***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: BACKGROUND In people who are infected with the hepatitis C virus ( HCV ) chronic infection often develops and is difficult to eradicate . We sought to determine whether treatment during the acute phase could prevent the development of chronic infection . METHODS Between 1998 and 2001 , we identified 44 patients throughout Germany who had acute hepatitis C. Patients received 5 million U of interferon alfa-2b subcutaneously daily for 4 weeks and then three times per week for another 20 weeks . Serum HCV RNA levels were measured before and during therapy and 24 weeks after the end of therapy . RESULTS The mean age of the 44 patients was 36 years ; 25 were women . Nine became infected with HCV through intravenous drug use , 14 through a needle-stick injury , 7 through medical procedures , and 10 through sexual contact ; the mode of infection could not be determined in 4 . The average time from infection to the first signs or symptoms of hepatitis was 54 days , and the average time from infection until the start of therapy was 89 days . At the end of both therapy and follow-up , 43 patients ( 98 percent ) had undetectable levels of HCV RNA in serum and normal serum alanine aminotransferase levels . Levels of HCV RNA became undetectable after an average of 3.2 weeks of treatment . Therapy was well tolerated in all but one patient , who stopped therapy after 12 weeks because of side effects . CONCLUSIONS Treatment of acute hepatitis C with interferon alfa-2b prevents chronic infection BACKGROUND The natural outcome of infection with hepatitis C virus ( HCV ) varies substantially among individuals . However , little is known about host and viral factors associated with a self-limiting or chronic evolution of HCV infection . METHODS From 1 January 2001 through 31 December 2008 , a consecutive series of 65 patients from Rio de Janeiro , Brazil , with a well-documented diagnosis of acute HCV infection , acquired via various routes , were enrolled in this study . Patients were prospect ively followed up for a median of 40 months after the estimated date of HCV infection with serial measurements of serum alanine aminotransferase , HCV RNA , and anti-HCV antibodies . Spontaneous viral clearance ( SVC ) was defined as undetectable levels of HCV RNA in serum , in the absence of treatment , for 3 consecutive HCV polymerase chain reaction tests within the first 6 months of follow-up . Cox proportional hazards regression was used to identify host and viral predictors of SVC . RESULTS The cumulative rate of SVC was 44.6 % ( 95 % confidence interval , 32.3%-57.5 % ) . Compared with chronic HCV evolution , patients with self-limiting disease had significantly lower peak levels of anti-HCV antibodies ( median , 109.0 vs 86.7 optical density-to-cutoff ratio [ od/co ] ; P<.02 ) , experienced disease symptoms more frequently ( 69.4 % vs 100 % ; P<.001 ) , and had lower viral load at first clinical presentation ( median , 4.3 vs 0.0 log copies ; P=.01 ) . In multivariate analyses , low peak anti-HCV level ( < 93.5 od/co ) was the only independent predictor for SVC ; the hazard ratio compared with high anti-HCV levels ( > or = 93.5 od/co ) was 2.62 ( 95 % confidence interval , 1.11 - 6.19 ; P=.03 ) . CONCLUSION Our data suggest that low levels of anti-HCV antibodies during the acute phase of HCV infection are independently related to spontaneous viral clearance Objective An epidemic of acute hepatitis C virus ( HCV ) infection in HIV-positive men-who-have-sex-with-men ( MSM ) is emerging in Europe , Australia and the USA . The aim of this study was to characterise the natural history of primary HCV in this setting and to assess host and viral factors which predict spontaneous clearance . Methods This prospect i ve longitudinal cohort study was carried out in 112 HIV-positive patients who were followed in a single centre ( the St Mary 's Acute HCV Cohort ) .  