Anthony B. Post

Selective Impairments in Dendritic Cell-Associated Function Distinguish Hepatitis C Virus and HIV Infection

Impaired APC functions may play important roles in chronicity of hepatitis C virus (HCV) and HIV infections. To investigate the separate and combined effects of HCV and HIV infection on immature dendritic cells (DCs), we evaluated myeloid-derived DC (MDC) and plasmacytoid-derived DC (PDC) frequencies and functions, measured by Toll-like receptor ligand-induced IFN-α and IL-12, in healthy controls and subjects with chronic HCV, HIV, and HCV-HIV infection. To evaluate the relation between innate and adaptive immunity, we measured HCV-specific IFN-γ-producing T cell frequency. MDC frequencies tended to be reduced in HIV infection (1.8-fold), while PDC frequencies were minimally reduced in HCV infection (1.4-fold). In contrast, a striking reduction in non-PDC-associated IFN-α production was observed in HIV-infected subjects (17-fold), while PDC-associated IFN-α production was markedly reduced in HCV-infected subjects (20-fold). Both non-PDC and PDC functions were impaired in HCV-HIV coinfection. MDC-associated IL-12 production was markedly reduced in both HCV and HIV-infected subjects (over 10-fold). Functional defects were attenuated with slowly progressive HIV infection. The proportion of subjects with HCV-specific T cell responses, and the number of Ags recognized were reduced in HCV-HIV subjects as compared with HCV singly infected subjects. A positive association was observed between MDC-associated IL-12 production and HCV-specific T cell frequency in HCV-infected subjects. These results indicate that immature DC function is dysregulated in HIV and HCV infections, but differentially, and that these defects are attenuated in slowly progressive HIV infection. These selectively different impairments may contribute to the reduced adaptive immune response to HCV in HCV-HIV coinfection.

Mushroom poisoning—from diarrhea to liver transplantation

Mushroom poisoning from the genus Amanita is a medical emergency, with Amanita phalloides being the most common species. The typical symptoms of nausea, vomiting, abdominal pain, and diarrhea are nonspecific and can be mistaken for gastroenteritis. If not adequately treated, hepatic and renal failure may ensue within several days of ingestion. In this case series, patients poisoned with Amanita virosa are described with a spectrum of clinical presentations and outcomes ranging from complete recovery to fulminant hepatic failure. Although there are no controlled clinical trials, a few anecdotal studies provide the basis for regimens recommended to treat Amanita poisoning. Use of i.v. penicillin G is supported by most reports. Silibinin, although preferred over penicillin, is not easily available in the United States. In those with acute liver failure, liver transplantation can be life saving.

Obesity and non-alcoholic fatty liver disease in chronic hepatitis C.

Background Superimposed non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) may affect HCV-related fibrosis. We performed a study to determine the relationship between NAFLD and chronic hepatitis C. Methods One hundred and twenty patients with chronic hepatitis C and available liver biopsies were included. Baseline liver biopsies were read by 1 hepatopathologist using Metavir, as well as a fatty liver pathology protocol. Patients’ baseline clinical, demographic, and virologic data were associated with the extent of steatosis (>33% vs. ≤33%), the type of fatty liver (no steatosis vs. steatosis only vs. NASH), and the stage of fibrosis seen on the liver biopsy. Results Seventy percent of patients were men and 80% were white. The mean age was 47.48 ± 5.70 years, mean BMI was 29.01 ± 5.01 kg/m2, and mean waist to hip ratio (W/H) was 0.90 ± 0.08. Patients with higher grade of steatosis had higher BMI (32.83 ± 6.26 vs. 28.49 ± 4.62, P = 0.034), more likely to have genotype 3 (21.4% vs. 5.7%, P = 0.037) and advanced fibrosis (92.9% vs. 62.3%, P = 0.033) than those with lower grade of steatosis. Of these, only HCV-genotype 3 remained independently associated with higher grade of steatosis. When patients with superimposed NASH (n = 22) were compared with those with only steatosis (n = 49) and those without steatosis (n = 49), patients with superimposed NASH had more evidence of obesity (BMI: 30.64 ± 5.23 vs. 29.90 ± 5.35 vs. 27.33 ± 4.07, P = 0.008; W/H: 0.97 ± 0.06 vs. 0.91 ± 0.08 vs. 0.87 ± 0.07, P < 0.001), more commonly infected with HCV genotype 3 (14% vs. 12% vs. 0%, P = 0.036) and had more advanced fibrosis (95.5% vs. 75.5% vs. 42.9%, P < 0.001). Race, gender, and age did not affect extent of steatosis or presence of superimposed NASH. Conclusion In conclusion, markers of obesity (BMI and W/H) and HCV genotype 3 are associated with the extent of steatosis and type of fatty liver. Higher grade of steatosis and presence of superimposed NASH are both associated with advanced hepatic fibrosis.

