Quinolones alter defense reactions mediated by macrophages

The innate host defense system is regulated in part by the number and activ ation of the function of neutrophils and macrophages. The immunological eff ects of a variety of quinolones on host defense functions of macrophage are reported. Ofloxacin (OFLX), lomefloxacin (LFLX), tosufloxacin (TFLX), fler oxacin (FLRX), sparfloxacin (SPFX) and levofloxacin (LVFX) significantly in hibited phagocytosis of Escherichia coli by macrophages. Moreover, TFLX mar kedly potentiated tile expression of the adhesion molecule Mac-1 by macroph ages. No significant alteration was detected in the adherence and the expre ssion of adhesion molecule Mac-1 in macrophages treated with the other quin olones. In contrast, OFLX, LFLX, TFLX, and LVFX were effective in significa ntly increasing the production of hydrogen peroxide. while the other agents did not. These results suggest that the quinolones at a therapeutic concen tration differentially affect phagocytosis, adhesion. and the production of hydrogen peroxide by macrophages. (C) 2001 Elsevier Science B.V. All right s reserved.