The proportion of suppressor-inducer T-lymphocytes is reduced in recurrent aphthous stomatitis.

A flow cytometric analysis of peripheral blood lymphocytes was undertaken in recurrent aphthous stomatitis patients. The project aimed at detecting differences within lymphocyte subsets using type-specific monoclonal antibodies. Peripheral blood samples were taken from RAS patients in both active and remission phases of the disease and from a group of healthy control subjects. There were no statistical differences between the active and remission phases within any of the lymphocyte subsets examined. There was, however, a significant difference between the RAS group and the control group. RAS patients have depressed CD4+ cell numbers and elevated CD8+ cell numbers. The CD4:CD8 ratio is also depressed. A dissection of the CD4+ subset shows raised numbers of CD4+, 4B4+ lymphocytes and depressed numbers of CD4+, 2H4+ lymphocytes. Previous studies have shown disruption of peripheral blood lymphocyte numbers in Behçet's syndrome. A similar pattern has now been shown in uncomplicated cases of minor RAS.