Plasma and peripheral blood mononuclear cells ( P BMC s ) were obtained at monthly intervals for 3 months and at 3-monthly intervals thereafter for a median of 45 months ( IQR=29–69 months ) . The primary end point was spontaneous clearance of HCV . Cox regression was used to assess the impact of clinical and virological variables on outcome , including liver function , CD4 count , rate of HCV RNA decline , T cell response and clonal sequence evolution within the HCV E2 envelope gene . Results 15 % of patients cleared HCV spontaneously , while 85 % progressed towards chronicity . The latter group included a significant proportion of ‘ fluctuating ’ progressors ( 37.5 % ) , in whom a fall followed by a rise ( > 1 log10 ) in viraemia was observed . This was associated with superinfection with new HCV strains and partially effective T cell responses . Spontaneous clearance was strongly associated with a 2.2 log10 viral load drop within 100 days of infection ( HR=1.78 ; p<0.0001 ) , elevated bilirubin ( ≥40 μmol/l ; HR=5.04 ; p=0.006 ) , elevated alanine aminotransferase ( ALT ; ≥1000 IU/ml ; HR=2.62 ; p=0.048 ) and baseline CD4 count ≥650 × 106/l ( HR=2.66 ; p=0.045 ) , and only occurred in patients with genotype 1 infection . Evolution to spontaneous clearance occurred in patients with low viral diversity in the presence of an early multispecific T cell response . Conclusions Spontaneous clearance of acute HCV in HIV-positive men can be predicted by a rapid decline in viral load , high CD4 count , elevated bilirubin and ALT , and is associated with low viral diversity and strong T cell responses Hepatitis C virus ( HCV ) is an important cause of liver disease throughout the world . However , the natural history and pathogenesis of this infection is still not completely understood . The aim of this study was to characterize the evolution of incident , asymptomatic HCV infection in a community-based population in Japan . The  Miyazaki Cohort Study is a prospect i ve study of adult residents in two villages , one of which has a very high prevalence of HCV . Nine hundred and seventy-three people from this village were enrolled in the cohort between 1984 and 1995 , with antibodies to HCV ( anti-HCV ) found in 23 % . During subsequent visits to annual health screens , new HCV seroconverters were identified among susceptible individuals , and their sequential sample s were tested for anti-HCV , HCV-RNA , and HCV core antigen . Fourteen participants ( six males , eight females ) acquired anti-HCV during the first 11 years of study follow-up , at an incidence rate of 362 per 100 000 person-years . Detectable HCV-RNA and high anti-HCV titres ( > 1:2048 ) were observed for more than 5 years following seroconversion in 80 % ( 8/10 ) of seroconverters with sufficient information , indicating the development of persistent infection in these subjects . Three ( 37.5 % ) of the eight sero converters with persistent infection had fairly consistent , albeit mild , alanine aminotransferase elevations ( 30 - 130 IU/L ) during the study . Anti-HCV seroconversions occurred at a very high rate in this community-based population in Japan , in which this infection is endemic . Persistence also developed at a high frequency among the cases of newly acquired infection , although the associated liver enzyme abnormalities were mild UNLABELLED Hepatitis C virus (HCV)/human immunodeficiency virus ( HIV ) coinfection poses a difficult therapeutic problem . Response to HCV-specific therapy is variable but might be influenced by host genetic factors , including polymorphisms of cytokine genes . Here , we studied whether interleukin-6 ( IL-6 ) C174 G gene polymorphism affects the response to antiviral treatment in HCV-infected HIV-positive subjects . We determined IL-6 genotypes in HIV-positive patients with acute ( n = 52 ) and chronic ( n = 60 ) hepatitis C treated with pegylated interferon-alpha . Two hundred ten HCV monoinfected , 197 HIV monoinfected , and 100 healthy individuals were studied as controls . Patients were classified into high and low producers according to IL-6 genotypes . Rates of sustained virological responses ( SVRs ) were compared between the IL-6 genotypes . Signal transducer and activator of transcription three phosphorylation was analyzed by Western blot