The protein metabolic response to HIV infection in young children.
BACKGROUND
Growth failure often precedes secondary infections in HIV-infected infants and children, suggesting that inadequate protein deposition may be an early manifestation of infection by the virus. However, the protein metabolic response elicited by the virus in young children is unknown.


OBJECTIVE
We compared children with HIV infection and age-matched children without HIV infection with regard to whole-body and splanchnic protein kinetics and synthesis of acute phase proteins (APPs).


METHODS
Whole-body and splanchnic leucine kinetics and fractional and absolute synthesis rates of 2 positive and 4 negative APPs were measured in 6 asymptomatic, HIV-infected children (4 males and 2 females) aged 6-17 mo and 4 uninfected children (3 females and 1 male) aged 7-9 mo who were in the fed state.


RESULTS
Compared with the control children, the HIV-infected children had significantly lower dietary energy and protein intakes and leucine balance and significantly faster leucine flux and fractional splanchnic leucine extraction; there was no significant difference between the groups in leucine oxidation rates. The HIV-infected children also had significantly higher plasma concentrations and absolute synthesis rates of the positive APPs and a significantly higher fractional synthesis rate of fibrinogen. The concentrations of 2 of the 4 negative APPs, albumin and HDL apolipoprotein A-I, were significantly lower in the HIV-infected children but were not associated with slower synthesis rates.


CONCLUSIONS
Children with HIV infection but without secondary infection have reduced protein balance because of an inability to down-regulate protein catabolism. Furthermore, the acute phase protein response elicited by HIV infection is characterized by higher concentrations and synthesis rates of positive APPs without lower concentrations of some negative APPs.
Jahoor
Farook
F
US Department of Agriculture, Agricultural Research Service, Children's Nutrition Research Center, Department of Pediatrics, Baylor College of Medicine, Houston, TX 77030, USA. fjahoor@bcm.tmc.edu
Abramson
Stuart
S
Heird
William C
WC
D000209:Acute-Phase Proteins / Q000096:biosynthesis / Q000378:metabolism; D016632:Apolipoprotein A-I / Q000097:blood; D016022:Case-Control Studies; D004044:Dietary Proteins / Q000493:pharmacokinetics*; D002149:Energy Intake; D005260:Female; D005340:Fibrinogen / Q000096:biosynthesis; D015658:HIV Infections / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007223:Infant; D007930:Leucine / Q000378:metabolism; D008297:Male; D012709:Serum Albumin / Q000032:analysis
D000209:Acute-Phase Proteins; D016632:Apolipoprotein A-I; D004044:Dietary Proteins; D012709:Serum Albumin; D005340:Fibrinogen; D007930:Leucine