Aliphatic alcohol contaminants of illegally produced spirits inhibit phagocytosis by human granulocytes

Context: Unregulated production of spirits in many countries leads to products containing appreciable levels of aliphatic alcohols (AAs) and is the main source of human exposure to these substances worldwide. Previous studies have confirmed that alcohol abuse can lead to ethanol-induced immunosuppression and thereby increased susceptibility to infectious diseases. Granulocytes, as professional phagocytic cells, play a crucial role in engulfment and killing of pathogenic microorganisms. Thus, a decrease in their phagocytic activity has been invoked as a factor in the impaired antimicrobial defense observed in alcoholics. However, AAs consumed as contaminants of illicit spirits may also influence phagocytosis, thereby contributing to a further decrease in microbicidal activity but, so far, this has not been studied. Objective: Therefore, the aim of this study was to measure granulocyte phagocytosis following treatment of granulocytes with those higher alcohols found in illegal spirits. Materials and methods: Granulocytes were isolated from human peripheral blood. Then phagocytosis of opsonized zymosan particles by granulocytes treated with AAs individually and in combination was determined. Results: These alcohols inhibited phagocytosis in a concentration-dependent manner and at lower concentrations when combined than when tested individually. Discussion and conclusion: Due to their synergistic effects, it is possible that, in combination with ethanol, they may inhibit phagocytosis in a clinically meaningful way in episodic heavy drinkers.