Factors associated with early virological response to peginterferon-α-2a/ribavirin in chronic hepatitis C

AIM: To evaluate the impact of sociodemographic/clinical factors on early virological response (EVR) to peginterferon/ribavirin for chronic hepatitis C (CHC) in clinical practice.

METHODS: We conducted a multicenter, cross-sectional, observational study in Hepatology Units of 91 Spanish hospitals. CHC patients treated with peginterferon α-2a plus ribavirin were included. EVR was defined as undetectable hepatitis C virus (HCV)-ribonucleic acid (RNA) or ≥ 2 log HCV-RNA decrease after 12 wk of treatment. A bivariate analysis of sociodemographic and clinical variables associated with EVR was carried out. Independent factors associated with an EVR were analyzed using a multiple regression analysis that included the following baseline demographic and clinical variables: age (≤ 40 years vs > 40 years), gender, race, educational level, marital status and family status, weight, alcohol and tobacco consumption, source of HCV infection, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, and gamma glutamyl transpeptidase (GGT) (≤ 85 IU/mL vs > 85 IU/mL), serum ferritin, serum HCV-RNA concentration (< 400 000 vs≥ 400 000), genotype (1/4 vs 3/4), cirrhotic status and ribavirin dose (800/1000/1200 mg/d).

RESULTS: A total of 1014 patients were included in the study. Mean age of the patients was 44.3 ± 9.8 years, 70% were male, and 97% were Caucasian. The main sources of HCV infection were intravenous drug abuse (25%) and blood transfusion (23%). Seventy-eight percent were infected with HCV genotype 1/4 (68% had genotype 1) and 22% with genotypes 2/3. The HCV-RNA level was > 400 000 IU/mL in 74% of patients. The mean ALT and AST levels were 88.4 ± 69.7 IU/mL and 73.9 ± 64.4 IU/mL, respectively, and mean GGT level was 82 ± 91.6 IU/mL. The mean ferritin level was 266 ± 284.8 μg/L. Only 6.2% of patients presented with cirrhosis. All patients received 180 mg of peginterferon α-2a. The most frequently used ribavirin doses were 1000 mg/d (41%) and 1200 mg/d (41%). The planned treatment duration was 48 wk for 92% of patients with genotype 2/3 and 24 wk for 97% of those with genotype 1/4 (P < 0.001). Seven percent of patients experienced at least one reduction in ribavirin or peginterferon α-2a dose, respectively. Only 2% of patients required a dose reduction of both drugs. Treatment was continued until week 12 in 99% of patients. Treatment compliance was ≥ 80% in 98% of patients. EVR was achieved in 87% of cases (96% vs 83% of patients with genotype 2/3 and 1/4, respectively; P < 0.001). The bivariate analysis showed that patients who failed to achieve EVR were older (P < 0.005), had higher ALT (P < 0.05), AST (P < 0.05), GGT (P < 0.001) and ferritin levels (P < 0.001), a diagnosis of cirrhosis (P < 0.001), and a higher baseline viral load (P < 0.05) than patients reaching an EVR. Age < 40 years [odds ratios (OR): 0.543, 95%CI: 0.373-0.790, P < 0.01], GGT < 85 IU/mL (OR: 3.301, 95%CI: 0.192-0.471, P < 0.001), low ferritin levels (OR: 0.999, 95%CI: 0.998-0.999, P < 0.01) and genotype other than 1/4 (OR: 4.716, 95%CI: 2.010-11.063, P < 0.001) were identified as independent predictors for EVR in the multivariate analysis.

CONCLUSION: CHC patients treated with peginterferon-α-2a/ribavirin in clinical practice show high EVR. Older age, genotype 1/4, and high GGT were associated with lack of EVR.

The chemotherapy long-term effect on cognitive functions and brain metabolism in lymphoma patients

AIM

A growing number of neuropsychological studies reported that chemotherapy may impair brain functions, inducing persistent cognitive changes in a subset of cancer survivors. The aim of this paper was to investigate the neural basis of the chemotherapy induced neurobehavioral changes by means of metabolic imaging and neuropsychological testing.

