Why are T cells tolerant to hepatitis B virus?
1 expression has been proved by recent studies to be positively correlated with the extent of HBV-specific T cell impairments. However, the degree of T cell exhaustion which affects the disease statuses of hepatitis B patients has so far been only evaluated in restricted and small groups of patients between those with established chronicity and subjects with acute HBV infection. Besides, whether levels of PD-1 expression on T cells differ between acute exacerbation of hepatitis B and chronic HBV infected patients is still unknown. A research article to be published on July 28, 2008 in the World Journal of Gastroenterology addresses this question. The research team led by Shu-Ling Zhang from Tongji Medical College of Huazhong University of Science and Technology in China examined the expression of PD-1 on antigen specific CD8+ T cells in peripheral blood of chronic hepatitis B (CHB) and acute exacerbation of hepatitis B (AEHB) patients. They found that the levels of PD-1 on total CD8+ T
