Monitoring intrahepatic CD8+ T cells by fine-needle aspiration cytology in chronic hepatitis C infection

Impairment of Recent Thymic Emigrants in HCV Infection

Hepatitis C Virus (HCV) often has a more favorable course in younger patients. Considering the involution of the thymic function with age, we investigated the output of recent thymic emigrants (RTE) in HCV patients. To evaluate RTE, we used a competitive quantitative PCR in order to determine the percentages of cells with cj-T cell receptor excision circles (TREC). This study was performed in 14 HCV patients at diagnosis and before any anti-HCV treatment. The results obtained in this group were compared to those obtained in a group of age-matched controls. We found that in the 14 HCV patients naive for anti-HCV treatment the mean percentage of cj-TREC was 3%. We could not detect a correlation between the percentages of cj-TREC and age or patients' viremia. In contrast, in the 26 age-matched controls mean percentage of cj-TREC was 5.6% (P=0.01). Our study describes a novel immune defect in HCV patients. Additional studies are needed to get further insight in the possible role of TREC defect in the pathogenesis and prognosis of the disease.

Gene expression analysis in serial liver fine needle aspirates

No method with low morbidity presently exists for obtaining serial hepatic gene expression measurements in humans. While hepatic fine needle aspiration (FNA) has lower morbidity than core needle biopsy, applicability is limited due to blood contamination, which confounds quantification of gene expression changes. The aim of this study was to validate FNA for assessment of hepatic gene expression. Liver needle biopsies and FNA procedures were simultaneously performed on 17 patients with chronic hepatitis C virus infection with an additional FNA procedure 1 week later. Nine patients had mild/moderate fibrosis and eight advanced fibrosis. Gene expression profiling was performed using Affymetrix microarrays and TaqMan qPCR; pathway analysis was performed using Ingenuity. We developed a novel strategy that applies liver-enriched normalization genes to determine the percentage of liver in the FNA sample, which enables accurate gene expression measurements overcoming biases derived from blood contamination. We obtained almost identical gene expression results (ρ = 0.99, P < 0.0001) comparing needle biopsy and FNA samples for 21 preselected genes. Gene expression results were also validated in dogs. These data suggest that liver FNA is a reliable method for serial hepatic tissue sampling with potential utility for a variety of preclinical and clinical applications.

Potential immunotherapeutic role of interleukin-2 and interleukin-12 combination in patients with hepatocellular carcinoma

Background

Many recent therapeutic interventions are necessary to improve the treatment of hepatocellular carcinoma (HCC), including immunotherapy, which seems to offer one of the new realistic therapeutic modalities. This study aims to investigate the optimization of immunotherapy for HCC patients by appraisal of both interferon (IFN)-γ levels and phenotyping of lymphocytes obtained from peripheral blood and fine-needle aspirates.

Methods

The isolated lymphocytes were cultured in the presence of interleukins (IL)-2, IL-4, and IL-12. Enzyme-linked immunosorbent assay and flow cytometric techniques were used for the assessment of human IFN-γ production and the studied T-cell subpopulations, respectively.

Results

Mixed cell populations of peripheral blood lymphocytes and tumor infiltrating lymphocytes treated with IL-2 plus IL-12 showed a marked and significant elevation in IFN-γ levels in their culture media, a significant decrease in the percentage of cluster of differentiation (CD)4⁺CD25⁺ regulatory T-cells, and a nonsignificant increase in the percentage of CD8⁺ cytotoxic T-cells. Meanwhile, IL-2 plus IL-4 treatment demonstrated nonsignificant effects.

Conclusion

Our data suggested that IL-12 together with IL-2 caused a suppression of CD4⁺CD25⁺ regulatory T-cells and an elevation of IFN-γ levels, which play a crucial immunotherapeutic role in the management of HCC patients.

Intrahepatic CD8+ T-lymphocyte response is important for therapy-induced viral clearance in chronic hepatitis B infection

BACKGROUND/AIMS

To determine which immune cells contribute to HBV-clearance during antiviral therapy, we performed a longitudinal analysis of intrahepatic immune cells during interferon-alpha therapy of chronic HBV-patients using the FNAB technique.

METHODS

Twenty chronic HBeAg+-patients were treated with pegylated alpha-interferon combined with lamivudine or placebo for 52 weeks. FNAB and blood specimens were obtained at week 0, 2, 8 and 52. CD4+- and CD8+ T-lymphocytes, CD56+ cells, IFNgamma and granzyme B (GrB) were immunocytochemically quantified.

RESULTS

The relative numbers of CD56+ cells and CD8+ T-lymphocytes were significantly higher in FNAB compared to blood at all time-points. Responders (n=9) exhibited significant increases in intrahepatic CD8+ and CD8+GrB+ lymphocytes, a small elevation in CD8+IFNgamma+ T-lymphocytes, no change in CD4+ T-lymphocytes, and a decrease in intrahepatic CD56+ cells during the first weeks of therapy. In non-responders (n=11) no significant changes in CD4+- and CD8+ T-lymphocytes and an increase in intrahepatic and CD56+ cells were observed during therapy.

CONCLUSIONS

The intrahepatic CD8+ T-lymphocyte, but not the CD4+ T-lymphocyte or NK/NKT-cell response, is important for HBV clearance during interferon-alpha therapy, and the antiviral effect may be mediated by both cytolytic and non-cytolytic mechanisms.