Obesity is independently associated with infection in hospitalised patients with end-stage liver disease

BACKGROUND

Infection is the most common cause of mortality in end-stage liver disease (ESLD). The impact of obesity on infection risk in ESLD is not established.

AIM

To characterise the impact of obesity on infection risk in ESLD.

METHODS

We evaluated the association between infection and obesity in patients with ESLD. Patients grouped as non-obese, obesity class I-II and obesity class III were studied using the Nationwide Inpatient Sample. Validated diagnostic code based algorithms were utilised to determine weight category and infections, including bacteraemia, skin/soft tissue infection, urinary tract infection (UTI), pneumonia/respiratory infection, Clostridium difficile infection (CDI) and spontaneous bacterial peritonitis (SBP). Risk factors for infection and mortality were assessed using multivariable logistic regression analysis.

RESULTS

Of 115 465 patients identified, 100 957 (87.5%) were non-obese and 14 508 (12.5%) were obese, with 9489 (8.2%) as obesity class I-II and 5019 (4.3%) as obesity class III. 37 117 patients (32.1%) had an infection diagnosis. Infection was most prevalent among obesity class III (44.0%), followed by obesity class I-II (38.9%) and then non-obese (31.9%). In multivariable modelling, class III obesity (OR = 1.41; 95% CI 1.32-1.51; P < 0.001), and class I-II obesity (OR = 1.08; 95% CI 1.01-1.15; P = 0.026) were associated with infection. Compared to non-obese patients, obese individuals had greater prevalence of bacteraemia, UTI, and skin/soft tissue infection as compared to non-obese patients.

CONCLUSIONS

Obesity is newly identified to be independently associated with infection in end-stage liver disease. The distribution of infection sites varies based on weight category.

Recurrence of hepatocellular carcinoma: importance of mRECIST response to chemoembolization and tumor size

Determining risk for recurrence of hepatocellular carcinoma (HCC) following liver transplantation (LT) is an important clinical need. We assessed consecutive patients who underwent LT for HCC following sequential transarterial chemoembolization (TACE). Treatment response was assessed using modified response evaluation criteria in solid tumors (mRECIST) categories: complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD). Cox proportional hazard models were used to predict HCC recurrence. One hundred seventy-three patients underwent TACE and imaging to assess response prior to LT. TACE responses were: CR = 23.7%, PR = 24.3%, SD = 27.7% and PD = 24.3%. Five-year HCC recurrence rate was 5.3% in patients responding to TACE (CR/PR), versus 17.6%, among patients who did not respond (SD/PD, p = 0.014). In multivariate analysis, independent pre-LT predictors of recurrence were response to TACE and largest radiologic size of tumor (>3 cm vs. ≤3 cm). HCC recurrence rate for patients with tumor size >3 cm and no response to TACE was 35.8%, compared with 1.9% for patients with tumor size ≤3 cm and response to TACE (p = 0.0007). We conclude that mRECIST criteria and tumor size differentiate patients with high or low likelihood of HCC recurrence after LT. These findings raise the possibility of incorporating response to TACE and largest tumor size to identify patients at highest risk for HCC recurrence.

Investigation of PNPLA3 and IL28B genotypes on diabetes and obesity after liver transplantation: insight into mechanisms of disease

To identify genetic risks for obesity and diabetes postliver transplantation (LT), LT recipients underwent genotyping for IL28B rs12979860 (n = 295) and PNPLA3 rs738409 (n = 205) polymorphism in both donors and recipients. The development of obesity and diabetes/impaired fasting glucose (IFG) was determined 1-5 years post-LT. Recipient PNPLA-3 genotype was independently associated with obesity (BMI > 30) at 3 years posttransplant (genotype CC 33.7%, CG 48.3% and GG 82.4%, p = 0.002), with an odds ratio (OR 2.54, CI 1.38-4.66, p = 0.003), associated with the G allele. Diabetes/IFG diagnosed within 5 years posttransplant associated with PNPLA-3 non-CC genotype (HR 1.59, 1.12-2.26, p = 0.010), but not IL28B TT genotype (HR 1.46, 0.94-2.27, p = 0.092). No genotype variable was independently predictive of diabetes/IFG. The combination of PNPLA-3 non-CC and IL28B TT genotype was associated with increased risk of diabetes/IFG compared to PNPLA-3 CC, IL28B non-TT (HR 2.64, CI 1.30-5.39, p = 0.008). Donor genotypes were not associated with any of the outcomes analyzed. In conclusion, PNPLA-3 non-CC genotype is associated with posttransplant obesity but not independently with diabetes/IFG. The lack of donor related risk suggests a peripheral rather than central mechanism of insulin resistance in liver transplant recipients.

Interactions of allelic variance of PNPLA3 with nongenetic factors in predicting nonalcoholic steatohepatitis and nonhepatic complications of severe obesity

OBJECTIVE

Allelic variation (rs738409C→G) in adiponutrin (patatin-like phospholipase domain-containing protein 3, PNPLA3) has been associated with hepatic steatosis and liver fibrosis. The physiologic impact of the PNPLA3 G allele may be exacerbated in patients with severe obesity. In this study, we investigated the interactions of PNPLA3 rs738409 with a broad panel of metabolic and histologic characteristics of nonalcoholic fatty liver disease and nonalcoholic steatohepatitis (NASH) in patients with medically complicated obesity.

