proliferative disorder. One death occurred due to complications from recurrent PSC.

CONCLUSIONS

Starting Anti-TNF therapy following orthotopic liver transplantation appears to be a potential option for inflammatory bowel disease management. Additional studies are needed, however, to confirm these findings and to further assess risks associated with this treatment strategy.

Frequency, clinical presentation, and outcomes of drug-induced liver injury after liver transplantation

Drug-induced liver injury (DILI) is increasingly being recognized as a common cause of acute hepatitis. The clinical impact of DILI after liver transplantation (LT) is not known. The aim of this study was to describe the frequency, clinical presentation, and outcomes of DILI in LT recipients. LT recipients with possible DILI were identified with electronic pathology records and clinical note database retrieval tools. Diagnostic criteria were applied to identify cases of DILI. Twenty-nine of 1689 LT recipients (1.7%) were identified with DILI. The mean age was 52 years, and 52% were women. The major indications for LT were primary sclerosing cholangitis (28%), cholangiocarcinoma (14%), and hepatocellular carcinoma (14%). The severity of DILI was mild or moderate in 92% of the cases. Nausea or diarrhea (31%), jaundice (24%), and pruritus (10%) were the most common symptoms at the time of diagnosis. The mean biochemistry values were as follows: alanine aminotransferase, 204 ± 263 U/L; aspartate aminotransferase, 108 ± 237 U/L; alkaline phosphatase, 469 ± 689 U/L; and total bilirubin, 1.9 ± 10.3 mg/dL. The median duration of medication use until the diagnosis of DILI was 57 days, and the major agent classes were antibiotics (48%), immunosuppressive agents (14%), and antihyperlipidemic drugs (7%). Trimethoprim-sulfamethoxazole was the most common implicated agent (n = 11). Serum liver enzymes improved within a median time of 34 days (range = 5-246 days) after drug withdrawal. Hepatic retransplantation or death did not occur. Among the 50 cases with possible DILI explained by other causes, 13 individuals (26%) had no alternative diagnosis despite histological findings compatible with DILI. In conclusion, DILI is a rare yet underrecognized event among LT recipients. The majority of cases are not clinically severe, and they resolve after drug cessation without hepatic retransplantation or death.

The use of sirolimus should be restricted in liver transplantation

Sirolimus and mTOR inhibitors are important additions to the therapeutic armamentarium to prevent allograft rejection, but their role in liver transplantation is evolving. De novo use of Sirolimus in the early post-transplant period has undoubtedly been influenced by the high incidence of hepatic artery thrombosis and decreased patient and graft survival leading to a black box warning. The jury remains undecided on the role of conversion from CNIs to mTOR inhibitors in those developing renal insufficiency and it must be noted that a second warning was issued by the FDA because of decreased survival in those conversion studies. Finally, the anti-atherogenic, antiviral, and anti-neoplastic effects associated with Sirolimus, which might favor their use in certain liver transplant patients, need further evaluation before firm recommendations can be made.

Present state of immunosuppressive therapy in liver transplant recipients

1. Our increasing understanding of the signaling pathways and cellular interactions in transplant immunobiology has facilitated targeted strategies using novel immunosuppressive agents. 2. The pattern of immunosuppressive drug use in the United States continues to change, and the changes include the use of antibody induction therapy and the agents used in maintenance therapy. 3. The driving forces behind the development of new immunosuppressive regimens are the long-term complications of current immunosuppressive regimens (particularly renal dysfunction and metabolic disturbances).

Use of sirolimus in liver transplant recipients with renal insufficiency: a systematic review and meta-analysis

Sirolimus is used in patients with renal insufficiency after liver transplantation (LT) and especially in those with calcineurin inhibitor (CNI)-associated nephrotoxicity. We conducted a systematic review of all randomized controlled trials and observational studies to test the hypothesis that the use of sirolimus is associated with an improvement in renal function at 1 year in LT recipients with renal insufficiency [glomerular filtration rate (GFR) < 60 mL/minute or creatinine level ≥ 1.5 mg/dL]. We performed a search of all major databases, conference proceedings, and relevant journals through December 2009 and contacted content experts, corresponding authors, and the pharmaceutical manufacturer. A random effects model was used to determine the pooled estimate of the change in renal function and pooled risk estimates of adverse events that may be associated with sirolimus-based therapy at 1 year. Eleven studies (three randomized controlled trials and eight observational studies) met the final inclusion criteria. A nonsignificant improvement of 3.38 mL/minute [95% confidence interval (CI) = -2.93 to 9.69] was observed in methodologically sound observational studies and controlled trials reporting the primary outcome. In controlled trials, baseline GFR >50 mL/min sirolimus use was associated with an improvement of 10.35 mL/minute (95% CI = 3.98-16.77) in GFR or creatinine clearance. Sirolimus was not significantly associated with death [relative risk (RR) = 1.12, 95% CI = 0.66-1.88] or graft failure (RR = 0.80, 95% CI = 0.45-1.41), although reporting was incomplete. It was associated with a statistically significant risk of infection (RR = 2.47, 95% CI = 1.14-5.36), rash (RR = 7.57, 95% CI = 1.75-32.70), ulcers (RR = 7.44, 95% CI = 2.03-27.28), and discontinuation of therapy (RR = 3.61, 95% CI = 1.32-9.89).

