Association of γ-glutamyl transferase (GGT) activity with treatment and clinical outcomes in chronic hepatitis C (HCV).

UNLABELLED: Increased γ-glutamyl transferase (GGT) activity is associated with liver injury and with mortality in the general population. Less is known about its association with chronic hepatitis C (HCV) outcomes. We examined GGT as a predictor of both virological response to treatment and long-term clinical outcomes in the Hepatitis C Anti-viral Treatment Against Cirrhosis Trial (HALT-C). HALT-C enrolled patients with advanced liver disease (Ishak fibrosis score ≥3) in two phases: a lead-in to establish lack of sustained viral response with full dose pegylated interferon (IFN) and ribavirin followed by a 3.5-year randomized trial with low-dose IFN. Low-dose IFN did not prevent liver disease progression, and patients were then followed for up to an additional 5 years off therapy. Analyses were performed for 1,319 patients who had GGT measured prior to initiation of treatment. Increases in risk with each increase in quintile of GGT (10-57, 58-89, 90-139, 140-230, 231-2,000 IU/L) were determined by logistic regression for treatment response or Cox regression for clinical outcomes. Baseline GGT was associated with male sex, nonwhite ethnicity, diabetes and insulin resistance, interleukin (IL)28B rs12979860 CT and TT genotypes, and numerous markers of liver disease injury and severity. In the lead-in phase, increasing GGT was strongly associated with diminished week 20 response, end of treatment response, and sustained virological response in both univariate and multivariate analyses controlling for factors known to be associated with treatment response (P < 0.0001). GGT was also associated with all clinical outcomes in univariate and multivariate analysis (P < 0.05) except for hepatocellular carcinoma (P = 0.46 in multivariate analysis). CONCLUSION: GGT is an independent predictor of both virological response and clinical outcomes among patients with advanced liver disease due to HCV.

Quantitative Analysis of Rhodobacter sphaeroides Storage Organelles via Cryo-Electron Tomography and Light Microscopy.

Bacterial cytoplasmic organelles are diverse and serve many varied purposes. Here, we employed Rhodobacter sphaeroides to investigate the accumulation of carbon and inorganic phosphate in the storage organelles, polyhydroxybutyrate (PHB) and polyphosphate (PP), respectively. Using cryo-electron tomography (cryo-ET), these organelles were observed to increase in size and abundance when growth was arrested by chloramphenicol treatment. The accumulation of PHB and PP was quantified from three-dimensional (3D) segmentations in cryo-tomograms and the analysis of these 3D models. The quantification of PHB using both segmentation analysis and liquid chromatography and mass spectrometry (LCMS) each demonstrated an over 10- to 20-fold accumulation of PHB. The cytoplasmic location of PHB in cells was assessed with fluorescence light microscopy using a PhaP-mNeonGreen fusion-protein construct. The subcellular location and enumeration of these organelles were correlated by comparing the cryo-ET and fluorescence microscopy data. A potential link between PHB and PP localization and possible explanations for co-localization are discussed. Finally, the study of PHB and PP granules, and their accumulation, is discussed in the context of advancing fundamental knowledge about bacterial stress response, the study of renewable sources of bioplastics, and highly energetic compounds.

Quantitative liver function tests improve the prediction of clinical outcomes in chronic hepatitis C: results from the Hepatitis C Antiviral Long-term Treatment Against Cirrhosis Trial.

