Leukemoid reaction in extremely low-birth-weight infants

Area of Science:

• Neonatal Medicine
• Pediatric Hematology
• Perinatology

Background:

• Extremely low-birth-weight (ELBW) infants (<1000 g) face numerous health challenges.
• Leukemoid reaction, characterized by elevated white blood cell (WBC) counts (>50,000/mm3), is a recently documented phenomenon in ELBW infants.
• The causes and implications of leukemoid reaction in this vulnerable population require further investigation.

Purpose of the Study:

• To determine the incidence of leukemoid reaction in ELBW infants.
• To evaluate the relationship between maternal and neonatal factors and leukemoid reaction.
• To assess the impact of leukemoid reaction on the survival of ELBW infants.

Main Methods:

• A retrospective case-controlled study was conducted on 60 ELBW infants born between July 1994 and June 1996.
• Infants with WBC counts ≥50,000/mm3 were classified as cases; the remainder were controls.
• Maternal and neonatal variables were analyzed for association with leukemoid reaction.

Main Results:

• The incidence of leukemoid reaction was 15% (9 out of 60 infants).
• No significant association was found between leukemoid reaction and maternal or neonatal variables, including sepsis and antenatal steroid use.
• Infants exhibiting leukemoid reaction demonstrated a better overall survival rate.

Conclusions:

• Leukemoid reaction is a rare occurrence in ELBW infants with an incidence of 15% in this cohort.
• The study did not identify specific maternal or neonatal factors associated with leukemoid reaction.
• A leukemoid response in ELBW infants appears to be a positive prognostic indicator for survival.