in HCV core-transfected human hepatoma cell line ( HUH7 ) cells . Distribution of IL-6 genotypes did not differ significantly between the study groups . SVR was achieved in 63 % of HIV/HCV coinfected patients . Carriers of the IL-6 high producer ( HP ) genotype had significantly higher SVR rates than patients with an IL-6 low producer genotype ( 70.1 % versus 52 % ; P < 0.002 ) . This effect was seen in both HIV-positive patients with acute ( 74 % versus 33 % ; P < 0.05 ) and chronic ( 66 % versus 33 % ; P < 0.05 ) hepatitis C. Multivariate analysis confirmed IL-6 HP carriage as an independent positive predictor for SVR ( Odd 's ratio 6.1 ; P = 0.004 ) . This effect corresponds to the in vitro observation that in HCV core-transfected HUH7 cells , IL-6 overcomes the HCV core-mediated inhibition of STAT3 activation . CONCLUSION Response rates to HCV-specific treatment are higher in HCV/HIV-positive patients carrying the IL-6 HP genotype , which might be because of IL-6 mediated STAT3 activation The aim of this study was to analyze the clinical performance of a new enzyme immunoassay ( EIA ) for hepatitis C virus ( HCV ) core antigen in comparison with the reverse transcription polymerase chain reaction ( RT‐PCR ) . A total of 310 patients with acute or chronic hepatitis C , and 132 HCV‐negative controls were studied .  Chemiluminescence EIA with monoclonal anti‐HCV core antigen was used , and qualitative and quantitative commercial RT‐PCRs and an in‐house nested RT‐PCR were performed . Compared with nested RT‐PCR , the core antigen assay showed 97 % sensitivity and 100 % specificity in 75 patients with chronic hepatitis C and 132 controls . HCV core antigen was positive in 16 ( 94 % ) of 17 patients with acute hepatitis C at initial consultation . In 3 persons prospect ively followed , core antigen was detected in the first available ( 1‐3 weeks ) post‐transfusion sample . In 167 anti‐HCV – positive individuals , 129 ( 77 % ) were viremic ; core antigen was detected in 126 ( 98 % ) compared with 129 ( 100 % ) for nested RT‐PCR and 121 ( 94 % ) for the commercial RT‐PCR . In 48 patients with chronic hepatitis C treated with interferon alfa , the concentration of core antigen before treatment was significantly ( P < .002 ) lower in patients with sustained response than in nonresponders . All responders had a sustained loss of core antigen , whereas all nonresponders remained core antigen positive . The concentrations of HCV core antigen and HCV RNA correlated significantly ( n = 48 , r = .627 , P < .001 ) . In conclusion , the HCV core antigen assay is useful for the diagnosis of acute and chronic hepatitis C , and for predicting and monitoring the effect of interferon alfa treatment OBJECTIVE Treating acute hepatitis C ( HCV ) in injection drug users ( IDUs ) is complicated by a high prevalence of psychiatric comorbidities that may lead to increased risk for depressive complications of interferon treatment . Effective screening strategies are needed to help non-psychiatric clinicians identify depressive disorders . METHODS Thirty IDUs with acute HCV completed the  Beck Depression Inventory ( BDI ) , underwent a psychiatric examination  , and were r and omized to 24 weeks of pegylated interferon treatment ( IFA ) or observation ( OBS ) . Sensitivity , specificity , positive ( PPV ) and negative predictive values ( NPV ) of the BDI for diagnosing depression ( with a cutoff > 10 ) were calculated . The psychiatrist 's diagnosis was used as the gold st and ard . Depression severity was assessed over time with the BDI . RESULTS Forty-seven percent of individuals met criteria for a depressive disorder . Sensitivity ( 91 % ) and NPV ( 92 % ) were high for the BDI ; specificity ( 58 % ) and PPV ( 56 % ) were low . BDI worsened in 2 patients completing the study ( one IFA , one OBS ) ; two IFA patients were discontinued for possible depression-related complications . At baseline , subject-rated fatigue was associated with alanine aminotransferase level . CONCLUSION The BDI is an ade 
    Output:
    
Marked heterogeneity in case definitions for recent HCV infection was observed .