Value of Cytoplasmic Vacuolization of Neutrophils in the Diagnosis of Bloodstream Infection

Abstract

This study assesses the sensitivity of several peripheral blood leukocyte parameters (absolute band count, absolute granulocyte count, the presence of cytoplasmic vacuolization of neutrophils [CVN], and the absolute lymphocyte count), either alone or in combination, for the detection of bloodstream infection in 168 patients with this condition. The granulocyte count was defined as the absolute neutrophil count plus the band count. Sensitivity of the single leukocyte parameters were as follows: 82 (48.8%) showed lymphocytopenia (<1,000/μL3 [<1.0×109/L]), 112 (66.7%) showed an elevated granulocyte count (>7,200/y.L3 [>7.2xl09/L]), 121 (72%) showed an elevated band count (>700/μL3 [>0.7×109/L]), and 152 (90.5%) showed the presence of CVN. We concluded the following: (1) The presence of CVN was significantly (P<.001) more sensitive for bloodstream infection than either an elevated granulocyte count or band count alone (90.5% vs 66.7% or 72.0%, respectively). (2) The inclusion of CVN significantly improved the sensitivity of every other leukocyte parameter; however, CVN was found in 15.9% of a group of 69 healthy persons and thus cannot be considered specific for bloodstream infections. (3) The addition of the band count did not significantly change the sensitivity of elevated granulocyte count and/or presence of CVN (97.0% vs 98.8%). (4) A significant number of patients with bloodstream infection had lymphocytopenia (48.8%), a finding that has not been previously emphasized.