Effect of pentoxifylline in vitro on neutrophil reactive oxygen production and phagocytic ability assessed by flow cytometry.

Neutrophil granulocytes have been described as agents of defence and destruction. The effect of pentoxifylline on the phagocytic ability and generation of reactive oxygen radicals of neutrophils was studied at concentrations of 1, 10 and 100 mg/L. Flow cytometry was used to study phagocytic ability by measuring uptake of fluorescein-labelled bacteria. The generation of reactive oxygen intermediates was estimated by the quantification of the intracellular conversion of dihydrorhodamine 123 to rhodamine 123. In vitro pentoxifylline treatment diminished neutrophil reactive oxygen production (at 10 mg/L -45% and at 100 mg/L -63%; p < 0.001 for both) and reduced neutrophil phagocytic ability (at 100 mg/L -23%; p < 0.05). Both effects were rapidly reversible after plasma exchange. We conclude that pentoxifylline could decrease oxidative tissue damage by neutrophils in septicaemia or after IV granulocyte transfusion.