POLYMORPHONUCLEAR LEUKOCYTE DEFORMABILITY IN TYPE-II DIABETES-MELLITUS AND IN AGING

The deformability of polymorphonuclear leukocytes (PMN) from patients with type II diabetes, from elderly healthy, and from young healthy co ntrols has been investigated by two techniques. Partial micropipette ( i.d. 2.7-4.0 mun) aspiration of individual PMNs under constant aspirat ion pressure of 8 mm H2O and measurement of the aspirated length as a function of time (creep experiments) and filtration studies, using the Hemorheometer, of PMN suspensions (2.2-10(6) cells/ml) through 5 mum Nuclepore filters under 6 cm H2O driving pressure have been carried ou t. The creep curves were similar in all three cases with both the diab etic and the elderly PMN showing a statistically significant decrease (p<0.001) from the control ones in deformability, while there was no s ignificant difference between them. The initial filtration flow rate e xperiments (performed only on diabetic and control samples) exhibited a decreased deformability of the diabetics, which was not statisticall y different, however. The increased rigidity of these leukocytes in di abetes and in ageing may be a contributing factor in the observed micr ovascular flow disturbances in these situations.