DESIGN AND METHODS

Consecutive patients undergoing bariatric surgery were selected for a prospective study. They underwent extensive laboratory and histologic (liver biopsy) assessment, as well as evaluation of rs738409 polymorphism by TaqMan assay.

RESULTS

Only 12 (8.3%) of the 144 patients had normal liver histology, with 72 (50%) NASH, of whom 15 (10.4% of total patients) had fibrosis stage 2-3. PNPLA3 GG genotype correlated positively (P < 0.05) with serum levels of alanine aminotransferase (ALT), asparate aminotransferase (AST), glucose, fibrinogen, and insulin-dependent diabetes mellitus, homeostasis model assessment-insulin resistance, and presence of NASH. Multivariate analysis indicated that PNPLA3 rs738409 G versus C allele remained an (independent) risk factor for NASH, in addition to CK-18 >145 IU/l, glucose >100 mg/dl, and C-reactive protein (CRP) >0.8 mg/dl. The probability of NASH increased from 9% (no risk factor) to 82% if all four risk factors were present.

CONCLUSIONS

In this cohort of patients with medically complicated obesity, PNPLA3 rs738409 G allelic expression is associated with hepatic (NASH) and nonhepatic complications of obesity, such as insulin resistance. These novel findings may be related to a greater impact of PNPLA3 variant in magnitude and scope in patients with severe obesity than in less obese populations. Further studies are needed to characterize the nature of these associations.

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.

Recipient IL28B polymorphism is an important independent predictor of posttransplant diabetes mellitus in liver transplant patients with chronic hepatitis C

IL28B polymorphisms are strongly associated with response to treatment for HCV infection. IL28B acts on interferon-stimulated genes via the JAK-STAT pathway, which has been implicated in development of insulin resistance. We investigated whether IL28B polymorphisms are associated with posttransplant diabetes mellitus (DM). Consecutive HCV patients who underwent liver transplantation between 1-1995 and 1-2011 were studied. Genotyping of the polymorphism rs12979860 was performed on DNA collected from donors and recipients. Posttransplant DM was screened for by fasting blood glucoses every 1-3 months. Of 221 included patients, 69 developed posttransplant DM (31%). Twenty-two patients with recipient IL28B genotype TT (48%), 25 with IL28B genotype CT (25%) and 22 with IL28B genotype CC (29%) developed posttransplant DM. TT genotype was statistically significantly associated with posttransplant DM over time (log rank p = 0.012 for TT vs. CT and p = 0.045 for TT vs. CC). Multivariate Cox regression analysis correcting for donor age, body mass index, baseline serum glucose, baseline serum cholesterol, recipient age and treated rejection, showed that recipient IL28B genotype TT was independently associated with posttransplant DM (hazard ratio 2.51; 95% confidence interval 1.17-5.40; p = 0.011). We conclude that the risk of developing posttransplant DM is significantly increased in recipients carrying the TT polymorphism of the IL28B gene.

Daclizumab induction therapy in liver transplant recipients with renal insufficiency

BACKGROUND

The role of interleukin 2 (IL-2) receptor antibodies to avoid the nephrotoxic effects of calcineurin inhibitors in the early post-liver transplant (LT) period is not well defined.

AIM

To examine the use of daclizumab induction in LT recipients with renal insufficiency.

METHODS

Between 2002 and 2005, 62 patients (median pre-LT creatinine 2.4 mg/dL, IQR 1.9-3.7) received daclizumab induction with tacrolimus being administered when serum creatinine was <2.0 mg/dL. A concurrent comparison group (n = 221, 2002-2005) received tacrolimus-based immunosuppression without daclizumab (median pre-LT creatinine 1.1 mg/dL, IQR 0.9-1.4). A second historical comparison group (n = 103, 1995-2005) not receiving daclizumab was matched to the daclizumab patients by pre-LT serum creatinine (2.2 mg/dL, IQR 1.8-3.1). All patients received mycophenolate mofetil and steroids.

RESULTS

Serum creatinine improved in the daclizumab group (-1.0 mg/dL, IQR -2.2 to -0.4) and worsened in the concurrent comparison group (+0.2 mg/dL, IQR 0-0.5) from pre-LT to 4 months. However, there was no difference when daclizumab group was compared with the historical comparison group matched on pre-LT creatinine (median change: -0.8 mg/dL vs. -0.7 mg/dL). Daclizumab induction was not associated with improvement in renal function at 4 months (P = 0.34) after adjusting for pre-LT creatinine, age, gender, hepatitis C status and simultaneous liver kidney transplantation.

CONCLUSION

The incremental benefit offered by induction therapy with IL-2 receptor antibodies to preserve renal function is questionable.

Antibody-based immunosuppression following liver transplantation: the plot thickens

The role of antibody-based immunosuppression in liver transplant recipients remains an area in which prospective trials are needed.

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.

Reduction of immunosuppression for transplant-associated skin cancer: thresholds and risks

BACKGROUND

Although evidence supports the efficacy of reducing immunosuppression for transplant-associated skin cancer, clinical thresholds for and risks associated with reduction are not well defined.

OBJECTIVES

In this study, experienced transplant physicians were surveyed regarding appropriate thresholds for consideration of reduction of immunosuppression and the likelihood of rejection and allograft compromise associated with various levels of reduction.

