Seasonal variation in suppressor T cell subsets and non-specific suppressor cell function in hay fever sufferers.

The helper/suppressor T cell ratio, as defined by monoclonal antibodies, was significantly higher in hay fever sufferers compared with controls (P less than 0.05), but only during or shortly after the pollen season. This was due to a reduction in the suppressor subset, which returned to control values in the winter. There was no significant difference in the non-specific concanavalin A-induced suppressor cell function compared with controls. The mean summer value was significantly lower than the winter value (P less than 0.05), but we cannot be sure that this was not the result of changes in laboratory conditions. No relationship was found between T cell subsets or suppressor cell function and total or specific IgE levels, or between T cell subsets and suppressor cell function. Our findings suggest that in hay fever, reduction in suppressor cell numbers and function is a secondary phenomenon.