REDUCED HYDROGEN-PEROXIDE PRODUCTION IN NEUTROPHILS FROM PATIENTS WITH DIABETES

We evaluated the effects of granulocyte colony-stimulating factors (G- CSF), granulocyte-macrophage colony-stimulating factors (GM-CSF) and p horbol myristate acetate (PMA) on H2O2 production in purified neutroph ils from patients with diabetes mellitus (DM), using flow cytometry. T wenty-two age-matched male subjects were selected: 11 were normal volu nteers and the remainder had DM. No significant differences in intrace llular H2O2 production per 60 min was observed in the 'resting' neutro phils from DM patients (37.2 +/- 20.4 A.U.) compared with those from n ormal volunteers (24.9 +/- 8.4 A.U.). The PMA-stimulated neutrophils f rom normal volunteers generated approximately 4-fold increases in H2O2 per 60 min compared with those from DM patients. Under similar cultur e conditions, G-CSF caused 1.6-fold increases of H2O2 in neutrophils f rom normal volunteers compared with those of DM patients. Increases af ter GM-CSF stimulation were 2-fold higher in volunteer neutrophils com pared with those from DM patients. The levels of G-CSF- or GM-CSF-stim ulated H2O2 production in neutrophils from DM patients were low and we re little different from non-stimulated resting cells. These data show ed that H2O2 production in neutrophils induced by PMA is impaired in p atients with DM, and neither G-CSF nor GM-CSF enhances its production.