Immunological factors are important in the pathogenesis of a spectrum of hepatobiliary diseases. To characterize the nature of specific immunological responses in liver disease, we determined lymphocyte changes in liver t i m e and in blood using flow cytometry. A total of 113 liver biopsy specimens was collected from patients with the following diseases: 19 chronic hepatitis B; 39 chronic non-A, non-B hepatitis; 27 alcoholic liver disease; 10 hepatic malignancy; 8 autoimmune hepatitis; 6 fatty liver and 4 primary biliary cirrhosis. The lymphocytes were isolated from the liver biopsy specimens by mechanical and enzymatic methods. The lymphocyte yield was 7,901 2 575 cells/mg of liver tissue. The viability of lymphocytes was 97.7% 2 0.3%. Lymphocytes were stained with four pairs of two-color mixed fluorescein-coqjugated monoclonal antibodies, including T4-T8 (CD4/CD8), Tll-B1 CDZ), and the ratios were determined by an Epics Profile flow cytometer. Immunophenotyping of lymphocytes in whole blood samples was simultaneously Variability in lymphocyte yield and different patterns of lymphocyte subsets were found in the liver biopsy specimens. The yields of lymphocytes from patients with chronic non-A, non-B and autoimmune hepatitis were highest, and the lowest yield was from patients with fatty liver. Patients with primary biliary cirrhosis, fatty liver and hepatic malignancy had relatively high ratios of CD4/CD8, CD56/CD8 and CD25/CD2; whereas patients with chronic hepatitis B, (CDZ-CDZO), NEMl-TS (CD56-CD8), IL-ZR1-T11 (CD25analyzed.