CONCLUSION

Conversion to sirolimus from CNIs is associated with a nonsignificant improvement in renal function in LT recipients with renal insufficiency, although the results are limited by heterogeneity, a risk of bias, and a lack of standardized reporting.

Safety and efficacy of ambrisentan for the treatment of portopulmonary hypertension

BACKGROUND

Ambrisentan is a selective endothelin-receptor antagonist that is approved by the US Food and Drug Administration for the treatment of pulmonary arterial hypertension. We describe hemodynamic responses and clinical outcomes of patients with portopulmonary hypertension (POPH) treated with ambrisentan.

METHODS

In this observational study, we prospectively identified and followed consecutive adult patients with POPH who received monotherapy with ambrisentan ≤ 10 mg daily from January 2007 until December 2009. Liver enzymes were assessed monthly. Pulmonary hemodynamic responses were assessed using echocardiograms and right-sided heart catheterizations.

RESULTS

We identified 13 patients (seven men) with POPH and began monotherapy with ambrisentan. The median age was 57 (interquartile range [IQR], 52-60). Patients were followed for a median of 613 days (IQR, 385-1,011). The median model for end-stage liver disease score was 10 (IQR, 8.5-15); eight patients had Child-Turcotte-Pugh A classification. Median time on ambrisentan therapy was 390 days (IQR, 363-611). Two patients died, one of advanced hepatocellular carcinoma and one of septic shock following pneumonia. The mean pulmonary artery pressure decreased from a baseline median of 58 mm Hg (IQR, 37-63) to 41 mm Hg (IQR, 27-48) (P = .004). The pulmonary vascular resistance median was reduced from 445 dynes/s/cm(5) (IQR, 329-834) to 174 dynes/s/cm(5) (IQR, 121-361) (P = .008). There was no difference in the longitudinal analysis of liver function tests (aspartate aminotransferase, alanine aminotransferase, total bilirubin, and international normalized ratio) after 12 months of therapy. One patient underwent successful liver transplantation and normalized pulmonary hemodynamic responses after transplantation.

CONCLUSIONS

In this small cohort of patients with moderate to severe pulmonary hypertension in the setting of POPH, we have shown that ambrisentan monotherapy can significantly improve pulmonary hemodynamic responses without adverse effect on hepatic function.

Recurrent primary biliary cirrhosis after liver transplantation

Recurrent primary biliary cirrhosis (PBC) is an important clinical outcome after liver transplantation (LT) in selected patients. Prevalence rates for recurrent PBC (rPBC) reported by individual LT programs range between 9% and 35%. The diagnostic hallmark of rPBC is histologic identification of granulomatous changes. Clinical and biochemical features are frequently absent with rPBC and cannot be used alone for diagnostic purposes. Some of the risk factors of rPBC may include recipient factors such as age, gender, HLA status and immunosuppression, as well as donor factors such as age, gender and ischemic time, although controversy exists. Most patients have early stage disease at the time of diagnosis, and there may be a role for therapy with ursodeoxycholic acid. While short- and medium-term outcomes remain favorable, especially if compared to patients transplanted for other indications, continued follow-up may identify reduced long-term graft and patient survival.

Recurrent primary biliary cirrhosis after liver transplantation

Recurrent primary biliary cirrhosis (PBC) is an important clinical outcome after liver transplantation (LT) in selected patients. Prevalence rates for recurrent PBC (rPBC) reported by individual LT programs range between 9% and 35%. The diagnostic hallmark of rPBC is histologic identification of granulomatous changes. Clinical and biochemical features are frequently absent with rPBC and cannot be used alone for diagnostic purposes. Some of the risk factors of rPBC may include recipient factors such as age, gender, HLA status and immunosuppression, as well as donor factors such as age, gender and ischemic time, although controversy exists. Most patients have early stage disease at the time of diagnosis, and there may be a role for therapy with ursodeoxycholic acid. While short- and medium-term outcomes remain favorable, especially if compared to patients transplanted for other indications, continued follow-up may identify reduced long-term graft and patient survival.

