Effect of tetracycline on the phagocytic function of human leukocytes.

Abstract

Phagocytosis and the intracellular killing of microbes are fundamental functions of polymorphonuclear neutrophil leukocytes. Bacteriostatic antibiotics are effective only with proper neutrophil function. Thus, inhibition of leukocyte function by bacteriostatic antibiotics may have important therapeutic implications. The possibility that these functions of peripheral blood leukocytes may be effected during antimicrobial therapy has not been investigated extensively. The purpose of the present study was to extend earlier investigations into the effect of tetracycline on phagocytosis of bacteria and yeast by human neutrophils. Reports on the effect of tetracycline on the function of leukocytes have been contradictory. In 1950 an engulfment-inhibiting effect was ascribed to chloratetracycline [1]. However, in a later report by other investigators, no such effect was demonstrated with tetracycline hydrochloride [2]. In more recent reports tetracycline hydrochloride has been shown to inhibit chemotaxis [3, 4] and maximal reduction of nitroblue tetrazolium dye (NBT) [5] by human leukocytes. In one study tetracyclines were shown to inhibit the bactericidal effect of serum, but not opsonization of bacteria [6].