PATIENTS AND METHODS

Fifty-two transplant physicians reviewed 13 hypothetical patient scenarios with graduated morbidity and mortality risk and provided opinions on the degree of reduction of immunosuppression that was warranted and the risks associated with various degrees of reduction.

RESULTS

Renal, liver and cardiac transplant physicians generally concurred on the level of reduction of immunosuppression warranted by various degrees of skin cancer. As morbidity and mortality from skin cancer increased, physicians were more likely to accept risk to allograft function from more aggressive reduction.

CONCLUSIONS

Reduction of immunosuppression is considered a reasonable adjuvant strategy in recipients of solid organ transplants who have substantial morbidity and mortality risk from skin cancer. Physicians are willing to accept an increased risk of allograft compromise when confronted by severe or extensive skin cancer. Further research is needed to define the precise correlation among levels of reduction of immunosuppression, therapeutic efficacy, and concomitant risks.

Recurrent autoimmune hepatitis after orthotopic liver transplantation

To determine the frequency, risk factors, and consequences of recurrent autoimmune hepatitis after liver transplantation, 41 patients with type 1 disease were monitored after surgery in accordance with a surveillance protocol. Tacrolimus or cyclosporine plus prednisone were administered to each patient, and liver biopsy examinations were performed at least annually according to protocol. Corticosteroid therapy was ultimately discontinued in only 2 patients. Recurrent disease was defined as the presence of lymphoplasmacytic infiltrates in liver tissue in the absence of other causes of allograft dysfunction. Autoimmune hepatitis recurred in 7 patients (17%), and the mean time to recurrence was 4.6 +/- 1 years. Recurrence was asymptomatic in 4 of 7 patients and detected only by surveillance liver biopsy assessment in 2 patients. Histological changes were mild, and there was no progression to cirrhosis during 4.9 +/- 0.9 years of observation. Five-year patient (86% v. 82%; P =.9) and graft (86% v. 67%; P =.5) survival rates were not statistically different between patients with and without recurrent disease. HLA-DR3 or HLA-DR4 occurred more commonly in patients with than without recurrence (100% v. 40%; P =.008) and healthy subjects (100% v. 49%; P =.01). Recurrent disease was unrelated to donor HLA status. In conclusion, recurrence after transplantation for type 1 autoimmune hepatitis is common. Its mild manifestations and favorable prognosis may reflect early detection by a surveillance protocol and/or continuous corticosteroid treatment. HLA-DR3- or HLA-DR4-positive recipients are at risk for recurrence regardless of donor HLA status.

Early identification of recipients with progressive histologic recurrence of hepatitis C after liver transplantation

Approximately half of patients undergoing liver transplantation (LT) for hepatitis C virus (HCV) develop histologic evidence of recurrence within the first postoperative year. Early identification of recipients at risk for more severe recurrence of HCV may be useful in selecting patients for antiviral therapy. We determined whether recipients at greatest risk for more severe recurrence of HCV can be identified by pre- and/or early post-LT HCV-RNA levels in serum or tissue. Serum and tissue samples were prospectively collected pre-LT and at 7 days, 4 months, 1 year, and at 3 years posttransplantation from patients undergoing LT for HCV. Hepatitis activity index (HAI) and fibrosis stage (FS) were assessed in all liver biopsies. Forty-seven patients (32 men) were studied. Higher HCV-RNA levels at 4 months post-LT (>/=10(9) copies/mL, n = 29) were associated with higher HAI at 1 year and at 3 years post-LT. The HAI seen on protocol biopsies at 4 months correlated significantly with fibrosis stage (FS) at 1 year (r =.56, P </=.001) and 3 years (r =. 53, P =.002). Higher HCV-RNA levels at 7 days and 4 months post-LT were sensitive (66% and 84%, respectively) and specific (92% and 63%, respectively) in identifying recipients with an HAI greater than 3 at 3 years. Higher pre- and early post-LT HCV-RNA levels are associated with more severe recurrence of HCV. The correlation of early HAI with subsequent FS suggests that higher mean HAI will eventually translate into more advanced stages of fibrosis. Patients at risk for more severe post-LT recurrence of HCV can be identified by early posttransplant HCV-RNA levels.

Utility of standard nutritional parameters in detecting body cell mass depletion in patients with end-stage liver disease

Protein-calorie malnutrition, best measured by body cell mass (BCM) depletion, has been associated with adverse outcomes in patients with end-stage liver disease. We prospectively measured BCM and multiple standard nutritional parameters in patients with end-stage liver disease to determine which, if any, of the traditionally measured nutritional parameters correlate with BCM. A detailed nutritional assessment, including BCM analysis, subjective global assessment, anthropometry, handgrip dynamometry, laboratory tests, and body composition measured by dual-energy X-ray absorptiometry was performed in 69 sequential patients awaiting liver transplantation. The frequency of abnormalities of specific parameters of nutritional status varied between 19% and 99%. Most of the commonly measured parameters of nutritional status correlated poorly with BCM. Patients with depleted BCM (lowest quartile for sex) had midarm circumference (P <.01), arm-muscle circumference (P <.001), handgrip strength (P <.001), blood urea nitrogen (P <.01), and creatinine (P <.01) values less than those for patients with greater BCM (highest 3 quartiles for sex). In multivariate analysis, arm-muscle circumference and handgrip strength were the best predictors of BCM. The combined criteria of handgrip strength less than 30 kg and arm-muscle circumference less than 23 cm have a sensitivity of 94% and a negative predictive value of 97% in identifying patients with depleted BCM. Although abnormalities of nutritional parameters are highly prevalent among patients with end-stage liver disease, most parameters of nutritional status do not correlate with BCM. In patients with end-stage liver disease, arm-muscle circumference and handgrip strength are the most sensitive markers of BCM depletion.