Insulin resistance, serum adipokines and risk of fibrosis progression in patients transplanted for hepatitis C

In the nontransplant setting diabetes mellitus is a risk factor for disease progression in patients with chronic hepatitis C virus (HCV) infection. The impact of early insulin resistance on the development of advanced fibrosis, even in the absence of clinically apparent diabetes mellitus, is not known. Our aim was to determine whether the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) can be used to identify insulin-resistant patients at risk for rapid fibrosis progression. Cohort study including patients transplanted for chronic HCV between January 1, 1995 and January 1, 2005. One hundred sixty patients were included; 25 patients (16%) were treated for diabetes mellitus and 36 patients (23%) were prediabetic, defined as HOMA-IR >2.5. Multivariate Cox regression analysis showed that insulin resistance (hazard ratio (HR) 2.07; confidence interval (CI) 1.10-3.91, p = 0.024), donor age (HR 1.33;CI 1.08-1.63, p = 0.007) and aspartate aminotransferase (HR 1.03;CI 1.01-1.05, p < 0.001) were significantly associated with a higher probability of developing advanced fibrosis, i.e. Knodell fibrosis stage 3 or 4, whereas steatosis (HR 0.94;CI 0.46-1.92, p = 0.87) and acute cellular rejection (HR 1.72;CI 0.88-3.36, p = 0.111) were not. In conclusion, posttransplant insulin resistance is strongly associated with more severe recurrence of HCV infection. HOMA-IR is an important tool for the identification of insulin resistance among patients at risk for rapid fibrosis progression after liver transplantation for HCV.

Impact of pegylated interferon and ribavirin treatment on graft survival in liver transplant patients with recurrent hepatitis C infection

Recurrent hepatitis C virus (HCV) infection is a major cause of morbidity and mortality after liver transplantation for HCV-related end stage liver disease. Although previous studies have shown a short-term effect of interferon-based treatment on fibrosis progression, it is unclear whether this translates to improved graft survival. We evaluated whether treatment of recurrent HCV leads to an improved graft survival. Cohort study included consecutive HCV patients who underwent liver transplantation between 1 January 1995 and 1 January 2005 in the Mayo Clinic, Rochester, MN. Two hundred and fifteen patients were included in the study. During a median follow-up of 4.4 years (interquartile range 2.2-6.6), 165 patients (77%) had biopsy-proven recurrent HCV infection confirmed by serum HCV RNA testing. Seventy-eight patients were treated. There were no differences in MELD-score, fibrosis stage or time towards HCV recurrence between treated and untreated patients at time of recurrence. There was a trend for greater frequency of acute cellular rejection among untreated patients. The incidence of graft failure was lower for patients treated within 6 months of recurrence compared to patients not treated within this time-period (log rank p = 0.002). Time-dependent multivariate Cox regression analysis showed that treatment of recurrent HCV infection was statistically significantly associated with a decreased risk of overall graft failure (hazard ratio 0.34; CI 0.15-0.77, p = 0.009) and a decreased risk of graft failure due to recurrent HCV (hazard ratio 0.24; CI 0.08-0.69, p = 0.008). In conclusion, although a cause and effect relationship cannot be established, treatment of recurrent HCV infection after liver transplantation is associated with a reduced risk of graft failure.

Survival in portopulmonary hypertension: Mayo Clinic experience categorized by treatment subgroups

To determine the natural history of portopulmonary hypertension (POPH), a retrospective screening-right heart catheterization-survival analysis of patients was performed. We categorized patients by three treatment subgroups: (1) no therapy for pulmonary hypertension (PH) or liver transplantation (LT), (2) therapy for PH alone and (3) therapy for PH followed by LT. Seventy-four patients were identified between 1994 and 2007. Nineteen patients received no therapy for PH and no LT representing the natural history of POPH. Five-year survival was 14%, and 54% had died within 1 year of diagnosis. Five-year survival in 43 patients receiving therapy for PH but no LT was 45%, and 12% had died within 1 year of diagnosis. Twelve patients underwent LT and 5-year survival for the nine receiving therapy for PH was 67% versus 25% in the three who were not pretreated with prostacyclin therapy. The survival of untreated patients with POPH was poor. Subgroups of patients selected to medical treatment with or without LT had better long-term survival. Mortality did not correlate with baseline hemodynamic variables, type of liver disease or severity of hepatic dysfunction. Medical therapy for POPH should be considered in all patients with POPH, but the treatment effects and impact on those considered for LT still requires well-designed, prospective study before practice guidelines can be suggested.

Hyponatremia and mortality among patients on the liver-transplant waiting list

BACKGROUND

Under the current liver-transplantation policy, donor organs are offered to patients with the highest risk of death.

METHODS

Using data derived from all adult candidates for primary liver transplantation who were registered with the Organ Procurement and Transplantation Network in 2005 and 2006, we developed and validated a multivariable survival model to predict mortality at 90 days after registration. The predictor variable was the Model for End-Stage Liver Disease (MELD) score with and without the addition of the serum sodium concentration. The MELD score (on a scale of 6 to 40, with higher values indicating more severe disease) is calculated on the basis of the serum bilirubin and creatinine concentrations and the international normalized ratio for the prothrombin time.

