Changes of Neutrophil Count in Peripheral Blood of the Neonate with Periventricular Leukomalacia

Lee, Hwan Seok; Park, Kyung Pil; Kim, Heng Mi

Abstract

PURPOSE
It is now well established that infection and inflammation play an important role in the pathogenesis of ischemic brain damage. The loss of neutrophils from systemic circulation is an associated finding in injury mediated by granulocyte. Periventricular leukomalacia(PVL) caused by ischemia is the principal form of brain injury in premature infants. This study was conducted to evaluate whether the low neutrophil count is associated with periventricular leukomalacia(PVL) in premature infants.
METHODS
Retrospective review of medical records was undertaken. Subjects were premature infants with a birth weight of less than 1,500 gm, admitted to the Neonatal Intensive Care Unit of Kyungpook University Hospital. A complete blood count of peripheral blood was done within the 1st hour of life. Neutropenia was defined as absolute neutrophil count <1,500/mm3, PVL as increased periven tricular echodensities followed by cyst formation on ultrasonography or corresponding signs on brain MRI.
RESULTS
Thirteen infants out of a total population of 37 revealed neutropenia. Respiratory distress syndrome and requirement for respiratory support were not different between infants with neutropenia(neutropenia group) and infants without neutropenia(control group). Intraventricular hemorrhage (IVH) and grade 3 and 4 IVH were more frequent in neutropenia group(P<0.05). There was no statistically significant increase of PVL in neutropenia group. The neutrophil count was 18,760.0+/-10,266.1/mm3, 7,272.0+/-7,435.0/mm3 infants with PVL and 11,131.7+/-3,386.5/mm3, 2,407.5+/-1,933.1/mm3 in infants without PVL, respectively. The frequency of mechanical ventilation and artificial surfactant therapy was higher in infants with PVL compared with infants without PVL, but statistical analysis was not performed due to small number of subjects.
CONCLUSION
A low number of neutrophils in the systemic circulation was not associated with an increased risk of PVL in premature infants.