FCGR1A and Sepsis: In cases of inflammation, the expression of CD64, a high affinity receptor to immunoglobulin G, is rapidly increased in the neutrophil population.11 It has been indicated that these CD64+ neutrophils may have reduced phagocytic activity in the first 48 hours of sepsis compared to healthy controls.12 After incubation with fluorescently labeled latex beads, the mean fluorescence intensity of neutrophils and monocytes was calculated.