The transcription factor T-bet regulates the production of interferon-γ and cytotoxic molecules in effector CD8 T cells, and its expression correlates with improved control of chronic viral ...infections. However, the role of T-bet in infections with differential outcome remains poorly defined. Here, we report that high expression of T-bet in virus-specific CD8 T cells during acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection was associated with spontaneous resolution, whereas T-bet deficiency was more characteristic of chronic evolving infection. T-bet strongly correlated with interferon-γ production and proliferation of virus-specific CD8 T cells, and its induction by antigen and IL-2 stimulation partially restored functionality in previously dysfunctional T-bet-deficient CD8 T cells. However, restoration of a strong interferon-γ response required additional stimulation with IL-12, which selectively induced the phosphorylation of STAT4 in T-bet(+) CD8 T cells. The observation that T-bet expression rendered CD8 T cells responsive to IL-12 suggests a stepwise mechanism of T cell activation in which T-bet facilitates the recruitment of additional transcription factors in the presence of key cytokines. These findings support a critical role of T-bet for viral clearance and suggest T-bet deficiency as an important mechanism behind chronic infection.
Acute hepatitis C virus infection accounts for approximately 20% of cases of acute hepatitis today. The aim of this study was to define the natural course of the disease and to contribute to the ...development of treatment strategies for acute hepatitis C virus.
The diagnosis of acute hepatitis C virus in 60 patients was based on seroconversion to anti-hepatitis C virus antibodies or clinical and biochemical criteria and on the presence of hepatitis C virus RNA in the first serum sample.
Fifty-one of 60 (85%) patients presented with symptomatic acute hepatitis C virus. In the natural (untreated) course of acute symptomatic hepatitis C (n = 46), spontaneous clearance was observed in 24 patients (52%), usually within 12 weeks after the onset of symptoms, whereas all asymptomatic patients (n = 9) developed chronic hepatitis C. The start of antiviral therapy (interferon-α with or without ribavirin) beyond 3 months after the onset of acute hepatitis induced sustained viral clearance in 80% of treated patients.
The management of acute hepatitis C has to take into account the high rate of spontaneous viral clearance within 12 weeks after the onset of symptomatic disease. Treatment of only those patients who remain hepatitis C virus RNA positive for more than 3 months after the onset of disease led to an overall viral clearance (self-limited and treatment induced) in 91% of patients, and unnecessary treatment was avoided in those with spontaneous viral clearance. Patients with asymptomatic acute hepatitis C virus infection are unlikely to clear the infection spontaneously and should be treated as early as possible.
Chronic hepatitis C is characterized by a weak or absent hepatitis C virus (HCV)-specific CD4
+ T-cell response in terms of antigen-specific proliferation or interferon gamma (IFN-γ) secretion. To ...clarify whether this is due to the absence or functional impairment of antigen-specific CD4
+ T cells we developed an assay that relies on the induced expression of the T-cell activation marker CD25 and is therefore independent from cytokine secretion or proliferation. In 10 of 20 patients with chronic hepatitis C, a significant number of antigen-specific activated CD4
+ T cells (mean 1.06%/patient; range, 0% to 5.2% of CD4
+ T cells) could be shown, whereas antigen-specific proliferation was present in only 1 of 20 patients. IFN-γ secretion was absent in all 13 patients tested. However, significant antigen-specific interleukin 10 (IL-10) and transforming growth factor β (TGF-β) secretion was present in 6 of 10 and 3 of 10 patients, respectively. In 8 patients with acute hepatitis C, irrespective of disease outcome, HCV-specific CD4
+ T cells were detected in all patients and at a significantly higher frequency (mean 3.7%/patient; range, 1.16% to 7.17%) in the first weeks of disease. A chronic course of disease was associated either with a loss of both IFN-γ secretion and proliferation, resembling an anergic state, or a loss of T-cell proliferation followed by a rapid decline in IFN-γ-producing cells, corresponding to exhaustion of the specific immune response. In conclusion, functional changes of HCV-specific CD4
+ T cells or failure to develop a long-lasting T-helper response may contribute to chronic hepatitis C viral persistence. (H
epatology 2003;37:1189-1198.)
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Secondary sclerosing cholangitis is a severe disease of the biliary tract. Over the last decade, several cases of sclerosing cholangitis in critically ill patients (SC-CIP) were reported. Reports in ...the literature so far are characterized by a wide variety of underlying causes of critical illness, thereby hindering a risk-factor analysis. We report on a homogenous cohort of critically ill patients with influenza A (H1N1) pneumonia and severe acute respiratory distress syndrome (ARDS), of whom a subgroup developed sclerosing cholangitis, allowing for probing of risk factors associated with SC-CIP.
Twenty-one patients (5 female, 16 male, 46.3 ± 10.8 years) with severe ARDS due to H1N1 pneumonia were retrospectively divided into two groups, characterized by the presence (n = 5) and absence of SC-CIP (n = 16). A large array of clinical data, laboratory parameters, and multi-detector computed tomography-derived measures were compared.
Both patient groups showed severe pulmonary impairment. Severity of disease on admission day and during the first 14 days of treatment showed no difference. The patients developing SC-CIP had a higher body mass index (BMI) (37.4 ± 6.0 kg/m(2) vs. 29.3 ± 6.8 kg/m(2); P = 0.029) and a higher volume of intraperitoneal fat (8273 ± 3659 cm(3) vs. 5131 ± 2268 cm(3); P = 0.033) and spent a longer cumulative period in the prone position during the first 14 days (165 ± 117 h vs. 78 ± 61 h; P = 0.038).