UNLABELLED: Risk for future clinical outcomes is proportional to the severity of liver disease in patients with chronic hepatitis C virus (HCV). We measured disease severity by quantitative liver function tests (QLFTs) to determine cutoffs for QLFTs that identified patients who were at low and high risk for a clinical outcome. Two hundred and twenty-seven participants in the Hepatitis C Antiviral Long-term Treatment Against Cirrhosis (HALT-C) Trial underwent baseline QLFTs and were followed for a median of 5.5 years for clinical outcomes. QLFTs were repeated in 196 patients at month 24 and in 165 patients at month 48. Caffeine elimination rate (k(elim)), antipyrine (AP) clearance (Cl), MEGX concentration, methionine breath test (MBT), galactose elimination capacity (GEC), dual cholate (CA) clearances and shunt, perfused hepatic mass (PHM), and liver and spleen volumes (by single-photon emission computed tomography) were measured. Baseline QLFTs were significantly worse (P = 0.0017 to P < 0.0001) and spleen volumes were larger (P < 0.0001) in the 54 patients who subsequently experienced clinical outcomes. QLFT cutoffs that characterized patients as "low" and "high risk" for clinical outcome yielded hazard ratios ranging from 2.21 (95% confidence interval [CI]: 1.29-3.78) for GEC to 6.52 (95% CI: 3.63-11.71) for CA clearance after oral administration (Cl(oral)). QLFTs independently predicted outcome in models with Ishak fibrosis score, platelet count, and standard laboratory tests. In serial studies, patients with high-risk results for CA Cl(oral) or PHM had a nearly 15-fold increase in risk for clinical outcome. Less than 5% of patients with "low risk" QLFTs experienced a clinical outcome. CONCLUSION: QLFTs independently predict risk for future clinical outcomes. By improving risk assessment, QLFTs could enhance the noninvasive monitoring, counseling, and management of patients with chronic HCV.

Clinical overview and treatment options for non-skeletal manifestations of mucopolysaccharidosis type IVA.

Mucopolysaccharidosis type IVA (MPS IVA) or Morquio syndrome is a multisystem disorder caused by galactosamine-6-sulfatase deficiency. Skeletal manifestations, including short stature, skeletal dysplasia, cervical instability, and joint destruction, are known to be associated with this condition. Due to the severity of these skeletal manifestations, the non-skeletal manifestations are frequently overlooked despite their significant contribution to disease progression and impact on quality of life. This review provides detailed information regarding the non-skeletal manifestations and suggests long-term assessment guidelines. The visual, auditory, digestive, cardiovascular, and respiratory systems are addressed and overall quality of life as measured by endurance and other functional abilities is discussed. Impairments such as corneal clouding, astigmatism, glaucoma, hearing loss, hernias, hepatomegaly, dental abnormalities, cardiac valve thickening and regurgitation, obstructive sleep apnea, tracheomalacia, restrictive and obstructive respiratory compromise, and muscular weakness are discussed. Increased awareness of these non-skeletal features is needed to improve patient care.

Coffee consumption is associated with response to peginterferon and ribavirin therapy in patients with chronic hepatitis C.

BACKGROUND & AIMS: High-level coffee consumption has been associated with reduced progression of pre-existing liver diseases and lower risk of hepatocellular carcinoma. However, its relationship with therapy for hepatitis C virus infection has not been evaluated. METHODS: Patients (n=885) from the lead-in phase of the Hepatitis C Antiviral Long-Term Treatment Against Cirrhosis Trial recorded coffee intake before retreatment with peginterferon α-2a (180 µg/wk) and ribavirin (1000-1200 mg/day). We assessed patients for early virologic response (2 log10 reduction in level of hepatitis C virus RNA at week 12; n=466), and undetectable hepatitis C virus RNA at weeks 20 (n=320), 48 (end of treatment, n=284), and 72 (sustained virologic response; n=157). RESULTS: Median log10 drop from baseline to week 20 was 2.0 (interquartile range [IQR], 0.6-3.9) among nondrinkers and 4.0 (IQR, 2.1-4.7) among patients that drank 3 or more cups/day of coffee (P trend<.0001). After adjustment for age, race/ethnicity, sex, alcohol, cirrhosis, ratio of aspartate aminotransferase to alanine aminotransferase, the IL28B polymorphism rs12979860, dose reduction of peginterferon, and other covariates, odds ratios for drinking 3 or more cups/day vs nondrinking were 2.0 (95% confidence interval [CI]: 1.1-3.6; P trend=.004) for early virologic response, 2.1 (95% CI: 1.1-3.9; P trend=.005) for week 20 virologic response, 2.4 (95% CI: 1.3-4.6; P trend=.001) for end of treatment, and 1.8 (95% CI: 0.8-3.9; P trend=.034) for sustained virologic response. CONCLUSIONS: High-level consumption of coffee (more than 3 cups per day) is an independent predictor of improved virologic response to peginterferon plus ribavirin in patients with hepatitis C.

