Abstract: Objective To study frequencies of presence of serum antinuclear antibody（ANA） and T-lymphocyte subsets changes in oral lichen planus（OLP）, recurrent oral ulcerations（ROU） and discoid lupus erythematosus（DLE） patients. Methods In this study, the serum levels of ANA were measured in a group of 80 Chinese OLP patients, 115 ROU patients, 31 DLE patients and to detect the peripheral blood T-lymphocyte subsets by flow cytometer. Results The frequencies of presence of serum ANA and T-lymphocyte subsets changes were different among three groups. The frequencies of presence of serum ANA in DLE group, OLP group, ROU group were 29.0%（9/31）, 6.25%（5/80） and 1.7%（2/115） respectively. The proportion of reduced CD3＋ T-lymphocytes subsets was 51.6%（DLE group）, 50%（OLP group） and 52.2%（ROU group） respectively. In OLP group, most patients（75%） had normal CD4＋ T-lymphocytes subsets. And in DLE group the proportion of reduced CD4+ T-lymphocytes subsets was 54.8%（17/31）. Conclusion There are significantly difference in T-lymphocyte subsets changes and frequencies of presence of serum ANA among DLE group, OLP group and RAU group.

Key words: oral medicine, antinuclear antibody, T-lymphocyte subsets