RESULTS

In 2005, there were 6769 registrants, including 1781 who underwent liver transplantation and 422 who died within 90 days after registration on the waiting list. Both the MELD score and the serum sodium concentration were significantly associated with mortality (hazard ratio for death, 1.21 per MELD point and 1.05 per 1-unit decrease in the serum sodium concentration for values between 125 and 140 mmol per liter; P<0.001 for both variables). Furthermore, a significant interaction was found between the MELD score and the serum sodium concentration, indicating that the effect of the serum sodium concentration was greater in patients with a low MELD score. When applied to the data from 2006, when 477 patients died within 3 months after registration on the waiting list, the combination of the MELD score and the serum sodium concentration was considerably higher than the MELD score alone in 32 patients who died (7%). Thus, assignment of priority according to the MELD score combined with the serum sodium concentration might have resulted in transplantation and prevented death.

CONCLUSIONS

This population-wide study shows that the MELD score and the serum sodium concentration are important predictors of survival among candidates for liver transplantation.

Hyponatremia and mortality among patients on the liver-transplant waiting list

BACKGROUND

Under the current liver-transplantation policy, donor organs are offered to patients with the highest risk of death.

METHODS

Using data derived from all adult candidates for primary liver transplantation who were registered with the Organ Procurement and Transplantation Network in 2005 and 2006, we developed and validated a multivariable survival model to predict mortality at 90 days after registration. The predictor variable was the Model for End-Stage Liver Disease (MELD) score with and without the addition of the serum sodium concentration. The MELD score (on a scale of 6 to 40, with higher values indicating more severe disease) is calculated on the basis of the serum bilirubin and creatinine concentrations and the international normalized ratio for the prothrombin time.

RESULTS

In 2005, there were 6769 registrants, including 1781 who underwent liver transplantation and 422 who died within 90 days after registration on the waiting list. Both the MELD score and the serum sodium concentration were significantly associated with mortality (hazard ratio for death, 1.21 per MELD point and 1.05 per 1-unit decrease in the serum sodium concentration for values between 125 and 140 mmol per liter; P<0.001 for both variables). Furthermore, a significant interaction was found between the MELD score and the serum sodium concentration, indicating that the effect of the serum sodium concentration was greater in patients with a low MELD score. When applied to the data from 2006, when 477 patients died within 3 months after registration on the waiting list, the combination of the MELD score and the serum sodium concentration was considerably higher than the MELD score alone in 32 patients who died (7%). Thus, assignment of priority according to the MELD score combined with the serum sodium concentration might have resulted in transplantation and prevented death.

CONCLUSIONS

This population-wide study shows that the MELD score and the serum sodium concentration are important predictors of survival among candidates for liver transplantation.

Long-term outcome of human leukocyte antigen mismatching in liver transplantation: results of the National Institute of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database

A perfect or nearly perfect human leukocyte antigen (HLA) match has been associated with better immediate and long-term survival of diseased donor kidney transplants. However, the effect of HLA matching for hepatic allografts remains poorly defined. Using data from the National Institutes of Diabetes and Digestive and Kidney Diseases Liver Transplantation Database, we investigated the association between HLA mismatches and hepatic allograft survival, disease recurrence, and immunosuppression interactions. A, B, and DR loci were used to calculate total mismatch scores of 0 (no mismatches in any loci) to 6 (mismatches in all loci). Seven hundred ninety-nine adults (male, 55%; female, 45%) underwent 883 liver transplants. The 10-year graft survival according to total mismatch score was as follows: 0-2, 60%; 3-4, 54%; and 5-6, 57%. There was a negative effect of mismatching at the A locus on patient survival, with shorter survival for patients with 1 or 2 mismatches compared with 0 mismatches [P = 0.05, hazard ratio (HR) = 1.6]. Patients on tacrolimus with 1 or 2 mismatches at B or DR loci appeared to have increased rates of patient and graft survival compared to patients with 0 mismatches, with the appearance of a protective effect of tacrolimus (HR = 0.67). The effect of HLA mismatching was more pronounced on certain disease recurrences. DR-locus mismatch increased recurrence of autoimmune hepatitis (P = 0.01, HR = 4.2) and primary biliary cirrhosis (P = 0.04, HR = 2). Mismatch in the A locus was associated with more recurrence of hepatitis C virus (P = 0.01, HR = 1.6) and primary sclerosing cholangitis (P = 0.03, HR = 2.9).

CONCLUSION

Mismatching at the A locus decreases patient survival in liver transplant recipients, and mismatching at the DR and A loci affects recurrence of autoimmune liver diseases and hepatitis C, respectively.

Celiac disease autoantibodies in severe autoimmune liver disease and the effect of liver transplantation

BACKGROUND/AIMS

Celiac disease (CD) is associated with primary biliary cirrhosis, primary sclerosing cholangitis and autoimmune hepatitis. We investigated the following: (i) the prevalence of tissue transglutaminase antibodies (tTGAs) and endomysial antibodies (EMAs) in end-stage autoimmune liver disease (ESALD), (ii) the correlation among auto-antibodies and the human leucocyte antigen (HLA) haplotype, and (iii) the effect of liver transplantation on antibody kinetics.