Maintenance peginterferon therapy and other factors associated with hepatocellular carcinoma in patients with advanced hepatitis C.

BACKGROUND & AIMS: Interferon reportedly decreases the incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis C. The Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial showed that 4 years of maintenance therapy with pegylated interferon (peginterferon) does not reduce liver disease progression. We investigated whether peginterferon decreases the incidence of HCC in the HALT-C cohort over a longer posttreatment follow-up period. METHODS: The study included 1048 patients with chronic hepatitis C (Ishak fibrosis scores ≥ 3) who did not have a sustained virologic response (SVR) to therapy. They were randomly assigned to groups given a half-dose of peginterferon or no treatment (controls) for 3.5 years and followed up for a median of 6.1 (maximum, 8.7) years. RESULTS: Eighty-eight patients developed HCC (68 definite, 20 presumed): 37 of 515 who were given peginterferon (7.2%) and 51 of 533 controls (9.6%; P = .24). There was a significantly lower incidence of HCC among patients given peginterferon therapy who had cirrhosis, but not fibrosis, based on analysis of baseline biopsy samples. After 7 years, the cumulative incidences of HCC in treated and control patients with cirrhosis were 7.8% and 24.2%, respectively (hazard ratio [HR], 0.45; 95% confidence interval [CI], 0.24-0.83); in treated and control patients with fibrosis, incidences were 8.3% and 6.8%, respectively (HR, 1.44; 95% CI, 0.77-2.69). Treated patients with a ≥ 2-point decrease in the histologic activity index, based on a follow-up biopsy, had a lower incidence of HCC than those with unchanged or increased scores (2.9% vs 9.4%; P = .03). CONCLUSIONS: Extended analysis of the HALT-C cohort showed that long-term peginterferon therapy does not reduce the incidence of HCC among patients with advanced hepatitis C who did not achieve SVRs. Patients with cirrhosis who received peginterferon treatment had a lower risk of HCC than controls.

Reduction in Hepatic Inflammation Is Associated With Less Fibrosis Progression and Fewer Clinical Outcomes in Advanced Hepatitis C.

OBJECTIVES: During the Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial, 3.5 years of maintenance peginterferon-alfa-2a therapy did not affect liver fibrosis progression or clinical outcomes among 1,050 previous interferon nonresponders with advanced fibrosis or cirrhosis. We investigated whether reduced hepatic inflammation was associated with clinical benefit in 834 patients with a baseline and follow-up biopsy 1.5 years after randomization to peginterferon or observation. METHODS: Relationships between change in hepatic inflammation (Ishak hepatic activity index, (HAI)) and serum alanine aminotransferase level, fibrosis progression and clinical outcomes after randomization, and hepatitis C virus (HCV) RNA decline before and after randomization were evaluated. Histological change was defined as a ≥ 2-point difference in HAI or Ishak fibrosis score between biopsies. RESULTS: Among 657 patients who received full-dose peginterferon/ribavirin "lead-in" therapy before randomization, year-1.5 HAI improvement was associated with lead-in HCV RNA suppression in both the randomized treated (P<0.0001) and control (P=0.0001) groups, even in the presence of recurrent viremia. This relationship persisted at year 3.5 in both the treated (P=0.001) and control (P=0.01) groups. Among 834 patients followed for a median of 6 years, fewer clinical outcomes occurred in patients with improved HAI at year 1.5 compared with those without such improvement in both the treated (P=0.03) and control (P=0.05) groups. Among patients with Ishak 3-4 fibrosis at baseline, those with improved HAI at year 1.5 had less fibrosis progression at year 1.5 in both the treated (P=0.0003) and control (P=0.02) groups. CONCLUSIONS: Reduced hepatic inflammation (measured 1.5 and 3.5 years after randomization) was associated with profound virological suppression during lead-in treatment with full-dose peginterferon/ribavirin and with decreased fibrosis progression and clinical outcomes, independent of randomized treatment.

Excess mortality in patients with advanced chronic hepatitis C treated with long-term peginterferon.