METHODS

We studied the resting brain [¹⁸F]FDG-PET/CT images of 50 adult cancer patients with diagnosis of lymphoma: 18 patients were studied prior and 32 after to chemotherapy. All patients underwent to a neuropsychological examination assessing cognitive impairment (tests for shifting attention, verbal memory, phonemic fluency), depression, anxiety and distress.

RESULTS

Compared to no chemotherapy patients, the treated group showed significant bilateral lower rate of glucose metabolism in prefrontal cortices, cerebellum, medial cortices and limbic brain areas. The metabolism of these regions negatively correlated with number of cycles and positively with post-chemotherapy time. The treated group showed a poorer performance in many frontal functions, but similar level of depression, anxiety and distress.

CONCLUSIONS

Chemotherapy induced significant long-term changes in metabolism of multiple regions with a prevailing involvement of the prefrontal cortex. The observed cognitive dysfunctions could be explained by these changes. The recovery from chemotherapy is probably affected by treatment duration and by the time elapsed after its end. We speculated that the mechanism could be an accelerating ageing / oxidative stress that, in some patients at risk, could result in an early and persistent cognitive impairment.

Mean atomic number quantitative assessment in backscattered electron imaging

A method for obtaining quantitative mean atomic number images in a scanning electron microscope for different kinds of samples has been developed. The backscattered electron signal is monotonically increasing with the mean atomic number Z, and accordingly Z can be given as a function of the image gray levels. From results obtained from Monte Carlo simulations, an exponential function is fitted to convert the backscattered registered gray levels into a Z image map. Once this fitting was performed, the reproducibility of the Z determination was checked through the acquisition of backscattered electron images from metal and mineral standards. The developed method can be applied to any unknown sample, always controlling the experimental conditions, as shown here for a thin section of a rock in which several unknown mineral phases are present; the results obtained herein are compared to quantitative assessments performed with X-ray spectra from each mineral phase.

NAA and NAAG variation in neuronal activation during visual stimulation

N-acetyl-aspartyl-glutamate (NAAG) and its hydrolysis product N-acetyl-aspartate (NAA) are among the most important brain metabolites. NAA is a marker of neuron integrity and viability, while NAAG modulates glutamate release and may have a role in neuroprotection and synaptic plasticity. Investigating on a quantitative basis the role of these metabolites in brain metabolism in vivo by magnetic resonance spectroscopy (MRS) is a major challenge since the main signals of NAA and NAAG largely overlap. This is a preliminary study in which we evaluated NAA and NAAG changes during a visual stimulation experiment using functional MRS. The paradigm used consisted of a rest period (5 min and 20 s), followed by a stimulation period (10 min and 40 s) and another rest period (10 min and 40 s). MRS from 17 healthy subjects were acquired at 3T with TR/TE = 2000/288 ms. Spectra were averaged over subjects and quantified with LCModel. The main outcomes were that NAA concentration decreased by about 20% with the stimulus, while the concentration of NAAG concomitantly increased by about 200%. Such variations fall into models for the energy metabolism underlying neuronal activation that point to NAAG as being responsible for the hyperemic vascular response that causes the BOLD signal. They also agree with the fact that NAAG and NAA are present in the brain at a ratio of about 1:10, and with the fact that the only known metabolic pathway for NAAG synthesis is from NAA and glutamate.

