Priming of blood neutrophils in children with cystic fibrosis: Correlationbetween 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 in fection, heterozygous, non-CF patients with chronic pulmonary infection, an d healthy controls. Circulating and platelet-activating factor (PAF)-primed phagocyte luminol luminescence responses to complement-opsonized zymosan w ere increased in both groups of infected CF and non-CF children relative to un-infected CF children and healthy control children and adults. The ratio between circulating and PAF-primed phagocyte responses was significantly e levated in all children with CF, and in these, the ratio could serve as an indicator of response to antibiotic treatment. The ratios of circulating an d PAF-primed phenotypic expression for CR1, CR3, and Fc gamma RIII (CD16), but not Fc gamma RII (CD32), correlated with the functional ratios. Phagocy te opsonin receptor response capacity might be used for evaluation of infla mmation and infection in CF patients.