Extremely low birth weight infants have lower Fc gamma RIII (CD 16) plasma levels and their PMN produce less Fc gamma RIII compared to adults.
The purpose of this study was to determine whether decreased Fc gamma RIII expression on the PMN of extremely low birth weight infants (ELBW) is due to decreased receptor synthesis or increased receptor shedding from the PMN surface. 42 ELBW, 12 larger infants and 14 adults were enrolled. Plasma and total cellular Fc gamma RIII were measured by ELISA, and PMN Fc gamma RIII expression was measured by flow cytometry. ELBW PMN plasma membrane expression of Fc gamma RIII as measured by log mean channel fluorescence (5.00 +/- 1.98 vs. 10.68 +/- 1.61, p < 0.050) and plasma Fc gamma RIII levels were both lower (7.5 +/- 6.1 vs. 82.4 +/- 64.8 nM, p < 0.05) than in adult controls. In follow-up studies, 14 ELBW (age = 29 +/- 14 days, range = 14-56 days) increased PMN expression of Fc gamma RIII (p < 0.001) but not plasma Fc gamma RIII. ELBW had lower total PMN-associated Fc gamma RIII than adults (2.3 +/- 0.9 vs. 6.8 +/- 2.2 ng/10(6) PMN, p = 0.006). ELBW's PMN produce less Fc gamma RIII than adults' PMN, and expression of this receptor is developmentally regulated.
Payne
N R
NR
Department of Neonatology, Children's Health Care, Minneapolis, MN 55404, USA.
Fleit
H B
HB
D000328:Adult; D000375:Aging / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology*; D017452:Receptors, IgG / Q000378:metabolism*
D017452:Receptors, IgG