Impaired neutrophil killing in a patient with defective degranulation of myeloperoxidase

A case of recurrent, superficial abscesses in an 18 year old girl, is described. Staphylococcus aureus was the pathogen most often implicated and on several occasions the abscesses required surgical drainage. Defects in humoral immunity, neutrophil chemotaxis or opsonophagocytosis were not observed. However, her neutrophil's ability to kill ingested S. aureus in vitro was impaired. This was associated with impaired luminol-dependent chemiluminescence in response to stimulation by either latex beads, or the chemotactic peptide FMLP plus cytochalasin B. Oxygen uptake and superoxide anion production were normal but release of myeloperoxidase by this patient's neutrophils occurred more slowly and to a lower extent than in control cells. These data suggest that the recurrent infections and diminished in vitro neutrophil bactericidal activity observed in this patient are associated with impaired degranulation of myeloperoxidase.