Comparative allograft histology after liver transplantation for cryptogenic cirrhosis, alcohol, hepatitis C, and cholestatic liver diseases

BACKGROUND

End-stage liver disease for which no cause can be identified, cryptogenic cirrhosis, is a common indication for liver transplantation. Allograft inflammation and fibrosis have been reported to recur with similar frequencies after liver transplantation for cryptogenic cirrhosis and hepatitis C (HCV).

METHODS

We determined sequential posttransplant allograft histology in four groups of recipients: 31 transplanted for cryptogenic cirrhosis, 70 for cholestatic etiologies, 40 for alcoholic liver disease, and 56 for HCV. Modified hepatitis activity index (HAI) and fibrosis stage were determined at 4 months, 1 year, and at most recent biopsy posttransplantation.

RESULTS

The prevalence of HAI > or = 2 among cryptogenic recipients was similar to that of cholestatic and alcoholic recipients at 4 months, 1 year, and at most recent evaluation (mean 45+/-17 months posttransplantation). For HCV-infected recipients, the frequency of HAI > or = 2 was more than for cryptogenic recipients at 1 year (52 vs. 29%, P=0.04) and at most recent evaluation (64 vs. 15%, P=0.003). Fibrosis scores for cryptogenic, cholestatic, and alcoholic recipients were similar at all timepoints. The proportion of HCV-infected recipients with fibrosis stage >2 was more than that of cryptogenic recipients at 4 months (29 vs. 12%, P=0.05), 1 years (46 vs. 7%, P=0.0002), and at most recent evaluation (42 vs. 15%, P=0.06). None of the cryptogenic recipients developed cirrhosis.

RESULTS

The frequency of elevated HAI and fibrosis stage in recipients who undergo transplantation for cryptogenic cirrhosis is similar to that of recipients who undergo transplantation for cholestatic etiologies and significantly less than that of HCV-infected recipients. Fibrosis stage and HAI are generally stable after transplantation for cryptogenic cirrhosis. These data do not suggest a viral etiology of liver disease in the majority of patients with cryptogenic cirrhosis.

Prevalence of TT virus infection in blood donors with elevated ALT in the absence of known hepatitis markers

OBJECTIVE

Recently a novel DNA virus (TT virus) has been identified in Japan and shown to be associated with elevated aminotransferase levels after blood transfusion. The exact role of TTV in the pathogenesis of liver disease is yet to be established. Our aim was to determine the prevalence and role of TTV in the pathogenesis of elevated transaminases in healthy blood donors in the absence of markers for viral hepatitis A-C.

METHODS

Stored sera were collected from 99 healthy blood donors with elevated alanine amino transferase (ALT) values that were discovered at the time of blood donation. A total of 146 samples were obtained from healthy donors with normal ALT values who were used as controls. None of the patients or controls had a history of blood transfusion or had clinical signs of acute or chronic hepatitis. Serological markers for hepatitis A, hepatitis B, and hepatitis C viruses were negative. TTV DNA was amplified and detected using polymerase chain reaction followed by gel electrophoresis.

RESULTS

Five of 99 (5%) samples obtained from donors with elevated ALT had TTV DNA detected by PCR, as compared to one of 146 (0.7%) of those with normal ALT (p = 0.006). Among those with elevated ALT, mean ALT values in patients with TTV (296 +/- 305 U/L) were higher than in patients without TTV (95 +/- 37 U/L), but the difference was not statistically significant (p = 0.08). The two samples with highest ALT values (both >450 U/L) were among the five samples with detectable TTV DNA in serum.

CONCLUSIONS

Although TTV is not likely to explain the majority of elevated ALT cases in otherwise healthy blood donors, TTV infection may potentially be associated with some cases. Based on these findings, we propose that the role of TTV in the pathogenesis of acute and chronic liver diseases merits further investigation.

Early detection of hepatitis C allograft reinfection after orthotopic liver transplantation: a molecular and histologic study

