Elevation of gamma delta T lymphocytes in peripheral blood and livers of patients with primary sclerosing cholangitis and other autoimmune liver diseases.

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease that is possibly an autoimmune disease. Although gamma delta T cells represent a small proportion of the total T-cell population in healthy individuals, there is evidence to suggest a role for these cells in autoimmunity. Accordingly, the aim of this study was to investigate the population of gamma delta T cells in patients with PSC, compared with other chronic liver diseases. An elevation in the percentage and absolute numbers of gamma delta T cells was found in the peripheral blood of patients with PSC (8.66% and 0.13 x 10(-6)/L [P < .01 and < .05, respectively]) and autoimmune hepatitis (AIH) (8.03% and 0.13 x 10(-6)/L [both P < 0.001]) compared with controls (4.10% and 0.06 x 10(-6)/L). We also found an elevation in the percentage and absolute numbers of gamma delta T cells in the portal areas of patients with PSC (10.55% and 4.33 [P < .001 and < .001, respectively]), AIH (7.16% and 4.55 [P = .001 and < .001, respectively]), and primary biliary cirrhosis (PBC) (5.57% and 3.49 [P = .008 and < .001, respectively]) when compared with controls (2.23% and 0.81). These findings suggest a role for gamma delta T cells in the mechanism of immune damage in autoimmune liver diseases.