UNLABELLED: Chronic hepatitis C virus infection can cause chronic liver disease, cirrhosis and liver cancer. The Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial was a prospective, randomized controlled study of long-term, low-dose peginterferon therapy in patients with advanced chronic hepatitis C who failed to respond to a previous course of optimal antiviral therapy. The aim of this follow-up analysis is to describe the frequency and causes of death among this cohort of patients. Deaths occurring during and after the HALT-C Trial were reviewed by a committee of investigators to determine the cause of death and to categorize each death as liver- or nonliver-related and as related or not to complications of peginterferon. Rates of liver transplantation were also assessed. Over a median of 5.7 years, 122 deaths occurred among 1,050 randomized patients (12%), of which 76 were considered liver-related (62%) and 46 nonliver-related (38%); 74 patients (7%) underwent liver transplantation. At 7 years the cumulative mortality rate was higher in the treatment compared to the control group (20% versus 15%, P = 0.049); the primary difference in mortality was in patients in the fibrosis compared to the cirrhosis stratum (14% versus 7%, P = 0.01); comparable differences were observed when liver transplantation was included. Excess mortality, emerging after 3 years of treatment, was related largely to nonliver-related death; liver-related mortality was similar in the treatment and control groups. No specific cause of death accounted for the excess mortality and only one death was suspected to be a direct complication of peginterferon. CONCLUSION: Long-term maintenance peginterferon in patients with advanced chronic hepatitis C is associated with an excess overall mortality, which was primarily due to nonliver-related causes among patients with bridging fibrosis.

A prospective study of the rate of progression in compensated, histologically advanced chronic hepatitis C.

UNLABELLED: The incidence of liver disease progression among subjects with histologically advanced but compensated chronic hepatitis C is incomplete. The Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial was a randomized study of 3.5 years of maintenance peginterferon treatment on liver disease progression among patients who had not cleared virus on peginterferon and ribavirin therapy. Patients were followed subsequently off therapy. Because maintenance peginterferon treatment did not alter liver disease progression, we analyzed treated and control patients together. Among 1,050 subjects (60% advanced fibrosis, 40% cirrhosis), we determined the rate of progression to cirrhosis over 4 years and of clinical outcomes over 8 years. Among patients with fibrosis, the incidence of cirrhosis was 9.9% per year. Six hundred seventy-nine clinical outcomes occurred among 329 subjects. Initial clinical outcomes occurred more frequently among subjects with cirrhosis (7.5% per year) than subjects with fibrosis (3.3% per year) (P<0.0001). Child-Turcotte-Pugh (CTP) score≥7 was the most common first outcome, followed by hepatocellular carcinoma. Following occurrence of a CTP score≥7, the rate of subsequent events increased to 12.9% per year, including a death rate of 10% per year. Age and sex did not influence outcome rates. Baseline platelet count was a strong predictor of all clinical outcomes. During the 8 years of follow-up, death or liver transplantation occurred among 12.2% of patients with advanced fibrosis and 31.5% of those with cirrhosis. CONCLUSION: Among patients with advanced hepatitis C who failed peginterferon and ribavirin therapy, the rate of liver-related outcomes, including death and liver transplantation, is high, especially once the CTP score reaches at least 7.

Serum fibrosis markers are associated with liver disease progression in non-responder patients with chronic hepatitis C.

OBJECTIVES: The aim of this study was to explore the association of serum fibrosis marker levels with the risk of clinical and histological disease progression in a large cohort of patients with chronic hepatitis C (CHC). METHODS: 462 prior non-responders to peginterferon and ribavirin enrolled in the randomised phase of the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial had baseline and annual serum samples tested for hyaluronic acid (HA), N-terminal peptide of procollagen type 3, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and YKL-40. All patients underwent a pretreatment liver biopsy and follow-up biopsies at years 2 and 4. Histological progression was defined as a ≥2 point increase in Ishak fibrosis score in patients without cirrhosis. Clinical outcomes included development of decompensation, hepatocellular cancer, death or an increase in the CTP (Child-Turcotte-Pugh) score to ≥7. RESULTS: Mean patient age was 49.5 years and 39% had histological cirrhosis at entry. Baseline HA, YKL-40 and TIMP-1 levels combined with other laboratory parameters were all significantly associated with clinical outcomes in the 69 (15%) patients with disease progression (p<0.0001). The best multivariate model to predict clinical outcomes included baseline bilirubin, albumin, international normalised ratio (INR) and YKL-40 levels. All of the baseline serum fibrosis marker levels were also significantly associated with histological fibrosis progression that developed in 70 (33%) of the 209 patients with cirrhosis (p <0.0001). However, baseline HA and platelet counts were best at predicting histological progression (area under the curve (AUC)=0.663). CONCLUSION: Pretreatment serum fibrosis marker levels are significantly increased in patients with CHC at risk of clinical and histological disease progression. If validated in additional cohorts, measurement of these markers could help identify patients with CHC who would benefit from more frequent and intensive monitoring.

