RESUMO
The percentage of lymphocyte subsets from the peripheral blood of healthy adults and hepatitis B surface antigen (HBsAg) carriers were analyzed by flow cytometry. The five lymphocyte subsets studied were:- T (CD3) cells, B (CD19) cells, CD4 cells, CD8 cells, Natural Killer (CD3- CD16+/CD56+) cells (NK cells) and the CD4/CD8 ratio. The percentage (mean +/- SD) for the five lymphocyte subsets from the healthy adults were (67.5 +/- 8.5)%, (12.4 +/- 4.5)%, (35.5 +/- 7.8)%, (36.8 +/- 8.5)%, (17.9 +/- 8.1)% and 1.1 +/- 0.6, respectively. HBsAg carriers positive for HBV-DNA had a lower CD4/CD8 ratio than the healthy population (P = 0.030). The percentage of CD8 cells in HBsAg carriers increased significantly (r = 0.28; P = 0.019) with an increase in ALT levels but the values remained within normal range. The percentage of NK cells and CD4/CD8 ratio in HBsAg carriers positive for anti-HBe were higher than HBsAg carriers negative for anti-HBe (92% of which are HBeAg positive) (P = 0.045 and P = 0.035, respectively). The CD4/CD8 ratio in HBsAg carriers negative for anti-HBe (92% positive for HBeAg) was also lower than in the healthy population (P = 0.042). HBsAg carriers positive for HBV-DNA, HBeAg and raised ALT levels had a lower CD4/ CD8 ratio than did the healthy population. The lower ratio was due to an increase in the percentage of CD8 cells. This suggests an activated immune response triggered by the infection in an attempt to clear the virus. HBsAg carriers with normal ALT levels and who are negative for HBV-DNA may be in a state of tolerance.