Granulocyte integrins before and after activation in acute ischaemic stroke

We examined in 19 subjects with acute ischaemic stroke (AIS) the PMN integr in pattern (CD11a, CD11b, CD11c, CD18), using indirect immunofluorescence a nd adopting a flow cytometer, at baseline and during activation, prolonged for 5 and 15 min, with 4-phorbol 12-myristate 13-acetate (PMA). At baseline , an increase in the expression of CD11c and CD18 and a decrease in the CD1 1b were evident in AIS subjects compared to normals. After activation, we f ound in normals a constant and significant increase of all PMN adhesive mol ecules, while in AIS subjects, we found an increase in CD11b and CD18, a de crease in CD11a and no variation in CD11c. While the basal upregulation of CD11c and CD18 may depend on the PMN spontaneous activation or on the incre ase of cytokines, the decrease of CD11b may be due to its self-consumption. After activation, the decrease in CD11a noted in AIS may be related to its cleavage or to an altered integrin phosphorylation/dephosphorylation balan ce. (C) 2001 Elsevier Science B.V. All rights reserved.