Negative regulation of the interferon response by an interferon-induced long non-coding RNA

Long non-coding RNAs (lncRNAs) play critical roles in diverse cellular processes; however, their involvement in many critical aspects of the immune response including the interferon (IFN) response remains poorly understood. To address this gap, we compared the global gene expression pattern of primary human hepatocytes before and at three time points after treatment with IFN-α. Among ∼200 IFN-induced lncRNAs, one transcript showed ∼100-fold induction. This RNA, which we named lncRNA-CMPK2, was a spliced, polyadenylated nuclear transcript that was induced by IFN in diverse cell types from human and mouse. Similar to protein-coding IFN-stimulated genes (ISGs), its induction was dependent on JAK-STAT signaling. Intriguingly, knockdown of lncRNA-CMPK2 resulted in a marked reduction in HCV replication in IFN-stimulated hepatocytes, suggesting that it could affect the antiviral role of IFN. We could show that lncRNA-CMPK2 knockdown resulted in upregulation of several protein-coding antiviral ISGs. The observed upregulation was caused by an increase in both basal and IFN-stimulated transcription, consistent with loss of transcriptional inhibition in knockdown cells. These results indicate that the IFN response involves a lncRNA-mediated negative regulatory mechanism. lncRNA-CMPK2 was strongly upregulated in a subset of HCV-infected human livers, suggesting a role in modulation of the IFN response in vivo.

Immune responses to hepatitis C and non-hepatitis C antigens in hepatitis C virus infected and HIV-1 coinfected patients

ObjectiveTo characterize immune phenotype and function in hepatitis C virus (HCV) infection in the presence and absence of HIV-1 infection. DesignCross-sectional comparison among controls (group A), patients with HCV infection (group B), HCV–HIV-1 coinfected patients (group C), coinfected patients receiving treatment for HIV-1 (group D), and untreated HIV-1 infected patients (group E). MethodsFlow cytometric analysis for lymphocyte phenotypes, lymphocyte proliferation and cytokine production by ELISPOT. ResultsHCV infected patients tended to have an increased percentage of activated (CD38, HLA-DR) CD8 cells (group A, 2 ± 1.4%; group B, 6 ± 3.9%;P = 0.08). Proliferative responses to non-HCV antigens were comparable in group A and group B subjects. A greater proportion of group B patients had stimulation indices (SI) > 3 to the HCV protein NS3 compared to group C and D patients (67%, 0%, and 11% respectively;P < 0.003), but only two patients in group B had SI ⩾ 5. The SI to NS3 was significantly higher in group B patients [median, 4; interquartile range (IQR), 3–9) than in group C (median, 2; IQR, 1–3;P < 0.04) or group D (median, 1; IQR, 1–4;P < 0.009) patients. Plasma HCV RNA levels correlated directly with alanine aminotransferase levels (ρ, 0.52;P < 0.05) and inversely with the number of CD4 lymphocytes (ρ, −0.55;P < 0.009) and proliferation to NS3 (ρ, −0.55;P < 0.009). ConclusionsLymphocytes of HCV infected patients show weak proliferative responses to HCV antigens while responses to other antigens are preserved. Infection with HIV-1 potentiates this deficiency. Poor CD4 T cell responses to HCV are associated with and may determine the failure to control HCV propagation.

