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.

Evolution of causes and risk factors for mortality post-liver transplant: results of the NIDDK long-term follow-up study.

Although mortality rates following liver transplantation (LT) are well described, there is a lack of detailed, prospective studies determining patterns of and risk factors for long-term mortality. We analyzed the multicenter, prospectively obtained The National Institute of Diabetes and Digestive and Kidney Diseases LT Database of 798 transplant recipients from 1990 to 1994 (follow-up 2003). Overall, 327 recipients died. Causes of death >1 year: 28% hepatic, 22% malignancy, 11% cardiovascular, 9% infection, 6% renal failure. Renal-related death increased dramatically over time. Risk factors for death >1 year (univariate): male gender, age/decade, pre-LT diabetes, post-LT diabetes, post-LT hypertension, post-LT renal insufficiency, retransplantation >1 year, pre-LT malignancy, alcoholic disease (ALD) and metabolic liver disease, with similar risks noted for death >5 years. Hepatitis C, retransplantation, post-LT diabetes, hypertension and renal insufficiency were significant risk factors for liver-related death. Cardiac deaths associated with age, male gender, ALD, cryptogenic disease, pre-LT hypertension and post-LT renal insufficiency. In summary, the leading causes of late deaths after transplant were graft failure, malignancy, cardiovascular disease and renal failure. Older age, diabetes and renal insufficiency identified patients at highest risk of poor survival overall. Diligent management of modifiable post-LT factors including diabetes, hypertension and renal insufficiency may impact long-term mortality.

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

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.

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.

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.

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.