Manual and semi-automatic quantification of in vivo ¹H-MRS data for the classification of human primary brain tumors

In vivo proton magnetic resonance spectroscopy (¹H-MRS) is a technique capable of assessing biochemical content and pathways in normal and pathological tissue. In the brain, ¹H-MRS complements the information given by magnetic resonance images. The main goal of the present study was to assess the accuracy of ¹H-MRS for the classification of brain tumors in a pilot study comparing results obtained by manual and semi-automatic quantification of metabolites. In vivo single-voxel ¹H-MRS was performed in 24 control subjects and 26 patients with brain neoplasms that included meningiomas, high-grade neuroglial tumors and pilocytic astrocytomas. Seven metabolite groups (lactate, lipids, N-acetyl-aspartate, glutamate and glutamine group, total creatine, total choline, myo-inositol) were evaluated in all spectra by two methods: a manual one consisting of integration of manually defined peak areas, and the advanced method for accurate, robust and efficient spectral fitting (AMARES), a semi-automatic quantification method implemented in the jMRUI software. Statistical methods included discriminant analysis and the leave-one-out cross-validation method. Both manual and semi-automatic analyses detected differences in metabolite content between tumor groups and controls (P < 0.005). The classification accuracy obtained with the manual method was 75% for high-grade neuroglial tumors, 55% for meningiomas and 56% for pilocytic astrocytomas, while for the semi-automatic method it was 78, 70, and 98%, respectively. Both methods classified all control subjects correctly. The study demonstrated that ¹H-MRS accurately differentiated normal from tumoral brain tissue and confirmed the superiority of the semi-automatic quantification method.

IL-17 expression by tubular epithelial cells in renal transplant recipients with acute antibody-mediated rejection

Acute rejection is still a common complication of kidney transplantation. IL-17 is known to be associated with allograft rejection but the cellular source and the role of this cytokine remains unclear. We investigated IL-17 graft expression in renal transplant recipients with acute antibody-mediated rejection (ABMR), acute T-cell-mediated rejection (TCMR), interstitial fibrosis and tubular atrophy (IFTA) and acute tubular damage due to calcineurin-inhibitor toxicity (CNI). In acute ABMR, tubular IL-17 protein expression was significantly increased compared to TCMR, where most of the IL-17⁺ cells were CD4⁺ graft infiltrating lymphocytes, IFTA and CNI control groups. The tubular expression of IL-17 in acute ABMR colocalized with JAK2 phosphorylation and peritubular capillaries C4d deposition. In addition, IL-17 tubular expression was directly and significantly correlated with the extension of C4d deposits. In cultured proximal tubular cells, C3a induced IL-17 gene and protein expression along with an increased in JAK2 phosphorylation. The inhibition of JAK2 abolished C3a-induced IL-17 expression. The use of steroids and monoclonal antibodies reduced IL-17 expression, JAK2 phosphorylation and C4d deposition in acute ABMR patients. Our data suggest that tubular cells represent a significant source of IL-17 in ABMR and this event might be mediated by the complement system activation featuring this condition.

Pathogenesis of occult chronic hepatitis B virus infection

Occult hepatitis B infection (OBI) is characterized by hepatitis B virus (HBV) DNA in serum in the absence of hepatitis B surface antigen (HBsAg) presenting HBsAg-negative and anti-HBc positive serological patterns. Occult HBV status is associated in some cases with mutant viruses undetectable by HBsAg assays; but more frequently it is due to a strong suppression of viral replication and gene expression. OBI is an entity with world-wide diffusion. The failure to detect HBsAg, despite the persistence of the viral DNA, is due in most cases to the strong suppression of viral replication and gene expression that characterizes this “occult” HBV infection; although the mechanisms responsible for suppression of HBV are not well understood. The majority of OBI cases are secondary to overt HBV infection and represent a residual low viremia level suppressed by a strong immune response together with histological derangements which occurred during acute or chronic HBV infection. Much evidence suggests that it can favour the progression of liver fibrosis and the development of hepatocellular carcinoma.

