Inhibition of phytohemagglutinin-induced lymphocyte proliferation by dexamethasone : mechanisms of individual susceptibility

Abstract Direct positive correlation has been shown between the level of stimulation of peripheral blood lymphocytes and of the inhibition degree of PHA stimulation by dexamethasone. On the basis of this correlation we subdivided all the examined individuals into three groups of susceptibility: resistant, sensitive, and intermediate. The studies carried out in these groups showed that the reception effectiveness of glucocorticoids (GC) was much higher in the sensitive group than in the group of resistant individuals. In this group interleukin 2 (IL-2) production was relatively high; in the intermediate group this parameter was lower, and in the group of sensitive individuals the mean indices of IL-2 production were the lowest. However, this latter group unlike the two others was heterogeneous and may be divided into two subgroups: high and low IL-2 producers. HLA antigens B7 and DR2 were also shown to be associated with a decrease in sensitivity to GC inhibition of PHA-induced lymphocyte proliferation. Our results indicate that the method we used is adequate enough for dividing individuals into sensitivity groups.