After orthotopic liver transplantation (OLT), patients with chronic hepatitis C virus (HCV) infection show nearly universal persistence of viremia and reinfection of the liver, but identifying the point at which the liver is reinfected morphologically can be difficult. One tool that may potentially be useful to detect reinfection is reverse transcriptase-polymerase chain reaction (RT-PCR), which has proven to be highly sensitive for detecting HCV RNA in formalin-fixed paraffin-embedded liver tissue. Our purpose was to gain insight into the time frame of HCV reinfection by assaying for HCV RNA in serial posttransplant liver biopsy specimens. Our study population consisted of 14 patients who underwent liver transplantation for hepatitis C and had confirmed HCV RNA in pretransplant serum, absence of HCV RNA in donor livers, and available consecutive posttransplant liver allograft specimens. We performed RT-PCR for HCV RNA in serial posttransplant liver biopsy specimens, beginning at 1 week until at least one biopsy from each tested positive. HCV RNA was detected in liver tissue by RT-PCR in 1-week post-OLT liver samples in 6 of 14 (42.8%) patients, the earliest being 5 days post-OLT. Eventually, each of the remaining eight samples became RT-PCR positive as well; the first detections occurred in these at 3 weeks (three cases), 4 weeks (three cases), 48 weeks (one case), and 144 weeks (one case). Histologic identification of hepatitis C recurrence was relatively insensitive in relation to these molecular data. These data suggest that (1) HCV RNA reinfection is nearly universal after liver transplantation in patients with chronic hepatitis C infection, (2) molecular reinfection by HCV occurs at a variable interval post-OLT, with the majority of allograft livers reinfected as early as 1 week, and (3) morphologic features of hepatitis C are usually appreciable at the time of "molecular" recurrence.

Long-term results of patients undergoing liver transplantation for primary sclerosing cholangitis

Liver transplantation is the only effective therapeutic option for patients with end-stage liver disease due to primary sclerosing cholangitis (PSC). In this study, we analyzed a single center's experience with 150 consecutive PSC patients who received 174 liver allografts. Mean follow-up was 55 months. Actuarial patient survival at 1, 2, 5, and 10 years was 93.7%, 92.2%, 86.4%, and 69.8%, respectively, whereas graft survival was 83.4%, 83.4%, 79.0%, and 60. 5%, respectively. The main indication for retransplantation was hepatic artery thrombosis, and the major cause of death was severe infection. Patients with PSC had a higher incidence of acute cellular and chronic ductopenic rejection compared to a non-PSC control group. Chronic ductopenic rejection adversely affected patient and graft survival. Biliary strictures, both anastomotic and nonanastomotic, were frequent and occurred in 16.2% and 27.2% of patients, respectively. The incidence of recurrent PSC was 20%. A negative impact on patient survival was not seen in patients with either postoperative biliary strictures or recurrence of PSC. Six patients (4%) had cholangiocarcinoma and 1 patient died related to recurrence of malignant disease. Seventy-eight percent of PSC patients had associated inflammatory bowel disease, most commonly chronic ulcerative colitis, which did not adversely impact patient outcome posttransplantation. Nine patients required proctocolectomy after liver transplantation; 5 because of intractable symptoms related to inflammatory bowel disease and 4 due to the development of colorectal carcinoma/high-grade dysplasia. Our data show that liver transplantation provides excellent long-term patient and graft survival for patients with end-stage PSC.

Clinical significance of TT virus infection in patients with chronic hepatitis C

OBJECTIVE

The TT virus (TTV) is a novel DNA virus that has recently been identified. The clinical significance of TTV infection in patients with chronic hepatitis C has not been determined. The aim of this study was to determine the prevalence and possible role of TTV in a well characterized population with chronic hepatitis C infection.

METHODS

Ninety patients with chronic HCV and known time of HCV acquisition were selected from approximately 250 patients followed at our institution. Characteristics including age, sex, histology, and length of disease were recorded. Direct sequencing of the NS5 region was used for HCV genotyping. TTV DNA detection was based on PCR.

RESULTS

TTV infection was present in 24 of 90 (27%) HCV patients. Patients were divided into four groups based on stage of disease; chronic hepatitis (CH, 29 patients), compensated cirrhosis (CC, 17 patients), decompensated cirrhosis (DC, 28 patients), and hepatocellular carcinoma (HCC, 16 patients). TTV was present in 2/29 (7%), 2/17 (12%), 11/28 (39%), and 9/16 (56%) in those with CAH, CC, DC, and HCC respectively. TTV was significantly more prevalent among those with advanced disease (DC and HCC) compared to those with stable disease (CH and CC; p = 0.001). Mean age, sex, and the time from exposure to HCV to development of complications were similar in TTV-positive and -negative patients. TTV infection was more common in patients infected with HCV genotype 1b. Univariate analysis showed that length of HCV infection, HCV genotype 1b, and TTV infection were important in predicting the stage of liver disease in HCV patients. However, after adjusting for length of HCV infection, TTV but not HCV genotype was important in predicting the stage of liver disease.

CONCLUSIONS

We conclude that 1) TTV infection is common in patients with chronic HCV; 2) TTV infection is more prevalent among patients with advanced HCV-associated liver disease (DC and HCC) than in those with stable disease (CH and CC); and 3) TTV infection is more common in patients with HCV genotype 1b but is independent from genotype in predicting the stage of HCV-associated liver disease.

The clinical significance of simultaneous infection with hepatitis G virus in patients with chronic hepatitis C

OBJECTIVES

Hepatitis G virus (HGV) is a recently discovered member of the flavivirus family that has been associated with acute and chronic hepatitis. HGV infection has been reported to coexist in 10-20% of patients with chronic hepatitis C. The significance of simultaneous infection with HGV and hepatitis C virus (HCV) remains to be clarified, as do the effects on HGV of therapeutic interventions such as interferon treatment or liver transplantation.

THE AIMS OF OUR STUDY WERE

1) to examine the frequency of HGV infection in the settings of liver transplantation and interferon therapy for hepatitis C; and 2) to compare HGV RNA levels before and after liver transplantation or interferon treatment.