Effect of HCV RNA suppression during peginterferon alfa-2a maintenance therapy on clinical outcomes in the HALT-C trial.

BACKGROUND & AIMS: The Hepatitis C Antiviral Long-term Treatment Against Cirrhosis (HALT-C) trial demonstrated that low-dose peginterferon maintenance therapy was ineffective in preventing clinical outcomes in patients with chronic hepatitis C, advanced fibrosis, and failure to achieve a sustained virologic response during lead-in phase treatment with standard dose peginterferon/ribavirin. This analysis was performed to determine whether suppressing HCV RNA during the trial was associated with a reduction in clinical outcomes. METHODS: Seven hundred sixty-four patients treated during the lead-in phase of HALT-C trial were randomized to either peginterferon alfa-2a (90 microg/week) maintenance therapy or no treatment (control) for 3.5 years. Clinical outcomes included an increase in Child-Turcotte-Pugh score, ascites, spontaneous bacterial peritonitis, hepatic encephalopathy, variceal hemorrhage, hepatocellular carcinoma, and mortality. RESULTS: During the lead-in, >or=4-log(10) decline in serum HCV RNA occurred in 178 patients; 82% of whom lost detectable HCV RNA and later broke through or relapsed. These patients had significantly (P = .003) fewer clinical outcomes whether randomized to maintenance therapy or control. Following randomization, serum HCV RNA increased significantly in all 90 control patients and in 58 of 88 receiving maintenance therapy. Only 30 patients had persistent suppression of HCV RNA by >or=4 log(10) during maintenance therapy. No significant reduction in clinical outcomes was observed in these patients. CONCLUSIONS: Viral suppression by >or=4 log(10) with full-dose peginterferon/ribavirin is associated with a significant reduction in clinical outcomes. Continuing low-dose peginterferon maintenance therapy, even in patients with persistent viral suppression, does not lead to a further decline in clinical outcomes.

Variants in interferon-alpha pathway genes and response to pegylated interferon-Alpha2a plus ribavirin for treatment of chronic hepatitis C virus infection in the hepatitis C antiviral long-term treatment against cirrhosis trial.

UNLABELLED: Combination treatment with pegylated-interferon-alpha (PEG IFN-alpha) and ribavirin, the current recommended therapy for chronic hepatitis C virus (HCV) infection, results in a sustained virological response (SVR) in only about half of patients. Because genes involved in the interferon-alpha pathway may affect antiviral responses, we analyzed the relationship between variants in these genes and SVR among participants in the Hepatitis C Antiviral Long-Term treatment Against Cirrhosis (HALT-C) trial. Patients had advanced chronic hepatitis C that had previously failed to respond to interferon-based treatment. Participants were treated with peginterferon-alpha2a and ribavirin during the trial. Subjects with undetectable HCV RNA at week 72 were considered to have had an SVR. Subjects with detectable HCV RNA at week 20 were considered nonresponders. We used TaqMan assays to genotype 56 polymorphisms found in 13 genes in the interferon-alpha pathway. This analysis compares genotypes for participants with an SVR to nonresponders. The primary analysis was restricted to European American participants because a priori statistical power was low among the small number (n = 131) of African American patients. We used logistic regression to control the effect of other variables that are associated with treatment response. Among 581 European American patients, SVR was associated with IFNAR1 IVS1-22G (adjusted odds ratio, 0.57; P = 0.02); IFNAR2 Ex2-33C (adjusted odds ratio, 2.09; P = 0.02); JAK1 IVS22+112T (adjusted odds ratio, 1.66; P = 0.04); and ADAR Ex9+14A (adjusted odds ratio, 1.67; P = 0.03). For the TYK2-2256A promoter region variant, a borderline association was present among European American participants (OR, 1.51; P = 0.05) and a strong relationship among African American patients; all 10 with SVR who were genotyped for TYK2 -2256 carried the A variant compared with 68 of 120 (57%) nonresponders (P = 0.006). CONCLUSION: Genetic polymorphisms in the interferon-alpha pathway may affect responses to antiviral therapy of chronic hepatitis C.

