T-cell clonality of peripheral blood from patients with chronic hepatitis C before and after treatment with interferon α

Immune-mediated liver cell damage has been likely to occur in patients with chronic hepatitis C virus (HCV) infection. To clarify the T-cell clonality in patients with chronic hepatitis C, we analyzed T-cell receptor (TCR) Vβ chain messages expressed in peripheral blood mononuclear cells (PBMC) before and after treatment with interferon (IFN)-α. PBMC from 15 patients with chronic hepatitis C and from six healthy subjects were examined. The 15 patients were allocated to three groups based on their response to IFN-α treatment as follows: responders (group A, n=5), transient responders (group B, n=5), and non-responders (group C, n=5). Twenty-two TCR Vβ repertoires Vβ 1–Vβ 20 expressed in PBMC were analyzed by reverse-transcription polymerase chain reaction (RT-PCR) and single strand conformation polymorphism (SSCP). In responders, the mean total number of T-cell clones in 22 TCR Vβ repertoires was significantly decreased from 97.4±40.1 to 62.6±32.1 (P<0.01) after treatment. In transient responders, although one patient showed a decrease, four patients showed an increase, with the mean total number of T-cell clones increasing from 66.4±28.0 to 79.8±28.8 after treatment. In non-responders, the mean total number of T-cell clones was almost unchanged between before and after treatment. No clear tendency towards the use of any specific Vβ was observed in any group of patients. These results suggest that T-cell clones accumulated in the peripheral blood of patients with chronic hepatitis C and that the number of clones may change in response to IFN-α treatment.