Late-onset neutropenia in neonatal intensive care unit in children's Hospital, Cairo University

ABSTRACT

Neutropenia, defined as absolute neutrophil count [ANC] <1500/mm[3], affects 6% to 58% of premature infants in the first week of life. This early-onset neutropenia in premature infants has previously been correlated with sepsis, maternal hypertension, severe asphyxia, and periventricular hemorrhage. Late-onset neutropenia, defined as ANC <1500/mm[3] at a postnatal age of =3 weeks, has been recently reported. The purpose of this study is to determine the prevalence of late-onset neutropenia in low birth weight [LBW] infants and to examine the factors that may be associated with this phenomenon.The study comprised 150 premature infants who were admitted to our tertiary-level neonatal intensive care unit[NICU] from August 2003 to June 2004. A weekly complete blood cell count [CBC] was performed routinely at day 1, and then weekly until discharge in all premature infants with birth weight =1500 g [n=86] who survived until discharge. Late-onset neutropenia was detected in 18 infants [21%]. In both neutropenic [n=18] and nonneutropenic infants [n= 68], ANC increased postnatally, remained above 5000/mm[3] for the first 3 weeks of life, and had a marked decrease at 4 weeks of age. Thereafter, ANC decreased to a level of 1300/mm3 in the neutropenic infants and 4000/mm[3] in the nonneutropenic infants. The neutropenic infants had a significantly lower hemoglobin, than did the nonnentropenic infants with similar platelet counts. None of the study infants received erythropoietin during their hospitalization. This late-onset neutropenia occurred at postnatal age of 4.5 +/- 1.8 weeks [range 3-10 weeks]. The duration of neutropenia was 1.2 +/- .7weeks [range 1-3weeks]. The neutropenic infants were stable, growing on full oral feedings, and had no signs or symptoms of sepsis. No adverse effects of late-onset neutropenia were apparent in these infants. Late-onset neutropenia appears to be a benign condition that is not associated with any particular complication and does not require specific treatment. Reference ranges after the early neonatal period and during the first few months of life in LBW and VLBW infants should probably be set at lower values