METHODS

Pre-treatment sera were available in 65 patients with chronic hepatitis C treated with interferon; pretransplant sera were available in 49 patients transplanted for end stage liver disease associated with chronic hepatitis C. Information collected included age, sex, risk factors for hepatitis, concurrent liver disease, patient and allograft survival, biochemical response to interferon, histological activity index, and degree of fibrosis/cirrhosis. HCV genotyping was performed by sequencing the NS-5 region. HGV quantitation was performed using a research-based branched DNA (bDNA) assay with a set of probes directed at the 5' untranslated region.

RESULTS

HGV was detected in 10 of 49 patients (20%) before transplant and in 13 of 65 patients (20%) treated with interferon. There was a female predominance among HGV-positive compared with HGV-negative transplant patients (80% vs 20%; p < 0.01), but such a difference was not observed in the interferon-treated group. Hepatic iron concentration was lower in hepatic explants from patients who were HGV-positive than in those who were HGV-negative (318 +/- 145 microg/g dry weight vs 1497 +/- 2202 microg/g dry weight; p = 0.02). HCV exposure after 1980 was more common in the HGV-positive patients than in those who were HGV-negative for the entire study population (10 of 20 [50%] vs 16 of 66 [24%]; p = 0.03), as well as for the nontransplant subgroup (8 of 12 [67%] vs 12 of 39 [31%]; p = 0.03). HGV RNA levels declined at 1 yr after transplant in seven of eight patients. Among nine patients tested during or after interferon treatment, HGV RNA levels declined from pretreatment levels in all and disappeared in three.

CONCLUSIONS

Among patients with chronic hepatitis C treated with either interferon or liver transplantation, the frequency of coinfection with HGV is about 20%. HGV may be a more recent virus in the US than HCV. Coinfection with HGV does not appear to affect the likelihood of response to interferon in patients with hepatitis C. Finally, HGV RNA levels appear to decline after both liver transplantation and interferon therapy, suggesting possible suppression by increased HCV replication in the former case, and a possible drug treatment effect in the latter.

Recurrence of primary sclerosing cholangitis following liver transplantation

Recurrence of primary sclerosing cholangitis (PSC) following liver transplantation has been suggested; however, it has not been fully defined because of numerous complicating factors and the lack of diagnostic criteria. In the present study, we investigated the recurrence of PSC by developing strict criteria and applying them to a large cohort of PSC patients who underwent liver transplantation. Between March 1985 and June 1996, 150 PSC patients underwent liver transplantation at the Mayo Clinic; mean follow up was 55 months. The incidence of nonanastomotic biliary strictures and hepatic histologic findings suggestive of PSC were compared between patients transplanted for PSC and a non-PSC transplant control group. Our definition of recurrent PSC was based on characteristic cholangiographic and histologic findings that occur in nontransplant PSC patients. By using strict criteria, 30 patients with other known causes of posttransplant nonanastomotic biliary strictures were excluded leaving 120 patients for analysis of recurrence of PSC. We found evidence of PSC recurrence after liver transplantation in 24 patients (20%). Of these, 22 out of 24 patients showed characteristic features of PSC on cholangiography and 11 out of 24 had compatible hepatic histologic abnormalities with a mean time to diagnosis of 360 and 1,350 days, respectively. Both cholangiographic and hepatic histologic findings suggestive of PSC recurrence were seen in nine patients. The higher incidence and later onset of nonanastomotic biliary strictures in patients with PSC compared with a non-PSC control group is supportive of the fact that PSC does recur following liver transplantation. We were unable to identify specific clinical risk factors for recurrent PSC, and the overall patient and graft survival in patients with recurrent PSC was similar to those without evidence of recurrence. Our observations provide convincing evidence that PSC frequently recurs in the hepatic allograft using strict inclusion and exclusion criteria.

Recurrent and new hepatitis C virus infection after liver transplantation

Chronic infection with the hepatitis C virus (HCV) is the most common reason for liver transplantation. We examined the results of laboratory tests for HCV on a cohort of patients who received a liver transplant between 1990 and 1994 at three large centers. Seven hundred twenty-two recipients and 604 donors were tested for antibody to HCV (anti-HCV) using a second-generation enzyme-linked immunoassay (EIA-2), followed by recombinant immunoblot (RIBA-2) and HCV RNA confirmation by reverse-transcription polymerase chain reaction (RT-PCR) (with genotyping and viral quantification). Diagnosis of posttransplantation infection required detection of serum HCV RNA that could be genotyped by sequencing or was repeatedly positive despite being unsequenceable. Twenty-five percent of transplantation candidates were seropositive for anti-HCV. Approximately 86% of anti-HCV-positive, 93% of RIBA-positive, and 97% of HCV RNA-positive candidates developed infection after transplantation. Pretransplantation HCV RNA was superior to RIBA-2 for predicting posttransplantation infection. Whereas HCV genotype was identified in nearly all candidates and changed little after transplantation, serum viral levels rose markedly after transplantation. Fifteen donors were either anti-HCV- or HCV RNA-positive. Recipients of grafts from donors with HCV RNA all developed infection, whereas infection was not detected in recipients of grafts from donors with anti-HCV but without detectable HCV RNA. The rate of new infection fell significantly (P =.02) after the introduction of EIA-2 screening of blood. Donor and candidate markers for HCV predict posttransplantation infection.

