Influence of ethanol concentration in the phagocytic function of neutrophils against Klebsiella pneumoniae isolates in an experimental model.

Background/purpose: Although the prevalence of pneumonia or other extrapulmonary infections is higher in people with alcoholism or acute alcohol intoxication, the possible relationship of acute alcohol intoxication to phagocytic function has not been investigated. Our aim was to determine whether acute alcohol intoxication suppresses phagocytic function in human neutrophils.

Methods: Twenty healthy individuals were enrolled for isolating neutrophils to evaluate the neutrophil phagocytic function at different alcohol concentrations. Klebsiella pneumoniae was isolated from clinical specimens of liver abscesses. The rate of K. pneumonia phagocytosis (K2 and non-K1/K2 isolates) by neutrophils was determined using flow cytometry and compared among the nine groups with different alcohol concentrations.

Results: The rate of phagocytic uptake decreased significantly with increasing alcohol concentration in both the K2 and non-K1/K2 K. pneumonia groups (r = -0.866, p = 0.03 vs. r = -0.975, p < 0.001). Moreover, the percentage of K. pneumoniae ingested by neutrophils decreased with age.

Conclusion: The ability of neutrophils to phagocytose virulent K2 K. pneumoniae was suppressed by ethanol at high concentrations. This finding may account for the higher prevalence of pneumonia or other extrapulmonary infection in people with acute alcohol intoxication.