Interpretation of positive transcription-mediated amplification test results from polymerase chain reaction-negative samples obtained after treatment of chronic hepatitis C.

UNLABELLED: The Siemens VERSANT transcription-mediated amplification (TMA) assay is extremely sensitive for the detection of hepatitis C virus (HCV) RNA in serum. Eleven of 180 subjects in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial who achieved polymerase chain reaction (PCR)-defined sustained virological response (SVR) at week 72 also had TMA-positive results from the same blood draw; six were positive on repeat testing. We report the follow-up on these 11 patients, and the reproducibility of TMA test results from PCR-negative samples in relationship to antiviral treatment outcome. Peginterferon and ribavirin treatment was initiated in 1145 prior interferon nonresponders with advanced hepatic fibrosis. Treatment was continued for 48 weeks if patients had undetectable HCV RNA by PCR at treatment week 20. Frozen serum samples from weeks 12, 20, 24, 48, and 72 were subsequently tested by TMA. Nine of the 11 patients returned for testing (median, 30 months after the week 72 visit), and all had undetectable HCV RNA by TMA and PCR. Among 759 PCR-negative samples obtained during treatment that were tested twice by TMA, 17% overall exhibited consistently positive results, and 21% exhibited inconsistently positive results. SVR was more likely if TMA was consistently negative than if consistently or inconsistently positive. With continued treatment, patients with inconsistently positive TMA results were more likely to become TMA-negative than TMA-positive (P < 0.0001). CONCLUSION: In PCR-negative samples, positive TMA results may indicate the presence of low levels of HCV RNA. However, because patients with positive TMA results may achieve SVR, management decisions during therapy should not be based on a single positive TMA test result.

Automated summaries of serious adverse events in the hepatitis C antiviral long-term treatment against cirrhosis trial.

BACKGROUND: Even though adverse event (AE) collection and official accounting are mandatory for clinical trials, there are limited detailed guidelines specifying how to summarize the event for reporting in a timely and expeditious manner. This article details the AE and serious adverse event (SAE) reporting summary developed for a large multi-center National Institutes of Health (NIH)-sponsored clinical trial. PURPOSE: To review and analyze the large volume of AE data reported by 10 sites (806 SAEs and 19,034 AEs from August 2000 to May 2007) the automated SAE summary was developed. It was designed to ensure timeliness and clarity in the complex process of AE review and reporting. METHODS: The AE and SAE case report forms (CRFs) as well as the automated SAE summary were developed within a database management system developed by the Data Coordinating Center (DCC) which allowed for web-based data entry at the DCC and 10 sites and offered immediate overall and site-specific reports accessible by the DCC, site, and NIH project staff. RESULTS: The automated SAE summary pulled data from multiple CRFs to create a succinct and informative summary and allowed for prompt and easy reporting to the regulatory agencies. The summary was adaptable to the needs of reviewers because of the availability of multiple search options.

Blunted cytopenias and weight loss: new correlates of virologic null response to re-treatment of chronic hepatitis C.

