ABSTRACT
The etiology of recurrent aphthous ulcers (RAU) has not been clearly defined. However, the results of several studies indicated the evidence of the role of immunological factors. The association between the regulator and effector component of the immune system in RAU needs clarifying by comparing major and minor type of RAU patients. The proportion of peripheral blood lymphocyte subsets were enumerated during active ulcer phase and analyzed in relation to ulcer types. Nineteen patients with RAU (12 minor type and 7 major type) and 8 healthy volunteers, of both sexes, aged 24-54 years old were tested. CD3+ (T cell), CD4+ (helper T cell), CD8+ (suppressor/cytotoxic T cell), CD19+ (B cell), and CD16+/CD56+ (NK cell) were determined by using appropriate monoclonal antibodies in double colored flow cytometry. The results showed that CD4+ was lower in RAU than control (P < 0.01). Comparing both types of RAU, it appeared that CD8+ was higher in the major type than the minor type (p < 0.01); CD4+/CD8+ ratio in the major type was lower than the minor type (P < 0.01). There was no difference in CD19+ and CD16+/CD56+ between any groups compared. The finding indicated that RAU was associated with abnormal proportions of CD4+ and CD8+ cells which was dependent on the severity of the lesion.