Marija Zeremski

Intrahepatic levels of CXCR3‐associated chemokines correlate with liver inflammation and fibrosis in chronic hepatitis C

Chemokines, chemotactic cytokines, may promote hepatic inflammation in chronic hepatitis C virus (HCV) infection through the recruitment of lymphocytes to the liver parenchyma. We evaluated the association between inflammation and fibrosis and CXCR3‐associated chemokines, interferon‐γ (IFN‐γ)–inducible protein 10 (IP‐10/CXCL10), monokine induced by IFN‐γ (Mig/CXCL9), and interferon‐inducible T cell α chemoattractant (I‐TAC/CXCL11), in HCV infection. Intrahepatic mRNA expression of these chemokines was analyzed in 106 chronic HCV‐infected patients by real‐time PCR. The intrahepatic localization of chemokine producer cells and CXCR3+ lymphocytes was determined in selected patients by immunohistochemistry. We found elevated intrahepatic mRNA expression of all three chemokines, most markedly CXCL10, in chronic HCV‐infected patients with higher necroinflammation and fibrosis. By multivariable multivariate analysis, intrahepatic CXCL10 mRNA expression levels were significantly associated with lobular necroinflammatory grade and HCV genotype 1. In the lobular region, CXCL10‐expressing and CXCL9‐expressing hepatocytes predominated in areas with necroinflammation. Strong CXCL11 expression was observed in almost all portal tracts, whereas CXCL9 expression varied considerably among portal tracts in the same individual. Most intrahepatic lymphocytes express the CXCR3 receptor, and the number of CXCR3+ lymphocytes was increased in patients with advanced necroinflammation. Conclusion: These findings suggest that the CXCR3‐associated chemokines, particularly CXCL10, may play an important role in the development of necroinflammation and fibrosis in the liver parenchyma in chronic HCV infection. (Hepatology 2008.)

The role of chemokines as inflammatory mediators in chronic hepatitis C virus infection.

Summary.  Hepatitis C virus (HCV) is a leading cause of chronic liver disease that can progress to cirrhosis and/or hepatocellular carcinoma. Intrahepatic inflammation and liver cell injury are defining features of chronic HCV infection. Chemokines, chemotactic cytokines that attract leucocytes to inflammatory sites, may be important in the development of intrahepatic inflammation. As T‐helper (Th)1 inflammatory cells, characterized by interferon (IFN)‐γ and interleukin (IL)‐2 secretion, predominate in the liver during chronic HCV infection, chemokines that attract these cells might be particularly important in disease progression. In this review, we focus on the role of Th1 chemokines, which are all members of the CXC or CC subfamilies. Among the CXC chemokines, the non‐ELR group comprised of IFN‐γ‐inducible protein 10 (IP‐10), monokine induced by IFN‐γ (Mig) and IFN‐inducible T‐cell‐α chemoattractant (I‐TAC), attract Th1 cells through the interaction with their receptor, CXCR3. Among the CC subfamily, Th1‐associated chemokines include regulated upon activation, normal T‐cell expressed and secreted (RANTES) and macrophage inflammatory proteins (MIP)1α and β. These chemokines attract cells through an interaction with their receptor, CCR5. While peripheral blood and intrahepatic levels of all of these chemokines are elevated in chronic hepatitis C patients, only select chemokines have been found to be correlated with hepatic inflammation. Among the six chemokines, IP‐10 has uniquely been shown to have prognostic utility as a marker of treatment outcome. In the future, chemokines might be used to monitor the natural course and progression of HCV‐associated liver disease, to identify patients with a high likelihood of achieving a therapeutic response, and they may even have potential as therapeutic targets.