Role of hyperglucagonemia in catabolism associated with type 1 diabetes: effects on leucine metabolism and the resting metabolic rate

The catabolic state of poorly controlled type 1 diabetes has largely been attributed to insulin deficiency. However, the role of hyperglucagonemia, which occurs concomitantly with insulin deficiency, has not been fully investigated. We studied the effects of hyperglucagonemia during insulin deprivation on energy expenditure (using indirect calorimetry) and protein metabolism (using L-[1-(13)C,15N]leucine and L-[1-(13)C]leucine as tracers) in 12 type 1 diabetic subjects. Five protocols were used: insulin treatment, insulin deprivation, insulin deprivation with suppression of endogenous glucagon with somatostatin (SRIH) and growth hormone replacement, insulin deprivation with endogenous glucagon suppression with SRIH (no growth hormone replacement), and insulin deprivation with SRIH and a high level of glucagon replacement (no growth hormone replacement). It was observed that leucine oxidation and the resting metabolic rate (RMR) were significantly lower during insulin treatment and insulin deprivation with concomitant SRIH infusion (lowering glucagon) than during insulin deprivation alone. Replacement of glucagon at a high level during SRIH infusion in the insulin-deprived state increased leucine oxidation and the RMR. Hyperglucagonemia was also associated with a trend for decreased protein synthesis. Hyperglucagonemia did not affect leucine transamination. Insulin replacement decreased leucine flux and oxidation. Leucine oxidation (R2 = 0.79) and the RMR (R2 = 0.81) were seen, by multiple regression analysis, to correlate with glucagon levels and not with other hormones. We conclude that while insulin deficiency increases protein breakdown, hyperglucagonemia is primarily responsible for the increased leucine oxidation and RMR seen during insulin deprivation.

Hepatitis G virus infection in patients transplanted for cryptogenic cirrhosis: red flag or red herring?

BACKGROUND

The significance of hepatitis G (HGV) infection in liver transplant recipients is not known. We set out to determine the pre-orthotopic liver transplantation (OLT) prevalence, the pre- and postoperative viral titers of HGV, and the allograft histology in patients infected with HGV who underwent OLT for cryptogenic cirrhosis.

METHODS

HGV RNA was measured using a research-based branched DNA assay. The assay used a target-specific probe set that was based on the 5'-untranslated region of the HGV genome. Allograft histology was assessed with protocol liver biopsies in all patients who survived longer than 6 months.

RESULTS

The preoperative prevalence of HGV infection in recipients transplanted for cryptogenic cirrhosis was 26%. Thirty-seven percent (12 of 33) of recipients who had serum available in the first postoperative month had HGV infection. Mean HGV RNA levels were 9.8 (+/-4.2) (viral molecular equivalents/ml x 10[6]) before OLT and 37.5 (+/-10.7) at 1 year after OLT. In 4 of the 11 cryptogenic recipients in whom HGV RNA was detectable in the first postoperative month, HGV RNA fell to undetectable levels at the most recent follow-up (mean 70 months). Of the five cryptogenic recipients who continue to have measurable HGV RNA, three have unexplained hepatitis histologically.

CONCLUSIONS

These findings suggest the following: 1) The prevalence of HGV infection in patients undergoing OLT for cryptogenic cirrhosis is about 25%. 2) In recipients persistently infected with HGV, mean HGV RNA titers increase after OLT. 3) HGV RNA becomes undetectable in about one third of recipients who had detectable HGV RNA in the first month after OLT. 4) Hepatitis of uncertain etiology occurs in 60% (3 of 5) of persistently HGV-infected cryptogenic recipients.

Skeletal muscle myosin heavy chain synthesis in type 1 diabetes

Although insulin's anticatabolic effect on protein metabolism in type 1 diabetes has been clearly shown to be related to the inhibition of protein breakdown, insulin's effect on muscle protein synthesis remains controversial. Cross-limb studies and measurements of synthesis rates of mixed muscle protein have yielded conflicting results. These measurements represent the mean synthesis of several muscle proteins and may miss changes in the synthesis rates of individual muscle proteins. We measured the fractional synthesis rates of myosin heavy chain (MHC), the principal muscle contractile protein, and mixed muscle protein (MMP) in six type 1 diabetic patients during insulin deprivation and insulin treatment. Comparisons were made with six healthy control subjects. Muscle biopsies were taken at 2 h and 8 h during a primed continuous infusion of L-[1-13C]leucine. MHC was purified by a preparative continuous elution gel electrophoresis, and fractional synthesis rates were calculated. We found that in type 1 diabetic subjects, the fractional synthesis rates of MHC and MMP during insulin treatment are similar to those of control subjects. Acute insulin deprivation did not affect either the synthesis rate or the ratio of MHC to MMP in type 1 diabetic subjects. In the postabsorptive state, acute insulin deprivation has no effect on MHC or MMP synthesis in type 1 diabetic patients.

