Transfusion in premature infants impairs production and/or release of red blood cells, white blood cells and platelets

Objective: To examine whether red blood cell transfusion in infants with anaemia of prematurity alters peripheral counts of red blood cell precursors, total white blood cells and white cell differential and platelets. Methodology: In 18 consecutive stable premature infants with anaemia of prematurity, peripheral cell counts were prospectively recorded immediately before transfusion of 20 mL/kg packed red blood cells (given over 6 h), and at 48 h after completion of the transfusion. Results: The median (interquartile range) haematocrit increased from 22.0% (21.3-24.0%) pre-transfusion to 37.0% (36.0-38.0%) post-transfusion (P < 0.001). Red-cell precursors decreased: median (interquartile range) reticulocytes from 3.7% (3.0-7.7%) to 3.7% (2.6-4.1%) (P = 0.03); and median (interquartile range) nucleated red blood cells from 0 G/L (0-0.2 G/L) to 0 G/L (0-0 G/L) (P = 0.03). The mean (SD) platelet count decreased from 420 G/L (154 G/L) to 313 G/L (101 G/L) (P = 0.001). The total white blood cell count and neutrophils did not change significantly; however, median (interquartile range) immature neutrophils decreased from 0.12 G/L (0.06-0.74 G/L) to 0.08 G/L (0.01-0.24 G/L) (P = 0.03). Lymphocytes, eosinophils, basophils and plasma cells remained unchanged. Monocytes increased (P = 0.01). Conclusions: Forty-eight hours after red blood cell transfusion to premature infants, there is an absolute decrease in red blood cell precursors, immature white blood cells and platelets, probably due to erythropoietin-suppression.