Polymorphonuclear leucocyte chemotaxis in patients with bacterial infections.

A new in vitro method of measuring the chemotaxis of polymorphonuclear leucocytes from peripheral blood has been used to calculate a chemotactic index. The mean chemotactic index in 15 patients with bacterial infection (434) was significantly less (P <0.0005) than in 15 normal controls (553) matched for age and sex. The reduction in chemotaxis could be correlated with the duration of the infection, with the greatest impairment being found in those patients with the shortest duration of infection. In five patients studied before and after appropriate therapy the chemotactic index returned to normal values with clearing of the infection. It is suggested that the impairment in chemotaxis may be due to prior phagocytosis of antibody-antigen complexes by the polymorphonuclear leucocytes.