Comparative metabolic profiling of paediatric ependymoma, medulloblastoma and pilocytic astrocytoma

Brain tumours are the most common solid tumours in children and a major cause of childhood mortality. The most common paediatric brain tumours include ependymomas, cerebellar astrocytomas and medulloblastomas. These brain tumours are highly heterogeneous regarding their histology, prognosis and therapeutic response. Subtle biochemical changes can be detected in intact tissues by High-Resolution Proton Magnetic Angle Spinning Spectroscopy (HR-MAS) revealing the status of tumour microheterogeneity and metabolic alterations before they are morphologically detectable. In this study, we present metabolic profiles by HR-MAS of 20 intact tissue samples from paediatric brain tumours. Tumour types include ependymoma, medulloblastoma and pilocytic astrocytoma. The metabolic characterization of paediatric brain tumour tissue by HR-MAS spectroscopy provided differential patterns for these tumours. The metabolic composition of the tumour tissue was highly consistent with previous in vivo and ex vivo studies. Some resonances detected in this work and not previously observed by in vivo spectroscopy also show potential in determining tumour type and grade (fatty acids, phenylalanine, glutamate). Overall, this work suggests that the additional information obtained by NMR metabolic profiling applied to tissue from paediatric brain tumours may be useful for assessing tumour grade and determining optimum treatment strategies.

MR imaging texture analysis of the corpus callosum and thalamus in amnestic mild cognitive impairment and mild Alzheimer disease

BACKGROUND AND PURPOSE

TA is a branch of image processing that seeks to reduce image information by extracting texture descriptors from the image. TA of MR images of anatomic structures in mild AD and aMCI is not well-studied. Our objective was to attempt to find differences among patients with aMCI and mild AD and normal-aging subjects, by using TA applied to the MR images of the CC and the thalami of these groups of subjects.

MATERIALS AND METHODS

TA was applied to the MR images of 17 patients with aMCI, 16 patients with mild AD, and 16 normal-aging subjects. The TA approach was based on the GLCM. MR images were T1-weighted and were obtained in the sagittal and axial planes. The CC and thalami were manually segmented for each subject, and 44 texture parameters were computed for each of these structures.

RESULTS

TA parameters showed differences among the 3 groups for the CC and thalamus. A pair-wise comparison among groups showed differences for AD-control and aMCI-AD for the CC; and for AD-control, aMCI-AD, and aMCI-control for the thalamus.

CONCLUSIONS

TA is a useful technique to aid in the detection of tissue alterations in MR images of mild AD and aMCI and has the potential to become a helpful tool in the diagnosis and understanding of these pathologies.

[Association of hyperhomocysteinemia with liver steatosis in patients with chronic hepatitis C]

BACKGROUND AND OBJECTIVES

Liver steatosis in chronic hepatitis C (CHC) is related to viral and metabolic factors and likely to genetic factors. The aim of this study was to know if hyperhomocysteinemia and methylenetetrahydrofolate reductase (MTHFR)-C677T polymorphisms are associated with liver steatosis in nonalcoholic patients with CHC.

PATIENTS AND METHOD

In 54 consecutive patients with CHC, alcohol consumption less than 40g/week, and no other causes of liver disease, a liver biopsy was performed. All variables were obtained at the time of biopsy. MTHFR-C677T was also performed in 128 healthy subjects, with age and gender similar to the patients.

RESULTS

Liver steatosis was found in 33 patients (61%), 30 of them having a mild degree. Hyperhomocysteinemia was more prevalent in patients with steatosis (61% vs 24%; p=0.008) and overweight tended to be more prevalent in the same patients (61% vs 33%; p=0.05). All patients with virus C genotype 3 had steatosis. Viral load, liver inflammatory and fibrosis score were not different in patients with and without steatosis. MTHFR-C677T polymorphism was similar in controls and cases and in cases with and without steatosis. A multiple logistic regression showed that hyperhomocysteinemia was associated with liver steatosis after adjustment for age and sex (OR: 3.94; 95% CI: 1.09-14.29), and adjustment for overweight (OR: 4.43; 95% CI: 1.27-15.51).

CONCLUSIONS

In nonalcoholic patients with CHC mild liver steatosis is frequent, and is associated with hyperhomocysteinemia. An association between steatosis and MTHFR-C677T polymorphism was not found.