BACKGROUND & AIMS: Peginterferon with ribavirin therapy for chronic hepatitis C leads to sustained loss of serum hepatitis C virus (HCV) RNA in half of treated patients. Although viral kinetic profiles in treatment responders shed light on the mechanism of action of interferon and ribavirin, minimal information is available to explain why some patients experience little or no virologic suppression. METHODS: We evaluated factors that might be associated with the lack of a week-20 virologic response in previous nonresponder patients undergoing peginterferon and ribavirin retreatment. Among 1145 patients enrolled in the Hepatitis C Antiviral Long-term Treatment against Cirrhosis Trial's lead-in treatment phase, 588 who received more than 80% of prescribed therapy for 20 weeks were analyzed. RESULTS: By week 20, 245 patients (41.7%) had undetectable HCV RNA (full response), 186 (31.6%) had a 1 log(10) or greater decrease in HCV RNA (partial response), and 157 (26.7%) had less than a 1 log(10) decrease (null response) in HCV RNA. Null response was associated independently with African American race, genotype-1 infection, and less reduction in body weight, platelets, and white blood cells during treatment. CONCLUSIONS: On-treatment variables associated with null response suggest a blunted systemic response to interferon. These observations have important implications for the design and analysis of trial results in which novel agents are evaluated. Further studies are needed to discern whether host interferon resistance, viral drug resistance, or both are playing a role in patients who have no virologic response to interferon treatment.

Safety and efficacy of pegylated interferon alpha-2a and ribavirin for the treatment of hepatitis C in patients with thalassemia.

Antiviral treatment of hepatitis C virus in thalassemia has raised concerns of ribavirin-induced hemolysis and increased iron loading. This study examined the change in liver iron concentration, transfusion requirement, virological response, and iron-related toxicities after pegylated interferon alpha-2a/ribavirin treatment in patients with thalassemia. Median transfusions increased by 44%. However, only 29% (4/14) of patients showed an increase of liver iron concentration > 5mg/g dry wt. and overall liver iron remained stable. One of 4 patients with genotype 2 or 3 demonstrated sustained viral response, compared with 50% with genotype 1 (6/12). No patient developed cardiac, liver or endocrine toxicities, although neutropenia occurred in 52%. The molar efficacy of deferoxamine improved with reduction in liver inflammation on biopsy (p=0.001). In conclusion, antiviral treatment is safe if transfusion requirement, iron toxicities and neutropenia are monitored.

Peripheral myelin protein 22 alters membrane architecture.

Peripheral myelin protein 22 (PMP22) is highly expressed in myelinating Schwann cells of the peripheral nervous system. PMP22 genetic alterations cause the most common forms of Charcot-Marie-Tooth disease (CMTD), which is characterized by severe dysmyelination in the peripheral nerves. However, the functions of PMP22 in Schwann cell membranes remain unclear. We demonstrate that reconstitution of purified PMP22 into lipid vesicles results in the formation of compressed and cylindrically wrapped protein-lipid vesicles that share common organizational traits with compact myelin of peripheral nerves in vivo. The formation of these myelin-like assemblies depends on the lipid-to-PMP22 ratio, as well as on the PMP22 extracellular loops. Formation of the myelin-like assemblies is disrupted by a CMTD-causing mutation. This study provides both a biochemical assay for PMP22 function and evidence that PMP22 directly contributes to membrane organization in compact myelin.

Viscoelastic and mechanical behavior of recombinant protein elastomers.

Recombinant DNA synthesis was employed to produce elastin-mimetic protein triblock copolymers containing chemically distinct midblocks. These materials displayed a broad range of mechanical and viscoelastic responses ranging from plastic to elastic when examined as hydrated gels and films. These properties could be related in a predictable fashion to polymer block size and structure. While these materials could be easily processed into films and gels, electrospinning proved a feasible strategy for creating protein fibers. All told, the range of properties exhibited by this new class of protein triblock copolymer in combination with their easy processability suggests potential utility in a variety of soft prosthetic and tissue engineering applications.

Self-assembly of block copolymers derived from elastin-mimetic polypeptide sequences.

Protein polymers derived from elastin-mimetic peptide sequences can be synthesized with near-absolute control of macromolecular architecture using genetic engineering techniques. Elastin-mimetic diblock and triblock copolymers have been prepared using this approach in which the individual elastin blocks display different phase behavior in aqueous solution. The selective collapse of the more hydrophobic blocks above the lower critical solution temperature was employed to drive the thermo-reversible self-assembly of elastin-mimetic diblock and triblock copolymer into protein-based nanoparticles and nano-textured hydrogels, respectively. These materials display considerable promise as biomaterials for applications in drug delivery and soft tissue augmentation.