Determinants of Hepatitis C Virus Treatment Completion and Efficacy in Drug Users Assessed by Meta-analysis

BACKGROUND Hepatitis C virus (HCV)-infected drug users (DUs) have largely been excluded from HCV care. We conducted a systematic review and meta-analysis of the literature on treatment completion and sustained virologic response (SVR) rates in DUs. We assessed the effects of different treatment approaches and services to promote HCV care among DUs as well as demographic and viral characteristics. METHODS Studies of at least 10 DUs treated with pegylated interferon/ribavirin that reported SVR were analyzed. Heterogeneity was assessed (Cochran test) and investigated (meta-regression), and pooled rates were estimated (random effects). RESULTS Thirty-six studies comprising 2866 patients were retrieved. The treatment completion rate among DUs was 83.4% (95% confidence interval [CI], 77.1%-88.9%). Among studies that included addiction-treated and untreated patients during HCV therapy, the higher the proportion of addiction-treated patients, the higher the HCV treatment completion rate (P < .0001). After adjusting for human immunodeficiency virus (HIV)/HCV coinfection, sex, and treatment of addiction, support services during antiviral therapy increased treatment completion (P < .0001). The pooled SVR rate was 55.5% (95% CI, 50.6%-60.3%). Genotype 1/4 (P = .0012) and the proportion of HIV-coinfected DUs (P = .0173) influenced the SVR rate. After adjusting for HCV genotype 1/4 and HIV/HCV coinfection, the SVR rate was positively correlated with involvement of a multidisciplinary team (P < .0001). CONCLUSIONS Treatment of addiction during HCV therapy results in higher treatment completion. Our pooled SVR rate is similar to that obtained in registration trials in the general population. Treatment of addiction during HCV therapy will likely be important for HCV-infected DUs undergoing treatment with more complex regimens including direct-acting antivirals.

Peripheral CXCR3-Associated Chemokines as Biomarkers of Fibrosis in Chronic Hepatitis C Virus Infection

BACKGROUND CXCR3-associated chemokines CXCL9-CXCL11 promote histologic progression in chronic hepatitis C virus (HCV) infection, as indicated by elevated intrahepatic levels of messenger RNA in patients with advanced inflammation and fibrosis. We evaluated the potential of peripheral chemokine levels to discriminate among patients with chronic HCV infection who had different stages of fibrosis. METHODS Peripheral levels of CXCR3-associated chemokines were measured by enzyme-linked immunosorbent assay of plasma samples obtained from 93 patients with chronic HCV infection. Of the subjects, 79 (85%) were white, and 68 (73%) were infected with HCV genotype 1. RESULTS Expression of all 3 chemokines, when analyzed as a group, was significantly associated with intrahepatic inflammation and fibrosis. Plasma levels of CXCL10 were significantly elevated in patients with advanced fibrosis, whereas CXCL9 levels were significantly elevated in patients with advanced inflammation. By proportional odds multivariate modeling, we observed an association between fibrosis and CXCL10 (P< .002) as well as between fibrosis and inflammation (P<.001). Of the individual parameters, the CXCL10 level was most useful in identifying patients with more-severe (stage 3-4) fibrosis. Discriminatory ability was improved by the combination of CXCL10 and CXCL9. CONCLUSIONS The strong association between CXCR3-associated chemokines and fibrosis suggests that they may have promise as noninvasive markers of hepatic fibrosis in a predominantly white HCV genotype 1-infected population.

Interferon gamma-inducible protein 10: a predictive marker of successful treatment response in hepatitis C virus/HIV-coinfected patients.

