Assessment of neutrophil function in healthy volunteers - Effects of age and gender

In atherogenesis and myocardial reperfusion injury attention has been focused on polymorphonuclear neutrophils (PMN). Hence it is important to develop simple and reliable tests to distinguish normal PMN function from pathological conditions. In the following investigation three PMN function assays are tested for effects of age and gender in healthy volunteers, in particular a new method of PMN adhesion. Samples have been taken from 80 healthy volunteers (40 male, 40 female; 20 younger, 20 older than 40 years respectively). PMN were separated from whole blood using density gradients. For PMN adhesion, PMN were run through the capillary tube of a plasma viscosimeter where they can adhere to the capillary surface. The adhesion index (NAD) was defined as the fraction of adhering PMN resuspended in saline solution (N-NAD) or plasma (P-NAD) compared to baseline values. PMN aggregation (NAG) was measured by differences in optical transmittance of a PMN suspension before and after addition of aggregating inductors such as adenosinediphosphate (ADP), collagen (COL) and formyl-methionyl-leucyl-phenylalanine (FMLP). PMN activation (NBT) was measured by the ingestion of nitroblue tetrazolium after PMN stimulation as phagocyting value (ph-NBT) and compared to the resting value (r-NBT). The following parameters of PMN function proved to be independent of age and gender (U-Test; Mann-Whitney): P-NAD(p(gender) = 0,3531, p(age) = 0,7254), NAG-ADP(p(gender) = 0,4884, p(age) = 0,1544), NAG-COL (p(gender) = 0,6546, p(age) = 0,5444), NAG-FMLP (p(gender) = 0,8436, p(age) = 0,0675) and r-NBT (p(gender) = 0,1516, p(age) = 0,3708). With the described assays for PMN adhesion, aggregation and activation simple and reliable tests of PMN function being independent of age and gender are available. Copyright (C) 1996 Elsevier Science Ltd