METHODS

Pretransplantation sera from 488 patients (310 with ESALD, and 178 with non-autoimmune disease) were tested for tTGAs. Positive samples were also tested for EMAs, and retested 6-12 and > or = 24 months post-transplantation. Results were correlated with the HLA type of the recipient.

RESULTS

Serological evidence of CD was found in 3% (ESALD) vs. 0.6% (non-autoimmune) of the patients (five-fold increased risk in ESALD). The prevalence of tTGAs (14.2 vs. 5.4%, P=0.0001) and EMAs (4.3 vs. 0.78%, P=0.01) was significantly higher in patients with the HLA-DQ2 or HLA-DQ8 haplotypes. tTGAs and EMAs normalized in 94 and 100%, respectively, without gluten exclusion post-transplantation. Post-transplantation, of the five patients with symptoms of 'classical' CD, three improved. Intestinal lymphoma was diagnosed in another two cases with clinically 'silent' CD.

CONCLUSIONS

Patients with ESALD, especially those who are HLA-DQ2 or HLA-DQ8 positive had a high prevalence of CD-associated antibodies. Both tTGAs and EMAs decreased post-transplantation without gluten withdrawal. Immunosuppression may improve symptoms of CD, but might not prevent progression to intestinal lymphoma.

Long-term survival and impact of ursodeoxycholic acid treatment for recurrent primary biliary cirrhosis after liver transplantation

The recurrence of primary biliary cirrhosis (PBC) in the hepatic allograft may impact patient and graft survival with long-term follow-up. The efficacy of ursodeoxycholic acid (UDCA) for treatment of recurrent PBC after liver transplantation (LT) remains less well known. The aims of this study were as follows: 1) to determine the significance of recurrent PBC on overall survival among PBC patients who underwent LT, and 2) to determine the efficacy of UDCA treatment after LT in patients with recurrent PBC. A retrospective cohort study was conducted of 154 PBC patients who underwent LT with at least 1 yr of follow-up after transplantation from 1985 through 2005. A total of 52 patients with recurrent PBC were identified. After adjusting for age and gender, recurrent PBC was not associated with death or liver retransplantation (hazard ratio, 0.97, 95% confidence interval, 0.41-2.31; P = 0.9). A total of 38 patients with recurrent PBC received UDCA at an average dose of 12 mg/kg/day for a mean duration of 55 months. Over a 36-month period, an estimated 52% of UDCA-treated patients experienced normalization of serum alkaline phosphatase and alanine aminotransferase compared to 22% of untreated patients. There was no significant difference in the rate of histological progression between subgroups. UDCA did not influence patient and graft survival. In conclusion, the development of recurrent PBC has little impact on long-term survival or need for retransplantation. While UDCA therapy is associated with biochemical improvement, its role in delaying histologic progression remains unknown. In this short period of treatment, UDCA was not associated with improved patient and graft survival compared to untreated patients.

Portopulmonary hypertension: Results from a 10-year screening algorithm

Portopulmonary hypertension (POPH) is the elevation of pulmonary artery pressure due to increased resistance to pulmonary blood flow in the setting of portal hypertension. Increased mortality has occurred with attempted liver transplantation in such patients and thus, screening for POPH is advised. We examined the relationship between screening echocardiography and right heart catheterization determinations of pressure, flow, volume, and resistance. A prospective, echocardiography-catheterization algorithm was followed from 1996 to 2005. Consecutive transplantation candidates underwent Doppler echocardiography to determine right ventricular systolic pressure (RVSP). Of 1,235 patients, 101 with RVSP >50 mm Hg underwent catheterization to measure mean pulmonary artery pressure (MPAP), flow via cardiac output (CO), central volume via pulmonary artery occlusion pressure (PAOP), and resistance via calculated pulmonary vascular resistance (PVR). Bland-Altman analysis suggested marked discordance between echocardiography-derived RVSP and catheterization results. All-cause pulmonary hypertension (MPAP >25 mm Hg) was documented in 90/101 (90%) patients. Using current pressure and resistance diagnostic guidelines (MPAP >25 mm Hg, PVR > or =240 dynes/s/cm(-5)), POPH was documented in 66/101 (65%) patients. Elevated MPAP was due to increased CO and/or PAOP in 35/101 (35%) patients with normal resistance (PVR <240 dynes/s/cm(-5)). The transpulmonary gradient (MPAP-PAOP) further characterized POPH in the presence of increased volume. Model for end stage liver disease (MELD) scores correlated poorly with MPAP and PVR. In conclusion, right heart catheterization is necessary to confirm POPH and frequently identifies other reasons for pulmonary hypertension (e.g., high flow and increased central volume) in liver transplantation candidates. Severity of POPH correlates poorly with MELD scores.

