PMN activation parameters.

Cytofluorometric analysis of the expression of CD11b and of LAP on the PMN cell surface in control subjects (C) and in patients with ET and PV. CD11b results are expressed as MFI arbitrary units. LAP results are expressed as percentage mAb-positive cells. Elastase activity of lysed PMNs isolated from whole blood. Results are mean ± SEM. Statistical analysis using Mann-Whitney U test for nonparametric data. *P < .05; ** = P < .01; both versus C.