Priming of Blood Neutrophils in Children with Cystic Fibrosis: Correlation between Functional and Phenotypic Expression of Opsonin Receptors before and after Platelet‐Activating Factor Priming

Blood phagocyte opsonin receptor CR1 (CD35) and CR3 (CD11b) functions were examined in cystic fibrosis (CF) patients with endobronchial Staphylococcus aureus or Pseudomonas aeruginosa chronic infection, CF patients without infection, heterozygous, non-CF patients with chronic pulmonary infection, and healthy controls. Circulating and platelet-activating factor (PAF)-primed phagocyte luminol luminescence responses to complement-opsonized zymosan were increased in both groups of infected CF and non-CF children relative to uninfected CF children and healthy control children and adults. The ratio between circulating and PAF-primed phagocyte responses was significantly elevated in all children with CF, and in these, the ratio could serve as an indicator of response to antibiotic treatment. The ratios of circulating and PAF-primed phenotypic expression for CR1, CR3, and FcgammaRIII (CD16), but not FcgammaRII (CD32), correlated with the functional ratios. Phagocyte opsonin receptor response capacity might be used for evaluation of inflammation and infection in CF patients.