Decreased CD4+/CD8+ ratio in major type of recurrent aphthous ulcers: comparing major to minor types of ulcers.

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.

Immunological changes and recovery in patients with dengue haemorrhagic fever.

In studying the immunological changes in dengue haemorrhagic fever, three phases of investigations had been carried out. During the earlier phase of investigation, significant immunological findings were obtained, namely the elevation of immunoglobulins, activation of complements, formation of circulating-immune-complexes and diminished number of T lymphocytes. The changes tended to recover during the convalescent phase. During the second phase of investigation, the extended studies revealed further confirmation of T cell impairment during the acute phase which tended to recover during the convalescent phase. Elevated number of Fc-receptor- and C3-receptor-bearing cells was also observed in some patients, variedly occurred during the acute or the convalescent phase. Elevated number of B cells was only found in small proportion. Significantly high number of activated RNA-rich lymphocytes was found in almost the half of patients. The virus-lymphocyte interaction has been demonstrated by the detection of viral antigen on the surface of lymphocytes in a proportion of patients. The circulating-immune-complexes was shown to contain viral (DEN-1) antigen. During the third phase of investigation, the impairment of T cells was further analyzed on their regulatory T populations. Impairment of total T lymphocytes, helper-T and suppressor-T was detected during the acute phase and tended to recover during the convalescent phase. The reversed changes occurred on B cells, The immunological changes and recovery are considered to be related to the stimulatory and suppressive effects of the dengue virus and regulatory mechanism.