Liver transplantation for cryptogenic cirrhosis

End-stage liver disease secondary to cryptogenic cirrhosis is the indication for orthotopic liver transplantation (OLT) in 7% to 14% of recipients. However, there are no reports documenting the outcome of OLT for this indication. The aim of this study was to determine (1) survival and (2) the incidence of histological recurrence of cryptogenic cirrhosis after OLT. Between March 1985 and December 1994, 560 OLTs were performed at our institution. Of these, 39 transplants for cryptogenic cirrhosis were in patients who met the following criteria: antinuclear antibody < 1:40; negative anti-smooth muscle antibody, antimitochondrial antibody, polymerase chain reaction for hepatitis C virus, and hepatitis B surface antigen results; normal ceruloplasmin and alpha-1 antitrypsin phenotype; transferrin saturation < 65%; and liver biopsy specimen not suggestive of hemochromatosis or other known disorders. Histological recurrence was assessed with protocol liver biopsies in all patients who survived longer than 6 months. The mean age of cryptogenic recipients at the time of transplantation was significantly lower (40.6 years; range, 3 to 63 years) than that of noncryptogenic recipients (48.5 years; range, 1-70; P < .03). Median modified Child's-Pugh score was slightly higher for cryptogenic recipients at the time of transplantation (10.0 + 0.08 standard error of mean [SEM]), than for the noncryptogenic recipients (9.0 + 0.03 SEM; P < .02). Actuarial survival was 72% (+ 0.07 SEM) at 1 and 58% (+ 0.08 SEM) at 5 years for cryptogenic recipients compared with 89% at 1 and 80% at 5 years for noncryptogenic recipients. The difference in survival was significant (P < .001) at both 1 and 5 years. Among the 27 cryptogenic recipients surviving more than 6 months (mean follow-up, 5.5 years), 6 have persistent hepatitis histologically without apparent infectious, vascular, biliary, or drug origins. Four patients (15%) had chronic active hepatitis, and 2 (7%) had steatohepatitis. No cases of recurrent cryptogenic cirrhosis were seen. OLT for cryptogenic cirrhosis is associated with a poor outcome compared with other indications, hepatitis of uncertain origin occurred in 22% of cryptogenic recipients surviving longer than 6 months, and no evidence of recurrence of cryptogenic cirrhosis was seen thus far in follow-up.

Protein metabolism and liver disease

In health, the liver orchestrates the metabolism of proteins and amino acids. When the liver is diseased, the regulation of protein metabolism is frequently disturbed. The manifestations of disturbed protein metabolism in liver disease are varied and change with disease aetiology and severity. The hallmarks of protein and amino acid metabolism in liver disease are lowered concentrations of circulating branched-chain and increased concentrations of circulating aromatic amino acids with concomitantly altered amino acid kinetics. The changes in amino acid kinetics in liver disease are characterized by increased endogenous leucine flux, an indicator of protein breakdown, and leucine oxidation in the post-absorptive state (when calculated using a reciprocal-pool model and normalized for body cell mass). In addition, the increase in whole-body protein synthesis in response to an amino acid infusion may be attenuated in patients with cirrhosis. These changes are often accompanied by clinically apparent muscle wasting, manifest as protein-calorie malnutrition, and associated low levels of hepatically synthesized plasma proteins. While the pathogenesis of these changes in protein and amino acid metabolism has not been elucidated, altered levels of circulating hormones, known to affect protein metabolism, are probably important. Lowered levels of micronutrients and trace metals and elevated levels of cytokines may also play a role.

Evidence for a catabolic role of glucagon during an amino acid load

Despite the strong association between protein catabolic conditions and hyperglucagonemia, and enhanced glucagon secretion by amino acids (AA), glucagon's effects on protein metabolism remain less clear than on glucose metabolism. To clearly define glucagon's catabolic effect on protein metabolism during AA load, we studied the effects of glucagon on circulating AA and protein dynamics in six healthy subjects. Five protocols were performed in each subject using somatostatin to inhibit the secretion of insulin, glucagon, and growth hormone (GH) and selectively replacing these hormones in different protocols. Total AA concentration was the highest when glucagon, insulin, and GH were low. Selective increase of glucagon levels prevented this increment in AA. Addition of high levels of insulin and GH to high glucagon had no effect on total AA levels, although branched chain AA levels declined. Glucagon mostly decreased glucogenic AA and enhanced glucose production. Endogenous leucine flux, reflecting proteolysis, decreased while leucine oxidation increased in protocols where AA were infused and these changes were unaffected by the hormones. Nonoxidative leucine flux reflecting protein synthesis was stimulated by AA, but high glucagon attenuated this effect. Addition of GH and insulin partially reversed the inhibitory effect of glucagon on protein synthesis. We conclude that glucagon is the pivotal hormone in amino acid disposal during an AA load and, by reducing the availability of AA, glucagon inhibits protein synthesis stimulated by AA. These data provide further support for a catabolic role of glucagon at physiological concentrations.

A cardiac rehabilitation compliance assessment tool

The Cardiac Rehabilitation Compliance Assessment (CRCA) tool was developed by the author to facilitate compliance among cardiac rehabilitation patients with their exercise and medical regimen. The 18-item tool is based on a review of the cardiac rehabilitation literature and the results of a telephone survey of cardiac rehabilitation patients who dropped out of an outpatient program (in other words, they had attended fewer than 18 of 36 sessions). The items are organized into six categories. Each item is assigned a value of 0 to 6 by the nurse. Items are totaled to determine if the patient is at high, moderate, or low risk for dropping out of the program and for noncompliance. Individualized motivational care plans can be formulated based on the CRCA assessment data.