INCREASED PERFORIN EXPRESSION IN MULTIPLE-SCLEROSIS PATIENTS DURING EXACERBATION OF DISEASE IN PERIPHERAL-BLOOD LYMPHOCYTES

The expression of perforin (P) in subpopulations of the PBL of multipl e sclerosis (MS) patients in stable and active phase of disease was in vestigated, by simultaneous detection of P (intracellular molecule) an d cell surface antigens. A significant increase of CD4(+)P(+) (p < 0.0 2) and CD16(+)P(+) (p < 0.001), and decrease of CD56(+)P(+) (p < 0.05) cells in active MS was found. In active disease there is a highly sig nificant increase(p < 0.001) of average fluorescence intensity (AFI) f or P in CD4(dim+) cells, and these cells are larger in size and have h igher granularity(p < 0.05) compared to CD4(bright) p(dim+) cells. Sur prisingly, there were no CD25(+)P(+) cells in either group of MS patie nts. These results show that CD4(+)P(+) cells are upregulated in activ e disease in cell number, in the level of P expression per cell, and i n the level of cell activation (increase in cell size and granularity) . It is suggested that CD4(+)P(+) cytotoxic cells may play a role in t he pathogenetic mechanisms of MS.