Transient neutropenia may be a risk of treating preterm neonates with high doses of recombinant erythropoietin

Late-onset neutropenia: defining limits of neutrophil count in very low birth weight infants

OBJECTIVE

To evaluate the incidence, onset, duration, characteristics and importance of late-onset neutropenia (defined as absolute neutrophil count<1500 μl(-1) at 3 weeks of age or later) in a group of very low birth weight (VLBW) infants.

STUDY DESIGN

Routine complete blood cell counts (CBCs) obtained from VLBW infants over a period of 7 years were gathered retrospectively, including those of newborns with weekly CBCs taken over a duration of at least 3 weeks. Data were obtained from between January 2003 and December 2009.

RESULT

CBCs of 399 newborns were included. Values were obtained from birth to 36 weeks of postnatal age. Late-onset neutropenia was observed in 259 cases (65%). Neutropenic infants had a mean of 0.5 weeks lower gestational age. Late-onset neutropenia was more frequent in children with intraventricular hemorrhage but not in patients who received erythropoietin. The median age of neutropenia onset was 7 weeks in extremely low birth weight infants and 6 weeks in VLBW infants. The fifth percentile of neutrophils between weeks 3 and 4 was 1280 μl(-1) and between weeks 13 and 15 was 500 μl(-1). The average duration was 2 weeks with normalized values after 18 weeks.

CONCLUSION

A neutrophil count <1500 μl(-1) after the third week of life is frequently observed in VLBW infants and should not be used as a lower reference limit. The fifth percentile varies according to postnatal age from around 1300 μl(-1) in week 4 of life, decreasing to a nadir of 500 μl(-1) between 3 and 4 months of age. Values normalize in the first year of life.

Late-onset blueberry muffin lesions following recombinant erythropoietin administration in a premature infant

Recombinant erythropoietin is being used in premature population for anemia of prematurity. It is considered very safe in this population, although risks are still being evaluated. We report the first case of dermal erythropoiesis as a side effect of recombinant erythropoietin in an extremely prematurely born infant presenting with late-onset blueberry muffin lesions.

Late-onset neutropenia in very low birthweight infants

AIM

To evaluate the incidence and duration of late-onset neutropenia (defined as an absolute neutrophil count (ANC) <1500 mm(-3) at a postnatal age of >3 wk) in a population of infants with birthweight <2000 g, and to determine whether copper deficiency, a possible cause of both anemia and neutropenia, may be associated with this complication.

METHODS

Complete blood cell count and differential were assessed in 247 low (LBW) and very low birthweight (VLBW) infants who were discharged after 3 wk of life. In neutropenic infants plasma copper and ceruloplasmin levels were also measured.

RESULTS

Late-onset neutropenia was detected in 11 out of 147 VLBW infants (7.5%) and in 7 out of 127 LBW infants (5.5%). A neutrophil count of <1000 mm(-3) was observed in 14 infants (5.1%). A significantly lower gestational age was found in neutropenic infants compared with non-neutropenic infants. In neutropenic infants ANCs were significantly correlated with hemoglobin and hematocrit. In addition, a significant negative correlation was found between neutrophil and reticulocyte counts. Plasma copper concentration was significantly correlated with birthweight. Oral copper sulfate was administered to infants with plasma copper concentration <50 microg dl(-1), and did not seem to affect ANC, hemoglobin, hematocrit or reticulocyte counts.

CONCLUSION

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.

A practical approach to evaluating and treating neutropenia in the neonatal intensive care unit

Neutropenia is a relatively common problem in the NICU, recognized in as many as 8% of patients at some time during their hospital stay. In most instances, neutropenia among NICU patients is of short duration and has little influence on outcome. In other cases it is prolonged and severe, and constitutes a serious antimicrobial defense deficiency. When a neonatologist discovers a low blood neutrophil count, choices must be made regarding further evaluation and treatment. The authors hope that the information provided in this article is useful in making these choices.