Background:Elevated pretreatment interferon (IFN) γ-inducible protein 10 (IP-10/CXCL10) levels are a marker of treatment nonresponse in hepatitis C virus (HCV)-monoinfected patients. We undertook this study to determine if IP-10 is a marker of treatment outcome in HCV/HIV-coinfected patients. Methods:Nineteen HCV/HIV-coinfected patients were treated with weight-based pegylated (PEG) IFNα-2b (1.5 μg/kg) once weekly plus weight-based ribavirin (1000 or 1200 mg) daily for up to 48 weeks. Plasma IP-10, monokine induced by IFNγ/CXCL9 (Mig), and IFN-inducible T-cell α-chemoattractant/CXCL11 (I-TAC) levels were measured by enzyme-linked immunosorbent assay on samples obtained frequently during the first 3 PEG-IFN doses and throughout treatment. Results:Median pretreatment plasma IP-10 (interquartile range [IQR]) levels were significantly lower in virological responders (n = 6) at 217 (IQR: 181-301) pg/mL compared with nonresponders (n = 13) at 900 (IQR: 628-2048) pg/mL (P = 0.002), whereas pretreatment Mig and I-TAC levels did not differ significantly. Plasma IP-10 levels of 400 pg/mL before treatment and on days 7 and 14 could be used to identify likely coinfected PEG-IFN/ribavirin nonresponders. PEG-IFN-induced elevations in IP-10 were greater in virological responders than in nonresponders (∼10-fold vs. ∼4-fold) after the first PEG-IFN dose. Conclusions:IP-10 may be a biomarker of HCV treatment outcome in difficult-to-treat HCV/HIV-coinfected patients.

Hepatitis C virus control among persons who inject drugs requires overcoming barriers to care.

Despite a high prevalence of hepatitis C virus (HCV) infection, the vast majority of persons who inject drugs (PWID) have not engaged in HCV care due to a large number of obstacles. Education about the infection among both PWID and providers remains an important challenge as does discrimination faced by PWID in conventional health care settings. Many providers also remain hesitant to prescribe antiviral therapy due to concerns about adherence and relapse to drug use resulting in reinfection. Presently, however, as a result of improvements in treatment efficacy combined with professional society and government endorsement of HCV treatment for PWID, a pressing need exists to develop strategies to engage these individuals into HCV care. In this article, we propose several strategies that can be pursued in an attempt to engage PWID into HCV management. We advocate that multidisciplinary approaches that utilize health care practitioners from a wide range of specialties, as well as co-localization of medical services, are strategies likely to result in increased numbers of PWID entering into HCV management. Pursuit of HCV therapy after stabilization through drug treatment is an additional strategy likely to increase PWID engagement into HCV care. The full impact of direct acting antivirals for HCV will only be realized if innovative approaches are pursued to engage all HCV infected individuals into treatment.

Hepatitis C virus-specific T-cell immune responses in seronegative injection drug users.

Summary.  T‐cell responses to hepatits C virus (HCV) antigens have been reported in high‐risk HCV seronegative persons, suggesting that an effective cellular immune response might be able to clear infection without the development of antibodies. Such findings, however, could be explained by waning antibody or cross‐reactivity to other antigens. To address these issues, we evaluated HCV‐specific T‐cell responses in 26 young (age 18–33 years) aviremic, seronegative injection drug users (IDUs) (median duration of injection, 6 years) by interferon‐γ enzyme‐linked immunospot (ELISpot) assay using 429 overlapping HCV peptides pooled in 21 mixes. Seventeen aviremic, seropositive IDUs (spontaneous resolvers) and 15 healthy people were used as positive and negative controls, respectively. The percentage of patients with HCV‐specific cellular immune responses was similar in seronegative and seropositive aviremic IDUs (46%vs 59%, P = 0.4), while these responses were not detected in any of the negative controls. Among the seronegative IDUs, six (23%) had intermediate to very strong responses to 10–20 peptide mixes and another six (23%) had moderately strong responses for two to six mixes. The 12 seronegative IDUs with HCV‐specific T‐cell responses had higher demographical and behavioural risk profiles than the 14 IDUs without T‐cell responses (estimated risk of HCV infection, 0.47 vs 0.26, P < 0.01). In conclusion, HCV‐specific T‐cell responses are common among high‐risk, seronegative IDUs. The responses are broad and are associated with risk factors for HCV exposure, suggesting that they reflect true exposure to HCV in seronegative persons.