HIV long-term non-progressors maintain brisk CD8 T cell responses to other viral antigens

Objective To examine the specificity of heightened CD8 cell responses in HIV-1-infected long-term non-progressors. Design Cross-sectional study examining CD8 cell responses to hepatitis C virus (HCV) peptides in HCV–HIV LTNP (n = 6), HCV–HIV progressors (n = 11), HCV singly infected patients (n = 32), HCV singly infected patients with self-limited disease (n = 10), HIV singly infected progressors (n = 7) and HCV-negative, HIV-negative controls (n = 10). Methods The frequency of HCV-reactive interferon γ-producing cells in peripheral blood was assayed by enzyme linked immunospot assay using a panel of 61 HCV-1-derived peptides. Results Five of six HCV–HIV LTNP had HCV-specific CD8 responses. In contrast, responses were observed in 2 of 32 HCV singly infected patients, 2 of the 10 HCV singly infected patients with self-limited disease, and 0 of 11 HCV–HIV progressors (P < 0.001). Both frequency of HCV-specific CD8 cells and number of HCV peptides recognized were greater in HCV–HIV LTNP than in other groups. Conclusions HIV-infected LTNP maintain heightened CD8 cell responses to HCV in addition to heightened HIV specific responses. Common mechanisms may underlie preservation of CD8 immune responses in these individuals. An improved understanding of these mechanisms will help to gain insight into protective antiviral immunity as well as to the means whereby these viruses impair host defenses.

HIV Coinfection Impairs CD28-Mediated Costimulation of Hepatitis C Virus–Specific CD8 Cells

BACKGROUND During human immunodeficiency virus (HIV) infection, reduced proportions of CD8 cells express CD28, the key costimulatory molecule for lymphocyte activation. However, it is unclear whether reduced CD28 expression affects immune responses to non-HIV antigens, potentially contributing to susceptibility to opportunistic infection. METHODS We measured CD4- and CD8-specific interferon- gamma responses to hepatitis C virus (HCV) peptide pools in subjects with chronic HCV monoinfection (n=14), in subjects with chronic HCV/HIV coinfection (n=15), and in healthy control subjects (n=10) by enzyme-linked immunospot assay in the presence and absence of CD28 costimulation. RESULTS Anti-CD28 agonist increased the cumulative frequency of HCV-specific CD4 cell responses in the subjects with HCV monoinfection and in those with HCV/HIV coinfection. In contrast, anti-CD28 agonist increased the breadth and cumulative frequency of HCV-specific CD8 cell responses only in the subjects with HCV monoinfection. Additionally, in the presence of anti-CD28 agonist, the proportion of subjects responding, the cumulative frequency, and the breadth of reactive CD8 cells were greater among the subjects with HCV monoinfection than among those with HCV/HIV coinfection. Finally, the HCV/HIV-coinfected subjects had lower proportions of CD8 cells that expressed CD28. CONCLUSIONS These results indicate that, during HCV/HIV coinfection, memory-effector CD8 cells have reduced responsiveness to CD28 costimulation. This appears to reflect a global effect that HIV has on the activation or differentiation state of CD8 cells that are responsive to other microbial pathogens. This functional defect has implications for the pathogenesis of HCV/HIV coinfection.

Resolution of spur cell anemia with liver transplantation: A case report and review of the literature

Spur cell anemia is an acquired hemolytic anemia, characterized by an increased percentage of abnormally shaped erythrocytes that are known as acanthocytes. The erythrocytes have numerous spicules irregularly distributed over the cell surface. Spur cell anemia has been described to occur in several conditions, including cirrhosis. We present an unusual case of a young patient with hemochromatosis, alcohol abuse, decompensated cirrhosis, and spur cell anemia who had a spontaneous resolution of the spur cell anemia after orthotopic liver transplantation. This finding suggests that the diseased liver may contribute to transformation of the erythrocyte to the spur cell.