Reduced priority MELD score for hepatocellular carcinoma does not adversely impact candidate survival awaiting liver transplantation

The liver organ allocation policy of the United Network for Organ Sharing (UNOS) is based on the model for end-stage liver disease (MELD). The policy provides additional priority for candidates with hepatocellular carcinoma (HCC) who are awaiting deceased donor liver transplantation (DDLT). However, this priority was reduced on February 27, 2003 to a MELD of 20 for stage T1 and of 24 for stage T2 HCC. The aim of this study was to determine the impact of reduced priority on HCC candidate survival while on the waiting list. The UNOS database was reviewed for all HCC candidates listed after February 27, 2002, The HCC candidates were grouped into two time periods: MELD 1 (listed between February 27, 2002, and February 26, 2003) and MELD 2 (listed between February 27, 2003 and February 26, 2004). For the two time periods, the national DDLT incidence rates for HCC patients were 1.44 versus 1.53 DDLT per person-year (p = NS) and the waiting times were similar for the two periods (138.0 +/- 196.8 vs. 129.0 +/- 133.8 days; p = NS). Furthermore, the 3-, 6- and 12-month candidate, patient survival and dropout rates were also similar nationally. Regional differences in rates of DDLT for HCC were observed during both MELD periods. Consequently, the reduced MELD score for stage T1 and T2 HCC candidates awaiting DDLT has not had an impact nationally either on their survival on the waiting list or on their ability to obtain a liver transplant within a reasonable time frame. However, regional variations point to the need for reform in how organs are allocated for HCC at the regional level.

Mycophenolate mofetil use is associated with decreased risk of late acute rejection in adult liver transplant recipients

Mycophenolate mofetil (MMF) used in a triple-drug regimen has been shown to decrease acute rejection rates, compared to a double-drug regimen. The impact of MMF on late acute rejection (LAR) episodes has not been well described. To investigate the risk of LAR (rejection > or = 6 months post-transplantation) data from the Scientific Registry of Transplant Recipients (SRTR) were used. We studied adult primary liver transplant recipients transplanted between June 1, 1995, and April 30, 2004, with hepatitis C virus (HCV) (n = 3356), hepatitis B virus (HBV) (n = 550) or a nonviral (n = 5740) primary cause of liver disease who were recorded as receiving continuous 3-(MMF + Tacro + steroids) versus 2-drug (Tacro + steroids) therapy for at least 6 months immediately post transplantation. Kaplan-Meier analysis showed significantly lower LAR rates 4 years post-transplant in 3- versus 2-drug HCV, HBV and nonviral disease patients. Multivariate regression confirmed 3- versus 2-drug therapy to be associated with a decreased risk of LAR. Late graft survival was significantly lower at 4 years post-transplant for patients with LAR 6-12 months post-transplantation versus patients with early rejection (78.0% vs. 87.0%, p < 0.001) and no rejection (88.1%, p < 0.001). Three-drug versus 2-drug therapy for a minimum of 6 months may offer a better treatment strategy to avoid the consequences and expense of LAR episodes.

Factor XII deficiency acquired by orthotopic liver transplantation: case report and review of the literature

Transmission of congenital clotting factor deficiencies after orthotopic liver transplantation is rare. There are published reports of liver donor-to-recipient transmission of protein C deficiency with dysfibrinogenemia, protein S, factor VII and factor XI deficiencies. We report a case of transmission of factor XII deficiency with liver transplantation in a patient with Budd-Chiari syndrome. There was a persistent elevation of the activated partial thromboplastin time (aPTT), but no evidence of bleeding while the patient was maintained on warfarin. The presence of a persistently abnormal aPTT may raise suspicion for the presence of a clotting factor deficiency; however, deficiencies of other clotting factors may not be readily apparent on routine blood tests performed in a donor. Being aware of the possibilities of transmission of these inherited deficiencies of coagulation factors will aid in their early detection and management in the transplant donor and recipient.

Post-transplant lymphoproliferative disorders following liver transplantation: incidence, risk factors and survival

This study investigates retrospectively the incidence, risk factors and mortality of post-transplant lymphoproliferative disorders (PTLD) in adult orthotopic liver transplant (OLT) recipients. Among 1206 OLT recipients at a single institution, 37 developed a PTLD. The incidence of PTLD was highest during the first 18 months and relatively constant thereafter with cumulative incidence of 1.1% at 18 months and 4.7% at 15 years. The risk of PTLD was approximately 10% to 15% of the risk of death without PTLD. During the first 4 years following OLT, PTLD were predominantly related to EBV, while afterward most PTLD were EBV negative. Significant risk factors for PTLD in OLT recipients were transplantation for acute fulminant hepatitis during the first 18 months following OLT (HR=2.6, p=0.007), and rejection therapy with high-dose steroids (HR=4.5, p=0.049) and OKT3 (HR=3.9, p=0.016) during the previous year. Therapy with high-dose steroids or OKT3 (HR=3.6, p=0.0071) were also significant risk factors for PTLD-associated mortality. OLT recipients remain at risk for PTLD years after transplantation. The strong association of PTLD with rejection therapy and the worse post-PTLD prognosis among recipients of rejection therapy indicate the need to balance the risk of immunosuppression against the risk of PTLD following rejection treatment.