Integrated internist — addiction medicine — hepatology model for hepatitis C management for individuals on methadone maintenance

Summary.  Despite a high prevalence of hepatitis C virus (HCV) among drug users, HCV evaluation and treatment acceptance are extremely low among these patients when referred from drug treatment facilities for HCV management. We sought to increase HCV treatment effectiveness among patients from a methadone maintenance treatment program (MMTP) by maintaining continuity of care. We developed, instituted and retrospectively assessed the effectiveness of an integrated, co‐localized care model in which an internist‐addiction medicine specialist from MMTP was embedded in the hepatitis clinic. Methadone maintenance treatment program patients were referred, evaluated by the internist and hepatologist in hepatitis clinic and provided HCV treatment with integration between both sites. Of 401 evaluated patients, anti‐HCV antibody was detected in 257, 86% of whom were older than 40 years. Hepatitis C virus RNA levels were measured in 222 patients, 65 of whom were aviremic. Of 157 patients with detectable HCV RNA, 125 were eligible for referral to the hepatitis clinic, 76 (61%) of whom accepted and adhered with the referral. Men engaged in MMTP <36 months were significantly less likely to be seen in hepatitis clinic than men in MMTP more than 36 months (odds ratio = 7.7; 95% confidence interval 2.6–22.9) or women. We evaluated liver histology in 63 patients, and 83% had moderate to advanced liver disease. Twenty‐four patients initiated treatment with 19 completing and 13 (54%) achieving sustained response. In conclusion, integrated care between the MMTP and the hepatitis clinic improves adherence with HCV evaluation and treatment compared to standard referral practices.

CXCL9 and CXCL10 chemokines as predictors of liver fibrosis in a cohort of primarily African-American injection drug users with chronic hepatitis C.

CXCL9 (monokine induced by IFN γ [Mig]) and CXCL10 (interferon [IFN] γ-inducible protein 10 [IP-10]) have been associated with hepatic fibrosis in predominantly white hepatitis C virus (HCV)-infected patients. We investigated their potential as noninvasive markers of hepatic fibrosis and fibrosis progression in African-American patients. Peripheral chemokine levels were measured in 115 HCV-infected patients within 4 months of liver biopsy; patients underwent a second biopsy after 3-5 years. CXCL10 levels appeared to be higher in patients with advanced fibrosis on the contemporaneous biopsy and were significantly higher in patients with advanced fibrosis compared with those with minimal fibrosis on the later biopsy (P = .0045). Therefore, CXCL10 has potential as a marker of fibrosis progression in African-American HCV-infected patients.

Induction of CXCR3- and CCR5-associated Chemokines during Acute Hepatitis C Virus Infection

BACKGROUND & AIMS Characterization of inflammatory mediators, such as chemokines, during acute hepatitis C virus (HCV) infection might shed some light on viral clearance mechanisms. METHODS Plasma levels of CXCR3 (CXCL9-11)- and CCR5 (CCL3-4)-associated chemokines, ALT, and HCV RNA were measured in nine injection drug users (median 26 samples/patient) before and during 10 acute (eight primary and two secondary) HCV infections. Using functional data analysis, we estimated smooth long-term trends in chemokine expression levels to obtain the magnitude and timing of overall changes. Residuals were analyzed to characterize short-term fluctuations. RESULTS CXCL9-11 induction began 38-53days and peaked 72-83days after virus acquisition. Increases in ALT levels followed a similar pattern. Substantial negative auto-correlations of chemokine levels at 1 week lags suggested substantial week-to-week oscillations. Significant correlations were observed between CXCL10 and HCV RNA as well as ALT and CXCR3-associated chemokines measured in the preceding week, CCL3-4 expression levels did not change appreciably during acute HCV infection. CONCLUSIONS Elevation of CXCR3-associated chemokines late during acute HCV infection suggests a role for cellular immune responses in chemokine induction. Week-to-week oscillations of HCV RNA, chemokines, and ALT suggest frequent, repeated cycles of gain and loss of immune control during acute hepatitis C.