Pegylated Interferon α-2b, Ribavirin and Amantadine for Chronic Hepatitis C

In an attempt to improve the efficacy of antiviral therapy for chronic hepatitis C, a three-drug combination of pegylated interferon α-2b, ribavirin, and amantadine has been suggested. Despite the initial enthusiasm, the role of amantadine in the treatment of chronic hepatitis C remains controversial. In a multi-center, open-label clinical trial, the potential efficacy and safety of this triple combination regimen were assessed. In this open-label pilot study, two separate patient populations with chronic hepatitis C and viremia were enrolled: treatment-naive and those who had failed a previous course of treatment. Patients were started on pegylated interferon α-2b at a dose of 1.5 μg/kg weekly with ribavirin, 1000–1200 mg/day, and amantadine, 200 mg/day, for 4 weeks, followed by pegylated interferon α-2b, 0.5 μg/kg weekly, ribavirin, 1000–1200 mg/day, and amantadine, 200 mg/day, for another 20 weeks. Patients with undetectable HCV RNA at week 24 continued this regimen for a total of 48 weeks and were followed for another 24 weeks. Patients with undetectable virus (< 50 IU/mL) after 24 weeks of follow-up were considered to have SVR. Health-related quality of life and safety data were also collected. Sixty-nine treatment-naive and 99 nonresponder patients with chronic hepatitis C were enrolled in the study. Of all patients enrolled, 74% were male, aged 47.27 ± 5.76 years; their body mass index (BMI) was 28.87 ± 5.05 kg/m2, 79.4% were white, 85% had HCV genotypes 1 and 4, and 36% had cirrhosis. Their baseline HCV RNA was 689,242 ± 698,030 IU/mL, with a baseline ALT of 107.25 ± 79.08. Of the entire cohort, 35 (21%) discontinued early due to side effects or loss to follow-up. Significant anemia (hemoglobin, < 10 g/dL) occurred in 11% (19/168), while severe anemia (hemoglobin, < 8.5 g/dL) occurred in 0.6% (1/168). In the treatment-naive group, sustained virologic response (SVR) was 34.3%, versus 19.4% for the group who had previously failed to respond to a course of treatment (P = 0.01). For both groups combined, virologic response after 24 weeks of therapy was 40.5%, with an end-of-treatment virologic response of 35.7% and a SVR of 26.2%. Patients with genotypes 1 and 4 had lower response rates than those with genotypes 2 and 3 (SVR, 21 vs. 46%; P = 0.001). Patients with advanced fibrosis (Metavir stages 3 and 4) tended to have lower response rates than those with minimal or mild fibrosis (Metavir stages 0–2) (SVR, 10 vs. 30%; P = 0.08). African-American patients with HCV had lower response rates than Caucasians or other ethnic groups (SVR, 4 vs. 29 vs. 20%; P = 0.04). Age, gender, and BMI did not affect SVR. The addition of amantadine to pegylated interferon α-2b and ribavirin does not seem to increase the efficacy of this antiviral regimen.

Resolution of Hepatitis B Viremia in a Renal Transplant Recipient Treated with Alpha-2b Interferon

A renal transplant patient developed symptomatic hepatitis after withdrawal from corticosteroids. Tests for hepatitis B e antigen and hepatitis B viral DNA were both positive prior to treatment with 1 million units alpha interferon three times weekly for 3 weeks followed by an increase to 3 million units alpha interferon three times weekly for a total of 16 weeks. At the end of treatment, hepatitis had clinically resolved with conversion to a hepatitis B e antibody positive and hepatitis B e antigen and viral DNA negative state. The renal allograft function remained excellent throughout the course of therapy with interferon.