Our results suggest that obesity, intraperitoneal fat volume, and a longer cumulative duration spent in the prone position may put patients with ARDS at risk of developing SC-CIP. These results lead us to propose that the prone position should be carefully deployed, particularly in abdominally obese patients, and that frequent checks be made for early hepatic dysfunction.
Chronic evolution of acute hepatitis C (aHC) occurs in more than 80% of patients but can frequently be prevented by early treatment with interferon (IFN)-alpha. Plasmacytoid dendritic cells (pDCs) ...are the major endogenous IFN-alpha producers, but their role in aHC is unknown. In this study, frequency, phenotype, and pDC function were analyzed in 13 patients with aHC and 32 patients with chronic hepatitis C (cHC) compared with 20 healthy controls, 33 sustained responders to antiviral treatment, 14 patients with acute hepatitis B (aHB), and 21 patients with nonviral inflammatory disease. In aHC, pDCs in the peripheral blood were significantly reduced compared with healthy controls (median, 0.1% vs. 0.36%, P < .0005) and were inversely correlated to alanine aminotransferase levels (r = -0.823; P < .005). Circulating pDCs in aHC were immature, as determined via reduced expression of HLA-DR and CCR7, and produced little amounts of IFN-alpha (median, 3.5 pg/50,000 peripheral blood mononuclear cells PBMCs vs. 498.4 pg/50,000 PBMCs in healthy controls; P < .0005). Less pronounced changes were present in cHC (median, 0.17%, 28.0 pg/50,000 PBMCs IFN-alpha, respectively). However, a significantly reduced frequency and IFN-alpha production was also found in self-limited aHB (median 0.1%, 8.6 pg/50,000 PBMCs) and in patients with nonviral inflammatory disease (median 0.19%, 7.5 pg/50,000 PBMCs). In conclusion, in aHC frequency and IFN-alpha-producing capacity of peripheral blood pDCs are dramatically reduced and inversely correlated with the degree of liver inflammation. In cHC there is incomplete recovery of pDC function, which, however, could be solely due to the chronic inflammatory state.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
BACKGROUND: CTL escape mutations have been described during acute hepatitis C in patients who developed chronic disease later on. Our aim was to investigate the mutual relationship between HCV ...specific CD8+ T cells and evolution of the viral sequence during early acute HCV infection. RESULTS: We sequenced multiple clones of NS3 1406 epitope in 4 HLA-A*02 patients with acute hepatitis C genotype 1b infection. Pentamers specific for the variants were used to monitor the corresponding CD8+ T cell response. We observed outgrowth of mutations, which induced only a weak and thus potentially insufficient CD8+ T cell response. In one patient we observed outgrowth of variant epitopes with similarities to a different genotype rather than de novo mutations most probably due to a lack of responsiveness to these likely pre-existing variants. We could show that in acute hepatitis C CTL escape mutations occur much earlier than demonstrated in previous studies. CONCLUSIONS: The adaption of the virus to a new host is characterized by a high and rapid variability in epitopes under CD8+ T cell immune pressure. This adaption takes place during the very early phase of acute infection and strikingly some sequences were reduced below the limit of detection at some time points but were detected at high frequency again at later time points. Independent of the observed variability, HCV-specific CD8+ T cell responses decline and no adaption to different or new antigens during the course of infection could be detected.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this phase 3 study involving patients with HCV genotype 1, 2, 4, 5, or 6 infection, including those with compensated cirrhosis, treatment with 12 weeks of sofosbuvir and velpatasvir resulted in a ...sustained virologic response in 99% of patients.
The hepatitis C virus (HCV), a single-stranded RNA virus of the family Flaviviridae with six major genotypes, infects up to 150 million people worldwide.
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Chronic HCV infection causes progressive liver fibrosis, which can lead to cirrhosis, hepatic decompensation, and hepatocellular carcinoma.
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As many as half a million people die annually from liver disease associated with chronic HCV infection.
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In recent years, the development of drugs that directly interfere with HCV replication has revolutionized HCV treatment. There are now effective combinations of direct-acting antiviral agents for most patients, but in choosing an appropriate regimen, clinicians must take into account . . .
Malignancies rarely cause of acute liver failure, the presence of which have to be ruled-out during transplant evaluation. Tumor-related liver ruptures sporadically occur and might further complicate ...patient management.
We report the case of a previously healthy 56-year-old male with complaints of abdominal pain. Initially, levels of liver enzymes were elevated, however, comprehensive imaging examinations revealed no gross abnormalities. As acute liver failure developed, transplantation was evaluated. Sudden liver rupture and hemorrhage forced the performance of an emergency laparotomy. Hepatectomy was planned, until a donor organ was allocated. Intraoperatively, the liver unexpectedly revealed diffuse tumor infiltration. Without further therapeutical options, the patient died. Immunohistochemistry showed metastatic infiltration of a carcinoma of unknown primary.
Even in previously healthy patients suffering from acute liver failure, exclusion of malignancies is mandatory before transplantation. As imaging might be misleading, a biopsy should be considered early in unresolved cases.
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