Rheological anomaly of neutrophils in Behçet's disease by suspension filtration time through a nuclepore filter

Micropore (diameter, 5 μm) passage of neutrophils under constant suction was studied in Behçet's disease by a modification of the Nuclepore filtration method. Filtration times for neutrophils (5000/μl) in neutrophil-erythrocyte suspensions in plasma were determined from suspension filtration times (filtered volume, 0.5 ml; suction pressure, 10 cmH₂O; temperature, 37°C) subtracted by those of neutrophil-poor erythrocyte suspensions in plasma of the same hematocrit values. Filtration times determined were significantly higher (p<0.01) in patients (10.9±5.4 sec; mean±S.D.; n=10) than in healthy subjects (4.9±1.2 sec; n=10). Filtration times for leukocytes of 5000/μl in whole blood were similarly determined to examine the effect of the preparation; the values were also significantly higher (p<0.001) in patients (8.8±5.3 sec; n=17) than in control (3.4±1.0 sec; n=17). The addition of the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP; 5 nM) to the neutrophil-erythrocyte suspensions resulted in immediate increases of the neutrophil filtration times to 165±100 sec in the patients which were significantly higher (p<0.01) than those to 39±18 sec in the control. These results suggest that neutrophils in Behçet's disease are in an active state, possibly with an increased resistance to flow through microvessels as well as with an increased response to chemotactic stimulations.