Post-transplant lymphoproliferative disorders following liver transplantation: incidence, risk factors and survival

This study investigates retrospectively the incidence, risk factors and mortality of post-transplant lymphoproliferative disorders (PTLD) in adult orthotopic liver transplant (OLT) recipients. Among 1206 OLT recipients at a single institution, 37 developed a PTLD. The incidence of PTLD was highest during the first 18 months and relatively constant thereafter with cumulative incidence of 1.1% at 18 months and 4.7% at 15 years. The risk of PTLD was approximately 10% to 15% of the risk of death without PTLD. During the first 4 years following OLT, PTLD were predominantly related to EBV, while afterward most PTLD were EBV negative. Significant risk factors for PTLD in OLT recipients were transplantation for acute fulminant hepatitis during the first 18 months following OLT (HR=2.6, p=0.007), and rejection therapy with high-dose steroids (HR=4.5, p=0.049) and OKT3 (HR=3.9, p=0.016) during the previous year. Therapy with high-dose steroids or OKT3 (HR=3.6, p=0.0071) were also significant risk factors for PTLD-associated mortality. OLT recipients remain at risk for PTLD years after transplantation. The strong association of PTLD with rejection therapy and the worse post-PTLD prognosis among recipients of rejection therapy indicate the need to balance the risk of immunosuppression against the risk of PTLD following rejection treatment.

Transplant center quality assessment using a continuously updatable, risk-adjusted technique (CUSUM)

Access to timely, risk-adjusted measures of transplant center outcomes is crucial for program quality improvement. The cumulative summation technique (CUSUM) has been proposed as a sensitive tool to detect persistent, clinically relevant changes in transplant center performance over time. Scientific Registry of Transplant Recipients data for adult kidney and liver transplants (1/97 to 12/01) were examined using logistic regression models to predict risk of graft failure (kidney) and death (liver) at 1 year. Risk-adjusted CUSUM charts were constructed for each center and compared with results from the semi-annual method of the Organ Procurement and Transplantation Network (OPTN). Transplant centers (N = 258) performed 59 650 kidney transplants, with a 9.2% 1-year graft failure rate. The CUSUM method identified centers with a period of significantly improving (N = 92) or declining (N = 52) performance. Transplant centers (N = 114) performed 18 277 liver transplants, with a 13.9% 1-year mortality rate. The CUSUM method demonstrated improving performance at 48 centers and declining performance at 24 centers. The CUSUM technique also identified the majority of centers flagged by the current OPTN method (20/22 kidney and 8/11 liver). CUSUM monitoring may be a useful technique for quality improvement, allowing center directors to identify clinically important, risk-adjusted changes in transplant center outcome.

Addition of MMF to dual immunosuppression does not increase the risk of malignant short-term death after liver transplantation

Immunosuppression is often incriminated for the increased risk of post-transplant malignancies. To examine whether triple- (MMF+Tacro+CS) versus dual-drug therapy (Tacro+CS) is associated with an increased incidence of malignancy, or death due to malignancy, data from a large registry of liver transplant recipients were analyzed. Data from adult primary liver recipients reported to the Scientific Registry of Transplant Recipients between June 1, 1995, and April 30, 2004, and recorded at transplant on triple-drug (n = 9180) or dual-drug (n = 10 099) therapy were included. Kaplan-Meier survival analysis showed no significant differences in death due to malignancy 4 years post-transplantation between the treatment groups. Multivariable analysis using Cox proportional hazard models confirmed no differences in risk of death due to malignancy between the groups (HR: 0.83, p = 0.107). Incidence of any post-transplant malignancy was also not significantly different. Older recipient age and cause of liver disease were significantly associated with an increased risk of malignancy-related death. These data utilizing relatively short follow-up suggest the addition of MMF to Tacro+CS at transplant is not associated with death due to malignancy, at least in the short term. Individual recipient factors appear to be important risk factors for malignancy-related death; elucidating these risk factors can assist in identifying who should be monitored most aggressively for post-transplant malignancies.

Patient selection in an era of donor liver shortage: current US policy

In the past, organ allocation in the US was based on anecdotal experience, self-interest and the opinions of single centers, with little support in the way of scientific evidence, mathematical survival modeling or validation. As organ transplantation became more successful, and as disparity between the number of patients on the waiting list and available organs became larger, a more justifiable donor allocation scheme became necessary. The current allocation scheme for donor livers is based on the model for end-stage liver disease/pediatric end-stage liver disease, which was introduced in 2002 by the United Network for Organ Sharing. This new allocation system has improved accuracy for predicting pretransplant mortality. In addition, the number of liver transplantations has risen for almost all etiologic categories, most noticeably for patients with hepatocellular carcinoma. Fewer patients have been registered on the liver transplant waiting list and fewer have been removed from the list because they have died or become too sick for transplantation. So far, this new allocation system has been a success, but it does have its shortcomings, and even with improvements to the system, the use of the donor organ pool still needs to be optimized.

