Stroke is a common cause of death and disability in our society. Stroke is
associated with changes in immune responses within the central nervous syst
em as well as systemically. The cel Is contributing to such changes as well
as the factors contributing to formation of the inflammatory infiltrate ob
served in stroke remain to be clarified. In this study, blood monocytes and
corresponding mononuclear cells (MNC) were separated and examined in paral
lel within 4 days and 1-3 months after onset of ischemic stroke. Numbers of
TNF-alpha-, IL-12-, IL-6-, and IL-10-secreting cells and of cells expressi
ng mRNA for matrix metalloproteinase (MMP)-1, -2, -7, -9 and tissue inhibit
or of MMP (TIMP)-1 were studied. The TNF-alpha-, IL-12-, and IL-6-secreting
monocytes and MNC were elevated during the acute phase compared to healthy
controls. Such differences were not observed when stroke patients were exa
mined during convalescence. The IL-10-secreting monocytes did not change ov
er the course of stroke. Levels of monocytes expressing MMP-1, MMP-7 and TI
MP-1 mRNA were elevated in the acute phase of stroke patients compared to c
onvalescence and healthy controls, as were levels of MMP-1, -2, -7, -9 and
TIMP-1 mRNA expressing blood MNC. The MMP-2 and -9 activity as measured by
zymography also was higher in MNC supernatants in the acute phase of stroke
compared to convalescence. The high levels of proinflammatory cytokines an
d MMPs in blood monocytes and MNC further demonstrate the presence of syste
mic aberrations in the acute phase of stroke. Such changes may contribute t
o the influx of blood-borne cells into the ischemic lesions during the acut
e phase of stroke.