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

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) V beta chain messages expressed in peripheral blood mononuclear cells (PBMC) before and after treatment with interferon (IFN)-alpha. PBMC from 15 patien ts with chronic hepatitis C and from six healthy subjects were examined. Th e 15 patients were allocated to three groups based on their response to IFN -alpha treatment as follows: responders (group A, n = 5), transient respond ers (group B, n = 5), and non-responders (group C, n = 5). Twenty-two TCR V beta repertoires V beta 1-V beta 20 expressed in PBMC were analyzed by rev erse-transcription polymerase chain reaction (RT-PCR) and single strand con formation polymorphism (SSCP). In responders, the mean total number of T-ce ll clones in 22 TCR V beta repertoires was significantly decreased from 97. 4 +/- 40.1 to 62.6 +/- 32.1 (P < 0.01) after treatment. In transient respon ders, although one patient showed a decrease, four patients showed an incre ase, with the mean total number of T-cell clones increasing from 66.4 +/- 2 8.0 to 79.8 +/- 28.8 after treatment. In non-responders, the mean total num ber of T-cell clones was almost unchanged between before and after treatmen t. No clear tendency towards the use of any specific V beta was observed in any group of patients. These results suggest that T-cell clones accumulate d in the peripheral blood of patients with chronic hepatitis C and that the number of clones may change in response to IFN-alpha treatment. (C) 2000 E lsevier Science Ireland Ltd. All rights reserved.