Leukocytes present in stored blood products can have a variety of biological
effects, including depression of immune function, thereby increasing nosocomial
infections and possibly resulting in organ failure and death. Premature infants,
given their immature immune state, may be uniquely predisposed to the effects
of transfused leukocytes.
To evaluate the clinical outcomes following implementation of a universal
prestorage red blood cell (RBC) leukoreduction program in premature infants
admitted to neonatal intensive care units (NICUs).
Design and Setting
Retrospective before-and-after study conducted in 3 Canadian tertiary
care NICUs from January 1998 to December 2000.
A total of 515 premature infants weighing less than 1250 g who were
admitted to the NICU, received at least 1 RBC transfusion, and survived at
least 48 hours were enrolled. The intervention group consisted of infants
admitted in the 18-month period following the introduction of universal leukoreduction
(n = 247) and the control group consisted of infants admitted during the 18
months prior to the introduction of universal leukoreduction (n = 268).
Main Outcome Measures
Primary outcomes were nosocomial bacteremia and NICU mortality, compared
before and after implementation of universal leukoreduction using multivariate
regression. Secondary outcomes included bronchopulmonary dysplasia, retinopathy
of prematurity, necrotizing enterocolitis, and intraventricular hemorrhage.
The proportion of infants who acquired bacteremia after an RBC transfusion
was 79/267 (29.6%) in the nonleukoreduction period and 63/246 (25.6%) in the
leukoreduction period. For NICU mortality, there were 45 deaths (16.8%) in
the nonleukoreduction period and 44 deaths (17.8%) in the leukoreduction period.
The adjusted odds ratio (OR) for bacteremia was 0.59 (95% confidence interval
[CI], 0.34-1.01) and for mortality was 1.22 (95% CI, 0.59-2.50). The adjusted
ORs for bronchopulmonary dysplasia and retinopathy of prematurity were 0.42
(95% CI, 0.25-0.70) and 0.56 (95% CI, 0.33-0.93), respectively. The adjusted
ORs for necrotizing enterocolitis and grade 3 or 4 intraventricular hemorrhage
were 0.39 (95% CI, 0.17-0.90) and 0.65 (95% CI, 0.35-1.19), respectively.
The adjusted OR for a composite measure of any major neonatal morbidity was
0.31 (95% CI, 0.17-0.56). Crude and adjusted rates for all secondary outcomes
suggest that leukoreduction was associated with improved outcomes.
Implementation of universal prestorage leukoreduction was not associated
with significant reductions in NICU mortality or bacteremia but was associated
with improvement in several clinical outcomes in premature infants requiring