Polymorphonuclear leukocyte rheology before and after chemotactic activation in different clinical conditions

We examined at baseline and after activation with N-formyl-methionyl-leucylphenylalanine (fMLP) the polymorphonuclear (PMN) leukocyte rheology expressed not only as filtration parameter (using the St. George's Filtrometer) but also as membrane fluidity (employing the fluorescent probe TMA-DPH) and cytosolic Ca2+ concentration (adopting the fluorescent probe Fura-2AM) in a group of subjects with vascular atherosclerotic disease (VAD), in a group of VAD subjects with type 2 diabetes mellitus (DM), in a group of type 1 diabetics, in a group of type 2 diabetics, in a group of hypertensives and in a group of subjects with chronic renal failure (CRF), The obtained results show that after activation the PMN filtration parameter (IRFR) was significantly and constantly reduced in normals and in all the examined groups although this reduction was more evident in diabetics of both types, in hypertensives and in CRF subjects. The PMN membrane fluidity after activation decreased significantly only in type 1 diabetics and in CRF subjects while PMN cytosolic Ca2+ content did not show any significant variation in normal controls and in CRF subjects. These data underline how the PMN rheological pattern needs to be examined at baseline and after activation, even if the mechanisms of these variations are not always demonstrated.