Mycophenolate mofetil combination therapy improves long-term outcomes after liver transplantation in patients with and without hepatitis C

To evaluate the impact of mycophenolate mofetil (MMF) on long-term outcomes of tacrolimus and corticosteroids, we analyzed data reported to the Scientific Registry of Transplant Recipients for 11,670 adult patients (3463 with hepatitis C [HCV]) who underwent primary, single-organ, liver transplantation between 1995 and 2001. Patients who were discharged from the hospital on tacrolimus-based immunosuppression with (n = 4466; n = 1323 HCV) or without MMF (n = 7204; n = 2140 HCV) were included in the analysis. Recipients treated at discharge with MMF, tacrolimus, and corticosteroids had significantly increased patient survival (81.0% vs. 77.0% at 4 years, P < 0.0001) and graft survival (76.4% vs. 72.9%, P < 0.0001), and lower rates of acute rejection (29.0% vs. 33.4%, P < 0.001) as compared to recipients treated at discharge with tacrolimus and corticosteroids alone. A trend toward lower rates of death from infection was observed (6.1% at 4 years for MMF vs. 7.1% at 4 years for tacrolimus and corticosteroids, P = 0.0508), but this result did not reach statistical significance. In multiple regression analyses, MMF triple therapy at discharge was associated with a reduced risk of death (hazard ratio [HR] = 0.77, P < 0.001), graft loss (HR = 0.81, P < 0.001), acute rejection (HR = 0.89, P = 0.002), and death from infectious complications (HR = 0.80, P = 0.007). Outcomes were similar for the cohort with HCV.In conclusion, the addition of MMF at discharge to tacrolimus-based immunosuppression is associated with improved long-term outcomes after liver transplantation in patients with and without HCV.

Differential effects of donor age in liver transplant recipients infected with hepatitis B, hepatitis C and without viral hepatitis

The variable impact of specific risk factors on survival outcomes based on pre-transplantation diagnosis was analyzed in adult liver transplant recipients reported to the Scientific Registry of Transplant Recipients: 778 with hepatitis B (HBV), 3463 with hepatitis C (HCV) and 7429 without viral hepatitis. Graft and patient survival for the HBV and no viral hepatitis groups did not differ significantly. The HCV group had significantly lower graft (p = 0.0019) and patient survival (p < 0.0001) than the no viral hepatitis group. Patient survival was significantly lower (p = 0.0011) for HCV compared to HBV patients; differences in graft survival approached significance (p = 0.0561). Donor age, which was not a risk factor in patients with HBV, was the strongest predictor of graft loss and death in patients with HCV, starting with donors >40 years. Donor age >60 years was the strongest predictor of graft loss and death in patients without viral hepatitis. The risks of graft loss and death were reduced for patients on tacrolimus-based immunosuppression with mycophenolate mofetil, regardless of disease etiology. There are clear differences in risk factors for poor outcomes based on underlying liver disease, particularly with regard to the impact of donor age.

Natural history of hepatopulmonary syndrome: Impact of liver transplantation

Few data exist concerning survival after the diagnosis of hepatopulmonary syndrome (HPS). Although orthotopic liver transplantation (OLT) frequently results in complete resolution of HPS, the relationship between transplantation and survival has not been described. The study rationale was to describe long-term survival in patients with HPS. Data were derived from patients diagnosed with HPS at Mayo Clinic (n = 61) between 1985 and 2002, including those undergoing OLT (n = 24) and those who did not (n = 37). A case-control, Kaplan-Meier survival analysis between HPS patients and 77 patients without HPS matched for liver disease cause, model for end-stage liver disease (MELD), severity of liver disease by the Child classification, and age was described for OLT and non-OLT groups. Patients with HPS had a mean partial pressure of arterial oxygen (PaO(2)) decline of 5.2 + 2.3 mm Hg per year awaiting OLT. For HPS patients, despite similar baseline PaO(2), brain uptake of technetium macroaggregated albumin ((99m)TcMAA), or measures of hepatic dysfunction, 5-year survival associated with OLT was 76% versus 23% who did not undergo transplantation (P < .0001). Comparing those who did not undergo transplantation, HPS patients had worse 5-year survival than matched controls (P = .0003). However, reasons to deny OLT (comorbidity) in the setting of HPS may well have contributed to observed survival differences. Baseline PaO(2) </=50 mm Hg was associated with worse survival irrespective of the decision to perform OLT. In conclusion, hypoxemia of HPS is frequently progressive. As OLT outcome relates to pretransplantation PaO(2), additional MELD points should advance the priority for OLT in HPS.